WO2024017754A1 - Phosphor, method for producing same, and radiation-emitting component - Google Patents

Abstract

The invention relates to a phosphor with the molecular formula M4Li2D2E2N8O:A, wherein M is an element or a combination of elements selected from the group of bivalent elements, D is an element or a combination of elements selected from the group consisting of Al and Ga, E is an element or a combination of elements selected from the group consisting of Ta and Nb, and A is at least one activator element. The invention also relates to a method for producing a phosphor and to a radiation-emitting component.

Description

Description FLUORESCENT, METHOD FOR PRODUCING IT AND RADIATION-EMITTING COMPONENT A phosphor and a method for producing a phosphor are specified. Furthermore, a radiation-emitting component is described. It is, among other things, a task to provide a phosphor with increased efficiency. In addition, a method for producing such a phosphor and a radiation-emitting component with high efficiency are to be provided. According to one embodiment, the phosphor has the molecular formula M ₄ Li ₂ D ₂ E ₂ N ₈ O:A. Here and below, phosphors are described using molecular formulas. The elements listed in the molecular formulas are in charged form. Here and in the following, elements and/or atoms in relation to the molecular formulas of the phosphors mean ions in the form of cations and anions, even if this is not explicitly stated. This also applies to element symbols if they are given without a charge number for the sake of clarity. Given the molecular formulas given, it is possible that the phosphor has other elements, for example in the form of impurities. Taken together, these impurities have at most 5 mol%, in particular at most 1 mol%, preferably at most 0.1 mol%. The phosphor is usually uncharged on the outside. This means that there can be a complete charge balance between positive and negative charges in the phosphor to the outside. However, it is also possible that the phosphor does not formally have a complete charge balance to a small extent.

According to one embodiment, M is an element or a combination of elements selected from the group of divalent elements.

In the present case, the term “valence” in relation to a specific element means how many elements with a simple opposite charge are required in a chemical compound to achieve charge balance. The term “valence” therefore includes the charge number of the element.

Elements with a valence of two are called bivalent elements. Divalent elements are often doubly positively charged in chemical compounds and have a charge number of +2. A charge balance in a chemical compound can take place, for example, via two additional elements that are single negatively charged, or another element that is doubly negatively charged.

According to one embodiment of the phosphor, D is an element or a combination of elements selected from the group formed by Al and Ga. In particular, D is a trivalent element. For example, D is triple positively charged and has a charge number of +3. D Al is preferred. According to one embodiment of the phosphor, E is an element or a combination of elements selected from the group formed by Ta and Nb. In particular, E is a pentavalent element. For example, E is five times positively charged and has a charge number of +5. E Ta is preferred.

According to one embodiment of the phosphor, A is at least one activator element. The phosphor preferably comprises a host structure into which foreign elements are introduced as activator elements. The host structure alters the electronic structure of the activator element such that electromagnetic radiation of an excitation wavelength absorbed by the phosphor causes an electronic transition from a ground state to an excited state in the phosphor. By emitting electromagnetic radiation with an emission spectrum, the phosphor returns to its ground state. The phosphor can have a single type of foreign element as an activator element or several types of foreign elements as activator elements. For example, the phosphor has only Ce or Eu as foreign elements or Ce and Eu as foreign elements.

According to one embodiment, the phosphor has the molecular formula M ₄ Li ₂ D ₂ E ₂ N ₈ O:A, where M is an element or a combination of elements selected from the group of divalent elements, D is an element or a combination of elements selected is from the group formed by Al and Ga, E is an element or a combination of elements selected from the group formed by Ta and Nb and A is at least one activator element. In particular, the phosphor has an improved photometric radiation equivalent. The photometric radiation equivalent (LER, English "luminous efficacy of radiation") of the phosphor is the quotient of a luminous flux, the electromagnetic radiation emitted by the phosphor, and the radiant power of the electromagnetic radiation emitted by the phosphor. The greater the photometric radiation equivalent, the greater the luminous flux that can be used by the eye for a given power.

According to one embodiment of the phosphor, M is an element or a combination of elements selected from the group formed by Ca, Sr and Ba. These elements are in particular bivalent elements. For example, M is Ba.

According to one embodiment of the phosphor, A is an element or a combination of elements selected from the group formed by Eu, Ce, Mn, Cr, Ni, Bi, Tb and Yb. In particular, A is an element or a combination of elements selected from the group formed by Eu and Ce. Eu is particularly present in the form Eu ²⁺ . Ce is particularly in the form Ce ³⁺ . Mn is in particular in the form Mn ⁴⁺ . Cr is present in particular in the form Cr ³⁺ . Ni is particularly present in the form Ni ²⁺ . Bi is particularly present in the form Bi ³⁺ . Tb is present in particular in the form Tb ³⁺ . Yb is particularly in the form Yb ³⁺ . According to one embodiment of the phosphor, A has a proportion of 0.01 mol% to 10 mol% inclusive, based on the element M. A preferably has a proportion of 0.1 mol% to 6 mol% inclusive, based on the element M.

According to an embodiment of the phosphor, a crystal structure of the host structure of the phosphor has an orthorhombic space group. For example, the crystal structure of the host structure of the phosphor has the space group Pnnm.

The crystal structure is a description of an arrangement of the atoms or ions in a crystalline material. The crystal structure is made up of a three-dimensional unit cell, which usually repeats itself periodically. In other words, the unit cell is the smallest repeating unit of the crystal structure of the host structure. The elements A, M, Li, D, E, N and 0 each occupy fixed positions in the unit cell, which are also referred to as point positions. The elements A and M can occupy equivalent point positions. This means that either A or M is located in the space described by the point position of the element M. Alternatively, A and M can occupy different point locations. In particular, element A is often not taken into account in a structure determination due to its insignificant contribution to the scattering density.

According to one embodiment of the phosphor, the crystal structure of the host structure has DN ₄ tetrahedra. The DN ₄ tetrahedra in particular have a tetrahedral gap. The tetrahedral gap is an area inside the respective tetrahedron. For example, the term "tetrahedral gap" refers to the area inside the tetrahedron that remains free when mentally touching balls are placed in the corners of the tetrahedron.

The N atoms of the DN ₄ tetrahedra span the tetrahedron, with the D atom located in the tetrahedral gap of the spanned tetrahedron. In other words, the tetrahedra are centered around the D atom. The D atom is surrounded by four N atoms in a tetrahedron shape. In particular, all N atoms that span the tetrahedron are at a similar distance to the D atom that is in the tetrahedral gap.

According to a further embodiment of the phosphor, the crystal structure of the host structure has EN ₄ tetrahedrons. In particular, the crystal structure of the host structure has DN ₄ tetrahedrons and EN ₄ tetrahedrons. The EN ₄ tetrahedra in particular have a tetrahedral gap. The N atoms of the EN ₄ tetrahedron span the tetrahedron, with the E atom located in the tetrahedral gap of the spanned tetrahedron. In other words, the tetrahedra are centered around the E atom. The E atom is surrounded by four N atoms in a tetrahedron shape. In particular, all N atoms that span the tetrahedron are at a similar distance to the E atom that is located in the tetrahedral gap.

According to one embodiment of the phosphor, the DN ₄ tetrahedra and/or the EN ₄ tetrahedra are corner-linked on all sides. Corner-linked on all sides means that each tetrahedron is linked to one corner of another tetrahedron across all four corners. The tetrahedra with corners linked on all sides preferably form a tetrahedral network. According to one embodiment of the phosphor, the DN ₄ tetrahedra and the EN ₄ tetrahedra are arranged alternately. In other words, a DN ₄ tetrahedron is linked to four EN ₄ tetrahedra via its corners and vice versa. In particular, a DN ₄ tetrahedron has no direct connection to another DN ₄ tetrahedron. In particular, an EN ₄ tetrahedron has no direct connection to another EN ₄ tetrahedron.

According to one embodiment of the phosphor, the crystal structure of the host structure has six-rings. In particular, the six-rings are arranged in a layer along the [100] direction. A six-ring includes in particular three DN ₄ tetrahedra and three EN ₄ tetrahedra.

According to one embodiment of the phosphor, the crystal structure of the host structure has four-rings. A four-ring preferably comprises two DN ₄ tetrahedra and two EN ₄ tetrahedra.

According to an embodiment of the phosphor, the crystal structure of the host structure has eight-rings. A ring of eight preferably comprises four DN ₄ tetrahedra and four EN ₄ tetrahedra.

Specifically, the four-rings and the eight-rings are arranged in a layer along the [001] direction.

According to one embodiment of the phosphor, the M atoms are arranged within the figure-of-eight rings. In particular, the M atoms have two different crystallographic positions. According to one embodiment of the phosphor, the crystal structure of the host structure has Li ₂ O dumbbells. In particular, the Li ₂ O dumbbells are arranged in channels formed by the four-rings. The Li ₂ O dumbbells are arranged, for example, between the layers of four-rings and eight-rings along the [001 ^{^} ] direction. A Li ₂ O dumbbell is preferably designed to be linear. A shape that has a main direction of extension is usually referred to as linear. In other words, a Li2O dumbbell is not angled. The Li2O dumbbells are particularly isolated. In other words, the Li atoms and the O atoms of one Li ₂ O dumbbell have no coordination and/or covalent bond to Li atoms and/or O atoms of another Li ₂ O dumbbell. According to an embodiment of the phosphor, the host structure has a BCT zeolite-like structure. As a rule, a BCT zeolite has four, six and eight rings made of tetrahedra. According to one embodiment of the phosphor, the crystal structure of the host structure is homeotypic to the crystal structure of the compound Sr4Li2Si4N8O. Crystal structures are particularly referred to as homeotypic if structural units of the crystal structures, for example tetrahedrons, can be assigned to one another in such a way that they are linked to one another in the same way and occupy the same point positions, but have different stoichiometric formulas. According to one embodiment, the phosphor has the molecular formula M _4-x A _x [D ₂ E ₂ N ₈ ]∙Li ₂ O. For example, this applies: 0.0001 ≤ x ≤ 0.025, preferably 0.001 ≤ x ≤ 0.015. The molecular formula M _4-x A _x [D ₂ E ₂ N ₈ ]∙Li ₂ O is in particular equivalent to the molecular formula M ₄ Li ₂ D ₂ E ₂ N ₈ O:A. The molecular formula M _{4- x} A _x [D ₂ E ₂ N ₈ ]∙Li ₂ O can be used to illustrate that the elements D, E and N form a framework structure. The elements M, A, Li and O are located in the interstices of the framework structure. Furthermore, the molecular formula M _4-x A _x [D ₂ E ₂ N ₈ ]∙Li ₂ O can clarify that the elements Li and O in the form of Li ₂ O dumbbells are present in the crystal structure. According to one embodiment, the phosphor has the molecular formula Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ . According to one embodiment, the phosphor absorbs electromagnetic radiation in the blue to ultraviolet range of the electromagnetic spectrum. In particular, the phosphor absorbs electromagnetic radiation in the wavelength range from 350 nanometers to 500 nanometers inclusive, preferably in the wavelength range from 400 nanometers to 500 nanometers inclusive. For example, the phosphor absorbs electromagnetic radiation in the wavelength range from 430 nanometers to 480 nanometers inclusive. In particular, the phosphor absorbs electromagnetic radiation that corresponds to the excitation wavelength. According to one embodiment, electromagnetic radiation emitted by the phosphor has an emission spectrum with an emission peak with an emission maximum in the wavelength range from 515 nanometers to 615 nanometers inclusive. The emission maximum is preferably in the wavelength range from and including 535 nanometers up to and including 585 nanometers, particularly preferably in the wavelength range from 555 nanometers up to and including 575 nanometers. For example, the emission maximum is around 565 nanometers.

The emission spectrum is an intensity distribution of the electromagnetic radiation emitted by the phosphor after excitation with electromagnetic radiation of the excitation wavelength. The emission spectrum is usually represented in the form of a diagram in which a spectral intensity or a spectral radiation flux per wavelength interval (“spectral intensity/spectral Radiation flux") of the electromagnetic radiation emitted by the phosphor is shown as a function of the wavelength the spectral radiation flux is plotted.

The phosphor with an emission maximum in the wavelength range from 515 nanometers to 615 nanometers inclusive is used in particular in a radiation-emitting component that is used for general lighting. Due to its emission in this wavelength range, the phosphor preferably leads to a higher efficiency, in particular a higher color rendering index, of the radiation-emitting component.

According to an embodiment of the phosphor, the electromagnetic radiation emitted by the phosphor has a dominant wavelength between and including 550 nanometers including 580 nanometers. In particular, the dominant wavelength is between 560 nanometers and 580 nanometers inclusive. The dominant wavelength is preferably between 565 nanometers and 575 nanometers inclusive. For example, the dominant wavelength is approximately 571 nanometers.

To determine the dominant wavelength of the electromagnetic radiation emitted by the phosphor, a straight line is drawn in the CIE standard diagram starting from the white point (x = 0.333, y = 0.333) through the color locus of the electromagnetic radiation. The intersection of the straight line with the spectral color line delimiting the CIE standard diagram denotes the dominant wavelength of the electromagnetic radiation. In general, the dominance wavelength differs from the wavelength of the emission maximum.

According to one embodiment of the phosphor, the emission peak has a half-width between 80 nanometers and 100 nanometers inclusive. The half-width is preferably in the range of 85 nanometers and 95 nanometers inclusive. For example, the half-width is approximately 89 nanometers.

The term "half-width" refers to a curve with a maximum, such as the emission spectrum, where the half-width is the area on the x-axis that corresponds to the two y-values that correspond to half the maximum.

According to one embodiment of the phosphor, the emission peak in the emission spectrum of the phosphor has more than one band, in particular two bands. The gangs are for example, due to different point positions that can be occupied by element A.

A process for producing a phosphor is also specified. In particular, the phosphor described here is produced using the process. Features and embodiments that are described in connection with the phosphor therefore also apply to the method and vice versa.

According to one embodiment of the method for producing a phosphor, the phosphor has the molecular formula M ₄ Li ₂ D2E2N ₈ O:A, where M is an element or a combination of elements selected from the group of divalent elements, D is an element or a combination of Elements selected from the group formed by Al and Ga, E is an element or a combination of elements selected from the group formed by Ta and Nb and A is at least one activator element. The method includes the steps of providing educts, mixing the educts to form a educt mixture and heating the educt mixture.

The steps are preferably carried out in the order given.

In particular, it is possible for the method to produce a mixture which comprises or consists of the phosphor. Other components of the mixture can be, for example, starting materials that did not react during the production of the phosphor, impurities and/or secondary phases that were formed during the production. According to one embodiment of the process, the starting materials are selected from the following group: elements of M, Li, D, E and A, oxides of M, Li, D, E and A, nitrides of M, Li, D, E and A , carbonates of M, Li, D, E and A. The elements of M, Li, D, E and A are in particular M, Li, D, E and A in their elemental form. In other words, in the elements of M, Li, D, E and AM, Li, D, E and A are not present in a compound. The nitrides can be complex nitrides. A complex nitride is, for example, a ternary nitride, i.e. a nitride that has two other chemical elements in addition to nitrogen. According to one embodiment of the method, nitrides of M, Li, E and D and/or oxides of M, Li and D and/or carbonates of M, Li and D, an oxide of A and elements of E and Li are used as starting material. In particular, Ba ₃ N ₂ , Ba ₂ TaN ₃ , Al ₂ O ₃ , AlN, LiN ₃ , Li ₂ O, Li ₂ CO ₃ , Li ₃ N, Eu ₂ O _{3 ,} elemental Li and elemental E are used as starting materials. According to one embodiment of the process, the educt mixture is heated to a temperature between 800 ° C and 1100 ° C inclusive. In particular, the educt mixture is heated to a temperature between 850 ° C and 1050 ° C inclusive, preferably to a temperature between 900 ° C and 1000 ° C inclusive. According to one embodiment of the process, the educt mixture is heated under a protective gas atmosphere. For example, the protective gas atmosphere is an atmosphere of N ₂ . In particular, heating the reaction mixture leads to an excess pressure of the protective gas during the reaction. According to one embodiment of the method, the educt mixture is heated for a time of 50 hours up to and including 200 hours, in particular for a time of 80 hours up to and including 120 hours. For example, heating occurs for a period of approximately 100 hours.

According to one embodiment of the process, elemental Li is used as starting material. Elemental Li becomes liquid especially at a temperature above 180 °C. It can therefore be used both as a starting material and as a flux in the process described here.

A radiation-emitting component is also specified. Preferably, the phosphor described above is suitable and intended for use in a radiation-emitting component described here. Features and embodiments that are described in connection with the phosphor and/or the method also apply to the radiation-emitting component and vice versa.

According to one embodiment, the radiation-emitting component comprises a semiconductor chip, which emits electromagnetic radiation of a first wavelength range during operation, and a conversion element with the previously described phosphor. The phosphor converts electromagnetic radiation of the first wavelength range into electromagnetic radiation of a second wavelength range, which is at least partially different from the first wavelength range. The electromagnetic radiation of the first wavelength range serves in particular as the excitation wavelength of the phosphor. The radiation-emitting component is, for example, a light-emitting diode (LED).

In particular, the semiconductor chip comprises an active semiconductor layer sequence which contains an active region which generates the electromagnetic radiation of the first wavelength range during operation of the component. The semiconductor chip is, for example, a light-emitting diode chip or a laser diode chip. The electromagnetic radiation of the first wavelength range is emitted through a radiation exit surface of the semiconductor chip.

According to at least one embodiment of the radiation-emitting component, the semiconductor chip emits electromagnetic radiation in the blue to ultraviolet range of the electromagnetic spectrum during operation. For example, the semiconductor chip emits electromagnetic radiation with a wavelength of approximately 448 nanometers.

According to one embodiment of the radiation-emitting component, the conversion element has a further phosphor. The further phosphor converts in particular the electromagnetic radiation of the first wavelength range into electromagnetic radiation of a third wavelength range. The third wavelength range is preferably at least partially different from the first wavelength range and/or the second wavelength range.

According to one embodiment of the radiation-emitting component, the conversion element has no further radiation-converting component, such as the additional phosphor.

In particular, a mixed light that is emitted by the radiation-emitting component is composed of the electromagnetic radiation of the first wavelength range, the second wavelength range and/or the third wavelength range.

According to one embodiment, the radiation-emitting component emits mixed light with a color temperature in the range from 4000 K to 7000 K inclusive, for example with a color temperature of approximately 5000 K. In particular, the mixed light is warm white, neutral white or cold white mixed light. For example, during operation the radiation-emitting component emits mixed light that has the color temperature of daylight.

According to one embodiment, a color locus of the mixed light is close to the Planck curve. The Planck curve is used in particular to determine the color temperature of a radiation-emitting component. The Planck curve can be represented as part of the CIE standard diagram and is based on a Planck radiator.

With the phosphor described here in the conversion element, a radiation-emitting component can advantageously be provided which has a high color rendering index (CRI). However, compared to comparable radiation-emitting components, in particular a single phosphor in the conversion element is sufficient to achieve the high color rendering index. A further phosphor is advantageously not necessary. In comparison with a radiation-emitting component with a silicate phosphor in the conversion element, for example, an approximately 6% higher color rendering index is observed.

Further advantageous embodiments, refinements and further developments of the phosphor, the method for producing a phosphor and the radiation-emitting component result from the following exemplary embodiments shown in conjunction with the figures.

Figure 1 shows a schematic representation of a phosphor according to an exemplary embodiment.

Figures 2 to 5 show schematic sections of a host structure of a phosphor according to an exemplary embodiment.

Figures 6 and 7 each show an emission spectrum of a phosphor according to an exemplary embodiment.

Figure 8 shows schematically various steps of a method for producing a phosphor according to an exemplary embodiment.

Figure 9 shows a schematic sectional view of a radiation-emitting component according to an exemplary embodiment. Figure 10 shows emission spectra of radiation-emitting components according to an exemplary embodiment and a comparative example.

Figure 11 shows a refined powder diffractogram of a phosphor according to an exemplary embodiment.

Identical, similar or identically acting elements are provided with the same reference numerals in the figures. The figures and the size relationships between the elements shown in the figures should not be considered to scale. Rather, individual elements, in particular layer thicknesses, can be shown exaggeratedly large for better representation and/or for better understanding.

The phosphor 1 according to the exemplary embodiment of FIG. 1 obeys the molecular formula M ₄ Li2D2E ₂ N8O:A, where M is an element or a combination of elements selected from the group of divalent elements, D is an element or a combination of elements selected from the group formed by Al and Ga, E is an element or a combination of elements selected from the group formed by Ta and Nb and A is at least one activator element. In particular, the phosphor 1 has the molecular formula Ba4Li ₂ Al ₂ Ta2N ₈ O:Eu ²⁺ .

The phosphor 1 of Figure 1 is in the form of particles. The particles in particular have a grain size between 500 nanometers and 100 micrometers inclusive.

In Tabelle 1 ist der gemessene Ausschnitt des reziproken Raumes über die Grenzen der zugehörigen Millerschen Indizes (hkl)angegeben. Als Qualitätsmerkmal für die Übereinstimmung von berechneten und gemessenen Intensitäten wird der Gütefaktor (goodness of fit, GooF) angegeben, der nahe bei 1 liegen sollte. Die Tabellen 2 und 3 zeigen die kristallographischen Lageparameter und die anisotropen Auslenkungsparameter von Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺. Die Wyckoff-Lage beschreibt die Symmetrie der Punktlagen nach R.W.G. Wyckoff. x, y und z geben die Atomlagen an. U_ani ist der Radius der anisotropen Auslenkungsparameter des jeweiligen Atoms. U_eq ist der Radius der isotropen Auslenkungsparameter des jeweiligen Atoms. Tabelle 2: Kristallographische Lageparameter von Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺.

Tabelle 3: Anisotrope Auslenkungsparameter von Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺.

Nach Anregung mit einer Wellenlänge von 448 Nanometern führt das Ausführungsbeispiel des Leuchtstoffs 1 mit der Summenformel Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺ zu dem Emissionsspektrum E1, das in der Figur 6 abgebildet ist. Das Emissionsspektrum E1 wird in einem Bereich von einschließlich 450 Nanometer bis einschließlich 750 Nanometer gezeigt. Das Emissionsspektrum E1 weist einen Emissionspeak mit einem Emissionsmaximum λ_max bei etwa 565 Nanometern auf. Die Halbwertsbreite (FWHM, engl. „full width at half maximum“) des Emissionspeaks beträgt etwa 89 Nanometer. Eine Dominanzwellenlänge λ_dom der von dem Leuchtstoff 1 mit der Summenformel Ba₄Li₂Al₂Ta₂N₈O:Eu2+ ausgesandten elektromagnetischen Strahlung liegt bei etwa 571 Nanometer. Diese und weitere optische Daten von Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺ sind in der Tabelle 4 zusammengefasst. Tabelle 4: Ausgewählte optische Daten von Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺.

In der Figur 7 ist ein Emissionsspektrum E2 des Leuchtstoffs 1 mit der Summenformel Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺ gezeigt. Hier wird im Vergleich zur Figur 6 die Wellenlänge der emittierten elektromagnetischen Strahlung jedoch nicht in Nanometer sondern in Elektronenvolt (eV) und reziproken Zentimetern (cm^-1) angegeben. Das Emissionsspektrum E2 ist in einem Bereich von einschließlich 3 eV bis einschließlich 1 eV beziehungsweise von einschließlich 24066 cm^-1 bis einschließlich 8066 cm^-1 abgebildet. In der Figur 7 sind ebenfalls zwei simulierte Gaußkurven G1 und G2 abgebildet. Eine Addition der simulierten Gaußkurven G1 und G2 stimmt mit dem gemessenen Emissionsspektrum E2 überein. Daraus, dass sich das Emissionsspektrum E2 aus den beiden simulierten Gaußkurven G1 und G2 zusammensetzten lässt, kann geschlossen werden, dass das Aktivator-Element Eu²⁺ beide kristallographische Punktlagen der Ba-Atome 5 besetzt. Hierdurch werden zwei Emissionsbanden hervorgerufen, die sich in den simulierten Gaußkurven G1 und G2 widerspiegeln. Ein Verfahren zur Herstellung eines Leuchtstoffs 1 gemäß einem Ausführungsbeispiel wird im Zusammenhang mit der Figur 8 beschrieben. In einem ersten Verfahrensschritt S1 werden Edukte des Leuchtstoffs 1 mit der Summenformel M₄Li₂D₂E₂N₈O:A bereitgestellt. Als Edukte werden vorliegend Oxide oder Carbonate von M, Li, D, E und A, insbesondere komplexe, Nitride von M, Li, D, E und A und/oder die Elemente von M, Li, D, E und A eingesetzt. Konkret können die Edukte Ba₃N₂, Ba₂TaN₃, Al₂O₃, Li₃N, Li₂CO₃, Ta, LiN₃, AlN, Li₂O, Li, Eu₂O₃ in ausgewählten Kombinationen eingesetzt werden. In einem zweiten Verfahrensschritt S2 werden die Edukte des Leuchtstoffs 1 zu einem Eduktgemenge vermengt und in ein Reaktionsgefäß überführt. Anschließend wird das Eduktgemenge für eine Zeit von einschließlich 50 Stunden bis einschließlich 200 Stunden auf eine Temperatur von einschließlich 800 °C bis einschließlich 1100 °C erhitzt. Ba₄Li₂Al₂Ta₂N₈O:Eu2+ Für die Synthese von Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺ werden Ba₃N₂, Al₂O₃, Li₃N und elementares Li im Verhältnis von 2:3:12:14 sowie Eu₂O₃ als Vorläufer für das Aktivator-Element in einer Glovebox unter Schutzgasatmosphäre, insbesondere einer N₂- Atmosphäre, innig vermengt und in eine Tantal-Ampulle mit Boden überführt. Die Tantal-Ampulle wird unter Verwendung einer Lichtbogenschweißanlage mit einem entsprechenden Deckel verschweißt. Anschließend wird die verschlossene Tantal- Ampulle in ein mit Argon gefülltes Quarzrohr eingebracht und für 100 h auf 900 °C erhitzt. Das Erhitzen des Eduktgemenges in einer verschlossenen Tantal-Ampulle führt zu einem Überdruck des Schutzgases während der Reaktion. In der Tabelle 5 sind Einwaagen für die Synthese von Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺ zusammengefasst. Die Tantal-Atome in der Verbindung stammen teilweise aus der Tantal-Ampulle, in der die Reaktion durchgeführt wird. Tabelle 5: Einwaagen für die Synthese von Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺. Edukt Einwaage

Alternativ können Ba3N2, Li2CO3, Ta, LiN3, AlN und elementares Li im Verhältnis von 4:3:6:3:6:21 sowie Eu₂O₃ als Vorläufer für das Aktivator-Element oder Ba₂TaN₃, Li₂O, AlN und elementares Li im Verhältnis von 2:1:2:8 sowie Eu₂O₃ als Vorläufer für das Aktivator-Element eingesetzt werden. Diese Startmaterialien werden in einer Glovebox unter Schutzgasatmosphäre, insbesondere einer N₂-Atmosphäre, innig vermengt und in eine Tantal-Ampulle mit Boden überführt. Die Tantal-Ampulle wird unter Verwendung einer Lichtbogenschweißanlage mit einem entsprechenden Deckel verschweißt. Anschließend wird die verschlossene Tantal- Ampulle in ein mit Argon gefülltes Quarzrohr eingebracht und für 100 h auf 950 °C erhitzt. Das Erhitzen des Eduktgemenges in einer verschlossenen Tantal-Ampulle führt zu einem Überdruck des Schutzgases während der Reaktion. In den Tabellen 6 und 7 sind Einwaagen für die alternative Synthese von Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺ zusammengefasst. Die Tantal- Atome in der Verbindung stammen teilweise aus der Tantal- Ampulle, in der die Reaktion durchgeführt wird. Tabelle 6: Einwaagen für eine alternative Synthese von Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺.

Tabelle 7: Einwaagen für eine alternative Synthese von Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺.

Das strahlungsemittierende Bauelement 13 gemäß dem Ausführungsbeispiel der Figur 9 weist einen Halbleiterchip 14, der im Betrieb elektromagnetische Strahlung eines ersten Wellenlängenbereichs emittiert, und ein Konversionselement 15 auf. Der Halbleiterchip 14 umfasst ein Substrat 16 auf das eine Halbleiterschichtenfolge 17 epitaktisch aufgewachsen ist. Die Halbleiterschichtenfolge 17 umfasst einen aktiven Bereich 18, der im Betrieb des Bauelements die elektromagnetische Strahlung des ersten Wellenlängenbereichs erzeugt. Bei der elektromagnetischen Strahlung des ersten Wellenlängenbereichs handelt es sich um elektromagnetische Strahlung im ultravioletten bis blauen Wellenlängenbereich des elektromagnetischen Spektrums. Beispielsweise emittiert der Halbleiterchip 14 elektromagnetische Strahlung mit einer Dominanzwellenlänge von ungefähr 447 Nanometer. Das Konversionselement 15 ist dem Halbleiterchip 14 nachgeordnet und umfasst den Leuchtstoff 1. Es ist jedoch auch möglich, dass das Konversionselement 15 anders in dem strahlungsemittierenden Bauelement 13 angeordnet ist. Das Konversionselement 15 kann einen weiteren Leuchtstoff 19 aufweisen. Alternativ ist es möglich, dass das Konversionselement 15 keine weitere strahlungskonvertierende Komponente aufweist. Der Leuchtstoff 1 konvertiert die elektromagnetische Strahlung des ersten Wellenlängenbereichs in elektromagnetische Strahlung eines zweiten Wellenlängenbereichs. Der zweite Wellenlängenbereich ist zumindest teilweise verschieden von dem ersten Wellenlängenbereich. Der weitere Leuchtstoff 19 konvertiert die elektromagnetische Strahlung des ersten Wellenlängenbereichs in elektromagnetische Strahlung eines dritten Wellenlängenbereichs. Der dritte Wellenlängenbereich ist zumindest teilweise verschieden von dem ersten Wellenlängenbereich und/oder dem zweiten Wellenlängenbereich. Das strahlungsemittierende Bauelement 13 gemäß dem vorliegenden Ausführungsbeispiel emittiert insbesondere weißes Mischlicht, das sich aus der elektromagnetischen Strahlung des ersten Wellenlängenbereichs, des zweiten Wellenlängenbereichs und, in dem Fall, dass der weitere Leuchtstoff 19 in dem Konversionselement 15 vorhanden ist, des dritten Wellenlängenbereichs zusammensetzt. Mit anderen Worten wird ein Teil der elektromagnetischen Strahlung des ersten Wellenlängenbereichs nicht im Konversionselement 15 konvertiert. Wird der Leuchtstoff 1 mit der Summenformel Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺ in dem Konversionselement 15 eingesetzt, so strahlt das strahlungsemittierende Bauelement 13 elektromagnetische Strahlung mit dem Emissionsspektrum T1 aus, das in der Figur 10 gezeigt ist. Die Figur 10 zeigt ebenfalls ein Emissionsspektrum T2, das von einem strahlungsemittierenden Bauelement 13 mit Sr₂Li₄Si₃O₄N₄:Eu2+ als Leuchtstoff 1 ausgesendet wird. Beide strahlungsemittierenden Bauelemente 13 erzeugen weißes Mischlicht mit einer Farbtemperatur (CCT, engl. „correlated color temperature“) von ungefähr 5000 K. Jedoch zeigt das strahlungsemittierende Bauelement 13 mit Ba₄Li₂Al₂Ta₂N₈O:Eu2+ einen um drei Punkte höheren Farbwiedergabeindex (CRI) als das strahlungsemittierende Bauelement 13 mit Sr₂Li₄Si₄O₄N₄:Eu²⁺. Der Farbwiedergabeindex ist mit Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺ als Leuchtstoff also um 6% verbessert. Die Eigenschaften der strahlungsemittierenden Bauelemente 13 mit Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺ (Ausführungsbeispiel) und Sr₂Li₄Si₄O₄N₄:Eu²⁺ (Vergleichsbeispiel) als Leuchtstoff 1 sind in der Tabelle 8 zusammengefasst. Tabelle 8: Eigenschaften der strahlungsemittierenden Bauelemente 13 mit Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺ und Sr₂Li₄Si₃O₄N₄:Eu²⁺.

In der Figur 11 ist ein Rietveld-verfeinertes Pulverdiffraktogramm R1 eines Leuchtstoffs 1 gemäß einem Ausführungsbeispiel, vorliegend Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺, gezeigt. Es ist die Intensität gegen den Beugungswinkel 2 ^ in Grad aufgetragen. Die weiße Linie entspricht dem berechneten Diffraktogram D1. Die schwarzen Sterne geben das gemessene Diffraktogramm D2 wieder. Bei der Linie D3 handelt es sich um den Differenzplot der Werte der Kurven D1 und D2. Die Markierungen D4 geben die theoretischen Reflexpositionen von Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺ wieder. Die Markierungen D5 entsprechen den theoretischen Reflexpositionen von TaO. Das Pulverdiffraktogramm R1 zeigt, dass neben dem Leuchtstoff 1 mit der Summenformel Ba₄Li₂Al₂Ta₂N₈O:Eu²⁺ auch TaO gebildet wurde. Die in Verbindung mit den Figuren beschriebenen Merkmale und Ausführungsbeispiele können gemäß weiteren Ausführungsbeispielen miteinander kombiniert werden, auch wenn nicht alle Kombinationen explizit beschrieben sind. Weiterhin können die in Verbindung mit den Figuren beschriebenen Ausführungsbeispiele alternativ oder zusätzlich weitere Merkmale gemäß der Beschreibung im allgemeinen Teil aufweisen. Diese Patentanmeldung beansprucht die Priorität der deutschen Patentanmeldung 102022 118 304.1, deren Offenbarungsgehalt hiermit durch Rückbezug aufgenommen wird. Die Erfindung ist nicht durch die Beschreibung anhand der Ausführungsbeispiele auf diese beschränkt. Vielmehr umfasst die Erfindung jedes neue Merkmal sowie jede Kombination von Merkmalen, was insbesondere jede Kombination von Merkmalen in den Patentansprüchen beinhaltet, auch wenn dieses Merkmal oder diese Kombination selbst nicht explizit in den Patentansprüchen oder Ausführungsbeispielen angegeben ist. Bezugszeichenliste 1 Leuchtstoff 2 Wirtsstruktur 3 AlN₄-Tetraeder 4 TaN₄-Tetraeder 5 Ba-Atom 6 Li₂O-Hantel 7 Vierer-Ring 8 Achter-Ring 9 Kanal 10 O-Atom 11 Li-Atom 12 Sechser-Ring 13 strahlungsemittierendes Bauelement 14 Halbleiterchip 15 Konversionselement 16 Substrat 17 Halbleiterschichtenfolge 18 aktiver Bereich 19 weiterer Leuchtstoff E1, E2 Emissionsspektren eines Leuchtstoffs G1, G2 Gaußkurven S1, S2, S3 Verfahrensschritte T1, T2 Emissionsspektren eines strahlungsemittierenden Bauelements R1 Rietveld-Verfeinerung von Ba₄Li₂Al₂Ta₂N₈O:Eu2+ D1 berechnetes Diffraktogramm D2 gemessenes Diffraktogramm D3 Differenzplot D4 berechnete Reflexpositionen von Ba₄Li₂Al₂Ta₂N₈O:Eu2+ D5 berechnete Reflexpositionen von TaO A crystal structure of the host structure 2 of the phosphor 1 according to the exemplary embodiment with the molecular formula Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ is shown in various schematic views in Figures 2 to 5. The host structure 2 in the present case comprises AlN ₄ tetrahedrons 3 and TaN ₄ tetrahedrons 4, as can be seen from FIG. 2. In Figure 2 the host structure is shown from the [001 ^{^} ] direction. The AlN ₄ tetrahedra 3 and the TaN ₄ tetrahedra 4 are corner-linked on all sides. An AlN ₄ tetrahedron 3 is linked via its four corners to form four TaN ₄ tetrahedra 4 and vice versa. In this way a tetrahedral network is formed. The Al atoms and the Ta atoms are arranged in the host structure 2. In other words, there is no mixed occupation of the point positions of the Al atoms and the Ta atoms. The AlN ₄ tetrahedra 3 and the TaN ₄ tetrahedra 4 are each spanned by four N atoms. There is a tetrahedral gap in the middle of the tetrahedrons. The tetrahedral gap is occupied by an Al atom or a Ta atom. Corner-sharing AlN4 tetrahedra 3 and TaN4 tetrahedra 4 share a common N atom. Ba atoms 5 and Li ₂ O dumbbells 6 are arranged in the spaces between the tetrahedral network. The crystal structure of the host structure 2 has two different point positions for the Ba atoms 5. In particular, the activator element A, in this case Eu ²⁺ , occupies the point positions of the Ba atoms. Figure 3, like Figure 2, shows a section of the host structure 2, but only the AlN4 tetrahedra 3 and the TaN ₄ tetrahedra 4 are shown here. The host structure is shown from the [001 ^{^} ] direction. The AlN ₄ tetrahedra 3 and the TaN ₄ tetrahedra 4 are arranged alternately. The tetrahedral network has four rings 7 made up of two AlN ₄ tetrahedra 3 and two TaN ₄ tetrahedra 4. Furthermore, the tetrahedral network comprises figure-8 rings 8 made up of four AlN ₄ tetrahedra 3 and four TaN ₄ tetrahedra 4. The Ba atoms 5 are arranged within the figure-eight rings 8. The tips of the AlN ₄ tetrahedra 3 and the TaN ₄ tetrahedra 4 point in the [001 ^{^} ] direction (in Figure 3 towards the back of the sheet) below). 4 shows a further section of the host structure 2 of the phosphor with the molecular formula Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ . The section is shown here from the [01 ^{^} 0] direction. The four-rings 7 in the previously described tetrahedral network form channels 9. Li ₂ O dumbbells 6 are arranged in the channels 9. The Li ₂ O dumbbells 6 are linear. In the Li ₂ O dumbbells 6, a Li atom 10 is arranged between two oxygen atoms 11. The Li ₂ O dumbbells 6 are isolated. In particular, the Li ₂ O dumbbells form 6 strands in the channels formed by the four-rings 7. The host structure 2 has six-rings 12 from the [1 ^{^} 00] direction, as shown in FIG. A six-ring 12 includes three AlN ₄ tetrahedra 3 and three TaN ₄ tetrahedra 4. The tips of two AlN ₄ tetrahedra 3 and two TaN ₄ tetrahedra 4 of a six-ring 12 point along the [1 ^{^} 00]- Direction (in Figure 5 to the back of the sheet), the tips of the third AlN ₄ tetrahedron 3 and the third TaN ₄ tetrahedron 3 of the six-ring 12 point along the [100] direction (in Figure 5 to the front of the sheet). The exemplary embodiment of the phosphor 1 with the molecular formula Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ crystallizes in the orthorhombic space group Pnnm. In a unit cell there are two formula units of the host structure 2 with the Molecular formula Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O included. The crystal structure structure of Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O is isotypic to that of Sr ₄ Li ₂ Al ₂ Ta ₂ N ₈ O. In addition, Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O is homeotypic to the compound Sr ₄ Li ₂ Si ₄ N ₈ O. The host structure 2 has a BCT zeolite-like structure. The most important crystallographic data of the host structure 2 of the phosphor 1 with the molecular formula Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu2+ are summarized in Table 1. Table 1: Crystallographic data of Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ .

Table 1 shows the measured section of the reciprocal space beyond the boundaries of the associated Miller indices (hkl). As a quality feature for agreement The goodness of fit (GooF) is given for calculated and measured intensities, which should be close to 1. Tables 2 and 3 show the crystallographic position parameters and the anisotropic deflection parameters of Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ . The Wyckoff position describes the symmetry of the point positions according to RWG Wyckoff. x, y and z indicate the atomic positions. U _ani is the radius of the anisotropic deflection parameters of the respective atom. U _eq is the radius of the isotropic deflection parameters of the respective atom. Table 2: Crystallographic position parameters of Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ .

Table 3: Anisotropic deflection parameters of Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ .

After excitation with a wavelength of 448 nanometers, the exemplary embodiment of the phosphor 1 with the molecular formula Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ leads to the emission spectrum E1, which is shown in FIG. 6. The emission spectrum E1 is shown in a range from 450 nanometers to 750 nanometers inclusive. The emission spectrum E1 has an emission peak with an emission maximum λ _max at approximately 565 nanometers. The full width at half maximum (FWHM) of the emission peak is approximately 89 nanometers. A dominant wavelength λ _dom of the electromagnetic radiation emitted by the phosphor 1 with the molecular formula Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu2+ is approximately 571 nanometers. These and other optical data for Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ are summarized in Table 4. Table 4: Selected optical data of Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ .

7 shows an emission spectrum E2 of the phosphor 1 with the molecular formula Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ . Here, in comparison to Figure 6, the wavelength of the emitted electromagnetic radiation is not given in nanometers but in electron volts (eV) and reciprocal centimeters (cm ^-1 ). The emission spectrum E2 is in one Range from 3 eV up to and including 1 eV or from 24066 cm ^-1 up to and including 8066 cm ^-1 shown. Two simulated Gaussian curves G1 and G2 are also shown in FIG. An addition of the simulated Gaussian curves G1 and G2 agrees with the measured emission spectrum E2. From the fact that the emission spectrum E2 can be composed of the two simulated Gaussian curves G1 and G2, it can be concluded that the activator element Eu ²⁺ occupies both crystallographic point positions of the Ba atoms 5. This creates two emission bands, which are reflected in the simulated Gaussian curves G1 and G2. A method for producing a phosphor 1 according to an exemplary embodiment is described in connection with FIG. 8. In a first process step S1, starting materials of the phosphor 1 with the molecular formula M ₄ Li ₂ D ₂ E ₂ N ₈ O:A are provided. The starting materials used here are oxides or carbonates of M, Li, D, E and A, in particular complex nitrides of M, Li, D, E and A and/or the elements of M, Li, D, E and A. Specifically, the starting materials Ba ₃ N ₂ , Ba ₂ TaN ₃ , Al ₂ O ₃ , Li ₃ N, Li ₂ CO ₃ , Ta, LiN ₃ , AlN, Li ₂ O, Li, Eu ₂ O ₃ can be used in selected combinations . In a second process step S2, the educts of the phosphor 1 are mixed to form a educt mixture and transferred to a reaction vessel. The educt mixture is then heated to a temperature of 800 ° C to 1100 ° C inclusive for a period of 50 hours up to and including 200 hours. Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu2+ For the synthesis of Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ , Ba ₃ N ₂ , Al ₂ O ₃ , Li ₃ N and elemental Li are used Ratio of 2:3:12:14 and Eu ₂ O ₃ as a precursor for the activator element are intimately mixed in a glovebox under a protective gas atmosphere, in particular an N ₂ atmosphere, and transferred to a tantalum ampoule with a base. The tantalum ampoule is welded to a corresponding lid using an arc welding system. The sealed tantalum ampoule is then placed in a quartz tube filled with argon and heated to 900 °C for 100 hours. Heating the reactant mixture in a sealed tantalum ampoule leads to an overpressure of the protective gas during the reaction. Table 5 summarizes the initial weights for the synthesis of Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ . The tantalum atoms in the compound come partly from the tantalum ampoule in which the reaction is carried out. Table 5: Weights for the synthesis of Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ . Educt weight

Alternatively, Ba3N2, Li2CO3, Ta, LiN3, AlN and elemental Li in the ratio of 4:3:6:3:6:21 as well as Eu ₂ O ₃ as a precursor for the activator element or Ba ₂ TaN ₃ , Li ₂ O, AlN and elementary Li in a ratio of 2:1:2:8 and Eu ₂ O ₃ can be used as precursors for the activator element. These starting materials are intimately mixed in a glovebox under a protective gas atmosphere, in particular an N ₂ atmosphere, and transferred to a tantalum ampoule with a base. The tantalum ampoule is welded to a corresponding lid using an arc welding system. The sealed tantalum ampoule is then placed in a quartz tube filled with argon and heated to 950 °C for 100 hours. Heating the reactant mixture in a sealed tantalum ampoule leads to an overpressure of the protective gas during the reaction. Tables 6 and 7 summarize the initial weights for the alternative synthesis of Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ . The tantalum atoms in the compound come partly from the tantalum ampoule in which the reaction is carried out. Table 6: Weights for an alternative synthesis of Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ .

Table 7: Weights for an alternative synthesis of Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ .

The radiation-emitting component 13 according to the exemplary embodiment in FIG. 9 has a semiconductor chip 14, which emits electromagnetic radiation of a first wavelength range during operation, and a conversion element 15. The semiconductor chip 14 includes a substrate 16 on which a semiconductor layer sequence 17 is epitaxially grown. The semiconductor layer sequence 17 includes an active region 18, which generates the electromagnetic radiation of the first wavelength range during operation of the component. The electromagnetic radiation of the first wavelength range is electromagnetic radiation in the ultraviolet to blue wavelength range of the electromagnetic spectrum. For example, the semiconductor chip 14 emits electromagnetic radiation with a dominant wavelength of approximately 447 nanometers. The conversion element 15 is arranged downstream of the semiconductor chip 14 and includes the phosphor 1. However, it is also possible for the conversion element 15 to be arranged differently in the radiation-emitting component 13. The conversion element 15 can have a further phosphor 19. Alternatively, it is possible that the Conversion element 15 has no further radiation-converting component. The phosphor 1 converts the electromagnetic radiation of the first wavelength range into electromagnetic radiation of a second wavelength range. The second wavelength range is at least partially different from the first wavelength range. The further phosphor 19 converts the electromagnetic radiation of the first wavelength range into electromagnetic radiation of a third wavelength range. The third wavelength range is at least partially different from the first wavelength range and/or the second wavelength range. The radiation-emitting component 13 according to the present exemplary embodiment emits in particular white mixed light, which is composed of the electromagnetic radiation of the first wavelength range, the second wavelength range and, in the case that the further phosphor 19 is present in the conversion element 15, of the third wavelength range. In other words, part of the electromagnetic radiation of the first wavelength range is not converted in the conversion element 15. If the phosphor 1 with the molecular formula Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ is used in the conversion element 15, the radiation-emitting component 13 emits electromagnetic radiation with the emission spectrum T1, which is shown in FIG. 10. Figure 10 also shows an emission spectrum T2 from one radiation-emitting component 13 with Sr ₂ Li ₄ Si ₃ O ₄ N ₄ :Eu2+ is emitted as phosphor 1. Both radiation-emitting components 13 generate white mixed light with a color temperature (CCT, "correlated color temperature") of approximately 5000 K. However, the radiation-emitting component 13 with Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu2+ shows a around three points higher color rendering index (CRI) than the radiation-emitting component 13 with Sr ₂ Li ₄ Si ₄ O ₄ N ₄ :Eu ²⁺ . The color rendering index is improved by 6% with Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ as a phosphor. The properties of the radiation-emitting components 13 with Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ (exemplary embodiment) and Sr ₂ Li ₄ Si ₄ O ₄ N ₄ :Eu ²⁺ (comparative example) as phosphor 1 are in the table 8 summarized. Table 8: Properties of the radiation-emitting components 13 with Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ and Sr ₂ Li ₄ Si ₃ O ₄ N ₄ :Eu ²⁺ .

11 shows a Rietveld-refined powder diffractogram R1 of a phosphor 1 according to an exemplary embodiment, in this case Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ . The intensity is plotted against the diffraction angle 2 ^ in degrees. The white line corresponds to the calculated diffractogram D1. The black stars indicate the measured Diffractogram D2 again. Line D3 is the difference plot of the values of curves D1 and D2. Markings D4 represent the theoretical reflex positions of Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ . The D5 markings correspond to the theoretical reflex positions of TaO. The powder diffractogram R1 shows that in addition to the phosphor 1 with the molecular formula Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ , TaO was also formed. The features and exemplary embodiments described in connection with the figures can be combined with one another according to further exemplary embodiments, even if not all combinations are explicitly described. Furthermore, the exemplary embodiments described in connection with the figures can alternatively or additionally have further features according to the description in the general part. This patent application claims the priority of German patent application 102022 118 304.1, the disclosure content of which is hereby incorporated by reference. The invention is not limited to these by the description based on the exemplary embodiments. Rather, the invention encompasses every new feature and every combination of features, which in particular includes every combination of features in the patent claims, even if this feature or this combination itself is not explicitly stated in the patent claims or exemplary embodiments. List of reference symbols 1 phosphor 2 host structure 3 AlN ₄ tetrahedron 4 TaN ₄ tetrahedron 5 Ba atom 6 Li ₂ O dumbbell 7 four-ring 8 eight-ring 9 channel 10 O-atom 11 Li atom 12 six-ring 13 radiation-emitting component 14 semiconductor chip 15 conversion element 16 substrate 17 semiconductor layer sequence 18 active region 19 further phosphor E1, E2 emission spectra of a phosphor G1, G2 Gaussian curves S1, S2, S3 process steps T1, T2 emission spectra of a radiation-emitting component R1 Rietveld refinement of Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu2+ D1 calculated diffractogram D2 measured diffractogram D3 difference plot D4 calculated reflection positions of Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu2+ D5 calculated reflection positions of TaO

Claims

Claims 1. Phosphor (1) with the molecular formula M ₄ Li ₂ D ₂ E ₂ N ₈ O:A, where - M is an element or a combination of elements selected from the group of divalent elements, - D is an element or a combination of elements selected from the group formed by Al and Ga, - E is an element or a combination of elements selected from the group formed by Ta and Nb, and - A is at least one activator element. 2. Phosphor (1) according to the preceding claim, in which M is an element or a combination of elements selected from the following group: Ca, Sr, Ba. 3. Phosphor (1) according to one of the preceding claims, in which A is an element or a combination of elements selected from the following group: Eu, Ce, Mn, Cr, Ni, Bi, Tb, Yb. 4. Fluorescent material (1) according to one of the preceding claims, in which A has a proportion of 0.01 mol% to 10 mol% inclusive, based on the element M. 5. Phosphor (1) according to one of the preceding claims, in which a crystal structure of a host structure (2) of the phosphor (1) has an orthorhombic space group. 6. Fluorescent material (1) according to one of the preceding claims, in which the crystal structure of the host structure (2) has DN ₄ tetrahedrons (3) and EN ₄ tetrahedrons (4). 7. Fluorescent material (1) according to one of the preceding claims, in which the crystal structure of the host structure (2) has Li ₂ O dumbbells (6). 8. Fluorescent material (1) according to one of the preceding claims, in which the fluorescent material (1) has the molecular formula Ba ₄ Li ₂ Al ₂ Ta ₂ N ₈ O:Eu ²⁺ . 9. Phosphor (1) according to one of the preceding claims, in which - the phosphor (1) absorbs electromagnetic radiation in the blue to ultraviolet range of the electromagnetic spectrum, and - electromagnetic radiation emitted by the phosphor (1) has an emission spectrum with an emission peak has an emission maximum in the wavelength range from 515 nanometers to 615 nanometers inclusive. 10. Phosphor (1) according to one of the preceding claims, in which the electromagnetic radiation emitted by the phosphor (1) has a dominant wavelength between 550 nanometers and 580 nanometers inclusive. 11. Fluorescent material (1) according to one of the preceding claims, in which the emission peak has a half-width between 80 nanometers and 100 nanometers inclusive. 12. Process for producing a phosphor (1) with the molecular formula M4Li2D2E2N8O:A, where - M is an element or a combination of elements selected from the group of divalent elements, - D is an element or a combination of elements selected from the group formed by Al and Ga, - E is an element or a combination of elements selected from the group formed by Ta and Nb, and - A is at least one activator element, comprising the steps: - Providing educts, - Mixing the educts to form a educt mixture, and - Heating the educt mixture. 13. A process for producing a phosphor (1) according to the preceding claim, wherein the starting materials are selected from the following group: elements of M, Li, D, E and A, oxides of M, Li, D, E and A, nitrides of M, Li, D, E and A, carbonates of M, Li, D, E and A. 14. A method for producing a phosphor (1) according to one of claims 12 or 13, wherein the educt mixture is heated to a temperature between 800 ° C and 1100 ° C inclusive. 15. A method for producing a phosphor (1) according to one of claims 12 to 14, wherein the educt mixture is heated under a protective gas atmosphere. 16. A method for producing a phosphor (1) according to one of claims 12 to 15, wherein elemental Li is used as starting material. 17. Radiation-emitting component (13) with: - a semiconductor chip (14), which emits electromagnetic radiation of a first wavelength range during operation, and - a conversion element (15) with a phosphor (1) according to one of claims 1 to 11, which converts electromagnetic radiation of the first wavelength range into electromagnetic radiation of a second wavelength range, which is at least partially different from the first wavelength range. 18. Radiation-emitting component (13) according to claim 17, in which the conversion element (15) has a further phosphor (19) which converts the electromagnetic radiation of the first wavelength range into electromagnetic radiation of a third wavelength range. 19. Radiation-emitting component (13) according to claim 17, in which the conversion element (15) has no further radiation-converting component.