Luminescent substance, method for producing a luminescent substance, and optoelectronic component

Abstract

A luminescent substance (1) having the empirical formula EA2-xSExSi5 -xAlxN8:RE is specified, where - EA is an element or a combination of elements selected from the group of divalent elements, - SE is an element or a combination of elements selected from the group of rare earth elements, - RE is an activator element, and - 0 ≤ x ≤ 2. Also specified is a method for producing a luminescent substance (1), and an optoelectronic component (10).

Description

[0001] 2024PF00113 25. April 2025P2024,0113 WO N - 1 -Description of a phosphor, a method for producing a phosphor, and an optoelectronic component. A phosphor and a method for producing a phosphor are described. Furthermore, an optoelectronic component is described. One objective is to provide a phosphor with increased efficiency. Other objectives include providing a method for producing a phosphor with increased efficiency and an optoelectronic component with increased efficiency. A phosphor is described. According to at least one embodiment, the phosphor has the molecular formula EA2-xSExSi5-xAlxN8:RE, where: - EA is an element or combination of elements selected from the group of divalent elements, - SE is an element or combination of elements selected from the group of rare-earth elements, - RE is an activator element, and - 0 ≤ x ≤ 2.Here and in the following, phosphors are described using their molecular formulas. The elements listed in these formulas are in charged form. Therefore, here and in the following, elements and / or atoms in relation to the molecular formulas of the phosphors refer to ions in the form of cations and anions, even if this is not explicitly stated. This also applies to element symbols, 2024PF00113 25 April 2025P2024,0113 WO N -. 2 -For the sake of clarity, these are given without charge numbers. With the given molecular formulas, it is possible that the phosphor contains other elements, for example, in the form of impurities. Taken together, these impurities constitute at most 5 mol%, in particular at most 1 mol%, preferably at most 0.1 mol%. According to the molecular formula described here, the phosphor contains only nitrogen as anion. However, it cannot be ruled out that other elements, especially anionic ones, are present in the form of impurities. The phosphor in question can be externally neutral. This means that there can be a complete charge balance between positive and negative charges within the phosphor. Conversely, it is also possible that the phosphor formally does not have a complete charge balance to a small extent.The term "valence" in relation to a specific element refers to how many elements with a single opposite charge are needed in a chemical compound to achieve charge balance. Thus, the term "valence" encompasses the element's charge number. Elements with a valence of two are called divalent elements. Divalent elements are often doubly positively charged in chemical compounds and have a charge number of +2. Charge balance in a chemical compound can be achieved, for example, by two additional elements that are singly negatively charged, or by another 2024PF00113 25 April 2025P2024,0113 WO N -. 3 -An element that is doubly negatively charged can be used. Divalent elements are generally selected from the group consisting of the alkaline earth elements and zinc. Rare earth elements include the chemical elements of the third transition group of the periodic table and the lanthanides. Rare earth elements are generally selected from the group consisting of sc, y, la, ce, pr, nd, pm, sm, eu, gd, tub, dy, ho, er, tem, yb, and lu. Such a phosphor can convert electromagnetic radiation of a specific wavelength or wavelength range, hereinafter referred to as primary radiation, into electromagnetic radiation of a second wavelength or wavelength range, hereinafter referred to as secondary radiation. The conversion of primary radiation into secondary radiation is also called wavelength conversion.In particular, during wavelength conversion, primary radiation is absorbed by a wavelength-converting element, converted into secondary radiation by electronic processes at the atomic and / or molecular level, and re-emitted. Primary and secondary radiation thus have at least partially different wavelength ranges, with the secondary radiation, according to one embodiment, having a longer wavelength range. In particular, pure scattering or pure absorption of electromagnetic radiation is not what is meant by the term "wavelength conversion" here. Activator elements are foreign elements that are introduced into the host structure of the phosphor. [The following appears to be unrelated and possibly a separate document:] 2024PF00113 April 25, 2025P2024,0113 WO N -. 4 -The host structure modifies the electronic structure of the activator element in such a way that the primary radiation absorbed by the phosphor excites an electronic transition within the activator element, which then returns to its ground state by emitting electromagnetic radiation with an emission spectrum, the secondary radiation. The activator element, which is incorporated into the host structure, is thus responsible for the wavelength-converting properties of the phosphor. In particular, the phosphor exhibits an absorption region in which it absorbs primary radiation. Activator elements are typically selected from the group consisting of rare-earth elements such as Eu, Ce, Tb, and Yb. Alternatively or additionally, activator elements can be selected from the group consisting of Mn, Bi, Cr, and Ni.Such a phosphor can be used – depending on the application – alone or together with other phosphors in light-emitting diodes (LEDs) to generate white or yellow light, for example as a yellow conversion phosphor for use in LEDs. In particular, the phosphor is suitable for converting blue primary radiation by LEDs into yellow radiation, for example in white light generation, in applications at high irradiances, and for full yellow conversion. According to at least one embodiment, EA comprises Mg, Ca, Sr, Ba, or combinations thereof, in particular Ca, Sr, Ba, or combinations thereof. According to at least one embodiment, EA comprises or consists of Ca. 2024PF00113 April 25, 2025P2024,0113 WO N -. 5 -According to at least one embodiment, SE comprises La, Y, or combinations thereof. According to at least one embodiment, SE comprises or consists of La. According to at least one embodiment, RE comprises or consists of Ce. Phosphors activated with Ce3+ exhibit lower quenching effects at high irradiance compared to phosphors activated with Eu 2+ to be activated. This is mainly due to the significantly shorter lifetime of the excited state for Ce. 3+ The typical lifetime of the excited state of a Ce 3+ -Ion lifetimes during conversion are typically less than 100 ns, while typical lifetimes for the excited state of Eu 2+ in the range of 1-10 µs. Therefore, especially at high irradiances, it can be advantageous to use Ce. 3+-activated phosphors. According to at least one embodiment, RE has a molar fraction between 0.0001 and 0.1 inclusive, based on the elements EA and SE. In other words, between 0.01% and 10% of the atomic layers of EA and SE are occupied by RE inclusive. The molecular formula EA 2-x SE x Si 5- xAlxN8:RE can therefore also be expressed as follows:(EA 2-x SE x ) 1-t RE t Si 5-x Al x N8, where t is between 0.0001 and 0.1 inclusive. According to at least one embodiment, the phosphor comprises a crystalline, for example ceramic, host lattice into which foreign elements are introduced as activator elements. The phosphor is, for example, a ceramic material. 2024PF00113 April 25, 2025P2024,0113 WO N - 6 -The crystalline host lattice is primarily composed of a three-dimensional unit cell that typically repeats periodically. In other words, the unit cell is the smallest recurring unit of the crystalline host lattice. The elements EA, SE, Si, Al, and N each occupy specific positions, called atomic layers, within the three-dimensional unit cell of the host lattice. Furthermore, the activator element RE, the divalent element EA, and the rare-earth element SE occupy equivalent atomic layers. In other words, either EA, SE, or RE occupies the position described by the atomic layers of elements EA and SE within a unit cell. Six lattice parameters are required to describe the three-dimensional unit cell of the crystalline host lattice: three lengths a, b, and c, and three angles α, β, and γ. The three lattice parameters a, b, and c are the lengths of the lattice vectors that span the unit cell.The other three lattice parameters α, β, and γ are the angles between these lattice vectors. α is the angle between b and c, β is the angle between a and c, and γ is the angle between a and b. V corresponds to the volume of the unit cell. According to at least one embodiment, the lattice parameter a lies in the range from 13.10 Å to 13.50 Å inclusive, the lattice parameter b in the range from 5.55 Å to 5.95 Å inclusive, and the lattice parameter c in the range from 9.60 Å to 10.00 Å inclusive. According to at least one further embodiment, the angles α, β, and γ are 90°, in particular exactly 90°. The unit cell volume lies in the range from 700 Å inclusive. 3 up to and including 800 Å 3 .2024PF00113 April 25, 2025P2024,0113 WHERE N - 7 -According to at least one embodiment, the phosphor has a host lattice with an orthorhombic space group. According to at least one embodiment, the phosphor crystallizes in the orthorhombic space group Pbcn (No. 60). In particular, the lattice parameters for the phosphor in the orthorhombic space group Pbcn are approximately a = 13.3085(2) Å, b = 5.73920(10) Å, c = 9.8121(2) Å, and the angles α, β, and γ are 90°. The unit cell volume is 749.45(2) Å. 3According to at least one embodiment, a crystal structure of the host lattice of the phosphor comprises (Si,Al)N₄ tetrahedra linked to each other at all sides. Each (Si,Al)N₄ tetrahedron is spanned by nitrogen atoms. The (Si,Al)N₄ tetrahedra may have a tetrahedral void. The tetrahedral void is a region within the respective tetrahedron. For example, the term "tetrahedral void" refers to the region within the tetrahedron that remains empty when touching spheres are placed at the vertices of the tetrahedron. The nitrogen atoms of the (Si,Al)N₄ tetrahedra span the tetrahedron, with a silicon atom or an aluminum atom located in the tetrahedral void of the spanned tetrahedron. The silicon atom or the aluminum atom is surrounded tetrahedrally by four nitrogen atoms. In particular, all atoms spanning the tetrahedron are at a similar distance from the Si atom or the Al atom located in the tetrahedral void.Vertex-linked on all sides means that each vertex of a (Si,Al)N4 tetrahedron is connected to at least one other (Si,Al)N4 tetrahedron via a shared vertex. 2024PF00113 April 25, 2025P2024,0113 WO N -. 8 -In other words, the N atom that links the (Si,Al)N4 tetrahedra together is part of both (Si,Al)N4 tetrahedra. According to at least one embodiment, the (Si,Al)N4 tetrahedra form layers within a plane of a unit cell, in particular parallel to the bc plane, wherein adjacent layers are linked to each other via at least one (Si,Al)N4 tetrahedron that is not part of the layers. In particular, each layer-sharing (Si,Al)N4 tetrahedron is corner-sharing with two (Si,Al)N4 tetrahedra from two adjacent layers. Viewed along a first of the crystallographic axes spanning the plane, for example the crystallographic c-axis, the layers are formed as strands of corner-sharing (Si,Al)N4 tetrahedra. According to at least one embodiment, each layer is rotated by 180° in the orientation of the (Si,Al)N4 tetrahedra relative to adjacent layers.In particular, all (Si,Al)N4 tetrahedra in a layer point in the same direction along a first crystallographic axis parallel to the plane of the layer, for example, along the crystallographic c-axis. The orientation of the (Si,Al)N4 tetrahedra within a layer exhibits different directions along the first crystallographic axis for neighboring layers. In other words, when viewed from above, a strand with an upward orientation alternates along a second crystallographic axis parallel to the plane of the layer and orthogonal to the first crystallographic axis, for example, along the crystallographic b-axis. 9 -The (Si,Al)N4 tetrahedra are separated by a strand of downward-facing (Si,Al)N4 tetrahedra. According to at least one embodiment, the (Si,Al)N4 tetrahedra are arranged in interconnected chains within a layer. Within a chain, one (Si,Al)N4 tetrahedron is linked to two other (Si,Al)N4 tetrahedra via a corner connection. According to at least one embodiment, the chains within a layer run in a zigzag pattern. In other words, the (Si,Al)N4 tetrahedra of a chain are arranged in a zigzag pattern. In particular, the chains are simple quadruple chains. This means that the chains are composed of repeating units of four (Si,Al)N4 tetrahedra each, with each of the repeating units not running linearly but having an offset that creates the zigzag pattern of the chains. In particular, one layer consists of condensed four-chain structures.In other words, the four-membered single chains of a layer are linked together. According to at least one embodiment, the orientation of the (Si,Al)N4 tetrahedra differs from that of neighboring chains. In particular, the (Si,Al)N4 tetrahedra of a chain are each oriented in the same direction perpendicular to the plane of the layer in which the chain is located. This orientation has different directions perpendicular to the plane of the layer for neighboring chains. In other words, when viewed from above, a chain with forward-facing (Si,Al)N4 tetrahedra alternates with a chain with forward-facing (Si,Al)N4 tetrahedra. 2024PF00113 April 25, 2025P2024,0113 WO N -. 10 -with a chain of backward-facing (Si,Al)N4 tetrahedra. According to at least one embodiment, the (Si,Al)N4 tetrahedra form interstices, with at least one interstice containing an EA atom or an SE atom. In particular, an interstice is a cavity that is at least partially surrounded by (Si,Al)N4 tetrahedra. In particular, EA atoms and SE atoms can be replaced by RE atoms at their atomic position. According to at least one embodiment, an excitation wavelength of the phosphor lies in the range between 350 nm and 500 nm inclusive, in particular between 400 nm and 470 nm inclusive, for example at 448 nm. In other words, the phosphor has an absorption range between 350 nm and 500 nm inclusive, in particular between 400 nm and 470 nm inclusive.For example, the phosphor absorbs electromagnetic radiation with a wavelength of approximately 448 nm. According to at least one embodiment, the phosphor emits electromagnetic radiation. In particular, the phosphor emits electromagnetic radiation after excitation with electromagnetic radiation. In other words, the phosphor emits secondary radiation after excitation with primary radiation. The primary radiation is, for example, electromagnetic radiation whose wavelength range lies within the absorption range of the phosphor. The secondary radiation has, in particular, a wavelength range that differs from the wavelength range of the 2024PF00113 25 April 2025P2024,0113 WO N -. 11 -The primary radiation is at least partially different. The emitted electromagnetic radiation, the secondary radiation, can be described in the form of an emission spectrum. 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 as a diagram in which the spectral intensity or spectral flux per wavelength interval ("spectral intensity / spectral flux") of the electromagnetic radiation emitted by the phosphor is plotted as a function of the wavelength λ. In other words, the emission spectrum represents a curve where the wavelength is plotted on the x-axis and the spectral intensity or spectral flux is plotted on the y-axis.According to at least one embodiment, a dominant wavelength of electromagnetic radiation emitted by the phosphor, particularly after excitation with electromagnetic radiation, lies in the range between 540 nm and 600 nm, particularly between 555 nm and 580 nm, for example at 568 nm. 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 and passing through the chromaticity coordinate of the electromagnetic radiation. The intersection of this straight line with the spectral chromaticity line bounding the CIE standard diagram designates the 2024PF00113 25 April 2025P2024,0113 WO N -. 12 -Dominance wavelength of electromagnetic radiation. In other words, the dominance wavelength is the monochromatic wavelength that produces the same color impression as a polychromatic light source. The dominance wavelength is therefore the wavelength perceived by the human eye. In general, the dominance wavelength differs from the wavelength of the emission maximum. The phosphor can thus efficiently emit yellow electromagnetic radiation after excitation. According to at least one embodiment, an emission spectrum of electromagnetic radiation emitted by the phosphor, particularly after excitation with electromagnetic radiation, exhibits an emission peak with an emission maximum located in the range between 500 nm and 600 nm, particularly between 530 nm and 570 nm, for example at 551 nm. The emission maximum is the wavelength λ. max, at which the emission curve of the phosphor reaches its maximum value. In other words, the phosphor can provide radiation in the yellow wavelength range and thus contribute to efficient and cost-effective solutions for the application. According to at least one embodiment, a half-width of an emission maximum of the phosphor lies in the range between and including 120 nm and 155 nm, in particular between and including 130 nm and 145 nm, for example at 137 nm. According to at least one embodiment, a color locus of an emission maximum of the phosphor, in particular after excitation with 2024PF00113 25 April 2025P2024,0113 WO N - 13 -electromagnetic radiation with an excitation wavelength of 448 nm, emitted electromagnetic radiation at a CIE x-value between 0.380 and 0.450 (inclusive) and a CIE y-value between 0.495 and 0.565 (inclusive) in the xy-CIE standard color system. In particular, the color coordinate of the electromagnetic radiation emitted by the phosphor is found at a CIE x-value between 0.405 and 0.425 (inclusive) and a CIE y-value between 0.520 and 0.540 (inclusive), for example, at a CIE x-value of 0.414 and a CIE y-value of 0.530. According to at least one embodiment, the phosphor has the chemical formula Ca 2-x La x Si 5-x Al x N8:Ce 3+ In other words, EA is Ca, SE is La, and RE is Ce. The phosphor has the chemical formula Ca. 2-x La x Si 5-x Al x N8:Ce 3+It is advantageously suited for converting blue primary radiation into radiation in the yellow wavelength range. Therefore, the phosphor with the chemical formula Ca is suitable 2-x La x Si 5-x Al x N8:Ce 3+ Advantageously for use as a yellow conversion phosphor in LEDs. A method for producing a phosphor is further described. Preferably, the phosphor is produced according to the embodiments mentioned above using the method described here. In particular, all descriptions of the phosphor also apply to the method and vice versa. According to at least one embodiment of the method for producing a phosphor with the molecular formula EA 2-x SE x Si 5-x Al x N8:RE, where2024PF00113 April 25, 2025P2024,0113 WO N - 14 -- EA is an element or combination of elements selected from the group of divalent elements, - SE is an element or combination of elements selected from the group of rare earth elements, - RE is an activator element, and - 0 ≤ x ≤ 2, the process comprises the steps of: - providing reactants, - mixing the reactants to form a reactant mixture, and - heating the reactant mixture. In particular, the process steps are carried out in the specified order. Specifically, the reactants are mixed in a glovebox under a protective gas atmosphere. The reactant mixture can then be transferred to a crucible, for example, made of tungsten. In particular, it is possible for the process to produce a mixture that includes or consists of the phosphor.Other components of the mixture may include, for example, reactants that did not react during the production of the phosphor, impurities, and / or by-phases formed during production. According to at least one embodiment of the process, the reactants are selected from a group comprising the oxides, nitrides, fluorides, oxalates, citrates, carbonates, amines, and imides of EA, SE, Si, Al, and RE. Preferably, the reactants are selected from a group comprising the oxides and nitrides of EA, SE, Si, Al, and RE. For example, Ca3N2, LaN, Si3N4, AlN, and CeO2 are used as reactants. In particular, 2024PF00113 25 April 2025P2024,0113 WO N -. 15 - Are the starting materials Ca3N2, LaN, Si3N4, AlN and CeO2 suitable for the production of a phosphor with the molecular formula Ca 2-x La x Si 5-x Al x N8:Ce 3+According to at least one embodiment, the reactant mixture is heated to a temperature between 1600 °C and 2000 °C inclusive, in particular between 1700 °C and 1950 °C inclusive, for example, to 1850 °C. According to at least one embodiment, the reactant mixture is heated at a pressure between 1 bar and 40 bar inclusive, in particular between 10 bar and 30 bar inclusive, for example, 20 bar. According to at least one embodiment, the reactant mixture is heated under a forming gas atmosphere. A forming gas atmosphere is in particular an N₂ / H₂ atmosphere, for example, with a ratio of 95 / 5 (N₂ / H₂). By heating the reactant mixture under a forming gas atmosphere, the synthesis of the phosphor takes place under reducing conditions. This enables a reduction of the reactants, for example, a reduction of RE. 4+ to RE 3+According to at least one embodiment, the reactant mixture is heated for between 1 hour and 24 hours, in particular between 2 hours and 10 hours, preferably between 3 hours and 6 hours, for example for 4 hours. 2024PF00113 25 April 2025P2024,0113 WO N - 16 -An optoelectronic component containing a phosphor is further described. Preferably, the phosphor described above is suitable and intended for use in the optoelectronic component described herein. Features and embodiments described in connection with the phosphor and / or the method also apply to the optoelectronic component and vice versa. According to at least one embodiment, the optoelectronic component comprises a semiconductor chip that emits electromagnetic radiation of a first wavelength range during operation and a conversion element with the phosphor described above. The phosphor converts electromagnetic radiation of the first wavelength range into electromagnetic radiation of a second wavelength range, which differs at least partially from the first wavelength range. The optoelectronic component is, for example, an LED.In particular, the semiconductor chip comprises an active layer sequence containing an active region. During operation of the optoelectronic device, the active region generates electromagnetic radiation of the first wavelength range, the primary radiation. For example, the semiconductor chip is a light-emitting diode chip or a laser diode chip. According to one embodiment, the primary radiation is emitted through a radiation emission surface of the semiconductor chip. The properties of the phosphor are already disclosed with respect to the phosphor and also apply to the 2024PF00113 25 April 2025P2024,0113 WO N -. 17 -Phosphor in the optoelectronic component. The phosphor converts the primary radiation completely or at least partially into electromagnetic radiation of a second wavelength range, the secondary radiation. In particular, the secondary radiation has wavelength ranges that differ at least partially from the primary radiation. The conversion element is arranged in the beam path of the primary radiation such that at least a portion of the primary radiation strikes the conversion element. According to at least one embodiment, the semiconductor chip emits primary radiation during operation with a wavelength or wavelength range between and including 250 nm and 500 nm, in particular between and including 400 nm and 500 nm. In other words, the semiconductor chip emits electromagnetic radiation in the ultraviolet to green wavelength range of the electromagnetic spectrum.For example, the semiconductor chip emits primary radiation at 448 nm. According to at least one embodiment, the phosphor emits in the yellow spectral range, particularly after excitation with the primary radiation of the semiconductor chip, preferably after excitation with a wavelength or wavelength range between and including 250 nm and 500 nm, particularly between and including 400 nm and 500 nm. In other words, the secondary radiation has wavelengths in the yellow spectral range. In particular, the phosphor emits electromagnetic radiation between and including 450 nm and 800 nm. 2024PF00113 April 25, 2025P2024,0113 WO N -. 18 -According to at least one embodiment, the conversion element comprises at least one further phosphor that converts electromagnetic radiation of the first wavelength range into electromagnetic radiation of a third wavelength range, which is at least partially different from the first and second wavelength ranges. In other words, the further phosphor converts the primary radiation into a further secondary radiation that differs at least partially from the secondary radiation of the phosphor itself. According to at least one embodiment, the third wavelength range comprises wavelengths in the red spectral range. In other words, the third wavelength range comprises wavelengths that are longer than the wavelengths of the second wavelength range. For example, the further phosphor comprises nitride phosphors such as (Sr,Ca)AlSiN3:Eu.By using an additional phosphor emitting in the red spectral range, in combination with a phosphor of the molecular formula EA2-xSExSi5-xAlxN8:RE, the optoelectronic component can emit white mixed light. This white mixed light can, in particular, be composed of electromagnetic radiation from the first wavelength range, electromagnetic radiation from the second wavelength range, and electromagnetic radiation from the third wavelength range. According to at least one embodiment, the optoelectronic component has a color rendering index (CRI) of at least 80, in particular 85. Specifically, the optoelectronic component emits, upon excitation of the 2024PF00113 25 April 2025P2024,0113 WO N -. 19 -A warm white mixed light with a CRI of at least 80 is produced by a phosphor with the chemical formula EA2-xSExSi5-xAlxN8:RE and a further phosphor (Sr,Ca)AlSiN3:Eu with blue primary radiation. In particular, the warm white mixed light has a correlated color temperature (CCT) in the range of 2500 K inclusive to 6000 K inclusive, for example, 4002 K, and a CRI of at least 80. According to at least one embodiment, the conversion element is free of any further phosphor. "Free of any further phosphor" means that only the phosphor with the chemical formula EA2-xSExSi5-xAlxN8:RE is contained in the conversion element of the optoelectronic device for wavelength conversion and leads to wavelength conversion within the optoelectronic device. A component that only contains the phosphor with the chemical formula EA2-xSExSi5-xAlxN8:RE in the conversion element can, for example, emit yellow radiation.According to at least one embodiment, the conversion element partially converts the primary radiation into secondary radiation, with the unconverted portion of the primary radiation being transmitted through the conversion element. In other words, a partial conversion of the primary radiation into secondary radiation takes place. In this case, the optoelectronic device emits mixed light composed of the primary and secondary radiation. For example, the optoelectronic device emits white light composed of primary radiation in the blue spectral range and secondary radiation in the yellow spectral range. 2024PF00113 April 25, 2025P2024,0113 WO N -. 20 -According to at least one embodiment, the conversion element completely converts the electromagnetic radiation of the first wavelength range into electromagnetic radiation of the second wavelength range. In other words, no primary radiation is transmitted through the conversion element. "No" in this context means that so little primary radiation is transmitted that it no longer perceptibly influences the light emitted by the component. For example, at most 10%, in particular at most 5%, and preferably at most 1% of the primary radiation is transmitted through the conversion element. The optoelectronic component then emits only the secondary radiation. In other words, a complete conversion of the primary radiation into secondary radiation takes place. Thus, the conversion element completely converts the primary radiation into secondary radiation.For example, the optoelectronic component emits yellow light without a blue component. Further advantageous embodiments, configurations, and further developments of the phosphor, the method for producing a phosphor, and the optoelectronic component are shown in the following exemplary embodiments in conjunction with the figures. FIG. 1 shows a schematic representation of the phosphor according to one exemplary embodiment; FIGS. 2 and 3 show sections of the crystal structure of the host material of the phosphor from different perspectives according to one exemplary embodiment each. 2024PF00113 April 25, 2025P2024,0113 WO N -. 21 -FIG. 4 shows a section of a crystal structure of a host material from a comparative example, FIG. 5 shows an emission spectrum of the phosphor according to an embodiment, FIG. 6 shows an optoelectronic component according to an embodiment, FIG. 7 shows an emission spectrum of an optoelectronic component according to an embodiment, and FIG. 8 shows an emission spectrum of an optoelectronic component according to a comparative example. Identical, similar, or similarly acting elements are designated with the same reference numerals in the figures. The figures and the relative sizes of the elements shown in the figures are not to be considered to scale. Rather, individual elements, in particular layer thicknesses, may be exaggerated for clarity and / or better understanding. The phosphor 1 according to the embodiment of FIG.1 has the molecular formula EA2-xSExSi5-xAlxN8:RE, where EA is a divalent element or a combination of divalent elements, SE is a rare earth element or a combination of rare earth elements, RE is an activator element, and 0 ≤ x ≤ 2. For example, the phosphor has the molecular formula Ca. 2-x La x Si 5-x Al x N8:Ce 3+ auf.2024PF00113 April 25, 2025P2024,0113 WO N - 22 - The synthesis of a phosphor 1 described here is shown using embodiments 1 and 2, both of which have the molecular formula Ca 2-x La x Si 5-x Al x N8:Ce 3+The following is explained: The reactants Ca3N2, LaN, Si3N4, AlN, and CeO2 were provided and mixed together. For example, the reactants were mixed in a glovebox under a protective gas atmosphere. The reactant mixture was then transferred to a crucible, for example, made of tungsten, and subsequently reacted under forming gas at a temperature between 1600 °C and 2000 °C, in particular between 1700 °C and 1950 °C, for example at 1850 °C, and a pressure of 20 bar for 4 hours. Table 1 shows the weights of the reactants for the preparation of embodiments 1 and 2 with the molecular formula Ca 2-x La x Si 5-x Al x N8:Ce 3+of phosphor 1. In both embodiments 1 and 2, the phosphor 1 with the molecular formula Ca La Si Al N : 3+2-xx 5-xx 8 Ce was obtained as the main phase mixed with other phases, and the phase Ca 3+2-xLaxSi5-xAlxN8:Ce was unambiguously identified by single-crystal diffractometry. Table 1 Ca2N3LaN Si3N4AlN CeO2 / g / g / g / g / g Embodiment 1 0.1805 0.5585 0.5124 0.7486 0.0200 Embodiment 2 0.1460 0.9037 0.8291 0.1211 0.0200 The structure of the phosphor 1 with the molecular formula Ca 2-x La x Si 5-x Al x N8:Ce 3+ was determined using single-crystal X-ray diffraction on a crystal 1 of embodiment 2. Ca 3+2-xLaxSi5-xAlxN8:Ce crystallizes in the orthorhombic space group Pbcn (No. 60) with the 2024PF00113 25 April 2025P2024,0113 WO N - 23 - Lattice parameters a = 13.3085(2) Å, b = 5.73920(10) Å, c = 9.8121(2) Å and a cell volume V = 749.45(2) Å 3Ca / La and Si / Al occupy the same crystallographic positions and were refined with mixed occupancy. Since Si and Al are not clearly distinguishable by X-ray diffraction, the Si / Al ratio is determined by the electroneutrality of the compound. This was taken into account during refinement via appropriate boundary conditions. From single-crystal structure refinement, the composition Ca 3+0.9La1.1Si3.9Al1.1N8:Ce was obtained. This composition could be confirmed by energy-dispersive X-ray analysis (EDX) within the limits of measurement accuracy for embodiment 1. The ratios of La and Ca as well as of Si and Al for two different crystals each from embodiments 1 and 2 of phosphor 1 with the molecular formula Ca 2-x La x Si 5-x Al x N8:Ce 3+are shown in Table 2. The ratios for crystals 1 and 2 of embodiment 1 and the ratios for crystal 2 of embodiment 2 were determined by energy-dispersive X-ray analysis; the ratios for crystal 1 of embodiment 2 were determined by X-ray diffraction analysis. The unit cell was confirmed for all crystals by single-crystal diffractometry. Table 2 shows that the phosphor 1 of embodiment 1 has a higher La than the phosphor 1 of embodiment 2. Table 2 L a / Ca Si / Al Crystal 1 of embodiment 1 - 1.6 2.6 ratio from energy-dispersive X-ray analysis 2024PF00113 April 25, 2025P2024.0113 WO N - 24 - Crystal 2 of embodiment 1- 1,6 2,6 Ratio from energy-dispersive X-ray analysis of crystal 2 of embodiment 2- 1,1 3,3Ratio from energy-dispersive X-ray analysis of crystal 1 of embodiment 2 - 1.2 3.5 Ratio from X-ray structure analysis Further crystallographic data of phosphor 1 with the molecular formula Ca 2-x La x Si 5-x Al x N8:Ce 3+The electron densities of crystal 1 of embodiment 2 are shown in Table 3. Table 3 lists the measured portion of the reciprocal space over the limits of the corresponding Miller indices (hkl). Δρmax and Δρmin indicate the deviations between the electron densities calculated from the model and those calculated from the measured reflections. The largest maxima are in the range of approximately 2 and approximately -1 electrons per ų, thus ensuring that no atom was overlooked. The two parameters R1 and wR2 are the refinement quality parameters. R1 describes the agreement between the structure factors observed from the reflections and the structure factors simulated from the determined structure model for all measured reflections. wR2 also describes this agreement, but with a slightly modified calculation basis based on squared structure factors. Obs / all refers to which reflections are included.All calculates these quality factors with all available reflexes. Obs calculates these quality factors only on the basis of those reflexes whose I / sigma ratio is large enough to assume that this reflex is actually measured meaningfully. 2024PF00113 April 25, 2025P2024,0113 WO N -. 25 - was. Furthermore, the goodness of fit (GooF) factor, which should be close to 1, is specified as a quality criterion for the agreement between the calculated and measured structure. Table 3 S ummenformel Ca 3+ 2-xLaxSi5-xAlxN8:CeCrystal system OrthorhombicSpace group Pbcn (No. 60)a / Å 13.3085(2)b / Å 5.73920(10)c / Å 9.8121(2)Cell volume / Å 3 749.45(2) T / K 296(2) Radiation Cu-Kα (λ = 1.542 Å) Measuring range 6.65 < θ < 71.99−16 ≤ h ≤ 16 −7 ≤ k ≤ 7 −12 ≤ l ≤ 12 Number of all reflections 22285 Independent reflections 739 Number of parameters 37Δρmax, Δρmin / eÅ −32.069 / −0.736 R1 (obs / all) 0.0370 / 0.0459wR2 (obs / all) 0.0889 / 0.0938GooF 1.116Table 4 shows the crystallographic position parameters of phosphor 1 with the molecular formula Ca 2-x La x Si 5-x Al x N8:Ce 3+ , which were determined using crystal 1 of embodiment 2. The Wyckoff position describes the symmetry of the point positions according to RWG Wyckoff. x, y, and z indicate the atomic positions. Uiso is the radius of the isotropic 2024PF00113 April 25, 2025P2024,0113 WO N - 26 - Displacement parameter of the respective atom. U ani is the radius of the anisotropic displacement parameter of the respective atom. Table 4 N ame Atom Wyckoff-x y Z BesetzUiso -typ Lage -ung *Uani L a01 La 8d 0,5651 0.7362 0.4209 0.5527 *0.010 1(4) 2 (9) 3(6) (13) 8(2) C a01 Ca 8d 0,5651 0.7362 0.4209 0.4473 *0.010 1(4) 2 (9) 3(6) (13) 8(2) p i02 Si 8d 0,2958 0.5071 0.3550 0.7789 0.0043 2(13) (3) 5(16) (5) (4) Si03 Si 8d 0.5 0.2988 0.25 0.77890.0048 (4) (5) (5) p i04 Si 8d 0,30340.2124 0.1133 0.7789 0.0067 8(13) (3) 5(16) (5) (4) A l02 Al 8d 0,2958 0.5071 0.3550 0.2211 0.0043 2(13) (3) 5(16) (5) (4) Al03 Al 8d 0.5 0.2988 0.25 0.22110.0048 (4) (5) (5) A l04 Al 8d 0,3034 0.2124 0.1133 0.2211 0.0067 8(13) (3) 5(16) (5) (4) N 005 N 8d 0,2569 0.7600 0.2766 1 0,0086 (4) (8) (5) (11) N 006 N 8d 0,2681 0.5150 0.5291 1 0,0085 (4) (9) (5) (11) N 007 N 8d 0,4239 0.4910 0.3411 1 0,0122 (4) (10) (6) (12) N 008 N 8d 0,4351 0.1500 0.1235 1 0,0116 (4) (10) (6) (12) The crystal structure of embodiment Ca 2-x La x Si 5-x Al x N8:Ce 3+ of phosphor 1 is shown in figures 22024PF00113 25 April 2025P2024,0113 WO N - 27 -and 3. FIG. 2 shows the crystal structure along the crystallographic a-axis. FIG. 3 shows the crystal structure along the crystallographic b-axis. The crystal structure of the exemplary embodiment Ca2-xLaxSi5-xAlxN8:Ce3+ of the phosphor 1 has Si- or Al-centered (Si,Al)N4 tetrahedra 2 spanned by N atoms 3. The (Si,Al)N4 tetrahedra 2 are linked on all sides via their vertices, thus forming a three-dimensional network. The (Si,Al)N4 tetrahedra 2 are arranged in layers parallel to the crystallographic bc plane of a unit cell. Within a layer, the (Si,Al)N4 tetrahedra 2 are arranged in chains in which an arrangement of the (Si,Al)N4 tetrahedra 2 in a zigzag pattern can be observed (FIG. 2). Each layer is therefore composed of condensed quadruple chains.In a top view of a layer, and thus along the crystallographic a-axis, a chain of forward-facing (Si,Al)N4 tetrahedra 2 alternates with a chain of backward-facing (Si,Al)N4 tetrahedra 2. Viewed along the crystallographic b-axis, the layers are recognizable as strands of corner-sharing (Si,Al)N4 tetrahedra 2 (FIG. 3). Adjacent layers are linked to each other via (Si,Al)N4 tetrahedra 2 that are not part of the layer. All (Si,Al)N4 tetrahedra 2 in a layer point in the same direction along the crystallographic c-axis. The orientation of the (Si,Al)N4 tetrahedra 2 within a layer shows for neighboring layers 2024PF00113 25 April 2025P2024,0113 WO N -. 28 -The (Si,Al)N4 tetrahedra are oriented in different directions along the crystallographic c-axis. In other words, each layer is rotated by 180° in the orientation of the (Si,Al)N4 tetrahedra relative to neighboring layers. Looking at the adjacent strands along the crystallographic b-axis, strands with upward-facing (Si,Al)N4 tetrahedra alternate with strands with downward-facing (Si,Al)N4 tetrahedra. The (Si,Al)N4 tetrahedra form spaces. These spaces contain Ca atoms 4 or La atoms 5. Figure 4 shows the crystal structure of a reference example with the molecular formula Ca2Si5N8 along the crystallographic b-axis. The reference example with the molecular formula Ca2Si5N8 is the high-temperature modification of the compound with the molecular formula Ca2Si5N8. The crystal structure of the comparative example with the molecular formula Ca₂Si₅N₈ has 6 SiN₄ tetrahedra and 4 Ca atoms. In comparison to the embodiment Ca 2-xLa x Si 5-x Al x N8:Ce 3+ In the phosphor 1, all SiN4 tetrahedra in each layer point in the same direction along the crystallographic c-axis. FIG. 5 shows an emission spectrum of crystal 1 of embodiment 2 of the phosphor 1 with the molecular formula Ca 2-x La x Si 5-x Al x N8:Ce 3+ The results after excitation with blue primary radiation with a wavelength of 448 nm are shown. The relative intensity I / I is plotted. max versus wavelength λ in nm. The emission spectrum shows emission in the yellow wavelength range with a dominant wavelength λ. dom of 568 nm. The emission band has a spectral full width at half maximum (FWHM) of 137 nm around the spectral maximum at 551 nm. The color coordinate of the 2024PF00113 25 April 2025P2024,0113 WO N - 29 -The electromagnetic radiation emitted by the phosphor has a CIE x value of 0.414 and a CIE y value of 0.530. The spectral data of crystal 1 of embodiment 2 of phosphor 1 with the molecular formula Ca 2-x La x Si 5-x Al x N8:Ce 3+ are summarized in Table 5. Table 5 Excitation at 448 nm Dominance wavelength λ dom 568 nm peak wavelength λ max 551 nm FWHM 137 nm C IE-x 0,414CIE-y 0.530FIG. 6 shows a schematic sectional view of an optoelectronic device 10 according to an exemplary embodiment. The optoelectronic device 10 comprises a semiconductor chip 11 with an active layer sequence and an active region (not explicitly shown here) which emits primary radiation during operation of the optoelectronic device 10. The primary radiation is electromagnetic radiation of a first wavelength range. Preferably, the primary radiation is electromagnetic radiation with wavelengths in the ultraviolet and / or visible range, for example, in the blue range. For example, the semiconductor chip 11 is a semiconductor diode chip that emits primary radiation with wavelengths from 400 nm inclusive to 500 nm inclusive. Alternatively, the semiconductor chip 11 can be a laser diode chip that, for example, emits primary radiation with a wavelength of 2024PF00113 25.April 2025P2024,0113 WO N -. 30 -448 nm. The primary radiation is emitted through the radiation exit surface 12. The optoelectronic component 10 further comprises a conversion element 13, which is configured to absorb the primary radiation and convert it, at least partially, into secondary radiation. The secondary radiation has a wavelength range with longer wavelengths than the primary radiation. For example, the conversion element 13 converts the primary radiation into secondary radiation in the yellow wavelength range. The conversion element 13 is positioned in the beam path of the primary radiation from the semiconductor chip 11 such that at least a portion of the primary radiation strikes the conversion element 13. For this purpose, the conversion element 13 can be placed in direct contact with the semiconductor chip 11, in particular the radiation exit surface 12, or it can be positioned at a distance from the semiconductor chip 11.The conversion element 13 comprises a phosphor 1 with the molecular formula EA2-xSExSi5-xAlxN8:RE. In particular, the conversion element 13 can convert the phosphor 1 with the formula Ca. 2-x La x Si 5-x Al x N8:Ce 3+ exhibit. The phosphor 1 can be embedded in a matrix material. Alternatively, the conversion element 13 can be free of a matrix material. In this case, the conversion element 13 can consist of the phosphor 1, for example, of a ceramic of the phosphor 1. 2024PF00113 April 25, 2025P2024,0113 WO N - 31 -The conversion element 13 can be free of any additional phosphor. In this case, the optoelectronic component 10 produces yellow light. Alternatively, the conversion element 13 can have at least one additional phosphor that converts the primary radiation into electromagnetic radiation of a third wavelength range, which is at least partially different from the first and second wavelength ranges. For example, the third wavelength range includes wavelengths in the red spectral region. The additional phosphor can be a nitride phosphor such as (Sr,Ca)AlSiN3:Eu. The optoelectronic component 10 can then, for example, emit white light. In particular, the optoelectronic component 10 can emit warm white light. For this purpose, the phosphor described here with the formula Ca 2-x La x Si 5-x Al x N8:Ce 3+with the red-emitting phosphor (Sr,Ca)AlSiN3:Eukoucombined and excited by means of a blue semiconductor chip 11, which emits a primary radiation of 448 nm. A simulated spectrum of this embodiment is shown in FIG. 7. FIG. 7 shows the relative intensity I / I max as a function of the wavelength λ in nm. The simulated spectrum of the optoelectronic device 10 according to the exemplary embodiment has a color temperature CCT of approximately 4000 K, in particular 4002 K, and a color rendering index CRI of 85. FIG. 8 shows a simulated white light spectrum of an optoelectronic device according to a comparative example. FIG. 8 shows the relative intensity I / I max 2024PF00113 April 25, 2025P2024,0113 WHERE N - 32 - as a function of wavelength λ in nm. The yellow-emitting phosphor YAG:Ce was used in this analysis. 3+combined with the red-emitting phosphor (Sr,Ca)AlSiN3:Eu and excited by means of a blue semiconductor chip 11, which emits primary radiation at 448 nm. The simulated spectrum of the optoelectronic device according to the comparison example has a color temperature CCT of approximately 4000 K, in particular 4002 K, and a color rendering index CRI of 68. The optoelectronic device described here with the phosphor Ca described here 2-x La x Si 5-x Al x N8:Ce 3+ achieves a higher CRI of 85 compared to a CRI of 68 for the optoelectronic component of the comparison example with the phosphor YAG:Ce 3+ Table 6 lists important characteristic values ​​of the optoelectronic component according to the exemplary embodiment and the comparative example. Table 6 Exemplary embodiment Comparative example Phosphors Ca 3+2-xLaxSi5-xAlxN8:Ce +YAG:Ce 3+ + (Sr,Ca)AlSiN3:Eu 2+ (Sr,Ca)AlSiN3:Eu2+ C CT 4002 K 4002 K CRI 85 68 The features and embodiments described in connection with the figures can be combined with one another according to further embodiments, even if not all combinations are explicitly described. Furthermore, the embodiments described in connection with the figures can be used alternatively or additionally. 2024PF00113 25 April 2025P2024,0113 WO N - 33 -further features as described in the general part. This patent application claims priority from German patent application 102024 113 715.0, the disclosure of which is hereby incorporated by reference. The invention is not limited to the exemplary embodiments described therein. Rather, the invention encompasses every new feature and every combination of features, which in particular includes every combination of features in the claims, even if that feature or combination itself is not explicitly stated in the claims or exemplary embodiments.

[0002] 2024PF00113 April 25, 2025P2024,0113 WHERE N - 34 - Reference symbol list 1 Fluorescent material 2 (Si,Al)N4 tetrahedron 3 N-Atom 4 Ca-Atom 5 La-Atom 6 SiN4 tetrahedron 10 optoelectronic component 11 semiconductor chip 12 radiation emission surface 13 conversion element

Claims

2024PF00113 25. April 2025P2024,0113 WO N - 35 -Claims 1. Phosphor (1) with the molecular formula EA2-xSExSi5-xAlxN8:RE, wherein - EA is an element or a combination of elements selected from the group of divalent elements, - SE is an element or a combination of elements selected from the group of rare earth elements, - RE is an activator element, - 0 ≤ x ≤ 2, and - the phosphor crystallizes in the space group Pbcn.

2. Phosphor (1) according to the preceding claim, wherein EA comprises Mg, Ca, Sr, Ba or combinations thereof, and / or wherein SE comprises La, Y or combinations thereof, and / or wherein RE comprises Ce.

3. Phosphor (1) according to at least one of the preceding claims, wherein the phosphor (1) has a host lattice (2) with an orthorhombic space group.

4. Phosphor (1) according to at least one of the preceding claims, wherein a crystal structure of the host lattice of the phosphor (1) comprises (Si,Al)N4 tetrahedra (2) that are corner-sharing on all sides. 5.Phosphor (1) according to the preceding claim, wherein the (Si,Al)N4 tetrahedra form layers within a plane of a unit cell, wherein adjacent layers are linked to each other via at least one (Si,Al)N4 tetrahedron that is not part of the layers. 2024PF00113 25 April 2025P2024,0113 WO N -. 36 -6. Phosphor (1) according to the preceding claim, wherein each layer is rotated by 180° in the orientation of the (Si,Al)N4 tetrahedra relative to adjacent layers.

7. Phosphor (1) according to at least one of claims 5 or 6, wherein the (Si,Al)N4 tetrahedra within a layer are arranged in interconnected chains, the chains within a layer running in a zigzag pattern, and wherein the orientation of the (Si,Al)N4 tetrahedra differs from that of adjacent chains.

8. Phosphor (1) according to at least one of claims 4 to 7, wherein the (Si,Al)N4 tetrahedra form interstices, at least one interstice containing an EA atom or an SE atom.

9. Phosphor (1) according to at least one of the preceding claims, wherein an excitation wavelength of the phosphor (1) is in the range between 350 nm and 500 nm inclusive. 10.Phosphor (1) according to at least one of the preceding claims, wherein a dominant wavelength of electromagnetic radiation emitted by the phosphor (1) is in the range between and including 540 nm and inclusive 600 nm.

11. Phosphor (1) according to at least one of the preceding claims, wherein an emission spectrum of electromagnetic radiation emitted by the phosphor (1) has an emission peak with an emission maximum which 2024PF00113 25 April 2025P2024,0113 WO N -. 37 - in the range between and including 500 nm and 600 nm.

12. Phosphor (1) according to at least one of the preceding claims, wherein a half-width of an emission maximum of the phosphor (1) is in the range between and including 120 nm and 155 nm.

13. Phosphor (1) according to at least one of the preceding claims, wherein the phosphor (1) has the molecular formula Ca 2-x La x Si 5-x Al x N8:Ce3+ 14. A method for producing a phosphor (1) having the molecular formula EA2-xSExSi5-xAlxN8:RE, wherein - EA is an element or a combination of elements selected from the group of divalent elements, - SE is an element or a combination of elements selected from the group of rare earth elements, - RE is an activator element, - 0 ≤ x ≤ 2, and - the phosphor crystallizes in the space group Pbcn, comprising the steps of - providing reactants, - mixing the reactants to form a reactant mixture, and - heating the reactant mixture.

15. A method according to the preceding claim, wherein the reactant mixture is heated to a temperature between 1600 °C and 2000 °C inclusive.

16. Optoelectronic component (10) comprising 2024PF00113 25 April 2025P2024,0113 WO N - 38 -- a semiconductor chip (20) which, in operation, emits electromagnetic radiation of a first wavelength range, and - a conversion element (30) comprising the phosphor (1) according to any one of claims 1 to 13, wherein the phosphor (1) converts the 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.

17. Optoelectronic component (10) according to the preceding claim, wherein the conversion element (30) comprises at least one further phosphor which converts electromagnetic radiation of the first wavelength range into electromagnetic radiation of a third wavelength range which is at least partially different from the first and second wavelength ranges. 18.Optoelectronic component (10) according to the preceding claim, wherein the optoelectronic component has a color rendering index (CRI) of at least 80.

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