TW202438505A - Materials for organic electroluminescent devices - Google Patents

Abstract

The present invention describes a composition comprising a hole-transporting host material, an electron-transporting host material, and a phosphorescent metal complex as well as devices comprising these compositions, especially OLED including an emission layer comprising these compositions.

Description

Materials for organic electroluminescent devices

The present invention describes a composition comprising a hole transporting host material, an electron transporting host material, and a phosphorescent metal complex, and an electronic device comprising such a composition, in particular an OLED including a light emitting layer containing the composition.

For example, US Pat. No. 4,539,507 describes the structure of an organic electroluminescent device, more particularly an organic light emitting diode (OLED), in which an organic semiconductor is used as the functional material. In general, a distinction is made here between fluorescent OLEDs, which use fluorescent luminophores as the luminescent compound, and phosphorescent OLEDs, which use phosphorescent luminophores as the luminescent compound. Typically, a phosphorescent luminophore is an organometallic complex that exhibits phosphorescence instead of fluorescence (MA Baldo et al. , Appl. Phys. Lett. 1999 , 75 , 4-6). For reasons of quantum mechanics, the energy and power efficiency can be increased by up to four times by using organometallic compounds as phosphorescent luminophores (also called triplet luminophores, because they exhibit triplet light). Red and green phosphorescent emitters have been widely recognized as emitters in the field of OLEDs at the same time. Emitters that emit in a relatively short wavelength range, in particular blue emitters, are usually selected from fluorescent emitters, also called singlet emitters. However, in the past few years, OLEDs comprising organometallic complexes that emit blue light have also been described in the prior art (such as, for example, Nature Photonics, Vol. 16, 2022, p. 212-218). Alternatively, OLEDs having a luminescent layer comprising a sensitizer combined with a fluorescent emitter have been described in the prior art of the past decade. In these systems, the sensitizer transfers its energy to the fluorescent emitter in order to increase the efficiency of the fluorescence. The sensitizer may be a phosphorescent organometallic complex as described, for example, in US 2021/0104682. The sensitizer may also be a donor-acceptor organic material (DA TADF material) exhibiting thermally activated delayed fluorescence, as described, for example, in WO 2015/022974. Despite good results achieved with OLEDs comprising organometallic complexes as phosphorescent emitters or as sensitizers for fluorescent emitters, there is still a need to improve OLED performance, in particular with regard to the lifetime, efficiency and operating voltage of the OLED, as well as the desired color values. In particular, in the case of blue-emitting OLEDs, improvements may be made with regard to the lifetime and efficiency of the device. An important starting point for achieving such improvements is the selection of the host material, the sensitizer and the emitter in the luminescent layer according to the luminescent system. A luminescent compound is herein understood to mean a compound that emits light during operation of an electronic device. A sensitizer compound is herein understood to mean a compound that transfers energy to a fluorescent luminescent body to promote luminescence. A host compound is herein understood to mean a compound that is present in a mixture in a greater proportion than the luminescent body and/or sensitizer compound. According to the present invention, the term matrix compound and the term host compound can be used synonymously. The host compound is preferably non-luminescent. Even if a plurality of different host compounds are present in a mixture of the luminescent layer, their individual proportions are generally greater than the proportion of the luminescent compound, or, if a plurality of luminescent compounds are present in a mixture of the luminescent layer, greater than the proportion of an individual luminescent compound. If a mixture of a plurality of compounds is present in the luminescent layer, the luminescent compound is generally a component that is present in a smaller amount, i.e., a component that is present in a smaller proportion than the other compounds present in the mixture of the luminescent layer. In this case, the luminescent compound is also referred to as a dopant. If a mixture of multiple compounds is present in the luminescent layer, the luminescent compound is generally a component present in a smaller amount, that is, a component present in a smaller proportion than other compounds present in the mixture of the luminescent layer. In this case, the luminescent compound is also referred to as a dopant. Moreover, even if multiple different host compounds are present in a mixture of the luminescent layer, their individual proportions are generally greater than the proportion of the sensitizer compound, or if multiple sensitizer compounds are present in a mixture of the luminescent layer, greater than the proportion of the individual sensitizer compounds. Since the sensitizer is preferably present in a smaller amount in the host compound, the sensitizer compound can also be referred to as a dopant. Host materials, metal complexes and fluorescent luminescent materials for organic electronic devices are well known to those skilled in the art. Many host materials, complexes and fluorescent luminescent materials have been developed for fluorescent and phosphorescent electronic devices. However, in the case of using a combination of host materials, sensitizers (when present) and luminescent materials in a luminescent layer, more particularly for a blue luminescent layer, there is still a need for improvement, particularly with respect to the efficiency, operating voltage and/or lifetime of the organic electronic device.

The problem to be solved by the present invention is to provide a composition that is particularly suitable as a light-emitting layer, preferably a blue or green light-emitting layer in an OLED. Surprisingly, it has been found that a composition comprising the compounds described in more detail below solves this problem and is particularly suitable for use in OLEDs. In particular, these OLEDs have a long life, high efficiency and low operating voltage. These compositions and electronic devices containing these compositions, in particular organic electroluminescent devices, are therefore the target of the present invention. The present invention therefore provides a composition comprising: - a hole-transporting host material; - an electron-transporting host material; and - a phosphorescent metal complex; characterized in that the hole-transporting host material is selected from a compound of formula (H-1): The symbols and signs used are as follows: M is selected from the group consisting of Si, Ge and Sn, preferably M is Si; A is a ring selected from a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more groups R; Y represents a group selected from NR ^N2 , O and S at each occurrence, preferably Y is NR ^N2 ; R ^M1 and R ^M2 represent H, D, F, Cl, Br, I, C(=O)R, OSO ₂ R, COOR, CON(R) ₂ , N(R) ₂ at each occurrence, the same or different. ; a straight-chain alkyl group having 1 to 40 C atoms, or a branched or cyclic alkyl group having 3 to 40 C atoms, or an alkenyl or alkynyl group having 2 to 40 C atoms, wherein each of the above groups may be substituted by one or more groups R, and wherein one or more CH ₂ groups in the above groups may be replaced by Si(R) ₂ , Ge(R) ₂ , Sn(R) ₂ , C═O, C═S, C═Se, C═NR, P(═O)(R), SO, SO ₂ , NR, -O-, -S-, -COO- or -CONR-, and wherein one or more H atoms in the above groups may be replaced by D, F, Cl, Br, I, CN or NO ₂ ; or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which in each case may be substituted by one or more radicals R; or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R, wherein the radicals R ^M1 and R ^M2 may be linked to one another and form a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more radicals R; R ^N1 , R ^N2 is, identically or differently on each occurrence, H, D, F, a linear alkyl group having 1 to 40 C atoms or a branched or cyclic alkyl group having 3 to 40 C atoms, each of which may be substituted by one or more radicals R and in which one or more H atoms may be replaced by D, F or CN, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R in each case; and wherein: when n=m=1, the radicals ^RN1 and ^RM1 and/or ^RN2 and ^RM2 may be linked to one another and form a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more radicals R; or when n=2, two radicals ^RN1 and/or two radicals R ^N2, when present, may be linked to one another and form a monocyclic or polycyclic aliphatic, aromatic or heteroaromatic ring system, which may be substituted by one or more groups R; R, identically or differently at each occurrence, represents H; D; F; Cl; Br; I; CHO; CN; C(=O)Ar; P(=O)(Ar) ₂ ; S(=O)Ar; S(=O) ₂ Ar; N(R') ₂ ; N(Ar) ₂ ; NO ₂ ; Si(R') ₃ ; B(OR') ₂ ; OSO ₂ R; linear alkyl, alkoxy or thioalkyl having 1 to 40 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl having 3 to 40 C atoms, each of which may be substituted by one or more radicals R', wherein in each case one or more non-adjacent CH ₂ radicals may be replaced by R'C=CR', C≡C, Si(R') ₂ , Ge(R') ₂ , Sn(R') ₂ , C=O, C=S, C=Se, P(=O)(R'), SO, SO ₂ , O, S or CONR' and wherein one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO ₂ ; an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, which in each case may be substituted by one or more radicals R'; or an aryloxy group with 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R'; wherein two radicals R may form a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more radicals R'; Ar is, identically or differently on each occurrence, an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, which in each case may also be substituted by one or more radicals R';R' represents, identically or differently on each occurrence, H; D; F; Cl; Br; I; CN; a linear alkyl, alkoxy or alkylthio radical having 1 to 20 C atoms or a branched or cyclic alkyl, alkoxy or alkylthio radical having 3 to 20 C atoms, wherein in each case one or more non-adjacent CH ₂ groups may be replaced by SO, SO ₂ , O, S and wherein one or more H atoms may be replaced by D, F, Cl, Br or I; or an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, n is 1 or 2; m is (2-n); and with the proviso that the electron transport material is not one of the following compounds: Furthermore, the following definitions of chemical groups apply for the purposes of the present application: Aryl for the purposes of the present invention contains 6 to 60 aromatic ring atoms, preferably 6 to 40 aromatic ring atoms, more preferably 6 to 20 aromatic ring atoms; heteroaryl for the purposes of the present invention contains 5 to 60 aromatic ring atoms, preferably 5 to 40 aromatic ring atoms, more preferably 5 to 20 aromatic ring atoms, of which at least one is a heteroatom. The heteroatom is preferably selected from N, O and S. This represents a basic definition. If other preferences are indicated in the description of the invention, for example with regard to the number of aromatic ring atoms or heteroatoms present, these apply. Aryl or heteroaryl means here a simple aromatic ring, i.e. benzene, or a simple heteroaromatic ring, such as pyridine, pyrimidine or thiophene, or a condensed (annellated) aromatic or heteroaromatic polycyclic ring, such as naphthalene, phenanthrene, quinoline or carbazole. Condensed (annellated) aromatic or heteroaromatic polycyclic rings in the sense of the present application consist of two or more simple aromatic or heteroaromatic rings condensed with one another. Aryl or heteroaryl, which may in each case be substituted by the abovementioned radicals and which may be attached to the aromatic or heteroaromatic ring system via any desired position, means in particular radicals derived from benzene, naphthalene, anthracene, phenanthrene, pyrene, dihydropyrene, chrysene, perylene, fluoranthene, benzanthracene, triphenylene, fused tetraphenylene, fused pentacene, benzopyrene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole ... Indole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenathiol, phenanthridine, pyrazole, indazole, imidazole, benzimidazole, naphthimidazole, phenanthrimidazole, pyridimidazole, pyrazinimidazole, quinoline imidazole, oxadiazole, benzoxadiazole, naphthoxazole, anthroxazole, phenanthroxazole, isothioazole, 1,2-thiazole, 1,3-thiazole, benzothiazole, pyrimidine, benzopyrimidine, quinoline, pyridine, phenanthroline, oxadiazole, azocarbazole, benzocarboline, phenanthroline, 1,2,3-triazole, 1 , 2,4-triazole, benzotriazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3,5-triazole, 1,2,4-triazole, 1,2,3-triazole, tetrazole, 1,2,4,5-tetraazole, 1,2,3,4-tetraazole, 1,2,3,5-tetraazole, purine, pteridine, indole and benzothiadiazole. Aryloxy as defined in the present invention means an aryl group as defined above bonded via an oxygen atom. Similar definitions apply to heteroaryloxy. An aromatic ring system in the sense of the present invention contains 6 to 60 C atoms, preferably 6 to 40 C atoms, more preferably 6 to 20 C atoms in the ring system. A heteroaromatic ring system in the sense of the present invention contains 5 to 60 aromatic ring atoms, preferably 5 to 40 aromatic ring atoms, more preferably 5 to 20 aromatic ring atoms, of which at least one is a heteroatom. The heteroatom is preferably selected from N, O and/or S. An aromatic or heteroaromatic ring system in the sense of the present invention is taken to mean a system which does not necessarily contain only aryl or heteroaryl groups, but rather a system in which a plurality of additional aryl or heteroaryl groups may be linked to non-aromatic units (preferably less than 10% of atoms other than H), such as, for example, sp ³ -mixed C, Si, N or O atoms, sp ² -mixed C or N atoms or sp-mixed C atoms. Thus, for example, systems such as 9,9'-spirobifluorene, 9,9'-diarylfluorene, triarylamines, diaryl ethers, stilbenes etc. are also intended to be aromatic ring systems in the sense of the present invention, such as systems in which two or more aryl groups are linked, for example, via linear or cyclic alkyl, alkenyl or alkynyl groups or via silicon groups. Furthermore, systems in which two or more aryl or heteroaryl groups are linked to one another via a single bond are also aromatic or heteroaromatic ring systems in the sense of the present invention, such as, for example, systems such as biphenyl, terphenyl or diphenyltriphenylamine. Aromatic or heteroaromatic ring systems with 5 to 60 aromatic ring atoms, which in each case may also be substituted by radicals as defined above and which may be attached to the aromatic or heteroaromatic radical via any desired position, mean in particular radicals derived from benzene, naphthalene, anthracene, benzanthracene, phenanthrene, triphenylene, pyrene, chrysene, perylene, fluoranthene, fused tetraphenyl, fused pentacene, benzopyrene, biphenyl, biphenylene, terphenyl, terphenylene, quaterphenyl, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis- or trans-indenofluorene. , truxene, isotruxene, spirotruxene, spiroistruxene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, indolocarbazole, indenocarbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenanthridine, phenanthridine, pyrazole, indazole, imidazole, benzimidazole, naphthimidazole, phenanthrimidazole, pyridimidazole zole), pyrazinimidazole, quinoxalinimidazole, oxadiazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isothioazole, 1,2-thiazole, 1,3-thiazole, benzothiazole, pyrimidine, benzopyrimidine, quinoline, 1,5-diazaanthracene, 2,7-diazapyrene, 2,3-diazapyrene, 1,6-diazapyrene, 1,8-diazapyrene, 4,5-diazapyrene, 4,5,9,10-tetrazapyrene Perylene, pyridine, phenanthridine, phenanthridine, phenathiophene, fluorubin, oxadiazole, nitrogen-doped carbazole, benzocarboline, phenathiophene, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole oxadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3,5-triazole, 1,2,4-triazole, 1,2,3-triazole, tetrazole, 1,2,4,5-tetraazole, 1,2,3,4-tetraazole, 1,2,3,5-tetraazole, purine, pteridine, indole and benzothiadiazole, or a combination of these radicals. For the purposes of the present invention, straight-chain alkyl radicals having 1 to 40 C atoms or branched or cyclic alkyl radicals having 3 to 40 C atoms or alkenyl or alkynyl radicals having 2 to 40 C atoms (in which, in addition, individual H atoms or CH The group ( ₂ ) may be substituted by a group under the above definitions of the groups) preferably means a group methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tertiary butyl, 2-methylbutyl, n-pentyl, dipentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, vinyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl or octynyl. Alkoxy or thioalkyl having 1 to 40 carbon atoms is preferably methoxy, trifluoromethoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, di-butoxy, tertiary butoxy, n-pentyloxy, di-pentyloxy, 2-methylbutoxy, n-hexyloxy, cyclohexyloxy, n-heptyloxy, cycloheptyloxy, n-octyloxy, cyclooctyloxy, 2-ethylhexyloxy, pentafluoroethoxy, 2,2,2-trifluoroethoxy, methylthio, ethylthio, n-propylthio, isopropylthio, n-butylthio, isobutylthio The invention further comprises a tertiary butylthio group, a n-pentylthio group, a di-pentylthio group, a n-hexylthio group, a cyclohexylthio group, a n-heptylthio group, a cycloheptylthio group, a n-octylthio group, a cyclooctylthio group, a 2-ethylhexylthio group, a trifluoromethylthio group, a pentafluoroethylthio group, a 2,2,2-trifluoroethylthio group, a vinylthio group, a propenylthio group, a butenylthio group, a pentylthio group, a cyclopentenylthio group, a hexenylthio group, a cyclohexenylthio group, a heptylthio group, a cycloheptylthio group, an octenylthio group, a cyclooctenylthio group, an ethynylthio group, a propynylthio group, a butynylthio group, a pentynylthio group, a hexynylthio group, a heptynylthio group or an octynylthio group. For the purpose of the present application, the situation that two radicals can form a ring with each other is particularly intended to mean that the two radicals are linked to each other by a chemical bond. This is illustrated with the following diagram: However, in addition, the above situation is also intended to mean that when one of the two radicals represents hydrogen, the second radical is bonded to the position where the hydrogen atom is bonded, and a ring is formed. This is illustrated in the following diagram: When two radicals form a ring with each other, it is preferred that the two radicals are adjacent radicals. In the sense of the present invention, adjacent radicals are radicals that are bonded to atoms that are directly connected to each other or to the same atom. When the index n is 2, the index m is equal to 0 and formula (H-1) corresponds to formula (H-1A) as described below: wherein the symbols have the same meanings as above and wherein the rings A are identically or differently selected from the following rings: monocyclic or polycyclic aliphatic ring systems, aromatic ring systems or heteroaromatic ring systems, which may be substituted by one or more groups R. When the index n is 1, the index m is equal to 1 and formula (H-1) corresponds to formula (H-1B) as described below: The symbols have the same meanings as above. Preferably, the hole transporting host material is selected from the compounds of formula (H-2), (H-3) and (H-4): wherein the symbols ^RN1 , ^RM1 , ^RM2 , M and Y and the indices n and m have the same meanings as above, and wherein: the rings B, C, D, E, F as described in formulae (H-2), (H-3) and (H-4) represent, at each occurrence, the same or different rings selected from the following: a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more groups R, and wherein when Y is NR ^N2 , the ring B may be bonded to ^RN1 and/or ^RN2 , the ring E may be bonded to the group ^RN1 , when Y is NR ^N2 , the ring F may be bonded to ^RN2 , and the rings C and D or E and F may be bonded to each other. Preferably, the groups ^RM1 and ^RM2 represent H, D, F, a linear alkyl group having 1 to 40 (preferably 1 to 20, more preferably 1 to 10) C atoms or a branched or cyclic alkyl group having 3 to 40 (preferably 3 to 20, more preferably 3 to 10) C atoms, wherein each of the above groups may be substituted by one or more groups R and wherein one or more _CH2 groups in the above groups may be replaced by Si(R) ₂ , Ge(R) ₂ , Sn(R) ₂ , NR, -O- or -S-, and wherein one or more H atoms in the above groups may be replaced by D, F, Cl, Br, I, CN or NO. ₂ ; or an aromatic or heteroaromatic ring system having 5 to 60 (preferably 5 to 40, more preferably 6 to 30, particularly preferably 6 to 18 aromatic ring atoms), which in each case may be substituted by one or more radicals R, wherein the radicals R ^M1 and R ^M2 may be linked to one another and form a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more radicals R. Very preferably, the radicals R ^M1 and R ^M2, identically or differently on each occurrence, represent an aromatic or heteroaromatic ring system having 5 to 60 (preferably 5 to 40, more preferably 6 to 30, particularly preferably 6 to 18) aromatic ring atoms, which in each case may be substituted by one or more radicals R. More preferably, the hole-transporting host material is selected from the compounds of the formulae (H-2-1), (H-3-1) and (H-4-1): wherein the symbols ^RN1 , M and Y and the rings B, C, D, E, F have the same meanings as above, and wherein two groups ^RN1 , two groups Y, two rings B, two rings C, two rings D, two rings E and two rings C are selected the same or differently. Preferably, the hole transporting host material is selected from the compounds of formula (H-2-2), (H-3-2) and (H-4-2): wherein the symbols M, Y and ^RN1 have the same meanings as above, and wherein: ^X1 to ^X8 represent, at each occurrence, the same or different, a group CR ^X or N; and wherein two adjacent groups selected from ^{X1 to X8 may form a monocyclic or polycyclic fused aryl or heteroaryl ring having 5 to 18 aromatic ring atoms or a monocyclic or polycyclic aliphatic ring having 5 to 18 ring atoms, which may be substituted by one or more groups R as defined above; V1 to} V12 represent, at each occurrence, the same or different, a group CR ^V or N; wherein ^V1 to ^V12 are selected from V1 to V13, V1 to V14, V1 to V15, V16 to V17, V17 to V18, V18 to V19, V19 to V20, ^V21 to V21 wherein two adjacent groups selected from V 1 to ^{V 16} may form a monocyclic or polycyclic fused aryl or heteroaryl ring having 5 to 18 aromatic ring atoms or a monocyclic or polycyclic aliphatic ring having 5 to 18 ring atoms, which may be substituted by one or more groups R as defined above; Z ¹ to Z ¹⁶ represent the groups CR ^Z or N identically or differently at each occurrence; wherein two adjacent groups selected from V ¹ to V ¹⁶ may form a monocyclic or polycyclic fused aryl or heteroaryl ring having 5 to 18 aromatic ring atoms or a monocyclic or polycyclic aliphatic ring having 5 to 18 ring atoms, which may be substituted by one or more groups R as defined above; ^RX , ^RV , R ^Z , identically or differently on each occurrence, represents H; D; F; Cl; Br; I; C(═O)R; OSO ₂ R; COOR; CON(R) ₂ ; a linear alkyl group having 1 to 40 C atoms or a branched or cyclic alkyl group having 3 to 40 C atoms or an alkenyl or alkynyl group having 2 to 40 C atoms, wherein each of the above groups may be substituted by one or more groups R and wherein one or more CH ₂ groups in the above groups may be replaced by Si(R) ₂ , Ge(R) ₂ , Sn(R) ₂ , C═O, C═S, C═Se, C═NR, P(═O)(R), SO, SO ₂ , NR, —O—, —S—, —COO— or —CONR— and wherein one or more H atoms in the above groups may be replaced by D, F, Cl, Br, I, CN or NO ₂ ; or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which in each case may be substituted by one or more radicals R; or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R, wherein two adjacent radicals ^RX , ^RZ , ^RV may be linked to one another and form a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more radicals R; and when ^X1 represents ^CRX , or ^Z1 represents ^CRZ , the corresponding ^RX or ^RZ may be substituted with R ^N1 forms a ring, and the ring is selected from a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more groups R; when ^X4 represents ^CRx , or ^Z8 represents ^CRz , the corresponding ^RX or ^Rz may form a ring with ^RN2 , and when Y is ^RN2 , the ring is selected from a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more groups R; when ^X5 represents ^CRx , or ^Z9 represents ^CRz , the corresponding ^RX or ^Rz may form a ring with ^RN4 , and when ^Y1 is R When X ⁸ represents CR ^X , or Z ¹⁶ represents CR Z , the corresponding ^RX or RZ may form a ring with ^RN3 , and the ring is selected from a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more groups R; When Z ⁴ and Z ⁵ or Z ¹² and ^{Z 13 represent} CR ^Z , the corresponding two groups ^{R Z} may together form a ring selected from a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more groups R; R has the same meaning as above. More preferably, the hole transporting host material is selected from the compounds of formula (H-2-2), (H-3-2) and (H-4-2): The symbols have the same meanings as above. Preferably, the radicals ^RN1 , ^RN2 are, identically or differently, H on each occurrence; D; F; linear alkyl radicals having 1 to 40 (preferably 1 to 20, more preferably 1 to 10) C atoms or branched or cyclic alkyl radicals having 3 to 40 (preferably 3 to 20, more preferably 3 to 10) C atoms, each of which may be substituted by one or more radicals R, and wherein one or more H atoms may be replaced by D, F or CN; aromatic or heteroaromatic ring systems having 5 to 60 aromatic ring atoms (preferably 5 to 40, more preferably 5 to 30, even more preferably 6 to 24, particularly preferably 6 to 18) aromatic ring atoms, which may in each case be substituted by one or more radicals R, and wherein: two radicals R ^N1 and/or two groups R ^N2 may be linked to each other and form a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more groups R. More preferably, the groups R ^N1 , R ^N2 are identically or differently at each occurrence an aromatic or heteroaromatic ring system having 5 to 60 (preferably 5 to 40, more preferably 5 to 30, even more preferably 6 to 24, particularly preferably 6 to 18) aromatic ring atoms, which in each case may be substituted by one or more groups R, and wherein: two groups R ^N1 and/or two groups R ^N2 may be linked to each other and form a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more groups R. According to a particularly preferred embodiment, the hole transport material is selected from the compounds of formula (H-2-2A): wherein ^X1 to ^X8 have the same meanings as above; and ^X9 to ^X28 represent, at each occurrence, the same or different radicals CR ^X or N; wherein two adjacent radicals selected from ^V9 to V28 may form a monocyclic or polycyclic fused aryl or heteroaryl ring having 5 to 18 aromatic ring atoms or a monocyclic or polycyclic aliphatic ring having 5 to 18 ring atoms, which may be substituted by one or more radicals R as defined above; and wherein X1 and X19, X23 ^{and X24} , X28 and X5, X8 and X9, X13 and X14 and/or X18 and X4 may be bonded to each other by a single bond or a divalent radical selected from the following: -C(R X0)2-, -C(R X0)2-, -C(R X0 ⁾ 2-, -C(R X0)2-, -C(R X0)2-, -C(R X0)2-, ^-C (R ^X0 )2-, -C(R X0)2-, -C(R X0)2-, -C(R ^X0 ) ^2- , -C(R X0)2-, -C(R X0)2-, -C ⁽ R ^X0 )2-, -C(R ^X0 )2-, -C(R ^X0 ) _2- , -C( ^R X0)2-, -C(R ^X0 )2-, -C(R X0)2-, -C(R X0)2-, -C( ^R X0)2-, -C(R X0)2-, -C(R X0)2- ^, -C(R X0)2-, -C(R X0)2-, -C(R ^X0 )2- )-, -C( ^RX0 )-, -Si( ^RX0 ) _2- , -N( ^RX0 )-, -O-, -S-, ^-BRX0- , -C(=O)-, -S(=O)-, _-SO2- and -P( ^RX0 )-, preferably with a single bond or -C( ^RX0 ) _2- , -C( ^RX0 )-C( ^RX0 )-, -Si(RX0) _2- , -N( ^RX0 )-, -O- or -S-, more preferably with a single bond or -C( ^RX0 ) _2- ^, -C( ^RX0 )-C( ^RX0 )- or -Si( ^RX0 ) _2- ; R ^X0 is independently selected at each occurrence from H; D; F; a linear alkyl group having 1 to 40 (preferably 1 to 20, more preferably 1 to 10) C atoms or a branched or cyclic alkyl group having 3 to 40 (preferably 3 to 20, more preferably 3 to 10) C atoms, wherein each of the above groups may be substituted by one or more groups R and wherein one or more CH ₂ groups in the above groups may be replaced by Si(R) ₂ , Ge(R) ₂ , Sn(R) ₂ , C=O, C=S, C=Se, C=NR, P(=O)(R), SO, SO ₂ , NR, -O-, -S-, -COO- or -CONR- and wherein one or more H atoms in the above groups may be replaced by D, F, Cl, Br, I, CN or NO ₂ ; or an aromatic or heteroaromatic ring system having 5 to 60 (preferably 5 to 60, more preferably 5 to 30, particularly preferably 6 to 18) aromatic ring atoms, which in each case may be substituted by one or more radicals R, wherein two adjacent radicals ^R0 may be linked to each other and form a monocyclic or polycyclic aliphatic ring system, aromatic ring system or heteroaromatic ring system, which may be substituted by one or more radicals R; wherein R has the same meaning as above. Preferably, when two adjacent groups selected from ^X1 to ^X28 , ^V1 to ^V12 and ^Z1 to ^Z16 form a condensed aryl or heteroaryl ring, preferably the condensed aryl or heteroaryl ring is selected from the groups of formula (A): wherein the dotted bonds represent bonds to the corresponding structures and wherein: W represents CR ^W or N; R ^W represents H, D, F, Cl, Br, I, C(=O)R, OSO ₂ R, COOR, CON(R) ₂ , a linear alkyl group having 1 to 40 C atoms, a branched or cyclic alkyl group having 3 to 40 C atoms, or an alkenyl or alkynyl group having 2 to 40 C atoms, wherein each of the above groups may be substituted by one or more groups R, and wherein one or more CH ₂ groups in the above groups may be substituted by Si(R) ₂ , Ge(R) ₂ , Sn(R) ₂ , C=O, C=S, C=Se, C=NR, P(=O)(R), SO, SO ₂ , -NR, -O-, -S-, -COO- or -CONR-, and one or more H atoms in the above groups may be replaced by D, F, Cl, Br, I, CN or _NO2 ; or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may be substituted by one or more groups R in each case; or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms, which may be substituted by one or more groups R, wherein two adjacent groups ^RW may be linked to each other and form a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more groups R; wherein R has the same meaning as above. For example, the compound of formula (H-2-2B) shown below corresponds to the compound of formula (H-2-2A), wherein two adjacent groups ^X2 and ^X3 and two adjacent groups ^X6 and ^X7 form a condensed aryl or heteroaryl ring of formula (A): The symbols and signs have the same meanings as above. Preferably, the groups ^RX , ^RV , ^RZ and ^RW represent H, D, F, Cl, Br, I, C(=O)R, _OSO2R , COOR, CON(R) ₂ , a linear alkyl group having 1 to 40 (preferably 1 to 20, more preferably 1 to 10) C atoms or a branched or cyclic alkyl group having 3 to 40 (preferably 3 to 20, more preferably 3 to 10) C atoms at each occurrence, wherein each of the above groups may be substituted by one or more groups R and wherein one or more _CH2 groups in the above groups may be substituted by Si(R) ₂ , Ge(R) ₂ , Sn(R) ₂ , C=O, C=S, C=Se, C=NR, P(=O)(R), SO, _SO2 , NR, -O-, -S-, -COO- or -CONR-substituted and one or more H atoms in the above groups may be replaced by D, F, Cl, Br, I, CN or _NO2 ; or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms (preferably 5 to 40, more preferably 6 to 30, even more preferably 6 to 24, particularly preferably 6 to 18) which may be substituted by one or more groups R in each case, wherein two adjacent groups ^RX , ^RZ , ^RV , ^RW may be linked to each other and form a monocyclic or polycyclic aliphatic ring system, aromatic ring system or heteroaromatic ring system which may be substituted by one or more groups R. More preferably, the radicals ^RX , ^RV , ^RZ and ^RW, identically or differently on each occurrence, represent H; D; F; a linear alkyl radical having 1 to 10 C atoms or a branched or cyclic alkyl radical having 3 to 10 C atoms, wherein each of the above radicals may be substituted by one or more radicals R and wherein one or more H atoms in the above radicals may be replaced by D, F or CN; or an aromatic or heteroaromatic ring system having 6 to 30 (preferably 6 to 24, more preferably 6 to 18) aromatic ring atoms, which in each case may be substituted by one or more radicals R, wherein two adjacent radicals ^RX , ^RZ , ^RV , RZ or RW may be substituted by one or more radicals R. ^W may be linked to each other and form a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more R groups. Preferably, R, identically or differently on each occurrence, represents H; D; F; Cl; Br; I; CN; straight-chain alkyl, alkoxy or thioalkyl having 1 to 40 (preferably 1 to 20, more preferably 1 to 10) C atoms or branched or cyclic alkyl, alkoxy or thioalkyl having 3 to 40 (preferably 3 to 20, more preferably 3 to 10) C atoms, each of which may be substituted by one or more radicals R'; or an aromatic or heteroaromatic ring system having 5 to 60 (preferably 5 to 30, more preferably 6 to 18) aromatic ring atoms, which in each case may be substituted by one or more radicals R'. Preferably, Ar, identically or differently on each occurrence, is an aromatic or heteroaromatic ring system of aromatic ring atoms having 5 to 60 (preferably 5 to 40, more preferably 6 to 30, even more preferably 6 to 24, particularly preferably 6 to 18) aromatic ring atoms, which in each case may also be substituted by one or more radicals R'. Preferably, R', identically or differently on each occurrence, represents H; D; F; Cl; Br; I; CN; linear alkyl, alkoxy or alkylthio having 1 to 10 C atoms or branched or cyclic alkyl, alkoxy or alkylthio having 3 to 10 C atoms; or an aromatic or heteroaromatic ring system having 6 to 18 aromatic ring atoms. Examples of suitable hole transporting host materials of formula (H-1) are described in the following table: The composition of the present invention comprises an electron-transmitting host material. Preferably, the electron-transmitting host material is selected from a compound comprising a group selected from the following: substituted or unsubstituted trioxane, pyrimidine, lactam, benzimidazole, quinazoline, quinoline, nitrogen-doped dibenzofuran, diazadibenzofuran, nitrogen-doped dibenzothiophene, diazadibenzothiophene, carboline and triptycene. Preferably, the electron-transmitting host material has a LUMO of ≤-2.10 eV, preferably ≤-2.30 eV, and more preferably ≤-2.40 eV, determined by quantum chemical calculations. The energy levels of molecular orbitals (such as the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO)), as well as the energy levels of the lowest triplet state T ₁ or the lowest excited singlet state S ₁ of the material were determined by quantum chemical calculations. For all quantum chemical calculations, Gaussian software package (Gaussian16) was used. The singlet ground state geometry was optimized at the theoretical B3LYP/6-31G(d) energy level. Subsequently, TD-DFT singlet and triplet excitation energies (vertical transitions) were calculated using the optimized ground state geometry and the same method (B3LYP/6-31G(d)). The default settings for SCF and geometric convergence were used. For structures containing heavy metal atoms, calculations are performed similarly to those for organic substances, except that the "LanL2DZ" basis set is used for metal atoms, while the "6-31G(d)" basis set is used for ligands. Energy calculations are given in hartree units as the HOMO energy level HEh or the LUMO energy level LEh. The HOMO and LUMO energy levels expressed in electron volts calibrated with reference to cyclic voltammetry measurements are determined as follows: For the purpose of this application, these values are considered to be the HOMO energy level and LUMO energy level of the material, respectively. The lowest triplet state _T1 is defined as the energy of the triplet state with the lowest energy, which is produced by the quantum chemical calculation. The lowest excited singlet state _S1 is defined as the energy of the excited singlet state with the lowest energy, which is produced by the quantum chemical calculation. The method described herein is independent of the software package used and always produces the same results. Examples of commonly used programs for this purpose are "Gaussian16" (Gaussian Inc.) and Q-Chem 4.1 (Q-Chem, Inc.). According to a preferred embodiment, the electron-transmitting host material is selected from compounds of formula (E-1), (E-2), (E-3) and (E-4), wherein ^{RE is} , at each occurrence, identically or differently, H; D; F; Cl; Br; ^I ; C(= _{O)R; OSO2R; COOR; CON(R)2; SiR10R11R12; N(ArN)2 ; a} ^{linear alkyl group} having 1 to 40 (preferably 1 to 20, more preferably 1 to 10) C atoms, or a branched or cyclic alkyl group having 3 to 40 (preferably 3 to 20, more preferably 3 to 10) C atoms, or an alkenyl or alkynyl group having 2 to 40 (preferably 2 to 20, more preferably 2 to 10) C atoms, wherein each of the above groups may be substituted by one or more groups R, and wherein one or more _CH2 groups in the above groups may be substituted by Si(R) ₂ , Ge(R) ₂ , Sn(R) ₂ , C=O, C=S, C=Se, C=NR, P(=O)(R), SO, SO ₂ , NR, -O-, -S-, -COO- or -CONR-, and one or more H atoms in the above groups may be replaced by D, F, Cl, Br, I, CN or NO ₂ ; or an aromatic or heteroaromatic ring system having 5 to 60 (preferably 5 to 40, more preferably 6 to 30, very preferably 6 to 18) aromatic ring atoms, which may be substituted by one or more groups R in each case; or an aralkyl or heteroaralkyl having 5 to 60 (preferably 5 to 40, more preferably 6 to 30, very preferably 6 to 18) aromatic ring atoms, which may be substituted by one or more groups R, wherein two groups R ^E may form a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more groups R; L, identically or differently at each occurrence, represents a single bond or an aromatic or heteroaromatic ring system having 5 to 30 (preferably 6 to 18) aromatic ring atoms, which may be substituted by one or more groups R; R ¹⁰ , R ¹¹ , R ^12, identically or differently at each occurrence, are selected from H; D; a linear alkyl group having 1 to 40 (preferably 1 to 20, more preferably 1 to 10) C atoms or a alkyl group having 3 to 40 (preferably 3 to 20, more preferably 3 to 10) C atoms; C atom-containing branched or cyclic alkyl group or an alkenyl or alkynyl group having 2 to 40 (preferably 2 to 20, more preferably 2 to 10) C atoms, wherein each of the above groups may be substituted by one or more groups R, and wherein one or more CH ₂ groups in the above groups may be replaced by Si(R) ₂ , Ge(R) ₂ , Sn(R) ₂ , C=O, C=S, C=Se, C=NR, P(=O)(R), SO, SO ₂ , NR, -O-, -S-, -COO- or -CONR-, and wherein one or more H atoms in the above groups may be replaced by D, F, Cl, Br, I, CN or NO. ₂ ; or an aromatic or heteroaromatic ring system having 5 to 60 (preferably 5 to 40, more preferably 6 to 30, very preferably 6 to 18) aromatic ring atoms, which may be substituted by one or more radicals R in each case; or an aralkyl or heteroaralkyl group having 5 to 60 (preferably 5 to 40, more preferably 6 to 30, very preferably 6 to 18) aromatic ring atoms, which may be substituted by one or more radicals R; ^ArN represents, identically or differently at each occurrence, an aromatic or heteroaromatic ring system having 5 to 60 (preferably 5 to 40, more preferably 6 to 30, very preferably 6 to 18) aromatic ring atoms, which may be substituted by one or more radicals R; and R has the same meaning as above. Preferably, the compounds of formula (E-1) to (E-4) contain at least one group ^RE representing: an aromatic ring system having 6 to 60 (preferably 6 to 40, more preferably 6 to 30, very preferably 6 to 18) aromatic ring atoms, which may be substituted by one or more groups R; a heteroaromatic ring system having 5 to 60 (preferably 5 to 40, more preferably 5 to 30, very preferably 5 to 18) aromatic ring atoms, which may be substituted by one or ^more groups R; a group N( ^ArN ) ₂ ; or ^a group ^SiR10R11R12 . Very preferably, ^RE is selected, identically or differently at each occurrence, from: an aromatic ring system having 6 to 60 (preferably 6 to 40, more preferably 6 to 30, very preferably 6 to 18) aromatic ring atoms, which may be substituted by one or more groups R; a heteroaromatic ring system having 5 to 60 (preferably 5 to 40, more preferably 5 to 30, very preferably 5 to ¹⁸ ) aromatic ring atoms, which may be substituted by one or ^more groups R; a group N( ^ArN ) ₂ ; or a group ^SiR10R11R12 . Preferably, R ¹⁰ , R ¹¹ , R ¹² are, at each occurrence, identically or differently, selected from linear alkyl groups having 1 to 40 (preferably 1 to 20, more preferably 1 to 10) C atoms or branched or cyclic alkyl groups having 3 to 40 (preferably 3 to 20, more preferably 3 to 10) C atoms, wherein each of the above groups may be substituted by one or more groups R and wherein one or more H atoms in the above groups may be replaced by D, F, Cl, Br, I, CN or NO ₂ ; or aromatic or heteroaromatic ring systems having 5 to 60 (preferably 5 to 40, more preferably 6 to 30, very preferably 6 to 18) aromatic ring atoms, which in each case may be substituted by one or more groups R. Very preferably, R ¹⁰ , R ¹¹ , R ¹² are identically or differently selected on each occurrence from aromatic or heteroaromatic ring systems having 5 to 60 (preferably 5 to 40, more preferably 6 to 30, very preferably 6 to 18) aromatic ring atoms, which in each case may be substituted by one or more radicals R. Very preferably, the electron-transporting host material is selected from compounds of formula (E-1-A) or (E-1-B), wherein the symbol L has the same meaning as above, and: L ¹ , L ² , L ³ , identically or differently on each occurrence, represent a single bond or an aromatic or heteroaromatic ring system with 6 to 18 aromatic ring atoms, which may be substituted by one or more radicals R; E is CR or N; the prerequisite is that at least two radicals E represent N; E ⁰ is NR ²² , O or S; RE ^' , identically or differently on each occurrence, represents: an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R; a radical N(Ar ^N ) ₂ ; or a radical SiR ¹⁰ R ¹¹ R ¹² ; wherein Ar ^N , R ¹⁰ , R ¹¹ and R ¹² have the same meanings as above; R ²⁰ , R ²¹ , R ²² is selected, identically or differently, at each occurrence from H; D; a linear alkyl group having 1 to 40 (preferably 1 to 20, more preferably 1 to 10) C atoms or a branched or cyclic alkyl group having 3 to 40 (preferably 3 to 20, more preferably 3 to 10) C atoms or an alkenyl or alkynyl group having 2 to 40 (preferably 2 to 20, more preferably 2 to 10) C atoms, wherein each of the above groups may be substituted by one or more groups R and wherein one or more CH ₂ groups in the above groups may be substituted by Si(R) ₂ , Ge(R) ₂ , Sn(R) ₂ , C═O, C═S, C═Se, C═NR, P(═O)(R), SO, SO ₂ , -NR, -O-, -S-, -COO- or -CONR-, and one or more H atoms in the above groups may be replaced by D, F, Cl, Br, I, CN or _NO2 ; or an aromatic or heteroaromatic ring system having 5 to 60 (preferably 5 to 40, more preferably 5 to 30, very preferably 6 to 18) aromatic ring atoms, which may be substituted by one or more groups R in each case; or an aralkyl or heteroaralkyl having 5 to 60 (preferably 5 to 40, more preferably 5 to 30, very preferably 6 to 18) aromatic ring atoms, which may be substituted by one or more groups R; r is an integer selected from 0, 1, 2 or 3; s is an integer selected from 0, 1, 2, 3 or 4; p is an integer selected from 0, 1 or 2; when p is 0, the group ^L3 is directly bonded to the 6-membered ring containing the group E. Examples of suitable electron transporting host materials are described in the following table: The composition comprises a phosphorescent metal complex. It is to be understood that phosphorescence in the context of the present invention means luminescence from excited states with a high spin multiplicity (i.e. spin state>1), in particular luminescence from excited triplet states. In the context of the present application, all luminescent complexes with transition metals or ytterbium elements, in particular all iridium, platinum and copper complexes, are to be regarded as phosphorescent emitters. Preferred phosphorescent metal complexes are compounds containing copper, molybdenum, tungsten, sulphurium, ruthenium, nirconium, rhodium, iridium, palladium, platinum, silver, gold or iridium, in particular compounds containing iridium or platinum. Examples of phosphorescent metal complexes can be found in applications WO 00/70655, WO 2001/41512, WO 2002/02714, WO 2002/15645, EP 1191613, EP 1191612, EP 1191614, WO 05/033244, WO 05/019373, US 2005/0258742, WO 2009/146770, WO 2010/015307, WO 2010/031485, WO 2010/054731, WO 2010/054728, WO 2010/086089, WO 2010/099852, WO 2010/102709, WO 2011/032626, WO 2011/066898, WO 2011/157339, WO 2012/007086, WO 2014/008982, WO 2014/023377, WO 2014/094961, WO 2014/094960、WO 2015/036074、WO 2015/104045、WO 2015/117718、WO 2016/015815、WO 2016/124304、WO 2017/032439、WO 2018/011186 and WO 2018/041769、WO 2019/020538, WO 2018/178001, WO 2019/115423 or WO 2019/158453. Preferred phosphorescent metal complexes that can be used in the composition according to the present invention are described in particular in Adv. Sci. 2021, 2100586 by Sungho Nam et al. and Sci. Adv. 2022, 8, eabq 1641 by Eungdo Kin et al. In addition, preferred phosphorescent metal complexes suitable as sensitizers for fluorescent light emitters as described above are described in EP 3 435 438 A2, more particularly compounds 2 and 3 on page 21; in CN 109111487, more particularly compounds on pages 76 and 77; in US 2020/0140471, more particularly compounds on pages 166 to 175; in KR2020108705, more particularly compounds on pages 8 to 14; in US 2019/0119312, more particularly compounds on pages 114 to 121; and in US 2020/0411775, more particularly compounds described on pages 123 to 128. The phosphorescent metal complexes disclosed in US2022115607 AA, US2022298193 AA, US2016072082 AA, and US2022271236 AA are also preferred. Preferably, the phosphorescent metal complex is a platinum complex or an iridium complex. Examples of suitable phosphorescent metal complexes are described below: Other examples of phosphorescent metal complexes suitable as phosphorescent emitters in phosphorescent OLEDs, and particularly suitable as sensitizers for fluorescent emitters (more particularly blue fluorescent emitters), are disclosed as follows: Preferably, the phosphorescent metal complex has a LUMO from -1.5 eV to -3.5 eV, preferably -1.7 eV to -3.3 eV, more preferably -1.9 eV to -3.0 eV, and even more preferably -1.9 eV to -2.6 eV, as defined by quantum chemical calculations. Preferably, the phosphorescent metal complex has a HOMO from -4.7 eV to -6.0 eV, as defined by quantum chemical calculations. Also preferably, the energy of the lowest triplet state T ₁ of the phosphorescent metal complex is higher than 2.55 eV, as defined by quantum chemical calculations. According to one of the preferred embodiments, the phosphorescent metal complex is a tetradentate platinum complex, more particularly a tetradentate platinum complex emitting blue light. A very suitable blue phosphorescent metal complex is a compound of formula (Pt-1) defined as follows: wherein: Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ are identical or different at each occurrence and represent a group ^CRY or N; or Y ¹ -Y ² and/or Y ³ -Y ⁴ or Y ⁴ -Y ⁵ may form a condensed aryl or heteroaryl ring having 5 to 18 aromatic ring atoms, which in each case may also be substituted by one or more groups R; E ⁵⁰ are identical or different at each occurrence and represent C( ^RC0 ) ₂ , ^NRNO , O or S; Ar ⁵⁰ are identical or different at each occurrence and represent an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which in each case may also be substituted by one or more groups R; Ar ⁵¹ , Ar ⁵² , Ar ^53, identically or differently, represents a condensed aryl or heteroaryl ring having 5 to 18 aromatic ring atoms, which may in each case also be substituted by one or more radicals R; ^RY, identically or differently on each occurrence, represents a radical selected from the group consisting of: H; D; F; Cl; Br; I; CHO; CN; C(=O)Ar; P(=O)(Ar) ₂ ; S(=O)Ar; S(=O) ₂ Ar; N(R) ₂ ; N(Ar) ₂ ; NO ₂ ; Si(R) ₃ ; B(OR) ₂ ; OSO ₂ R; linear alkyl, alkoxy or thioalkyl having 1 to 40 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl having 3 to 40 C atoms, each of which may be substituted by one or more radicals R, wherein in each case one or more non-adjacent CH ₂ radicals may be replaced by RC=CR, C≡C, Si(R) ₂ , Ge(R) ₂ , Sn(R) ₂ , C=O, C=S, C=Se, P(=O)(R), SO, SO ₂ , O, S or CONR and wherein one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO ₂ ; an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R in each case; and an aryloxy group with 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R; wherein two radicals ^RY together may form an aliphatic, aromatic or heteroaromatic ring system, which may be substituted by one or more radicals R; R ^CO, identically or differently on each occurrence, represents a radical selected from the group consisting of: H; D; a linear alkyl group with 1 to 40 C atoms, which may be substituted by one or more radicals R; an aryl or heteroaryl group with 6 to 18 aromatic ring atoms, which may be substituted by one or more radicals R in each case; wherein two radicals R ^C may together form an aliphatic, aromatic or heteroaromatic ring system, which may be substituted by one or more radicals R; R ^NO represents, identically or differently on each occurrence, a radical selected from the group consisting of: H; D; F; linear alkyl radicals having 1 to 40 C atoms or branched or cyclic alkyl radicals having 3 to 40 C atoms, each of which may be substituted by one or more radicals R, and in which one or more H atoms may be replaced by D, F or CN; aromatic or heteroaromatic ring systems having 5 to 60 aromatic ring atoms, which may in each case be substituted by one or more radicals R; R and Ar have the same meanings as above. Preferably, Ar ^50, identically or differently on each occurrence, is an aromatic or heteroaromatic ring system having 5 to 40 (more preferably 5 to 30, even more preferably 6 to 18) aromatic ring atoms, which in each case may also be substituted by one or more radicals R. Preferably, Ar ⁵¹ , Ar ⁵² , Ar ⁵³ , identically or differently, represent a condensed aryl or heteroaryl ring having 6 aromatic ring atoms, which in each case may also be substituted by one or more radicals R. Preferably, ^RY represents, identically or differently on each occurrence, H; D; F; linear alkyl, alkoxy or alkylthio having 1 to 40 (preferably 1 to 20, more preferably 1 to 10) C atoms or branched or cyclic alkyl, alkoxy or alkylthio having 3 to 40 (preferably 3 to 20, more preferably 3 to 10) C atoms, each of which may be substituted by one or more radicals R, in which in each case there are one or more non-adjacent CH ₂ groups may be replaced by RC=CR, C≡C, O or S and one or more H atoms may be replaced by D or F; an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms (preferably 5 to 40, more preferably 5 to 30, particularly preferably 5 to 18) aromatic ring atoms, which in each case may be substituted by one or more groups R. Preferably, R ^CO represents, identically or differently on each occurrence, a radical selected from the group consisting of: H; D; linear alkyl having 1 to 10 (preferably 1 to 6, more preferably 1 to 3) C atoms, which may be substituted by one or more radicals R; aryl or heteroaryl having 6 to 18 (preferably 6 to 12) aromatic ring atoms, which may in each case be substituted by one or more radicals R; wherein two radicals R ^CO may together form an aliphatic, aromatic or heteroaromatic ring system, which may be substituted by one or more radicals R. Preferably, R ^NO represents, identically or differently at each occurrence, a group selected from the following: an aromatic or heteroaromatic ring system having 5 to 60 (preferably 5 to 40, more preferably 5 to 30, particularly preferably 5 to 18) aromatic ring atoms, which may in each case be substituted by one or more groups R. According to a preferred embodiment, the composition further comprises a fluorescent luminescent body. Preferred fluorescent luminescent bodies are aromatic anthraceneamines, aromatic anthracenediamines, aromatic pyreneamines, aromatic pyrenediamines, aromatic chrysenamines or aromatic chrysenamines. Aromatic anthraceneamines refer to compounds in which one diarylamine group is directly bonded to an anthracene group (preferably at the 9 position). Aromatic anthracenediamines are compounds in which two diarylamine groups are directly bonded to anthracene groups (preferably at the 9,10-positions). Aromatic pyreneamines, pyrenediamines, fastamines and fastdiamines are defined similarly, in which the diarylamine groups are preferably bonded to the 1-position or 1,6-positions of pyrene. Other preferred luminophores are indenofluorene amine or indenofluorene diamine (for example, according to WO 2006/108497 or WO 2006/122630), benzoindenofluorene amine or benzoindenofluorene diamine (for example, according to WO 2008/006449), and dibenzoindenofluorene amine or dibenzoindenofluorene diamine (for example, according to WO 2007/140847), and indenofluorene derivatives containing condensed aromatic groups disclosed in WO 2010/012328. Other preferred luminophores are benzanthracene derivatives as disclosed in WO 2015/158409, anthracene derivatives as disclosed in WO 2017/036573, fluorene dimers linked by heteroaryl groups as disclosed in WO 2016/150544, or phenanthrene derivatives as disclosed in WO 2017/028940 and WO 2017/028941. Also preferred are pyrenarylamines as disclosed in WO 2012/048780 and WO 2013/185871. Also preferred are the benzoindenofluorene amine disclosed in WO 2014/037077, the benzoindenofluorene amine disclosed in WO 2014/106522, and the indenofluorene disclosed in WO 2014/111269 or WO 2017/036574, WO 2018/007421. Also preferred are the luminescent bodies comprising dibenzofuran or indenodibenzofuran moieties as disclosed in WO 2018/095888, WO 2018/095940, WO 2019/076789, WO 2019/170572, WO 2020/043657, WO 2020/043646, and WO/2020/043640. Also preferred are boron derivatives disclosed in, for example, WO 2015/102118, CN108409769, CN107266484, WO2017195669, US2018069182, WO 2020/208051, WO2021/058406, and WO 2021/094269. Very preferred fluorescent luminescent bodies are described in WO 2021/090932, more particularly pages 129 to 133, 157 to 166, 171 to 187, 200 to 211, 222 to 227, 236 to 252, 255; WO 2020/054676, more particularly pages 44 to 104; WO 2020/017931, more particularly pages 17 to 39; WO 2020/218079, more particularly pages 64 to 258; WO 2018/212169, more particularly pages 33 to 42; WO 2019/235452, more particularly pages 46 to 168; US 10,249,832, more particularly pages 19 to 106; and WO 2021/014001, more particularly pages 107 to 129. Preferably, the fluorescent luminescent body has an emission peak wavelength between 420 and 550 nm. Preferably, the fluorescent luminescent body has a half-width at half height of FWHM ≤ 50 nm, preferably FWHM ≤ 40 nmm, more preferably FWHM ≤ 30 nm. The following experimental part describes a method for determining FWHM. The optical bandwidth of a light source is measured by its half-width at half height (FWHM). The term FWHM refers to the width of a light signal at half its maximum intensity. The FWHM of the fluorescent luminescent body is measured here at the peak emission wavelength λ _max (which corresponds to the wavelength of the first maximum of the emission spectrum). In order to determine the peak emission wavelength of the fluorescent luminescent body, the fluorescent luminescent body is dissolved in toluene and the photoluminescence spectrum is obtained using a fluorescence spectrometer. More specifically, a concentration of 1 mg/100 mL is used. The solution is excited in a fluorescence spectrometer (e.g. Hitachi F-4500). Usually, the first maximum is also the global maximum of the spectrum. In order to determine the FWHM of the fluorescent luminescent body, the wavelength value at half the peak emission wavelength maximum is subtracted. Preferably, according to the definition of quantum chemical calculation, the fluorescent luminescent body has a LUMO from -1.5 eV to -3.0 eV, preferably from -2.1 eV to -2.5 eV, and more preferably from -2.2 eV to -2.4 eV. Preferably, according to the definition of quantum chemical calculation, at least one fluorescent luminescent body has a HOMO from -4.7 eV to -6 eV, preferably from -4.8 eV to -5.2 eV, and more preferably from -4.9 eV to -5.1 eV. According to a preferred embodiment, the fluorescent luminescent body is selected from the compound of formula (F-1): wherein: Ar ³⁰ , Ar ³¹ , Ar ³² represent, at each occurrence, identically or differently, a substituted or unsubstituted aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms; Y ³⁰ represents B or N; Y ³¹ , Y ³² , Y ³³ represent, at each occurrence, identically or differently, O, S, C(R ⁰ ) ₂ , C═O, C═S, C═NR ⁰ , C═C(R ^{0 ) 2 , Si(R 0 )} ₂ , BR ⁰ , NR ⁰ , PR ⁰ , SO ₂ , SeO ₂ or a chemical bond, with the prerequisite that if Y ³⁰ is B, at least one of the groups Y ³¹ , Y ³² , Y ³³ represents NR 0 , and if Y ₃₀ is N, the groups Y ³¹ , Y ³² , Y 33 represent NR ⁰ . at least one of ^{Y 32} and Y ³³ represents BR ⁰ ; R ⁰ represents, on each occurrence, H, D, F, a linear alkyl radical having 1 to 20 (preferably 1 to 10) C atoms or a branched or cyclic alkyl radical having 3 to 20 (preferably 3 to 10) C atoms, each of which may be substituted by one or more radicals R, wherein in each case one or more non-adjacent CH ₂ radicals may be replaced by O or S and wherein one or more H atoms may be replaced by D or F; or an aromatic or heteroaromatic ring system having 5 to 40 (preferably 5 to 30, more preferably 6 to 18) aromatic ring atoms, which may be substituted by one or more radicals R in each case, wherein two adjacent radicals R ⁰ may be taken together to form an aliphatic or aromatic ring system, which may be substituted by one or more groups R, wherein R has the same definition as in claim 1; and q is 0 or 1. Examples of suitable fluorescent luminescent bodies are described in the following table: According to a preferred embodiment, the composition comprises at least one, two, three or four (when present) deuterated materials selected from the following: hole transport host materials, electron transport host materials, phosphorescent metal complexes and (when present) fluorescent luminescent bodies. More preferably, the composition comprises at least one, two, three or four (when present) deuterated materials selected from the following: hole transport host materials, electron transport host materials, phosphorescent metal complexes and (when present) fluorescent luminescent bodies, wherein the degree of deuteration is equal to or higher than 10%. Preferably, it is equal to or higher than 30%, more preferably, it is equal to or higher than 60%, and even more preferably, it is equal to or higher than 90%. The degree of deuteration (DD) corresponds to the number of deuterium atoms in a compound as a percentage of the total number of deuterium and protium atoms in the compound, as follows: Wherein: _ND is the number of deuterium atoms in the compound _NP is the total number of deuterium and protium atoms in the compound. In the following, "D" represents deuterium and "H" (hydrogen) represents more protium. The composition according to the present invention may also contain other organic or inorganic compounds that are also used in electronic devices, such as other luminophores or other host materials. The composition of the present invention can be processed by vapor deposition or from solution. If the composition is applied from a solution, a formulation of the composition of the present invention containing at least one other solvent is required. Such formulations may be, for example, solutions, dispersions or emulsions. For this purpose, it is preferred to use a mixture of two or more solvents. The present invention therefore further provides a formulation comprising the composition of the present invention and at least one solvent. Suitable and preferred solvents are, for example, toluene, anisole, o-, m- or p-xylene, methyl benzoate, trimethylol, tetrahydronaphthalene, veratrol, THF, methyl-THF, THP, chlorobenzene, dioxane, phenoxytoluene (particularly 3-phenoxytoluene), (-)-fennel, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, 1-methylnaphthalene, 2-methylbenzothiazole, 2-phenoxyethanol, 2-pyrrolidone, 3-methylanisole, 4-methylanisole, 3,4-dimethylanisole, 3,5-dimethylanisole, acetophenone, α-terpineol, benzophenone Thiazole, butyl benzoate, isopropylbenzene, cyclohexanol, cyclohexanone, cyclohexylbenzene, decahydronaphthalene, dodecylbenzene, ethyl benzoate, indane, methyl benzoate, NMP, p-isopropyltoluene, phenyl ethyl ether, 1,4-diisopropylbenzene, dibenzyl ether, diethylene glycol butyl methyl ether, triethylene glycol butyl methyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, tripropylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 2-isopropylnaphthalene, pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene, 1,1-bis(3,4-dimethylphenyl)ethane, hexamethylindane, or a mixture of these solvents. The present invention also provides the use of the composition of the present invention in an organic electronic device (preferably in a light-emitting layer). The organic electronic device is preferably selected from an organic integrated circuit (OIC), an organic field effect transistor (OFET), an organic thin film transistor (OTFT), an organic electroluminescent device, an organic solar cell (OSC), an organic optical detector and an organic photoreceptor, and the organic electroluminescent device is particularly preferred. Very preferred organic electroluminescent devices containing the composition of the present invention (described above or as preferred) are organic light emitting transistors (OLET), organic field quenching devices (OFQD), organic light emitting electrochemical cells (OLEC, LEC, LEEC), organic laser diodes (O-lasers) and organic light emitting diodes (OLED); OLEC and OLED are particularly preferred, and OLED is the most preferred. In a particularly preferred embodiment of the present invention, the electronic device is an organic electroluminescent device, preferably an organic light emitting diode (OLED), which contains the composition described above in the light emitting layer (EML). Here, light emitting layer (Light emission layer) and light-emitting layer (light-emitting layer) are used synonymously. In a particularly preferred embodiment of the present invention, the organic electroluminescent device is an organic electroluminescent device comprising an anode, a cathode and at least one organic layer, the organic layer comprising at least one luminescent layer, wherein the at least one luminescent layer comprises the composition as described above. In a very particularly preferred embodiment of the present invention, the organic electroluminescent device is an organic light-emitting diode comprising an anode, a cathode and at least one organic layer, the organic layer comprising at least one luminescent layer, wherein the at least one luminescent layer comprises the composition as described above, i.e., a composition comprising a hole-transporting host material, an electron-transporting host material and a phosphorescent metal complex, wherein the luminescence of the luminescent layer is phosphorescent luminescence generated by the phosphorescent metal complex. In this case, the light-emitting layer preferably comprises: 60 volume % to 99 volume % of a host material comprising a hole transport host material and an electron transport host material; 1 to 40 volume % of a phosphorescent metal complex; based on the entire composition of the light-emitting layer. In another very preferred embodiment of the present invention, the organic electroluminescent device is an organic light-emitting diode comprising an anode, a cathode and at least one organic layer, wherein the organic layer comprises at least one light-emitting layer, wherein the at least one light-emitting layer comprises the composition as described above, that is, a composition comprising a hole-transporting host material, an electron-transporting host material, a phosphorescent metal complex as a sensitizer, and a fluorescent body, wherein the sensitizer transfers the energy absorbed in the organic light-emitting diode to the fluorescent body, and the fluorescent body emits fluorescence. In this case, the light-emitting layer preferably comprises: 60 volume % to 98.5 volume % of a host material comprising a hole-transporting host material and an electron-transporting host material; 1 to 35 volume % of a phosphorescent metal complex as a sensitizer; and 0.05 to 5 volume % of a fluorescent light-emitting body, based on the total composition of the light-emitting layer. If the compound is processed from a solution, it is preferred to use the corresponding amounts in weight % instead of the amounts specified above in volume %. In addition to the cathode, the anode and the layer comprising the composition of the present invention, the electronic device may comprise other layers. The layers are selected in various cases, for example, from one or more hole injection layers, hole transport layers, hole blocking layers, luminescent layers, electron transport layers, electron injection layers, electron blocking layers, exciton blocking layers, intermediate layers, charge generation layers (IDMC 2003, Taiwan; Session 21 OLED (5), T. Matsumoto, T. Nakada, J. Endo, K. Mori, N. Kawamura, A. Yokoi, J. Kido, Multiphoton Organic EL Device Having Charge Generation Layer ) and/or organic or inorganic p/n junctions. However, it should be noted that not every one of these layers necessarily has to be present. The order of the layers in the organic light-emitting diode is preferably as follows: anode/hole injection layer/hole transport layer/luminescent layer/electron transport layer/electron injection layer/cathode. The order of these layers is the preferred order. At the same time, it should be pointed out again that not all of the layers mentioned must be present and/or other layers may be present in addition. The organic light-emitting diode of the present invention may contain two or more luminescent layers. According to the present invention, at least one of the luminescent layers contains the composition as described above. More preferably, the luminescent layers in this case have several maxima between 380 nm and 750 nm in total, so that the overall result is white luminescence; in other words, various luminescent compounds are used in the luminescent layers that can fluoresce or phosphoresce and emit blue or yellow or orange or red light. Particularly preferred are three-layer systems, i.e. systems with three luminescent layers, wherein the three layers exhibit blue, green and orange or red luminescence (for basic constructions, see, for example, WO 2005/011013). It should be noted that, in order to generate white light, instead of a plurality of luminescent compounds of different colors, a single luminescent compound emitting in a wide wavelength range is also suitable. Suitable charge transport materials that can be used in the hole injection layer, hole transport layer, electron blocking layer or electron transport layer of the organic electroluminescent device of the present invention are, for example, compounds disclosed in Chem. Rev. 2007, 107(4), 953-1010 by Y. Shirota et al. or other materials used in these layers according to the prior art. The material used in the electron transport layer can be any material used as an electron transport material in the electron transport layer in the prior art. Particularly suitable are aluminum complexes such as Alq ₃ , zirconium complexes such as Zrq ₄ , benzimidazole derivatives, trisoxane derivatives, pyrimidine derivatives, pyridine derivatives, pyridine derivatives, quinoline derivatives, quinoline derivatives, oxadiazole derivatives, aromatic ketones, lactams, boranes, diazaphosphole derivatives and phosphine oxide derivatives. Other suitable materials are the derivatives of the above compounds disclosed in JP 2000/053957, WO 2003/060956, WO 2004/028217, WO 2004/080975 and WO 2010/072300. Preferred hole transport materials, in particular materials that can be used in hole transport, hole injection or electron blocking layers, are indenofluoramine derivatives (for example according to WO 06/122630 or WO 06/100896), amine derivatives disclosed in EP 1661888, hexaazatriphenyl derivatives (for example according to WO 01/049806), amine derivatives with condensed aromatic rings (for example according to US 5,061,569), amine derivatives disclosed in WO 95/09147, monobenzoindenofluoramine (for example according to WO 08/006449), dibenzoindenofluoramine (for example according to WO 07/140847), spirodifluoramine (for example according to WO 2012/034627 or EP 12000929.5 which has not been published yet), fluorenylamine (for example according to WO 2014/015937, WO 2014/015938 and WO 2014/015935), spirodibenzopyranamine (for example according to WO 2013/083216), and dihydroacridine derivatives (for example WO 2012/150001). Preferred cathodes for electronic devices are metals with low work functions, metal alloys or multilayer structures composed of various metals, for example, alkali earth metals, alkali metals, main group metals or pyridine elements (for example, Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.). Also suitable are alloys consisting of alkali metals or alkali earth metals and silver, for example alloys consisting of magnesium and silver. In the case of multilayer structures, in addition to the metals mentioned, it is also possible to use other metals with a relatively high work function, such as Ag or Al, in which case, for example, metal combinations such as Ca/Ag, Mg/Ag or Ba/Ag are usually used. It is also preferred to introduce a thin intermediate layer of a material with a high dielectric constant between the metal cathode and the organic semiconductor. Examples of useful materials for this purpose are alkali metal fluorides or alkali earth metal fluorides, but also the corresponding oxides or carbonates (for example LiF, _Li2O , _BaF2 , MgO, NaF, CsF, _Cs2CO3 , _etc. ). For this purpose, it is also possible to use lithium quinolinate (LiQ). The layer thickness of this layer is preferably between 0.5 and 5 nm. Preferred anodes are materials with a high work function. Preferably, the anode has a work function of greater than 4.5 eV relative to a vacuum. Firstly, metals with a high redox potential are suitable for this purpose, such as Ag, Pt or Au. Secondly, metal/metal oxide electrodes (such as Al/Ni/NiO _x , Al/PtO _x ) may also be preferred. For some applications, at least one of the electrodes must be transparent or partially transparent in order to be able to irradiate organic materials (organic solar cells) or to be able to emit light (OLED, O-laser). Preferred anode materials here are conductive mixed metal oxides. Particularly preferred are indium tin oxide (ITO) or indium zinc oxide (IZO). Also preferred are conductive doped organic materials, in particular conductive doped polymers. Furthermore, the anode can also consist of two or more layers, for example an inner layer of ITO and an outer layer of a metal oxide, preferably tungsten oxide, molybdenum oxide or vanadium oxide. During the manufacturing process, the organic electronic device is appropriately structured (depending on the application), equipped with contacts and finally sealed, since the life of the device of the invention is shortened in the presence of water and/or air. In another preferred embodiment, an organic electronic device comprising a composition according to the invention is characterized in that one or more organic layers comprising a composition according to the invention are applied by sublimation. In this case, the materials are applied by vapor deposition in a vacuum sublimation system at an initial pressure of less than ^10-5 mbar, preferably less than ^10-6 mbar. However, in this case, the initial pressure may also be even lower, for example less than ^10-7 mbar. Also preferred is an organic electroluminescent device, characterized in that one or more layers are applied by an OVPD (organic vapor deposition) method or with the aid of a carrier gas sublimation method. In this case, the materials are applied at a pressure between 10 ^-5 mbar and 1 bar. A special example of this method is the OVJP (organic vapor jet printing) method, in which the materials are applied directly by means of a nozzle and thus structured (e.g. MS Arnold et al. Appl. Phys. Lett. 2008, 92, 053301). Also preferred is an organic electroluminescent device characterized in that one or more organic layers comprising the composition of the invention are produced from a solution, for example by spin coating, or by any printing method, such as screen printing, quick-dry printing, nozzle printing or lithography, but more preferably by LITI (light-induced thermal imaging, thermal transfer printing) or inkjet printing. For this purpose, it is necessary that the components of the composition of the invention are soluble compounds. High solubility can be achieved by appropriate substitution of the corresponding compounds. The advantage of processing from solution is that the layers comprising the composition of the invention can be applied in a very simple and inexpensive manner. This technology is particularly suitable for large-scale production of organic electronic devices. In addition, it is possible to use hybrid methods, in which, for example, one or more layers are applied from solution and one or more other layers are applied by vapor deposition. These methods are generally known to those skilled in the art and can be applied to organic electroluminescent devices. The invention therefore further provides a method for producing an organic electronic device comprising the composition according to the invention as described above or as preferred, characterized in that at least one organic layer comprising the composition according to the invention is applied by vapor deposition, in particular by a sublimation method and/or by an OVPD (organic vapor phase deposition) method and/or by carrier gas sublimation, or from a solution, in particular by spin coating or by a printing method. In the production of organic electronic devices by vapor deposition, there are in principle two methods by which an organic layer comprising the composition according to the invention and which may comprise a plurality of different components can be applied to any substrate or applied by vapor deposition to any substrate. First, the materials used can initially be charged separately into material sources and ultimately evaporated from different material sources ("co-evaporation"). Secondly, the various materials can be premixed (premixed system) and the mixture can initially be charged into a single material source from which it is ultimately evaporated ("premixed evaporation"). In this way, it is possible to achieve vapor deposition of a layer with a uniform distribution of the components in a simple and rapid manner without the need for precise activation of multiple material sources. The present invention therefore further provides a method, characterized in that a composition as described above or as preferred is deposited from at least two material sources successively or simultaneously from the vapor phase, optionally together with other materials as described above or as preferred, and an organic layer is formed. The present invention therefore further provides a method, characterized in that a composition as described above or as preferred is used as a material source for vapor deposition of a host system and, optionally together with other materials, an organic layer is formed. The present invention further provides a method for manufacturing an organic electronic device comprising a composition of the present invention as described above or described as being preferred, characterized in that an organic layer is applied using a formulation of the present invention as described above. It should be noted that variations of the embodiments described in the present invention are within the scope of the present invention. Unless this is expressly excluded, any feature disclosed in the present invention may be exchanged with an alternative feature for the same purpose or an equal or similar purpose. Unless otherwise stated, any feature disclosed in the present invention should therefore be considered an example of a general series or as an equal or similar feature. All features of the present invention can be combined with each other in any way, unless specific features and/or steps are mutually exclusive. This is especially true for the preferred features of the present invention. Similarly, features of non-essential combinations can be used alone (rather than in combination). The technical teachings disclosed by the present invention can be extracted and combined with other examples. The present invention is described in more detail with the following embodiments, but it is not intended to limit the present invention.

The following describes an embodiment of an OLED device according to a preferred embodiment of the present invention. The manufacture of OLEDs has been described many times in the literature, for example in WO 04/058911. The method can be adapted to the following conditions, i.e. layer thickness variations, layer sequence and materials. The following discloses an embodiment of an OLED device structure according to a preferred embodiment of the present invention. All exemplary OLED devices feature the following ordered layer structure: - glass plate (hereinafter also glass substrate or substrate), - indium tin oxide (hereinafter ITO), - hole injection layer (hereinafter HIL) - hole transport layer (hereinafter HTL), - electron blocking layer (hereinafter EBL), - light emitting layer (hereinafter EML), - hole blocking layer (hereinafter HBL), - electron transport layer (hereinafter ETL), - electron injection layer (hereinafter EIL), - aluminum (hereinafter cathode). The glass substrate with structured 50 nm thick ITO was pre-treated with oxygen plasma and then with argon plasma. Thereafter, the materials for HIL, HTL, EBL, EML, HBL, ETL and EIL are deposited on the pre-treated glass substrate by thermal vapor deposition in a vacuum chamber. Detailed information about the HIL, HTL, EBL, EML, HBL, ETL and EIL of the OLED device embodiments is given in Table A. The materials used in these embodiments are listed in Table B. Finally, the cathode is formed by an aluminum layer with a thickness of 100 nm. According to one embodiment of the present invention, the EML comprises a hole transporting host material, an electron transporting host material, and a phosphorescent metal complex material. All materials of the EML are deposited simultaneously at a specific deposition rate, i.e., by co-evaporation, to form a (uniform, amorphous) mixture. The deposition rate of each material can be selected so that each material is present in the mixture at a specific volume fraction (Vol.-%). For example, the composition of the EML comprising 40 Vol.-% of a hole transporting host material denoted as HH, 40 Vol.-% of an electron transporting host material denoted as EH, and 10 Vol.-% of a phosphorescent metal complex material denoted as D is represented in Table A below as HH:EH:D (45%:45%:10%). This notation convention is similarly applied to describe the composition of the EML comprising two or four different materials, and also to the HIL, HTL, EBL, HBL, ETL and EIL of the OLED device if the OLED device comprises more than one material. The performance of the OLED device can be measured by standard methods. To this end, the electroluminescence (EL) spectrum and the external quantum efficiency (EQE) can be determined from the current/voltage/brightness characteristic line (IUL characteristic line) of the assumed Lambertian emission profile. The EL spectrum can be recorded at a luminescence density of 1000 cd/m² and the CIE 1931 x and y coordinates can be calculated from the EL spectrum. The operating voltage U is defined as the voltage required for a current density of 10 mA/cm². EQE represents the external quantum efficiency at a current density of 10 mA/cm². In Table A, the EQE is given as the relative EQE (rel. EQE) for Example 1 (Ex1) of the present invention, which has a rel. EQE of 100%. The life LT90 is defined as the time after which the brightness drops to 90% of the initial brightness during operation at a constant current density of 5 mA/cm². In Table A, the lifetime is given as the relative lifetime (rel. LT) with respect to Example 1 (Ex1) of the present invention, which has a rel. LT of 100%. The following Examples Ex1, Ex2, Ex3, Ex4 and Ex5 correspond to the embodiments according to the present invention, and Ex1 is an OLED device according to the prior art, such as WO2010/054729). Details of each HIL, HTL, EBL, EML, HBL, ETL and EIL are given in Table A. The molecular structures used are given in Table B. Examples of preferred embodiments of the present invention given in Table A include fluorenylamine as HTL and HTM in HIL. Example Ex1 : EML comprises a hole transporting host material H-1, an electron transporting host material E-2 and a phosphorescent metal complex material D-3. This OLED device can be compared with the OLED device specified in Example StA1 in Table A. The difference between the two devices lies in the electron-transporting host material used in the respective EMLs, namely, E-1 in the case of StA1; and E-2 in the case of Ex2. Compared with the device according to StA1, the device according to Ex1 has a superior lifetime and a superior EQE. Example Ex2 : The EML comprises a hole-transporting host material H-1, an electron-transporting host material E-2, a phosphorescent metal complex material D-3 and a fluorescent light-emitting body FL-1. This OLED device can be compared with the OLED device specified in Example StA1. The difference between the two devices lies in the electron-transmitting host material used in the respective EMLs, namely, E-1 in the case of StA1 and E-2 in the case of Ex2. Furthermore, the EML in Ex2 includes a fluorescent luminophore Fl-1, while the EML of StA1 does not. Compared with the device according to StA1, the device according to Ex2 has a superior lifetime and a superior EQE. Example Ex3 : Another embodiment of the subject matter according to the present invention is provided by replacing the phosphorescent metal complex material D-3 in Ex1 with the phosphorescent metal complex material D-1 given in Table B. Example Ex4 : The phosphorescent metal complex material D-3 in Ex1 is replaced by the phosphorescent metal complex material D-2 given in Table B to provide another embodiment of the subject matter of the present invention. Example Ex5 : The phosphorescent metal complex material D-3 in Ex2 is replaced by the phosphorescent metal complex material D-2 given in Table B to provide another embodiment of the subject matter of the present invention. Table A : Description of HIL, HTL, EBL, EML, HBL, ETL and EIL of an exemplary OLED device. Table B : Structural formula of OLED materials

Claims (22)

A composition comprising: - a hole transporting host material; - an electron transporting host material; and - a phosphorescent metal complex; wherein the hole transporting host material is selected from compounds of formula (H-1): The symbols and reference numerals used are as follows: M is selected from the group consisting of Si, Ge and Sn; A is a ring selected from a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more groups R; Y represents a group selected from NR ^N2 , O and S at each occurrence, the same or different; R ^M1 and R ^M2 represent H, D, F, Cl, Br, I, C(=O)R, OSO ₂ R, COOR, CON(R) ₂ , N(R) ₂ ; a straight-chain alkyl group having 1 to 40 C atoms, or a branched or cyclic alkyl group having 3 to 40 C atoms, or an alkenyl or alkynyl group having 2 to 40 C atoms, wherein each of the above groups may be substituted by one or more groups R, and wherein one or more CH ₂ groups in the above groups may be replaced by Si(R) ₂ , Ge(R) ₂ , Sn(R) ₂ , C═O, C═S, C═Se, C═NR, P(═O)(R), SO, SO ₂ , NR, -O-, -S-, -COO- or -CONR-, and wherein one or more H atoms in the above groups may be replaced by D, F, Cl, Br, I, CN or NO ₂ ; or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which in each case may be substituted by one or more radicals R; or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R, wherein the radicals R ^M1 and R ^M2 may be linked to one another and form a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more radicals R; R ^N1 , R ^N2 is, identically or differently on each occurrence, H, D, F, a linear alkyl group having 1 to 40 C atoms or a branched or cyclic alkyl group having 3 to 40 C atoms, each of which may be substituted by one or more radicals R and in which one or more H atoms may be replaced by D, F or CN, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R in each case; and wherein: when n=m=1, the radicals ^RN1 and ^RM1 and/or ^RN2 and ^RM2 may be linked to one another and form a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more radicals R; or when n=2, two radicals ^RN1 and/or two radicals R ^N2, when present, may be linked to one another and form a monocyclic or polycyclic aliphatic, aromatic or heteroaromatic ring system, which may be substituted by one or more groups R; R, identically or differently at each occurrence, represents H; D; F; Cl; Br; I; CHO; CN; C(=O)Ar; P(=O)(Ar) ₂ ; S(=O)Ar; S(=O) ₂ Ar; N(R') ₂ ; N(Ar) ₂ ; NO ₂ ; Si(R') ₃ ; B(OR') ₂ ; OSO ₂ R; linear alkyl, alkoxy or thioalkyl having 1 to 40 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl having 3 to 40 C atoms, each of which may be substituted by one or more radicals R', wherein in each case one or more non-adjacent CH ₂ radicals may be replaced by R'C=CR', C≡C, Si(R') ₂ , Ge(R') ₂ , Sn(R') ₂ , C=O, C=S, C=Se, P(=O)(R'), SO, SO ₂ , O, S or CONR' and wherein one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO ₂ ; an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, which in each case may be substituted by one or more radicals R'; or an aryloxy group with 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R'; wherein two radicals R may form a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more radicals R'; Ar is, identically or differently on each occurrence, an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, which in each case may also be substituted by one or more radicals R';R' represents, identically or differently on each occurrence, H; D; F; Cl; Br; I; CN; a linear alkyl, alkoxy or alkylthio radical having 1 to 20 C atoms or a branched or cyclic alkyl, alkoxy or alkylthio radical having 3 to 20 C atoms, wherein in each case one or more non-adjacent CH ₂ groups may be replaced by SO, SO ₂ , O, S and wherein one or more H atoms may be replaced by D, F, Cl, Br or I; or an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, n is 1 or 2; m is (2-n); and with the proviso that the electron transport material is not one of the following compounds: . The composition according to claim 1, wherein the hole transport host material is selected from compounds of formula (H-2), (H-3) and (H-4): wherein the symbols ^RN1 , ^RM1 , ^RM2 , M and Y and the labels n and m have the same meanings as in claim 1, and wherein: the rings B, C, D, E, F as described in formulas (H-2), (H-3) and (H-4) represent, at each occurrence, the same or different rings selected from a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more groups R, and wherein when Y is NR ^N2 , the ring B may be bonded to ^RN1 and/or NR ^N2 , the ring E may be bonded to the group ^RN1 , when Y is NR ^N2 , the ring F may be bonded to NR ^N2 , and the rings C and D or E and F may be bonded to each other. The composition according to claim 1 or 2, wherein the hole transport host material is selected from compounds of formula (H-2-1), (H-3-1) and (H-4-1): wherein the symbols ^RN1 , M and Y and the rings B, C, D, E, F have the same meanings as above, and wherein two radicals ^RN1 , two radicals Y, two rings B, two rings C, two rings D, two rings E and two rings C are selected the same or differently at each occurrence. The composition according to one or more of the preceding claims, wherein the hole transporting host material is selected from compounds of formula (H-2-2), (H-3-2) and (H-4-2): wherein the symbols M, Y and ^RN1 have the same meanings as in claim 1, and wherein: ^X1 to ^X8 represent, at each occurrence, the same or different, a group CR ^X or N; and wherein two adjacent groups selected from X1 to X8 may form a monocyclic or polycyclic fused aryl or heteroaryl ring having 5 to 18 aromatic ring atoms or a monocyclic or polycyclic aliphatic ring having 5 to 18 ring atoms, which may be substituted by one or more groups R as defined above; ^V1 to ^V12 represent, at each occurrence, the same or different, a group CR ^V or N; wherein ^V1 to ^V12 are selected from V1 to V13, V1 to V14, V1 to V15, V1 to V16, V17 to V18, V19 to V20, V21 to V217, V22 to V23, ^V24 to V25 wherein two adjacent groups selected from V 1 to ^{V 16} may form a monocyclic or polycyclic fused aryl or heteroaryl ring having 5 to 18 aromatic ring atoms or a monocyclic or polycyclic aliphatic ring having 5 to 18 ring atoms, which may be substituted by one or more groups R as defined above; Z ¹ to Z ¹⁶ represent the groups CR ^Z or N identically or differently at each occurrence; wherein two adjacent groups selected from V ¹ to V ¹⁶ may form a monocyclic or polycyclic fused aryl or heteroaryl ring having 5 to 18 aromatic ring atoms or a monocyclic or polycyclic aliphatic ring having 5 to 18 ring atoms, which may be substituted by one or more groups R as defined above; ^RX , ^RV , R ^Z , identically or differently on each occurrence, represents H; D; F; Cl; Br; I; C(═O)R; OSO ₂ R; COOR; CON(R) ₂ ; a linear alkyl group having 1 to 40 C atoms or a branched or cyclic alkyl group having 3 to 40 C atoms or an alkenyl or alkynyl group having 2 to 40 C atoms, wherein each of the above mentioned groups may be substituted by one or more groups R and wherein one or more CH ₂ groups in the above mentioned groups may be replaced by Si(R) ₂ , Ge(R) ₂ , Sn(R) ₂ , C═O, C═S, C═Se, C═NR, P(═O)(R), SO, SO ₂ , NR, —O—, —S—, —COO— or —CONR— and wherein one or more H atoms in the above mentioned groups may be replaced by D, F, Cl, Br, I, CN or NO ₂ ; or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which in each case may be substituted by one or more radicals R; or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R, wherein two adjacent radicals ^RX , ^RZ , ^RV may be linked to one another and form a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more radicals R; and when ^X1 represents ^CRX , or ^Z1 represents ^CRZ , the corresponding ^RX or ^RZ may be substituted with R ^N1 forms a ring, and the ring is selected from a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more groups R; when ^X4 represents ^CRx , or ^Z8 represents ^CRz , the corresponding ^RX or ^Rz may form a ring with ^RN2 , and when Y is ^RN2 , the ring is selected from a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more groups R; when ^X5 represents ^CRx , or ^Z9 represents ^CRz , the corresponding ^RX or ^Rz may form a ring with ^RN4 , and when ^Y1 is R When X ⁸ represents CR ^X , or Z ¹⁶ represents CR Z , the corresponding ^RX or R ^Z may form a ring with ^RN3 , and the ring is selected from a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more groups R; When Z ⁴ and Z ⁵ or Z ¹² and ^{Z 13 represent} CR ^Z , the corresponding two groups ^{R Z} may together form a ring selected from a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more groups R; R has the same meaning as in claim 1. The composition according to one or more of the preceding claims, wherein the hole transporting host material is selected from compounds of formula (H-2-2), (H-3-2) and (H-4-2): wherein such symbols have the same meanings as in claims 1 and 4. The composition according to one or more of the preceding claims, wherein the hole transporting host material is selected from a compound of formula (H-2-2A), wherein ^X1 to ^X8 have the same meanings as in claim 4; and ^X9 to ^X28 represent, at each occurrence, identically or differently, a group CR ^X or N; wherein two adjacent groups selected from ^V9 to ^V28 may form a monocyclic or polycyclic fused aryl or heteroaryl ring having 5 to 18 aromatic ring atoms or a monocyclic or polycyclic aliphatic ring having 5 to 18 ring atoms, which may be substituted by one or more groups R as defined above; and wherein ^X1 and ^X19 , ^X23 and ^X24 , ^X28 and ^X5 , ^X8 and ^X9 , ^X13 and ^X14 and/or ^X18 and ^X4 may be bonded to each other by a single bond or a divalent group selected from the following: -C(R ^X0 ) ₂ -, -C(R ^X0 )-C(R ^X0 )-, -Si(R ^X0 ) ₂ -, -N(R ^X0 )-, -O-, -S-, -BR ^X0 -, -C(═O)-, -S(═O)-, -SO ₂ - and -P(R ^X0 )-; R ^X0 is independently selected at each occurrence from H; D; F; a linear alkyl group having 1 to 40 atoms or a branched or cyclic alkyl group having 3 to 40 C atoms, wherein each of the above groups may be substituted by one or more groups R and wherein one or more CH ₂ groups in the above groups may be substituted by Si(R) ₂ , Ge(R) ₂ , Sn(R) ₂ , C═O, C═S, C═Se, C═NR, P(═O)(R), SO, SO ₂ , NR, -O-, -S-, -COO- or -CONR-, and one or more H atoms in the above groups may be replaced by D, F, Cl, Br, I, CN or _NO2 ; or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may be substituted by one or more groups R in each case, wherein two adjacent groups ^R0 may be linked to each other and form a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more groups R; wherein R has the same meaning as in claim 1. A composition according to one or more of the preceding claims, wherein the electron-transmitting host material is selected from a compound comprising a group selected from the group consisting of substituted or unsubstituted triazoles, pyrimidines, lactams, benzimidazoles, quinazolines, quinazolines, nitrogen-doped dibenzofurans, diazadibenzofurans, nitrogen-doped dibenzothiophenes, diazadibenzothiophenes, carbolines and triptycenes. The composition according to one or more of the preceding claims, wherein the electron-transmitting host material is selected from compounds of formula (E-1), (E-2), (E-3) and (E-4), wherein ^RE, at each occurrence, is identically or differently H; D; F; Cl; Br; I; C(=O)R; _OSO2R ; COOR; CON(R) ₂ ; ^SiR10R11R12 ; N( ^ArN ) ² _; a linear alkyl group having 1 to 40 C atoms, a branched or cyclic alkyl group having 3 to 40 C atoms, or an alkenyl or alkynyl group having 2 ^to 40 C atoms, wherein each of the above groups may be substituted by one or more groups R and wherein one or more _CH2 groups in the above groups may be substituted by Si(R) ₂ , Ge(R) ₂ , Sn(R) ₂ , C=O, C=S, C=Se, C=NR, P(=O)(R), SO, _SO2 , NR, -O-, -S-, -COO- or -CONR-substituted and one or more H atoms in the above radicals may be replaced by D, F, Cl, Br, I, CN or _NO2 ; or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R in each case; or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R, wherein two radicals ^RE may form a monocyclic or polycyclic aliphatic ring system, an aromatic ring system or a heteroaromatic ring system, which may be substituted by one or more radicals R; L represents, identically or differently at each occurrence, a single bond or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, which may be substituted by one or more radicals R; R ¹⁰ , R ¹¹ , R ¹² are selected, at each occurrence, identically or differently, from H; D; a linear alkyl group having 1 to 40 C atoms, or a branched or cyclic alkyl group having 3 to 40 C atoms, or an alkenyl or alkynyl group having 2 to 40 C atoms, wherein each of the above groups may be substituted by one or more groups R, and wherein one or more CH ₂ groups in the above groups may be replaced by Si(R) ₂ , Ge(R) ₂ , Sn(R) ₂ , C═O, C═S, C═Se, C═NR, P(═O)(R), SO, SO ₂ , NR, —O—, —S—, —COO— or —CONR—, and wherein one or more H atoms in the above groups may be replaced by D, F, Cl, Br, I, CN or NO ₂ ; or an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R in each case; or an aralkyl or heteroaralkyl group with 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R; ^ArN represents, identically or differently at each occurrence, an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R; and R has the same meaning as in claim 1. The composition according to claim 8, wherein the compound of formula (E-1) to (E-4) includes at least one group ^RE , which represents: an aromatic ring system having 6 to 60 aromatic ring atoms, which may be substituted by one or more groups R; a heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may be substituted by one or more groups R; a group N( ^ArN ) ₂ ^; or ^{a group SiR10R11R12} . The composition according to claim 8 or 9, wherein the radical ^RE in formula (E-1) to (E-4) is selected, identically or differently at each occurrence, from: an aromatic ring system having 6 to 60 aromatic ring atoms, which may be substituted by one or more radicals R; a heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R; a radical N( ^ArN ) ₂ ; or ^{a radical SiR10R11R1} . The composition according to any one of claims 8 to 10, wherein the electron-transmitting host material is selected from a compound of formula (E-1-A) or (E-1-B), wherein the symbol L has the same meaning as in claim 8, and: L ¹ , L ² , L ^3, at each occurrence, identically or differently, represent a single bond or an aromatic or heteroaromatic ring system having 6 to 18 aromatic ring atoms, which may be substituted by one or more radicals R; E is CR or N; the prerequisite being that at least two radicals E represent N; E ⁰ is NR ²² , O or S; RE ^', at each occurrence, identically or differently, represents: an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R; a radical N(Ar ^N ) ₂ ; or a radical SiR ¹⁰ R ¹¹ R ¹² ; wherein Ar ^N , R ¹⁰ , R ¹¹ and R ¹² have the same meanings as in claim 8; R ²⁰ , R ²¹ , R ²² is selected, identically or differently at each occurrence, from H; D; a linear alkyl group having 1 to 40 C atoms, or a branched or cyclic alkyl group having 3 to 40 C atoms, or an alkenyl or alkynyl group having 2 to 40 C atoms, wherein each of the above groups may be substituted by one or more groups R and wherein one or more CH ₂ groups in the above groups may be replaced by Si(R) ₂ , Ge(R) ₂ , Sn(R) ₂ , C═O, C═S, C═Se, C═NR, P(═O)(R), SO, SO ₂ , NR, -O-, -S-, -COO- or -CONR- and wherein one or more H atoms in the above groups may be replaced by D, F, Cl, Br, I, CN or NO ₂ replacement; or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which in each case may be substituted by one or more groups R; or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms, which may be substituted by one or more groups R; r is an integer selected from 0, 1, 2 or 3; s is an integer selected from 0, 1, 2, 3 or 4; p is an integer selected from 0, 1 or 2; when p is 0, the group L ³ is directly bonded to the 6-membered ring containing the group E. A composition according to one or more of the preceding claims, wherein the phosphorescent metal complex is a platinum complex or an iridium complex. A composition according to one or more of the preceding claims, wherein the phosphorescent metal complex is a tetradentate platinum complex. The composition according to one or more of the preceding claims, wherein the energy of the lowest triplet state _T1 of the phosphorescent metal complex is higher than 2.55 eV as defined by quantum chemical calculations. A composition according to one or more of the preceding claims, wherein the composition further comprises a fluorescent luminescent body. The composition of claim 15, wherein the fluorescent light emitting body has an emission peak wavelength between 420 and 550 nm and has a half-width (FWHM) ≤ 50 nm. The composition according to any one of claims 19 to 23, wherein the fluorescent luminescent body is selected from the compound of formula (F-1): Ar ³⁰ , Ar ³¹ , Ar ³² represent, at each occurrence, identically or differently, a substituted or unsubstituted aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms; Y ³⁰ represents B or N; Y ³¹ , Y ³² , Y ³³ represent, at each occurrence, identically or differently, O, S, C(R ⁰ ) ₂ , C═O, C═S, C═NR ⁰ , C═C(R ^{0 ) 2 , Si(R 0} ₎ ² _, BR ⁰ , NR ⁰ , PR ⁰ , SO ₂ , SeO ₂ or a chemical bond, with the prerequisite that if Y ³⁰ is B, at least one of the groups Y ³¹ , Y ³² , Y ³³ represents NR 0 and if Y ³⁰ is N, the groups Y ³¹ , Y ³² , Y 33 represent NR ⁰ . at least one of ^{the following} represents BR ⁰ ; R ⁰ represents, identically or differently on each occurrence, H; D; F; a linear alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, each of which may be substituted by one or more radicals R, wherein in each case one or more non-adjacent CH ₂ radicals may be replaced by O or S and wherein one or more H atoms may be replaced by D or F; or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which may be substituted by one or more radicals R, wherein two adjacent radicals R ⁰ may together form an aliphatic or aromatic ring system, which may be substituted by one or more radicals R, wherein R has the same definition as in claim 1; and q is 0 or 1. A composition according to one or more of the preceding claims, wherein it comprises at least one deuterated material selected from a hole transporting host material, an electron transporting host material, a phosphorescent metal complex and a fluorescent luminescent body (when present), wherein the degree of deuteration is equal to or greater than 10%. A formulation comprising a composition according to one or more of the preceding claims and a solvent. An organic light-emitting diode comprising at least one composition according to one or more of claims 1 to 18. An organic light-emitting diode comprising: - an anode; - a cathode; and - at least one light-emitting layer, wherein the light-emitting layer comprises at least one composition according to one or more of claims 1 to 18. An organic light-emitting diode comprising: - an anode; - a cathode; - at least one light-emitting layer, wherein the light-emitting layer comprises at least one composition according to one or more of claims 15 to 18, wherein the phosphorescent metal complex is a sensitizer, and wherein the sensitizer transfers the energy absorbed in the organic light-emitting diode to the fluorescent body, and the fluorescent body emits light by fluorescence.