CN112467058B - A ternary exciplex composite material host and its OLED device preparation - Google Patents

Abstract

The invention discloses a ternary exciplex composite material main body and preparation of an OLED device thereof, wherein the OLED device comprises: an anode, a cathode, an organic functional layer disposed between the anode and the cathode; the organic functional layer comprises a hole injection layer, an organic light-emitting layer, an electron transport layer and an electron injection layer which are sequentially arranged in the direction from the anode to the cathode; the organic light-emitting layer comprises a host composite material and a guest material, the host composite material is a ternary exciplex formed by mixing an electron donor, a first electron acceptor and a second electron acceptor, and the electron donor is

The first electron acceptor is

The second electron acceptor is

The guest material is selected from one or more of a thermal activity delayed fluorescence material, a triplet-triplet annihilation material, a fluorescence material and a phosphorescence material. The main body composite material has good electron transmission efficiency and thermal stability, is beneficial to enhancing the efficacy and the luminous efficiency of an OLED device, and is suitable for solution processing.

Description

A ternary exciplex composite material host and its OLED device preparation

technical field

The invention relates to the technical field of electroluminescence devices, in particular to a ternary exciplex composite material main body and the preparation of OLED devices thereof.

Background technique

Organic light-emitting diodes (OLEDs for short) have the advantages of self-illumination, fast response, wide visibility, low driving voltage, energy saving, light and thin, and flexible processing, which greatly meet consumers' demands for continuous update of display technology. Require. At the same time, OLED devices also show broad application prospects and huge market demand in the field of lighting.

Thermally activated delayed fluorescence (TADF) materials have an intramolecular electron donor (D)-electron acceptor (A) structure, the maximum theoretical efficiency can reach 100%, singlet excited state and triplet excited state energy The level is close to 0.5-1.0eV. As the main material of the light-emitting layer to form an OLED device, it has the characteristics of high luminous efficiency, no need for Eu, Ir rare earth metal elements, and low mass production cost; because the traditional single-component main material (1,3- Bis(carbazol-9-yl)benzene, abbreviated as mCP) has a lower glass transition temperature (Tg) (~60°C) which deteriorates the performance of OLED devices, and the replacement of mCP host by the new exciplex system host is beneficial To solve the above problems, it can be formed by using two existing materials with different transport properties, which will increase the charge transport capacity and make the electron-hole transport more balanced, thereby reducing the driving voltage of light emission and improving the performance and stability of the device. Existing exciplex host systems mainly focus on the research of binary D-A exciplex systems, and there are few reports on exciplex host systems with more than ternary exciplexes. The new structure system of OLED has room for further development.

Therefore, the prior art still needs to be improved and developed.

Contents of the invention

In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a ternary exciplex composite material host and its OLED device preparation, aiming to solve the problem of existing traditional single host and binary exciplex host systems. The limitations of OLED devices open up new technical routes.

Technical scheme of the present invention is as follows:

所述第一电子受体为

所述第二电子受体为

所述客体材料选自迟热活性延迟荧光材料、三线态-三线态湮灭材料、荧光材料和磷光材料中的一种或多种。A ternary exciplex composite material host OLED device, wherein the OLED device includes: an anode, a cathode, and an organic functional layer arranged between the anode and the cathode; the organic functional layer includes an organic functional layer according to A hole injection layer, an organic light-emitting layer, an electron transport layer and an electron injection layer are arranged in sequence from the anode to the cathode; the material of the organic light-emitting layer includes a host composite material and a guest material, and the host composite material is provided by electrons A ternary exciplex formed by mixing body, first electron acceptor and second electron acceptor, the electron donor is

The first electron acceptor is

The second electron acceptor is

The guest material is selected from one or more of delayed thermally active delayed fluorescent materials, triplet-triplet annihilated materials, fluorescent materials and phosphorescent materials.

A method for preparing an OLED device with a ternary exciplex composite material host, comprising the steps of:

provide the anode;

A hole injection layer, an organic light emitting layer, an electron transport layer and an electron injection layer are sequentially formed on the anode by a solution method, and the hole injection layer, the organic light emitting layer, the electron transport layer and the electron injection layer constitute an organic functional layer;

forming a cathode on the organic functional layer to obtain an OLED device;

or,

provide the cathode;

An electron injection layer, an electron transport layer, an organic light-emitting layer and a hole injection layer are sequentially formed on the cathode by a solution method, and the electron injection layer, the electron transport layer, the organic light-emitting layer and the hole injection layer constitute an organic functional layer;

forming an anode on the organic functional layer to obtain an OLED device;

所述第一电子受体为

所述第二电子受体为

所述客体材料选自热活性延迟荧光材料、三线态-三线态湮灭材料、荧光材料和磷光材料中的一种或多种。The material of the organic light-emitting layer includes a host composite material and a guest material, and the host composite material is a ternary exciplex composed of an electron donor, a first electron acceptor, and a second electron acceptor, wherein, The electron donor is

The first electron acceptor is

The second electron acceptor is

The guest material is selected from one or more of thermally active delayed fluorescent materials, triplet-triplet annihilation materials, fluorescent materials and phosphorescent materials.

Beneficial effects: The ternary exciplex formed by mixing the electron donor with the above chemical structure and two electron acceptors used in the present invention has good electron transport efficiency and thermal stability, and can effectively capture excitons and The balance carrier, which is the organic light-emitting layer formed by the host composite material and one or more guest materials selected from thermally active delayed fluorescent materials, triplet-triplet annihilation materials, fluorescent materials and phosphorescent materials, is conducive to enhancing The efficacy efficiency and luminous efficiency of the OLED device; at the same time, the electron donor and the two electron acceptors of the ternary exciplex are organic small molecules, which are suitable for the preparation of OLED devices by solution processing; in addition, the ternary exciplex Broaden the composition of OLED exciplex host system. Formed a new technical route. The OLED device obtained above can be used as a display device, a white light lighting device, and the like.

Description of drawings

Figure 1 shows the work of energy transfer in the organic light-emitting layer formed by the binary exciplex host (a) and the ternary exciplex host (b) respectively as the host and the guest (such as TADF material) in the embodiment of the present invention. Schematic diagram of the principle.

FIG. 2 is a schematic structural diagram of a vertical OLED device in an embodiment of the present invention.

Fig. 3 is a comparison diagram of energy levels of materials used in each layer of OLED devices prepared in Examples 1 and 2 and Comparative Examples 1 and 2 in Example 3 of the present invention.

Detailed ways

The present invention provides a ternary exciplex composite material main body and its OLED device preparation. In order to make the purpose, technical solution and effect of the present invention clearer and clearer, the present invention will be further described in detail below. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

所述第一电子受体为

所述第二电子受体为

所述客体材料选自热活性延迟荧光材料、三线态-三线态湮灭材料、荧光材料和磷光材料中的一种或多种。An embodiment of the present invention provides a ternary exciplex composite material host OLED device, the OLED device includes: an anode, a cathode, and an organic functional layer arranged between the anode and the cathode, the organic functional layer The layer includes a hole injection layer, an organic light-emitting layer, an electron transport layer and an electron injection layer arranged in sequence from the anode to the cathode; the material of the organic light-emitting layer includes a host composite material and a guest material, and the host composite material is A ternary exciplex formed by mixing an electron donor, a first electron acceptor and a second electron acceptor, the electron donor being

The first electron acceptor is

The second electron acceptor is

The guest material is selected from one or more of thermally active delayed fluorescent materials, triplet-triplet annihilation materials, fluorescent materials and phosphorescent materials.

In this example, the ternary exciplex formed by mixing the electron donor with the above structure and two electron acceptors has good electron transport efficiency and thermal stability, and can effectively capture excitons and balance Carriers, which are the organic light-emitting layer formed by the host composite material and one or more guest materials selected from thermally active delayed fluorescent materials, triplet-triplet annihilation materials, fluorescent materials and phosphorescent materials, which is conducive to enhancing The efficacy efficiency and luminous efficiency of the OLED device; at the same time, the electron donor and the two electron acceptors of the ternary exciplex are organic small molecules, which are suitable for the preparation of OLED devices by solution processing; in addition, the ternary exciplex Broaden the composition of OLED exciplex host system. The OLED device obtained above can be used as a display device, a white light lighting device, and the like.

Referring to Fig. 1, specifically, compare the working principle of energy transfer of the organic light-emitting layer formed by the ternary exciplex as the host composite material and the guest material (such as TADF material) (b) and the binary exciplex as the host recombination The working principle (a) of the energy transfer of the organic light-emitting layer formed by the material and the guest material (such as TADF material); it can be seen that the organic light-emitting layer formed by the ternary exciplex has the Dual energy transfer channels make it have better electron transfer efficiency, can more effectively capture excitons and balance carriers, so that the OLED device based on the ternary exciplex in this embodiment has better luminescence performance and efficacy efficiency.

In one embodiment, the mass ratio of the electron donor, the first electron acceptor, and the second electron acceptor is 1-10:1:1-10. Within this mass ratio range, the ternary exciplex formed by the electron donor, the first electron acceptor, and the second electron acceptor has better electron transport efficiency and thermal stability, and can more effectively capture the excimer complex. Carriers and balance carriers, the organic light-emitting layer formed by the composite material of the host material and the guest material is more conducive to enhancing the efficacy efficiency and luminous efficiency of the OLED device. Preferably, the guest material is a thermally active delayed fluorescence material.

In one embodiment, the thermally active delayed fluorescent material is selected from

中的一种或多种。优选地，所述热活性延迟荧光材料为

one or more of. Preferably, the thermally active delayed fluorescent material is

中的一种或多种；In one embodiment, the triplet-triplet annihilation (TTA) material may be selected from but not limited to

one or more of

中的一种或多种；The fluorescent material can be selected from but not limited to

one or more of

中的一种或多种。The phosphorescent material can be selected from but not limited to

one or more of.

In one embodiment, the mass ratio of the host composite material to the guest material is 1˜100:1.

In one embodiment, the thickness of the organic light-emitting layer may be 10-100 nm, such as 10 nm, 30 nm, 50 nm, 60 nm, 100 nm and so on.

缩写为PSSA)修饰的(3,4-亚乙二氧基噻吩)-聚(苯乙烯磺酸)(m-PEDOT:PSS)、聚[(9,9-二辛基芴基-2,7-二基)-co-(4,4'-(N-(对丁基苯基))二苯胺)](TFB)、聚(9-乙烯基咔唑)(PVK)、聚[双(4-苯基)(4-丁基苯基)胺](Poly-TPD)、N,N'-二苯基-N,N'-(1-萘基)-1,1'-联苯-4,4'-二胺(NPB)、1，1-二[4-[N，N'-二(p-甲苯基)氨基]苯基]环己烷(TAPC)、

中的一种或多种。所述空穴传输层的厚度为50～80nm，例如，50nm、60nm、80nm等；所述空穴传输层的材料可为本领域常用的空穴传输层材料。所述电子阻挡层的厚度为5～20nm，例如，5nm、15nm、20nm等；所述电子阻挡层的材料可为本领域常用的电子阻挡材料。In one embodiment, other hole functional layers may also be arranged between the anode and the organic light-emitting layer, such as at least one of a hole transport layer and an electron blocking layer; During the hole injection layer and the hole transport layer (or electron blocking layer), the hole injection layer is arranged close to the anode, and the hole transport layer (or electron block layer) is arranged close to the organic light-emitting layer; when the hole injection layer, the hole When the transport layer and the electron blocking layer are used, the hole injection layer is arranged close to the anode, the electron blocking layer is arranged close to the organic light-emitting layer, and the hole transport layer is arranged between the hole injection layer and the electron blocking layer. The thickness of the hole injection layer is 50-80nm, for example, 50nm, 60nm, 80nm, etc.; the material of the hole injection layer can be selected from but not limited to 2,3,6,7,10,11-hexacyano Base-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN), 4,4-(9-(2-ethylhexyl)-9H-carbazole-3,6- Diyl)diphenol (MO ₃ ), poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) (PEDOT:PSS), poly(4-styrenesulfonic acid) (structure is

Abbreviated as PSSA) modified (3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) (m-PEDOT:PSS), poly[(9,9-dioctylfluorenyl-2,7 -diyl)-co-(4,4'-(N-(p-butylphenyl))diphenylamine)](TFB), poly(9-vinylcarbazole)(PVK), poly[bis(4 -phenyl)(4-butylphenyl)amine](Poly-TPD), N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4 ,4'-diamine (NPB), 1,1-bis[4-[N,N'-bis(p-tolyl)amino]phenyl]cyclohexane (TAPC),

one or more of. The thickness of the hole transport layer is 50-80 nm, for example, 50 nm, 60 nm, 80 nm, etc.; the material of the hole transport layer can be a hole transport layer material commonly used in the field. The thickness of the electron blocking layer is 5-20 nm, for example, 5 nm, 15 nm, 20 nm, etc.; the material of the electron blocking layer can be an electron blocking material commonly used in the field.

Liq)或LiF。所述电子传输层的厚度为50～80nm，例如，50nm、60nm、80nm等。所述电子传输层的材料可为但不限于

ZnO、TiO₂、BaTiO₃、掺铝氧化锌、掺锂氧化锌、掺镁氧化锌、CdS、ZnS、MoS、WS和CuS中的一种或多种；所述空穴阻挡层的厚度为5～20nm，例如，5nm、15nm、20nm等；所述空穴阻挡层的材料可为但不限于

或双-4，6-(3，5-二-4-吡啶基苯基)-2-甲基嘧啶或4，6-双(3，5-二(3-吡啶)基苯基)-2-甲基嘧啶或其衍生物。In one embodiment, other electronic functional layers, such as a hole blocking layer, can also be arranged between the cathode and the organic light-emitting layer, and an electron injection layer, an electron injection layer, and an electron injection layer are also arranged between the cathode and the organic light-emitting layer. When the transport layer and the hole blocking layer are used, the electron injection layer is arranged close to the cathode, the hole blocking layer is arranged close to the organic light-emitting layer, and the electron transport layer is arranged between the electron injection layer and the hole blocking layer. The thickness of the electron injection layer is 1-10nm, for example, 1nm, 5nm, 10nm, etc.; the material of the electron injection layer can be but not limited to 8-hydroxyquinoline-lithium (

Liq) or LiF. The thickness of the electron transport layer is 50-80nm, for example, 50nm, 60nm, 80nm and so on. The material of the electron transport layer can be but not limited to

One or more of ZnO, TiO ₂ , BaTiO ₃ , aluminum-doped zinc oxide, lithium-doped zinc oxide, magnesium-doped zinc oxide, CdS, ZnS, MoS, WS and CuS; the thickness of the hole blocking layer is 5 ~20nm, for example, 5nm, 15nm, 20nm, etc.; the material of the hole blocking layer can be but not limited to

Or bis-4,6-(3,5-bis-4-pyridylphenyl)-2-methylpyrimidine or 4,6-bis(3,5-bis(3-pyridylphenyl)-2 - methylpyrimidine or derivatives thereof.

In one embodiment, the material of the anode can be selected from but not limited to indium tin oxide (ITO), aluminum doped zinc oxide (AZO), antimony doped tin oxide (ATO) and fluorine doped tin oxide (FTO). ) in one or more.

In one embodiment, the material of the cathode may be selected from but not limited to one or more of Al, Ag, Cu and Au.

Specifically, the ternary exciplex composite host OLED device of this embodiment can be configured in different types, that is, the ternary exciplex composite host OLED device can be configured as an OLED device with an upright structure, It can also be configured as an OLED device with an inverted structure. Taking the hole injection layer as the hole functional layer, the electron injection layer, the electron transport layer and the hole blocking layer as the positive OLED device as an example, the structure of the OLED device is further described, as shown in Figure 2 , the OLED device comprises from bottom to top: anode 10, hole functional layer 20 (i.e. hole injection layer), organic light-emitting layer 30, electron function layer 40 (including hole blocking layer 41, electron transport layer 42 and electron injection layer) layer 43), cathode 50; wherein, the material of the organic light-emitting layer 30 includes a host composite material and a guest material, and the host composite material is a three-component mixture formed by an electron donor, a first electron acceptor, and a second electron acceptor. An exciplex, wherein the electron donor is mCP, the first electron acceptor is DTDP-TRZ, and the second electron acceptor is OXD-7; the guest material is selected from thermally active delayed fluorescence One or more of triplet-triplet annihilation material, fluorescent material and phosphorescent material.

The embodiment of the present invention also provides a method for preparing an OLED device based on a ternary exciplex composite material, including the steps of: including traditional upright device preparation steps (S10, S20, S30) and inverted device preparation steps (S10', S20 ', S30').

S10, providing an anode;

S20, sequentially forming a hole injection layer, an organic light-emitting layer, an electron transport layer and an electron injection layer on the anode by a solution method, the hole injection layer, the organic light-emitting layer, the electron transport layer and the electron injection layer constitute an organic function layer;

S30, forming a cathode on the organic functional layer to obtain the OLED device;

or,

S10', providing a cathode;

S20', sequentially forming an electron injection layer, an electron transport layer, an organic light-emitting layer and a hole injection layer on the cathode by a solution method, the electron injection layer, the electron transport layer, the organic light-emitting layer and the hole injection layer constitute an organic functional layer;

S30', forming an anode on the organic functional layer to obtain the OLED device;

所述第一电子受体为

所述第二电子受体为

所述客体材料选自热活性延迟荧光材料、三线态-三线态湮灭材料、荧光材料和磷光材料中的一种或多种。The material of the organic light-emitting layer includes a host composite material and a guest material, and the host composite material is a ternary exciplex composed of an electron donor, a first electron acceptor, and a second electron acceptor, wherein, The electron donor is

The first electron acceptor is

The second electron acceptor is

The guest material is selected from one or more of thermally active delayed fluorescent materials, triplet-triplet annihilation materials, fluorescent materials and phosphorescent materials.

In one embodiment, in step S20, before forming the organic light emitting layer, at least one of the hole transport layer and the electron blocking layer may be sequentially formed; hole transport layer and electron blocking layer. In step S30, before forming the electron transport layer, a hole blocking layer may also be formed; for example, before forming the electron transport layer, the hole blocking layer may be deposited by physical vapor deposition, thermal evaporation method or solution method. In step S20', before forming the organic light-emitting layer on the cathode, a hole blocking layer can also be formed; for example, before forming the organic light-emitting layer on the cathode, holes can be formed by physical vapor deposition, thermal evaporation or solution method barrier layer. In step S30', before forming the hole injection layer, at least one of the electron blocking layer and the hole transport layer can also be sequentially formed; for example, before forming the hole injection layer, physical vapor deposition, thermal evaporation or solution The electron-blocking layer and the hole-transporting layer are sequentially formed. That is, other functional layers can be prepared in the OLED device of this embodiment, and the material selection and thickness of each layer in the OLED device are the same as those described above, and will not be repeated here.

In this embodiment, the preparation method of each layer can be a chemical method or a physical method, wherein the chemical method includes but not limited to chemical vapor deposition method, continuous ion layer adsorption and reaction method, anodic oxidation method, electrolytic deposition method, and co-precipitation method. One or more; physical methods include but are not limited to solution methods (such as spin coating, printing, blade coating, dipping and pulling, soaking, spraying, roller coating, casting, slot coating method or strip coating method, etc.), evaporation method (such as thermal evaporation method, electron beam evaporation method, magnetron sputtering method or multi-arc ion coating method, etc.), deposition method (such as physical vapor deposition method, atomic layer deposition method, pulsed laser deposition method, etc.) in one or more.

In one embodiment, when preparing a positive OLED device, in order to obtain a high-quality hole functional layer, the anode needs to undergo a pretreatment process. The pretreatment process specifically includes: cleaning the anode, and then treating the clean anode with ultraviolet-ozone or oxygen plasma to further remove organic matter attached to the surface of the anode and improve the work function of the anode.

In one embodiment, the obtained OLED device is packaged. Wherein, the encapsulation process may adopt common machine encapsulation, or manual encapsulation. Preferably, in the encapsulation environment, the oxygen content and the water content are both lower than 1ppm, so as to ensure the stability of the device.

The present invention will be described in detail below through specific examples.

Example 1 Preparation of ternary exciplex composite material host OLED device

The structure of the red OLED device is ITO (anode)/m-PEDOT:PSS (hole injection layer, 60nm)/AQb1:mCP:DTDP-TRZ:OXD-7 (organic light-emitting layer, 50nm, AQb1 is the guest material, The mass ratio of the ternary exciplex mCP:DTDP-TRZ:OXD-7 is 35:35:30)/DPEPO (hole blocking layer, 15nm)/TmPyPB (electron transport layer, 60nm)/Liq (electron injection layer , 1nm)/Al (cathode, 100nm); Its preparation comprises the following steps:

(1) On the ITO glass, spin-coat a layer of 60nm hole injection layer (m-PEDOT:PSS) at a speed of 4000r/min, and anneal at 120°C for 10min in a glove box;

(2) In a nitrogen atmosphere, spin-coat a 50nm organic light-emitting layer on the hole injection layer at a speed of 1000r/min (the mass ratio of AQb1:mCP:DTDP-TRZ:OXD-7 is 10:35:35:30 ), annealed at 50°C for 10 minutes;

(3) Deposit a 15nm hole blocking layer (the material is DPEPO) on the organic light-emitting layer under a vacuum degree of 10 ⁻⁵ mbar;

(4) Deposit a 60nm electron transport layer (the material is TmPyPB) on the hole blocking layer at a vacuum of 10 ⁻⁵ mbar;

(5) Deposit a 1-nm electron injection layer (the material is Liq) on the electron transport layer at a vacuum of 10 ⁻⁵ mbar;

(6) Under a vacuum degree of 10 ⁻⁵ mbar, a layer of 100 nm Al was spin-coated on the electron injection layer as a cathode to obtain a red light OLED device.

Preparation of Comparative Example 1 OLED device based on DTDP-TRZ

The structure of the red OLED device is ITO (anode)/m-PEDOT:PSS (hole injection layer, 60nm)/AQb1 (10wt%):DTDP-TRZ (organic light-emitting layer, 50nm, AQb1 is the guest material, DTDP- TRZ is the host material)/DPEPO (hole blocking layer, 15nm)/TmPyPB (electron transport layer, 60nm)/Liq (electron injection layer, 1nm)/Al (cathode, 100nm); its preparation includes the following steps:

(1) On the ITO glass, spin-coat a layer of 60nm hole injection layer (material is m-PEDOT:PSS) at a speed of 4000r/min, and anneal at 120°C for 15min in a glove box;

(2) In a nitrogen atmosphere, spin-coat a 50nm organic light-emitting layer on the hole injection layer at a speed of 1000r/min (the content of AQb1 is 10wt%, and the content of DTDP-TRZ is 90wt%) at 50°C Annealing 10min;

(3) Deposit a 15nm hole blocking layer (the material is DPEPO) on the organic light-emitting layer under a vacuum degree of 10 ⁻⁵ mbar;

(4) Deposit a 60nm electron transport layer (the material is TmPyPB) on the hole blocking layer at a vacuum of 10 ⁻⁵ mbar;

(5) Deposit a 1-nm electron injection layer (the material is Liq) on the electron transport layer at a vacuum of 10 ⁻⁵ mbar;

(6) Under a vacuum of 10 ⁻⁵ mbar, a layer of 100 nm Al was deposited on the electron injection layer as a cathode to obtain a red light OLED device.

Example 2 Preparation of OLED devices based on ternary non-exciplexes

):OXD-7(有机发光层，50nm，AQb1为客体材料，三元非激基复合物mCP:TDP-TRZ:OXD-7的质量比为35:35:30)/DPEPO(空穴阻挡层，15nm)/TmPyPB(电子传输层，60nm)/Liq(电子注入层，1nm)/Al(阴极，100nm)；该红光OLED器件制备包括如下步骤：The structure of the red OLED device is ITO (anode)/m-PEDOT:PSS (hole injection layer, 60nm)/AQb1:mCP:TDP-TRZ (TDP-TRZ structure is

):OXD-7 (organic light-emitting layer, 50nm, AQb1 as the guest material, the mass ratio of the ternary non-excimer complex mCP:TDP-TRZ:OXD-7 is 35:35:30)/DPEPO (hole blocking layer , 15nm)/TmPyPB (electron transport layer, 60nm)/Liq (electron injection layer, 1nm)/Al (cathode, 100nm); This red light OLED device preparation comprises the following steps:

(1) On the ITO glass, spin-coat a layer of 60nm hole injection layer (m-PEDOT:PSS) at a speed of 4000r/min, and anneal at 120°C for 10min in a glove box;

(2) In a nitrogen atmosphere, spin-coat a 50nm organic light-emitting layer (the mass ratio of AQb1:mCP:TDP-TRZ:OXD-7 is 10:35:35:30) on the hole injection layer at 50°C Annealing 10min;

(3) Deposit a 15nm hole blocking layer (the material is DPEPO) on the organic light-emitting layer under a vacuum degree of 10 ⁻⁵ mbar;

(4) Deposit a 60nm electron transport layer (the material is TmPyPB) on the hole blocking layer at a vacuum of 10 ⁻⁵ mbar;

(5) Deposit a 1-nm electron injection layer (the material is Liq) on the electron transport layer at a vacuum of 10 ⁻⁵ mbar;

(6) Under a vacuum of 10 ⁻⁵ mbar, a layer of 100 nm Al was deposited on the electron injection layer as a cathode to obtain a red light OLED device.

Comparative example 2 Preparation of OLED device based on TDP-TRZ

The structure of the red OLED device is ITO (anode)/m-PEDOT:PSS (hole injection layer, 60nm)/AQb1 (10wt%):TDP-TRZ (organic light-emitting layer, 50nm, AQb1 is the guest material, TDP- TRZ is the host material)/DPEPO (hole blocking layer, 15nm)/TmPyPB (electron transport layer, 60nm)/Liq (electron injection layer, 1nm)/Al (cathode, 100nm); the preparation of the red OLED device includes the following steps :

(1) On the ITO glass, spin-coat a layer of 60nm hole injection layer (material is m-PEDOT:PSS), and anneal in air at 140°C for 15min;

(2) In a nitrogen atmosphere, spin-coat a 50nm organic light-emitting layer (the content of AQb1 is 10wt%, and the content of AQb1 is 90wt%) on the hole injection layer, and anneal at 50°C for 10min;

(3) Deposit a 15nm hole blocking layer (the material is DPEPO) on the organic light-emitting layer under a vacuum degree of 10 ⁻⁵ mbar;

(4) Deposit a 60nm electron transport layer (the material is TmPyPB) on the hole blocking layer at a vacuum of 10 ⁻⁵ mbar;

(5) Deposit a 1-nm electron injection layer (the material is Liq) on the electron transport layer at a vacuum of 10 ⁻⁵ mbar;

(6) Under a vacuum of 10 ⁻⁵ mbar, a layer of 100 nm Al was deposited on the electron injection layer as a cathode to obtain a red light OLED device.

Performance test analysis of embodiment 3 OLED device

The energy levels of the materials used in the preparation of OLED devices in Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Figure 3. It can be seen that the energy levels of TDP-TRZ and DTDP-TRZ with similar structures are slightly different.

The luminous properties of the OLED devices prepared in Examples 1, 2 and Comparative Examples 1, 2 (the turn-on voltage (V _on ) when the brightness is 10 cd m ^-2 , the characteristic emission peak (EL _peak /nm), and the brightness at 10 Maximum current efficiency (CE _max /cd·A ^-1 ), maximum power efficiency (PE _max /lm·W ^-1 ) and maximum external quantum efficiency (EQE _max , (%)) in the range of ~1000cd·m ^-2 , And the coordinates of the International Commission on Illumination (CIE, (x, y))) when the brightness is 100cd·m ^-2 are tested, and the test results are shown in Table 1. It can be seen that, compared with DTDP-TRZ, ternary exciplexes (mCP, TDP-TRZ and OXD-7) as host composite materials and TADF materials as guest materials have better luminescent properties.

Table 1

The ratio of the performance parameter of the OLED device prepared by the embodiment in Table 1 to the performance parameter of the OLED device prepared by the corresponding comparative example is used as the gain of the performance parameter of the OLED device prepared by the embodiment, and converted to obtain embodiment 1, 2 The gain of some performance parameters (CE _max , PE _max and EQE _max ) of the prepared OLED device is shown in Table 2, and the gain of EQE of the OLED device prepared in Example 1 is the EQE gain of the OLED device prepared in Example 2 1.3 times of that; it shows that compared with ternary non-exciplexes, ternary exciplexes have better application prospects as host composite materials.

Table 2

In summary, the present invention provides a ternary exciplex composite material body and its OLED device preparation. The base complex has good electron transport efficiency and thermal stability, and can effectively capture excitons and balance carriers. It is a host composite material selected from thermally active delayed fluorescent materials, triplet-triplet annihilation materials, fluorescent materials One or more of the phosphorescent materials are the organic light-emitting layer formed by the guest material; it is beneficial to enhance the efficiency and luminous efficiency of the OLED device; at the same time, the electron donor and the two electron acceptors of the ternary exciplex are both The organic small molecule is suitable for processing and preparing OLED devices by a solution method; in addition, the ternary exciplex broadens the composition of the main system of the OLED exciplex. The OLED device obtained above can be used as a display device, a white light lighting device, and the like.

It should be understood that the application of the present invention is not limited to the above examples, and those skilled in the art can make improvements or transformations according to the above descriptions, and all these improvements and transformations should belong to the protection scope of the appended claims of the present invention.

Claims (2)

1. A ternary exciplex composite material host OLED device, characterized in that, the OLED device comprises: an anode, a cathode, and an organic functional layer arranged between the anode and the cathode; the organic The functional layer includes a hole injection layer arranged in sequence from the anode to the cathode, an organic light-emitting layer, an electron transport layer and an electron injection layer; the organic light-emitting layer includes a host composite material and a guest material, and the host composite material is made of A ternary exciplex formed by mixing an electron donor, a first electron acceptor and a second electron acceptor, the electron donor being

or

The first electron acceptor is

The second electron acceptor is

or

The guest material is selected from one or more of thermally active delayed fluorescent materials, triplet-triplet annihilation materials, fluorescent materials and phosphorescent materials; the electron donor, the first electron acceptor, and the second electron acceptor The mass ratio is 1~10:1:1~10; The thermally active delayed fluorescent material is selected from

,

one or more of The triplet-triplet annihilation material is selected from

one or more of The fluorescent material is selected from

and

one or more of The phosphorescent material is selected from

one or more of The mass ratio of the host composite material to the guest material is 1-100:1; The material of the hole injection layer is 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, 4,4-(9 -(2-Ethylhexyl)-9H-carbazole-3,6-diyl)diphenol, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid), poly(4- Styrenesulfonic acid) modified (3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid), poly[(9,9-dioctylfluorenyl-2,7-diyl)-co -(4,4'-(N-(p-butylphenyl))diphenylamine)], poly(9-vinylcarbazole), poly[bis(4-phenyl)(4-butylphenyl) amine], N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, 1,1-di[4-[N , N'-bis(p-tolyl)amino]phenyl]cyclohexane,

and

one or more of The material of the electron transport layer is

One or more of ZnO, TiO ₂ , BaTiO ₃ , aluminum-doped zinc oxide, lithium-doped zinc oxide, magnesium-doped zinc oxide, CdS, ZnS, MoS, WS and CuS; The material of the electron injection layer is 8-hydroxyquinoline-lithium or LiF; The material of the anode is selected from one or more of indium tin oxide, aluminum-doped zinc oxide, antimony-doped tin oxide and fluorine-doped tin oxide; The material of the cathode is selected from one or more of Al, Ag, Cu and Au. 2. a kind of preparation method of ternary exciplex composite material host OLED device as claimed in claim 1, is characterized in that, comprises the step: provide the anode; A hole injection layer, an organic light emitting layer, an electron transport layer and an electron injection layer are sequentially formed on the anode by a solution method, and the hole injection layer, the organic light emitting layer, the electron transport layer and the electron injection layer constitute an organic functional layer; forming a cathode on the organic functional layer to obtain the OLED device; or, provide the cathode; An electron injection layer, an electron transport layer, an organic light-emitting layer and a hole injection layer are sequentially formed on the cathode by a solution method, and the electron injection layer, the electron transport layer, the organic light-emitting layer and the hole injection layer constitute an organic functional layer; forming an anode on the organic functional layer to obtain the OLED device; The material of the organic light-emitting layer includes a host composite material and a guest material, and the host composite material is a ternary exciplex composed of an electron donor, a first electron acceptor, and a second electron acceptor, wherein, The electron donor is

The first electron acceptor is

The second electron acceptor is

The guest material is selected from one or more of thermally activated delayed fluorescent materials, triplet-triplet annihilation materials, fluorescent materials and phosphorescent materials.

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