LIGHT-CONVERTING MATERIAL

Description

Subject of the invention

[0001] The present invention relates to a light-converting material containing a luminescent material with semiconductor nanoparticles (quantum materials), wherein the semiconductor nanoparticles are located on the surface of the luminescent material and the emission of the semiconductor nanoparticles lies in the emission range of the luminescent material. Furthermore, the invention relates to a method for producing the light-converting material and its use as a conversion material in a light source for partially or completely converting light from a primary light source. The luminescent material can be a downconverter or an upconverter. In the case of a downconverter, the light from the primary light source is shorter-wavelength and more energetic than the emitted light; for example, ultraviolet and / or blue light can be converted into light with a longer wavelength.In the case of an upconverter, the light from the primary light source has a longer wavelength and lower energy than the emitted light; for example, several infrared photons can be converted into a single photon with a shorter wavelength. The present invention further relates to a light-converting mixture, a light source, a method for producing the light source, and a lighting unit containing the light-converting material according to the invention. Background of the invention

[0002] Around 20% of domestic energy consumption is used to generate light. Conventional incandescent bulbs are inefficient, and the most efficient fluorescent lamps contain up to 10 mg of mercury. Solid-state lighting devices, such as light-emitting diodes (LEDs), are a promising alternative because they offer better efficiency in converting electrical energy into light (energy efficiency), a longer service life, and greater mechanical stability than conventional light sources. LEDs can be used in a wide range of applications, including displays, automotive and sign lighting, and residential and street lighting. Depending on the inorganic semiconductor compound used to manufacture them, an LED can emit monochromatic light in different regions of the spectrum.However, "white" light, which is required by a very large portion of the lighting industry, cannot be produced with a conventional LED. Current solutions for generating white light involve either using three or more LEDs of different colors (e.g., red, green, and blue, or "RGB") or using a color-conversion layer made of a conventional phosphor material (e.g., YAG:Ce) to generate white light from an LED's ultraviolet (UV) or blue emission. This converts blue light to light with a longer wavelength, and the combination of blue and yellow light is perceived by the human eye as white light. However, such white light is almost always sub-ideal and, in many cases, has undesirable or unpleasant properties that may require improvement or correction. The simpler design of conversion LEDs is aimed at the mass market for lighting equipment.Currently, these LED lamps are still significantly more expensive than conventional incandescent bulbs, and most fluorescent lamps and commercially available white LEDs emit a bluish, cool-white light with poor color rendering properties. This perceived poor quality of white light stems from the yellow conversion phosphor material YAG:Ce, which lacks emission in the green and red parts of the spectrum.

[0003] For displays, it is important to have three or more primary colors with a narrow spectral full width at half maximum (FWHM), which can be achieved with LEDs (typical FWHM < 30 nm). This allows a wide color space to be covered. "Color space" is usually defined as the range of chromaticities obtainable by mixing three colors. However, the solution of using three or more differently colored LEDs is too costly and complex for many applications. It is therefore desirable to have a light source that enables a wide color space coverage with a single LED, which can be achieved using narrowband-emitting conversion materials. One method for providing LEDs for a broad-spectrum light source uses phosphors that convert the short-wavelength LED light into light with a longer wavelength.For example, a phosphor that emits light over a wide range of green wavelengths can be excited with blue light from an LED that produces a narrow blue spectrum. The green light generated by the phosphor is then used as a component of the white light source. By combining multiple phosphors, one can, in principle, create a broad-spectrum white light source, provided the light conversion efficiencies of the phosphors are sufficiently high. This would lead to improved color rendering properties. Further details can be found in "Status and prospects for phosphor-based white LED packaging," Z. Liu et al., Xiaobing Front. Optoelectron. China 2009, 2(2): 119-140.

[0004] Unfortunately, lighting designers don't have a random set of phosphors to choose from. There are only a limited number of conventional phosphors that can be used in LEDs. These phosphors contain rare earth elements and offer sufficient light conversion efficiencies. The emission spectrum of these phosphors cannot be easily modified. Furthermore, the spectra are less than ideal because the light emitted is not constant as a function of wavelength. Therefore, even combining several phosphors does not produce an optimal white light source. In addition, currently used red phosphors emit light deep into the long-wavelength red spectral range, which further reduces the brightness of such LEDs and thus their efficiency.

[0005] US patents US 7,102,152 B2, US 7,495,383 B2, and US 7,318,651 B2, as well as US patent application US 2013 / 0341590 A1, disclose devices and methods for emitting light, using both semiconductor nanoparticles in the form of quantum dots (QDs) and non-quantum fluorescent materials to convert at least a portion of the original light emitted by a light source of the device into light with a longer wavelength. QDs possess a high quantum efficiency and a narrow emission spectrum with a central emission wavelength that can be tuned by their size.

[0006] WO 2017 / 004145 A1 describes stabilized QD structures suitable for use in LEDs. A combination of both QDs and conventional phosphors can improve light quality. QD additives can bring improvements, but have the disadvantage of high self-absorption, meaning they absorb light emitted when they themselves are excited. This reduces the overall energy efficiency of the light conversion. Furthermore, QDs and commercially available red emitters also reabsorb the green phosphor emission, which leads to a decrease in energy efficiency and, furthermore, to a shift in the emission spectrum, making targeted color planning more difficult. Furthermore, the use of QD materials and phosphors can lead to segregation during LED production, which no longer ensures a homogeneous distribution of the light-converting materials.The result is reduced energy efficiency and insufficient control of the desired color reproduction.

[0007] In some applications, clusters of densely packed QDs are desirable. Such densely packed QD clusters exhibit a phenomenon known as fluorescence resonance energy transfer (FRET), see, for example, Joseph R. Lakowicz, "Principles of Fluorescence Spectroscopy," 2nd ed., Kluwer Academic / Plenum Publishers, New York, 1999, pp. 367–443. FRET occurs between a donor QD emitting at a shorter (e.g., bluer) wavelength and an acceptor QD located in close proximity and emitting at a longer wavelength. A dipole-dipole interaction occurs between the dipole moment of the donor emission transition and the dipole moment of the acceptor absorption transition. The efficiency of the FRET process depends on the spectral overlap between the donor absorption and the acceptor emission. The FRET distance between quantum dots is typically 10 nm or less.The efficiency of the FRET effect is highly dependent on the distance. FRET leads to a color change (red shift) and a loss of efficiency in light conversion. For this reason, previous work has sought to avoid clustering of QDs in light-converting materials.

[0008] Semiconductor nanoparticles are a class of nanomaterials whose physical properties can be tuned over a wide range by adjusting the particle size, composition, and shape. Fluorescence emission, in particular, is one of the particle-size-dependent properties of this class. The tunability of fluorescence emission is based on the quantum confinement effect, according to which a reduction in particle size leads to a "particle in a box" behavior, resulting in a blue shift in the band gap energy and thus in light emission. For example, the emission of CdSe nanoparticles can be tuned from 660 nm for particles with a diameter of -6.5 nm to 500 nm for particles with a diameter of ~2 nm.Similar behavior can be achieved for other semiconductor nanoparticles, resulting in a broad spectral range covering the ultraviolet (UV) range (using, for example, ZnSe or CdS) through the visible (VIS) range (using, for example, CdSe or InP) to the near infrared (NIR) range (using, for example, InAs). A change in the shape of the nanoparticles has already been demonstrated for several semiconductor systems, with the rod shape being particularly important. Nanorods have properties that differ from those of spherical nanoparticles. For example, they exhibit emission that is polarized along the long axis of the rod, whereas spherical nanoparticles exhibit unpolarized emission.Another attractive property of colloidal semiconductor nanoparticles is their chemical accessibility, which allows these materials to be processed in a variety of ways. The semiconductor nanoparticles can be applied from solution by spin coating or spray coating in the form of thin layers, or they can be embedded in plastics. Jan Ziegler et al. describe in "Silica-Coated InP / ZnS Nanocrystals as Converter Material in White LEDs," Advanced Materials, Vol. 20, No. 21, October 13, 2008, pages 4068-4073, the fabrication of white LEDs with the addition of a silicone composite layer containing a light-emitting conversion material on a high-performance blue LED chip.

[0009] The use of semiconductor nanoparticles in LED applications was described, among other things, in US 2015 / 0014728 A1, which concerns a phosphor-matrix composite powder that can be used in an LED. The phosphor-matrix composite powder contains a matrix and several phosphors or quantum dots with a size of 100 nm or less dispersed in the matrix, with the composite powder having a size of 20 µm or more and a specific surface roughness. The described composite powder requires precise adjustment of the proportions of the phosphors and quantum dots during its production in order to achieve the desired emission behavior. Subsequent adjustment of the proportions is not possible, which leads to limited flexibility in the applicability of the composite powder in the production of LEDs.Furthermore, the energy conversion efficiency depends heavily on the type and quantity of phosphor materials dispersed in the matrix. In particular, when the quantity of phosphors and / or quantum dots is high, sintering the material becomes difficult. Furthermore, porosity increases, making efficient irradiation with excitation light difficult and compromising the mechanical strength of the material. However, if the quantity of phosphor materials dispersed in the matrix is ​​too small, achieving sufficient light conversion becomes difficult.

[0010] Given the numerous deficiencies of the known light conversion materials mentioned above, including the known combinations of QDs with conventional phosphors (conversion phosphors), there is a need for semiconductor nanoparticle materials and compositions containing such materials with conventional phosphors that do not exhibit such deficiencies. In particular, there is a need for conversion materials with low to negligible reabsorption and low self-absorption, leading to higher light conversion efficiency and improved color space controllability.

[0011] It would therefore be desirable to have light-converting materials based on semiconductor nanoparticles that are characterized by low reabsorption and self-absorption, thus increasing the energy efficiency of an LED. Furthermore, it would be desirable to have light-converting materials based on semiconductor nanoparticles that are characterized by improved miscibility with conventional phosphors, thus avoiding the disadvantages described above (e.g., reduced energy efficiency and inadequate control of color rendering) that arise due to demixing effects during LED manufacturing.

[0012] The use of quantum materials without additional excitation, as envisioned in the present invention, requires a high material input to achieve the desired emission spectrum. This leads to negative effects, such as the previously described FRET, as well as increased efficiency losses due to scattering and reflection of light by the particles in the silicone. Furthermore, due to the toxicity of using Cd-containing semiconductor nanoparticles, reducing the loading is important.

[0013] The article by Ziegler, J. et al.: "Silica-Coated InP / ZnS Nanocrystals as Converter Material in White LEDs" in Advanced Materials, Wiley-VCH Germany, Volume 20, No. 21, 2008, pages 4068 to 4073, presents a solution for correcting the emission spectrum of the phosphor YAG:Ce by adding red-emitting InP-based nanocrystals and a green-emitting conversion phosphor Sr 0.94 Al 2 O 4 :Eu 0.06 . Fig. 1B of this article shows a spectrum with a maximum at 605 nm resulting from the emission of the red-emitting nanocrystals and with a maximum at 545 nm resulting from the emission of the green-emitting conversion phosphor Sr 0.94 Al 2 O 4 :Eu 0.06 . The maximum at 545 nm results from the superposition of a green emission at about 520 nm and a yellow emission of the YAG / Ce converter at 565 nm.

[0014] US 2005 / 0135079 A1 shows a flash module comprising a light source that emits primary light. A first wavelength-converting cover layer on the light source serves to provide a first light color. The first wavelength-converting cover layer contains a plurality of quantum dots dispersed in a matrix material. In one embodiment, a second wavelength-converting cover layer is formed from conventional phosphor material dispersed in a matrix. The second wavelength-converting cover layer comprises wavelength-converting materials that emit a second radiation that is not strongly absorbed by the quantum dots in the wavelength-converting coating.The second wavelength-converting capping layer slightly charges the light source to allow primary light to pass through the second wavelength-converting capping layer to excite the quantum dots in the first wavelength-converting capping layer. Object of the invention

[0015] The object of the present invention is therefore to provide a light-converting material based on semiconductor nanoparticles that does not have the above-described disadvantages of the prior art. In particular, it is an object of the present invention to provide a light-converting material based on semiconductor nanoparticles that has improved miscibility with conventional phosphors and thus enables more efficient production of LEDs, since losses due to demixing effects during mixing are avoided. A further object of the present invention is to provide a light-converting material based on semiconductor nanoparticles that enables increased LED efficiency and significantly reduced material consumption in the LED.Furthermore, it is an object of the present invention to provide a light-converting material based on semiconductor nanoparticles that is characterized by easy processability in the production of LEDs and enables LED manufacturers to use existing equipment and machinery for the production of LEDs. Furthermore, the present invention aims to provide a light-converting material based on semiconductor nanoparticles that enables improved and more targeted adjustment of LED emission compared to conventional semiconductor nanoparticles used in films, thus allowing for more flexible use.A further object of the present invention is to provide a light-converting material based on semiconductor nanoparticles that enables increased LED brightness and is also characterized by narrowband emission, thereby avoiding energy losses in the long-wave spectral range and enabling improved color space coverage in displays. When used in films, the aim of the present invention is to reduce material consumption and thus enable better efficiency. Furthermore, the light-converting material according to the invention should be capable of being coated using known coating methods used in the production of phosphors for applying barrier layers, wherein such an additional barrier layer is not absolutely necessary for the light-converting material. Description of the invention

[0016] Surprisingly, it has been found that the above-described objects are achieved by a light-converting material comprising a luminescent material and at least one type of semiconductor nanoparticles located on the surface of the luminescent material. The luminescent material and the at least one type of semiconductor nanoparticles must be selected such that the emission of the semiconductor nanoparticles lies within the emission range of the luminescent material. This means that both the semiconductor nanoparticles and the luminescent material emit light of a similar wavelength.

[0017] For example, the semiconductor nanoparticles and the luminescent material can both emit in the violet, blue, cyan, green, yellow, orange, or red spectral range. It is also possible for the semiconductor nanoparticles and the luminescent material to emit in adjacent spectral ranges of different colors, such as the violet and blue, blue and cyan, cyan and green, green and yellow, yellow and orange, or orange and red spectral range.

[0018] Furthermore, it was surprisingly found that the reabsorption of the emission from luminescent materials, which normally leads to losses, in this case leads to an increase in efficiency and enables significantly lower material consumption, while retaining the advantages of the narrowband emission of the semiconductor nanoparticles. This allows for more efficient use of the light-converting material as well as improved miscibility of the light-converting material with conventional phosphors, thus enabling more economical production of efficient LEDs characterized by improved performance characteristics such as energy efficiency, brightness, and stability.

[0019] Thus, the above-mentioned tasks are achieved by a light-converting material comprising a luminescent material and semiconductor nanoparticles. The semiconductor nanoparticles are located on the surface of the luminescent material, and the emission of the semiconductor nanoparticles lies in the emission range of the luminescent material. Ideally, the luminescent material exhibits high absorption in the wavelength range of the primary light source and efficient emission near the absorption of the semiconductor nanoparticle. A portion of the photons emitted by the luminescent material is used to further excite the emission of the semiconductor nanoparticle.

[0020] The inventors have discovered that semiconductor nanoparticles exhibit improved physical properties when located on the surface of luminescent materials, making them more suitable for combination with conventional phosphors or as phosphor replacements in lighting applications. In particular, the inventors have found that the use of the inventive light-converting material in light sources results in reduced self-absorption effects of the semiconductor nanoparticles at high absorption of the primary light source, enabling controlled color adjustment and high efficiency. Furthermore, the inventive light-converting material suppresses fluorescence resonance energy transfer (FRET) and its associated undesirable consequences.Semiconductor nanoparticles typically exhibit very high photoluminescence intrinsic absorption and low absorption in the desired blue or ultraviolet spectral range and therefore must be used in high concentrations. A light-converting material of the present invention is thus characterized by high reabsorption of the efficient emission of the luminescent material and reduced intrinsic absorption.

[0021] Furthermore, a method for producing the light-converting material according to the invention is provided, which comprises the following steps: (A) providing a luminescent material suspension in a solvent; and (B) adding a semiconductor nanoparticle suspension in a solvent.

[0022] The present invention further provides a light-converting mixture comprising one or more of the light-converting materials of the invention.

[0023] The light-converting material according to the invention and the light-converting mixture according to the invention enable the partial or complete conversion of ultraviolet and / or blue light into light with a longer wavelength, such as green or red light.

[0024] Furthermore, the present invention provides a light source which contains at least one primary light source and at least one light-converting material according to the invention or at least one light-converting mixture according to the invention.

[0025] The light source of the present invention can be used in a lighting unit.

[0026] The present invention further provides a method for producing the light source according to the invention, wherein the light-converting material according to the invention or the light-converting mixture according to the invention is applied as a film by spin coating, spray coating or in the form of a film as a laminate to the primary light source or a carrier material.

[0027] Preferred embodiments of the invention are described in the dependent claims. Description of the characters

[0028] Figure 1 : Relative spectral energy distribution of the emission of the prepared light-converting materials from Examples 1 and 2 as well as the luminescent starting material. Figure 2 : Relative spectral energy distribution of the emission of the prepared light-converting materials from Examples 3 and 4 as well as the luminescent starting materials. Figure 3 :Relative spectral energy distribution of the emission of the prepared light-converting materials from Examples 5 to 8 as well as a luminescent starting material and a light-converting material consisting of semiconductor nanoparticles and unactivated orthosilicate, which was prepared in an analogous manner to Example 6. Figure 4 : Relative spectral energy distribution of the emission of the prepared light-converting materials from Examples 10 and 11 and of the luminescent starting material. Figure 5 : Relative spectral energy distribution of the emission (normalized to the maximum of all samples) of the prepared light-converting material from Example 6 as well as of the luminescent starting material and a light-converting material consisting of semiconductor nanoparticles and unactivated orthosilicate, which was prepared in an analogous manner. Figure 6 :Emission spectra of the LEDs prepared from the light-converting materials of Examples 10 and 11 with a blue LED (λ max = 450 nm). Figure 7 :Emission spectrum of the LED produced from the light-converting material from Example 9 and a blue LED (λ max = 450 nm) (solid line), and emission spectrum of an LED produced from a similarly synthesized light-converting material on unactivated orthosilicate and a blue LED (λ max = 450 nm) (dotted line). For both LEDs, the proportion of light-converting material in the silicone was 12 wt.%. Additionally, an LED based on light-converting material on unactivated orthosilicate was produced at the same color coordinate as the LED with the light-converting material from Example 9 (dashed line), resulting in an increase in the concentration of the light-converting material in the silicone from 12% to 20% (+67%). All spectra are normalized to the highest maximum. Figure 8 :Emission spectra of the LEDs fabricated from the light-converting material from Example 12 and a violet LED (λ max = 410 nm), as well as the light-converting material from Example 13 and a blue LED (λ max = 450 nm). This illustrates that no additional energy transfer occurs when the substrate emission is shorter than 50 nm or longer than 50 nm than the semiconductor nanoparticle emission. Figure 9 : Absorption and emission spectrum of the diluted toluene suspension of the semiconductor nanoparticles used in Example 5 and a silicate with a peak emission at 520 nm. The core exciton absorption band has a maximum at 515 nm, and the emission maximum is at 525 nm. Figure 10 :Absorption spectrum of the diluted toluene suspension of the semiconductor nanoparticles used in Example 5 and modeled core exciton absorption band and emission spectrum of a silicate with a peak emission at 520 nm. The core exciton absorption band has a maximum at 515 nm and the emission maximum is at 525 nm. Definitions

[0029] As used in the present application, the term "light-converting material" refers to a combination of a luminescent material and at least one type of semiconductor nanoparticles, wherein the semiconductor nanoparticles are located on the surface of the luminescent material, and the emission of the semiconductor nanoparticles lies in the emission range of the luminescent material. In addition to the at least one type of semiconductor nanoparticles, the light-converting material may comprise other types of semiconductor nanoparticles whose emission does not necessarily lie in the emission range of the luminescent material. The other types of semiconductor nanoparticles are preferably also located on the surface of the luminescent material.

[0030] As used in the present application, the term "luminescent material" or "luminescent material" refers to a material in particulate form that can convert light of a first wavelength into light of a second wavelength. The luminescent material is in the form of macroscopic particles that are not nanoparticles. Preferably, the luminescent material is crystalline. The luminescent material can be an upconverter that converts light of a first wavelength into light of a second wavelength, where the light of the second wavelength is shorter in wavelength than the light of the first wavelength, or a downconverter that converts light of a first wavelength into light of a second wavelength, where the light of the second wavelength is longer in wavelength than the light of the first wavelength. Typically, downconverter materials emit longer-wavelength (e.g.,green or red) light. In a preferred embodiment, the luminescent material is a downconverter. The luminescent material should exhibit good absorption of the light from the primary light source.

[0031] Possible luminescent materials are phosphors or conversion phosphors containing an inorganic matrix and at least one activator, i.e., a light-converting center. Furthermore, the luminescent material can have a specific intrinsic absorption in the visible range and is thus colored or colorless. In a preferred embodiment, the luminescent material, as used in the present invention, is transparent. In the present invention, the luminescent material serves as a carrier material for the semiconductor nanoparticles and, in addition to the primary light source, as an additional excitation for the emission of the semiconductor nanoparticles.Due to the transparency of the luminescent material, light emitted by a primary light source, the material itself, another phosphor, or another light-converting material can pass through the material unhindered and without loss, thereby increasing the efficiency of the application of the light-converting material according to the invention in an LED. In the case of an opaque luminescent material, it should at least have a high reflectivity.

[0032] As used in this application, the terms "phosphor", "conversion phosphor" or "phosphor", used synonymously herein, refer to a particulate fluorescent inorganic material having one or more emitting centers. The emitting centers are created by activators, usually atoms or ions of a rare earth metal element such as La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, and / or atoms or ions of a transition metal element such as Cr, Mn, Fe, Co, Ni, Cu, Ag, Au and Zn, and / or atoms or ions of a main group metal element such as Na, Ti, Sn, Pb, Sb and Bi. Examples of phosphors or conversion phosphors include aluminate-based phosphors such as garnets, silicate-based phosphors, orthosilicate-based phosphors, phosphate-based phosphors, thiogallate-based phosphors, sulfide-based phosphors and nitride-based phosphors.Phosphor materials within the meaning of the present invention exhibit no quantum confinement effects whatsoever. Such non-quantum confined phosphor materials can be phosphor particles with or without a silicon dioxide coating. A phosphor or conversion phosphor within the meaning of the present application is understood to be a material that absorbs radiation in a specific wavelength range of the electromagnetic spectrum, preferably in the blue or UV spectral range, and emits light in another wavelength range of the electromagnetic spectrum, preferably in the violet, blue, green, yellow, orange, or red spectral range. The term "radiation-induced emission efficiency" is also to be understood in this context; that is, the conversion phosphor absorbs radiation in a specific wavelength range and emits radiation in another wavelength range with a specific efficiency.The term "shift in emission wavelength" means that a conversion phosphor emits light at a different wavelength than another or similar conversion phosphor, i.e. shifted to a smaller or larger wavelength.

[0033] The term "semiconductor nanoparticle" (quantum material) refers in the present application to a nanoparticle composed of a semiconductor material. Semiconductor nanoparticles are any discrete units with at least one submicrometer dimension, which in some embodiments is less than 100 nm and in some other embodiments has a largest dimension (length) of less than one micrometer. In some other embodiments, the dimension is less than 400 nm. The semiconductor nanoparticle can have any symmetric or asymmetric geometric shape, and non-limiting examples of possible shapes include elongated, round, elliptical, pyramidal, etc. A specific example of a semiconductor nanoparticle is an elongated nanoparticle, also referred to as a nanorod or nanobar, made of a semiconducting material.Other semiconductor nanorods that can be used are those with a metal or metal alloy region on one or both ends of the respective nanorod. Examples of such elongated semiconductor-metal nanoparticles and their preparation are described in WO 2005075339, the disclosure of which is hereby incorporated by reference. Other possible semiconductor-metal nanoparticles are shown in WO 2006134599, the disclosure of which is hereby incorporated by reference.

[0034] Furthermore, semiconductor nanoparticles in a core-shell or core-multishell configuration are known. These are discrete semiconductor nanoparticles characterized by a heterostructure in which a "core" of one type of material is covered by a "shell" of another material. In some cases, the shell is grown on the core, which serves as a "seed." The core-shell nanoparticle is then also referred to as a "seeded" nanoparticle. The term "seed" or "core" refers to the innermost semiconductor material contained in the heterostructure. Known semiconductor nanoparticles in a core-shell configuration are shown, for example, in EP 2 528 989 B1.

[0035] For example, dot-shaped semiconductor nanoparticles are known in which a spherical shell is arranged symmetrically around a spherical core (so-called quantum dots within quantum dots). Furthermore, rod-shaped semiconductor nanoparticles are known in which a spherical core is arranged asymmetrically within an elongated rod-shaped shell (so-called quantum dots within quantum rods). The term nanorod refers to a nanocrystal with a rod-like shape, i.e., a nanocrystal formed by enhanced growth along a first ("longitudinal") axis of the crystal, while the dimensions along the other two axes are kept very small. A nanorod has a very small diameter (typically less than 10 nm) and a length that can range from about 6 nm to about 500 nm. Typically, the core has a nearly spherical shape.However, cores with different shapes, such as pseudopyramids, cube-octahedra, rods, and others, can also be used. Typical core diameters range from about 1 nm to about 20 nm. For symmetric point-like semiconductor nanoparticles in a core-shell configuration (quantum dots within quantum dots), the total particle diameter d 2 is typically much larger than the core diameter d 1 . The magnitude of d 2 relative to d 1 influences the optical absorption of the symmetric point-like semiconductor nanoparticle in a core-shell configuration.

[0036] As is known, a semiconductor nanoparticle in a core-shell configuration can comprise additional outer shells that can provide better optical and chemical properties, such as a higher quantum yield (QY) and improved durability. The semiconductor nanoparticle then exhibits a core-multishell configuration. For a rod-shaped semiconductor nanoparticle in a core-multishell configuration, the length of the first shell can generally range between 10 nm and 200 nm, and in particular between 15 nm and 160 nm. The thicknesses of the first shell in the other two dimensions (radial axis of the rod shape) can range between 1 nm and 10 nm. The thicknesses of the additional shells can generally range between 0.3 nm and 20 nm, and in particular between 0.5 nm and 10 nm.

[0037] Other embodiments include nanotetrapods (as described in US Pat. No. 8,062,421 B2), which comprise a core made of a first material and at least one arm, but typically four additional arms, made of a second material, wherein the core and the arms differ in their crystal structure. Such nanotetrapods exhibit a large Stokes shift.

[0038] The term "core material" refers to the material that forms the core of semiconductor nanoparticles in a core-shell or core-multishell configuration. The material can be a Group II-VI, III-V, IV-VI, or I-III-VI semiconductor, or any combination of one or more of these. For example, the core material can be selected from the group consisting of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, GaAs, GaP, GaAs, GaSb, GaN, HgS, HgSe, HgTe, InAs, InP, InSb, AlAs, AlP, AlSb, Cu2S, Cu2Se, CuGaS2, CuGaSe2, CuInS2, CuInSe2, Cu2(InGa)S4, AgInS2, AgInSe2, Cu2(ZnSn)S4, alloys thereof and mixtures thereof.

[0039] The term "shell material" refers to the semiconductor material from which the shell of a semiconductor nanoparticle with a core-shell configuration or each of the individual shells of a semiconductor nanoparticle with a core-multishell configuration is constructed. The material can be a Group II-VI, III-V, IV-VI, or I-III-VI 2 semiconductor, or any combination of one or more of these. For example, the shell material can be selected from the group consisting of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, GaAs, GaP, GaAs, GaSb, GaN, HgS, HgSe, HgTe, InAs, InP, InSb, AlAs, AlP, AlSb, Cu2S, Cu2Se, CuGaS2, CuGaSe2, CuInS2, CuInSe2, Cu2(InGa)S4, AgInS2, AgInSe2, Cu2(ZnSn)S4, alloys thereof, and mixtures thereof. Due to the toxicity of Cd, ZnS is preferred as the shell material. This has the disadvantage of poor absorption in the typical range of the blue LED around 450 nm.Here, the additional absorption leads to a particularly great advantage in the end application.

[0040] The term "ligand" refers to an external surface coating of the semiconductor nanoparticles, which leads to a passivation effect and serves to prevent agglomeration or aggregation of the nanoparticles by overcoming van der Waals forces. Ligands that can be used generally include: phosphines and phosphine oxides, such as trioctylphosphine oxide (TOPO), trioctylphosphine (TOP), or tributylphosphine (TBP); phosphonic acids, such as dodecylphosphonic acid (DDPA), tridecylphosphonic acid (TBPA), octadecylphosphonic acid (ODPA), or hexylphosphonic acid (HPA); amines, such as dodecylamine (DDA), tetradecylamine (TDA), hexadecylamine (HDA), or octadecylamine (ODA); imines, such as polyethyleneimine (PEI); thiols, such as hexadecanethiol or hexanethiol. Mercaptocarboxylic acids, such as mercaptopropionic acid or mercaptoundecanoic acid; and other acids, such as myristic acid, palmitic acid, oleic acid, caproic acid or adipic acid.

[0041] The term "coating material" refers to a material that forms a coating on the surface of the particles of the light-converting material. The term "coating" is used herein to describe one or more layers of a material provided on another material and partially or completely covering the outer surface or the solvent-accessible surface of the other material. From the wording used, it is understood that the coating applied to each individual primary particle of the light-converting material results in the production of a plurality of different coated primary particles that are separate from one another, rather than a plurality of particles contained or encapsulated together in the same coating material in the form of a uniform matrix. The primary particles of the light-converting material typically contain multiple semiconductor nanoparticles.The coating material (coating material) can at least partially penetrate the internal structure of the coated material, provided the coating still serves as a barrier to provide sufficient protection against external physical influences or the passage of potentially harmful substances, such as oxygen, moisture, and / or free radicals. This increases the stability of the light-converting material, leading to improved durability and service life. Additionally, in some embodiments, the coating material imparts additional functionality to the light-converting material, such as reduced sensitivity to heat, reduced light refraction, or improved adhesion of the light-converting materials in polymers or encapsulating materials.Furthermore, irregularities on the surface of the particles of the light-converting material can be smoothed by applying one or more coating materials. Such surface smoothing enables good processability of the light-converting material and reduces unwanted optical scattering effects of the emitted light at the surface of the material, leading to increased efficiency.

[0042] The term "encapsulant" refers to a translucent matrix material, including the light-converting materials of the invention, as well as the light-converting mixtures of the invention. The translucent matrix material can be a silicone, a polymer (formed from a liquid or semi-solid precursor material such as a monomer), an epoxy, a glass, or a hybrid of a silicone and epoxy. Specific, but non-limiting, examples of the polymers include fluorinated polymers, polyacrylamide polymers, polyacrylic acid polymers, polyacrylonitrile polymers, polyaniline polymers, polybenzophenone polymers, poly(methyl methacrylate) polymers, silicone polymers, aluminum polymers, polybisphenol polymers, polybutadiene polymers, polydimethylsiloxane polymers, polyethylene polymers, polyisobutylene polymers, polypropylene polymers, polystyrene polymers, polyvinyl polymers, polyvinyl butyral polymers, or perfluorocyclobutyl polymers.Silicones can include gels such as Dow Corning®< OE-6450, elastomers such as Dow Corning®< OE-6520, Dow Corning®< OE-6550, Dow Corning®< OE-6630, and resins such as Dow Corning®< OE-6635, Dow Corning®< OE-6665, Nusil LS-6143 and other Nusil products, Momentive RTV615, Momentive RTV656, and many other products from other manufacturers. Furthermore, the encapsulant can be a (poly)silazane, such as a modified organic polysilazane (MOPS) or a perhydropolysilazane (PHPS). The proportion of the light-converting material or the light-converting mixture, based on the potting material, is in the range of 1 to 300 wt.%, preferably in the range of 3-50 wt.%.

[0043] In the context of the present invention, the term "emission" describes a stimulated emission or induced emission of a photon triggered by another photon. An emission spectrum is the electromagnetic spectrum emitted by atoms, molecules, or materials without the incoming electromagnetic radiation of the same frequency. While discrete energy levels produce a line spectrum, energy bands produce a continuous spectrum. Both the line spectrum and the continuous emission spectrum are also referred to as "emission bands" in the context of the present invention. The emission band thus describes the emission intensity measured in an emission spectrum as a function of wavelength. The wavelength at which the emission intensity is maximum is referred to as the "emission maximum" λ em,max.

[0044] In the context of the present invention, the term "absorption" generally refers to the absorption of a wave or particle, such as an electromagnetic wave or a photon, into an absorbing substance or body, thereby exciting it to a higher energy state. During absorption, the transmission of the wave or radiation through a substance or body is attenuated. Further attenuating effects resulting from scattering or reflection are summarized in optics, together with those of absorption, under the term extinction, also known as absorbance. For example, in semiconductor nanoparticles, absorption generally occurs via the following two mechanisms (1) and (2): (1)Direct excitation of the allowed exciton transition in the nucleus. In Figure 9 This is evident in the absorption spectrum in the range of approximately 490 to 550 nm as a narrow band. (2) Excitation of the band gap in the shell. This is in Figure 9illustrated by the absorption intensity increasing towards smaller wavelengths.

[0045] In the context of the present invention, the term "excitation" refers to the intensity of the emission that occurs as a function of the excitation wavelength.

[0046] "Emission" refers to the physical process by which a particle's higher-energy quantum state is transformed into a lower-energy quantum state by emitting a photon, creating light. The frequency of the emitted light is a function of the energy of the quantum mechanical transition. Since energy must be conserved, the energy difference between the two quantum mechanical states is equal to the energy of the emitted photon. The energy states of quantum mechanical transitions can lead to the emission of light over a very wide frequency range. For example, visible light is emitted by the coupling of electronic states in atoms and molecules. In these cases, the phenomenon is called fluorescence or phosphorescence.

[0047] An "emission spectrum" is the electromagnetic spectrum emitted by atoms, molecules, or materials without receiving electromagnetic radiation of the same frequency. The counterpart of an emission spectrum is the absorption spectrum. While discrete energy levels produce a line spectrum, energy bands produce a continuous spectrum.

[0048] An "absorption spectrum" is the electromagnetic spectrum of a material that contains dark spectral lines. It occurs when broadband (white) light passes through matter and photons of specific wavelengths or wavelength ranges are absorbed. The absorbed photons are absent from the passing light, which is why the spectrum is black at those wavelengths. If the photons are absorbed by exciting atoms, they involve sharply defined amounts of energy and thus wavelengths, and the dark regions are correspondingly dark lines. In molecules, on the other hand, many absorbable energy values ​​are often close together, forming broad, dark regions in the spectrum, called absorption bands. The observed absorption spectrum is characteristic of the type of matter through which the radiation passes.In the context of the present invention, both discrete absorption lines and closely spaced absorption wavelengths are referred to as absorption bands. An absorption band thus describes the absorption intensity measured in an absorption spectrum as a function of wavelength.

[0049] An "exciton" is a bound electron-hole pair in an insulator or semiconductor. An exciton can move through the crystal, transporting its excitation energy without charge transfer, as the exciton is electrically neutral. Excitons have an integer spin. An exciton plays a major role in the absorption of light in semiconductors. For example, it can be formed when a photon enters a semiconductor and excites an electron to transition from the valence band to the conduction band. The electron and the oppositely charged hole created in the valence band attract each other through the Coulomb force. Excitons provide additional energy levels for the absorption of photons. Using Bohr's atomic model, the energy levels of exciton formation can be partially predicted for a material. These energy levels lie below the band gap.In addition, excitons increase the transition probability of electrons and enhance an already existing absorption of photons in the energy range of the band gap.

[0050] In the core of semiconductor nanoparticles, the band gap changes when the particles fall below the size of twice the exciton Bohr radius and so-called quantum confinement occurs. In this process, the band gap shifts to higher energies or shorter wavelengths. Discrete energy levels arise in the conduction band and valence band, whereas continuous energy levels exist in the macroscopic solid. Therefore, for example, a CdSe core with a size of less than 10 nm only absorbs and emits electromagnetic radiation with a wavelength below approximately 550 nm, whereas a macroscopic solid absorbs radiation from approximately 700 nm. Since the shell is typically significantly larger than the core, the band gap corresponds to that of the macroscopic solid, and the conduction band and valence band have continuous energy levels.The band gap of the shell material is usually at a higher energy than the smallest exciton absorption energy in the core. In this case, a pronounced absorption band of the exciton transition can be observed in the core, at lower energy or at a longer wavelength. The absorption of the shell then begins at a higher energy or shorter wavelength. This is also reflected in the absorption spectrum in . Figure 9 (solid line) in which the core exciton absorption is visible as a band in the range 490 to 550 nm, while the band gap absorption of the shell increases continuously below 450 nm.

[0051] The exciton Bohr radius ab * is calculated using the following formula: a b * = ε r m / μ a b where ε r is the size-dependent dielectric constant, m is the mass, µ is the reduced mass and ab is the Bohr radius (0.053 nm).

[0052] The wavelength at which the core exciton absorption band has its maximum is called λ ex,max. This is determined by the local maximum in the range 490 to 530 nm of the absorption spectrum curve in the Figures 9 and 10 (solid line). Preferred embodiments of the invention

[0053] The present invention, as described above, relates to a light-converting material comprising a luminescent material and at least one type of semiconductor nanoparticles, wherein the semiconductor nanoparticles are located on the surface of the luminescent material and the emission of the semiconductor nanoparticles is in the range of the emission of the luminescent material.

[0054] It is preferred that the emission band of the semiconductor nanoparticles and the emission band of the luminescent material completely or partially overlap.

[0055] It is further preferred that the emission maximum of the semiconductor nanoparticles and the emission maximum of the luminescent material be separated by a maximum of 50 nm. The following equation (1) then applies:

[0056] It is particularly preferred that the emission maximum of the semiconductor nanoparticles and the emission maximum of the luminescent material be separated by a maximum of 30 nm. The following equation (2) then applies:

[0057] It is further particularly preferred that the emission maximum of the semiconductor nanoparticles and the emission maximum of the luminescent material be separated by a maximum of 20 nm. The following equation (3) then applies:

[0058] In a most preferred embodiment, the emission maximum of the luminescent material is shifted by up to 20 nm into the shorter wavelength spectral range compared to the emission maximum of the semiconductor nanoparticles. The following equation (4) then applies:

[0059] Emission spectra for the present invention can be recorded using any spectrometer capable of determining the emission intensity as a function of wavelength. The emission maximum can be determined using suitable software for processing and evaluating emission spectra. Suitable spectrometers include, for example, the USB 2000, HR 4000, or the QE65 Pro from Ocean Optics.

[0060] In a preferred embodiment, the luminescent material and the semiconductor nanoparticles are selected such that the excitation of the semiconductor nanoparticles lies within the excitation range of the luminescent material. This means that both the semiconductor nanoparticles and the luminescent material are excited by or absorb light of a similar wavelength. For example, the semiconductor nanoparticles and the luminescent material can both be excited in the ultraviolet, violet, blue, or cyan spectral range.

[0061] It is preferred that the excitation band of the semiconductor nanoparticles and the excitation band of the luminescent material completely or partially overlap with the emission band of the primary light source.

[0062] In the present invention, the maximum of the core exciton absorption band of the semiconductor nanoparticles and the emission maximum of the luminescent material are separated by a maximum of 50 nm.

[0063] The following equation (5) then applies:

[0064] It is more preferable that the maximum of the core exciton absorption band of the semiconductor nanoparticles and the emission maximum of the luminescent material be within 30 nm of each other. The following equation (6) then applies:

[0065] In a most preferred embodiment, the maximum of the core exciton absorption band of the semiconductor nanoparticles and the emission maximum of the luminescent material are separated by a maximum of 10 nm. The following equation (7) then applies:

[0066] For the present invention, absorption and emission spectra can be recorded using any spectrometer suitable for determining absorption intensity or emission intensity as a function of wavelength. Absorption and emission maxima can be determined using suitable software for processing and evaluating spectra. Suitable spectrometers and software are known to those skilled in the art.

[0067] Absorption spectra of semiconductor nanoparticles in suspension (e.g., toluene, ethanol, or water) are generally measured in the present invention as follows: Using a UV-VIS spectrometer (e.g., UV-2550 from Shimadzu), the absorption is measured as a function of wavelength compared to the pure solvent. Care must be taken to ensure that the absorption in the wavelength range under investigation lies between 30% and 100%. If this range is exceeded, the suspension must be diluted or concentrated accordingly.

[0068] Absorption spectra of luminescent materials are generally measured in the present invention as follows: A powder sample of the material prepared in a sample holder is gradually excited with monochromatic electromagnetic radiation and the number of emitted photons is detected by means of a photomultiplier at a 90° angle to the excitation source.

[0069] In the present invention, emission spectra of semiconductor nanoparticles are measured using a Hamamatsu Photonics C9920-02 measurement system and the procedure specified by the manufacturer. The absorption of the suspension at the selected excitation wavelength should be in the range of 15% to 40%. This is achieved by adjusting the concentration in the respective solvent.

[0070] In the case of a band emission of the luminescent material, it is preferred that the emission band of the luminescent material completely or partially overlaps with the core exciton absorption band of the semiconductor nanoparticles.

[0071] To determine the overlap of the bands, the normalized emission or absorption spectra are used, from which the overlapping area A OL of the emission band of the luminescent material and the core exciton absorption band of the semiconductor nanoparticles is determined. Subsequently, the ratio of the overlapping areas A OL to the total area of ​​the core exciton excitation band A ex of the semiconductor nanoparticles is calculated: A OL / A ex . The total area A ex is obtained by modeling the core exciton absorption band, as shown in Figure 10 is shown.

[0072] It is preferred that the overlap A OL between the emission band of the luminescent material and the core exciton absorption band of the semiconductor nanoparticles be at least 50%, based on the total area of ​​the core exciton excitation band A ex . The following equation (8) then applies: A OL / A ex * 100 % > 50 %

[0073] In the present invention, it is preferred that the overlap be at least 80%. The following equation (9) then applies: A OL / A ex * 100 % > 80 %

[0074] Figures 9 and 10 show an example where the overlap is at least 80%.

[0075] In the case of line emission of the luminescent material, it is preferred that the emission band with the maximum intensity (emission maximum λ em,max ) of the luminescent material and the maximum of the core exciton absorption band (λ ex,max ) of the semiconductor nanoparticles are located a maximum of 50 nm apart. Equation (5) then applies. It is particularly preferred that the emission maximum λ em,max of the luminescent material and the maximum of the core exciton absorption band λ ex,max of the semiconductor nanoparticles are located between 0 and 30 nm apart. Equation (6) then applies. It is most preferred that the maximum of the core exciton absorption band λ ex,max of the semiconductor nanoparticles and the emission maximum λ em,max of the luminescent material are located a maximum of 10 nm apart. Equation (7) then applies. Figure 9 shows an example in which the conditions of equations (5) to (9) are met.

[0076] The resulting light-converting material of the present invention can be in bulk, powder form, thick or thin layered material, or self-supporting material in the form of a film. Furthermore, it can be embedded in a potting material. The light-converting material can comprise additional materials, such as ligands and / or coating materials.

[0077] The luminescent material used in the light-converting material is colored or colorless and preferably transparent. Light emitted by a primary light source or by another luminescent material can be absorbed by the luminescent material used, and light reaching the semiconductor nanoparticles on the surface of the luminescent material used can be absorbed by them and converted into light of the same or longer wavelength and emitted, thereby increasing the efficiency of the LED when using the light-converting material according to the invention.

[0078] Alternatively, in the case of using a transparent luminescent material, the light from a primary light source or from another luminescent material can pass unhindered and without loss through the luminescent material used and reach the semiconductor nanoparticles on the surface, by which it is absorbed, converted into light with a longer wavelength and then emitted, thereby increasing the efficiency when using the light-converting material according to the invention in an LED.

[0079] In the present invention, the luminescent material serves as a carrier material and simultaneously ensures more efficient excitation of the semiconductor nanoparticles located on the surface of the luminescent material. The semiconductor nanoparticles can be distributed randomly or in a defined arrangement on the surface of the luminescent material.

[0080] In a preferred embodiment of the present invention, the weight fraction of the semiconductor nanoparticles located on the surface of the luminescent material is in the range of 0.1 to 5 wt.%, based on the total weight of the light-converting material.

[0081] In the present invention, the luminescent material is not limited in terms of its chemical composition. Suitable luminescent materials include, for example, inorganic phosphors, which contain activators, i.e., emitting centers. Such inorganic phosphors are luminescent within the meaning of the present invention because they exhibit specific intrinsic absorption and convert short-wavelength light. They are therefore suitable as carrier materials for the semiconductor nanoparticles.

[0082] In a preferred embodiment of the present invention, the luminescent material is an inorganic phosphor selected from the group comprising luminescent metal oxides, silicates and halo-silicates, phosphates and halophosphates, borates, haloborates and borosilicates, aluminates, gallates and aluminosilicates, molybdates and tungstates, sulfates, sulfides, selenides and tellurides, nitrides and oxynitrides, SiAlO ions, complex metal-oxygen compounds, halogen compounds, and oxy-compounds, such as preferably oxysulfides or oxychlorides. The compounds are typically activated with metals selected from the list consisting of Eu, Ce, Mn, Tb, Sm, Cr, Sn, Pb, Sb, Bi, Cu, and Ag, or mixtures thereof. Particularly preferred activators are Eu(II), Ce(III), Mn(II), Mn(IV), Eu(III), Tb(III), Sm(III), Cr(III), Sn(II), Pb(II), Sb(III), Bi(III), Cu(I) and Ag(I) and mixtures thereof.

[0083] Preferred luminescent complex metal-oxygen compounds are luminescent antimonates, luminescent arsenates, luminescent germanates, luminescent hafnates, luminescent halogermanates, luminescent indates, luminescent lanthanates, luminescent niobates, luminescent scandates, luminescent stannates, luminescent tantalates, luminescent titanates, luminescent vanadates, luminescent halovanadates, luminescent phosphovanadates, luminescent yttrates and luminescent zirconates.

[0084] Examples of luminescent metal oxides include: M 2+< O:D, M 3+< O 3 :D and M 4+< O 2 :D, wherein M 2+< Zn, Fe, Co, Ni, Cd, Cu and / or one or more alkaline earth metals, preferably Be, Mg, Ca, Sr and / or Ba; M 3+< Al, Ga, Sc, Y, La and / or one or more rare earth metals selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; M 4+< Ti, Zr, Ge, Sn and / or Th; and D is one or more activators selected from the list consisting of Eu, Ce, Mn, Tb, Sm, Cr, Sn, Pb, Sb, Bi, Cu and Ag.

[0085] Preferred examples of luminescent metal oxides are: Al 2 O 3 :D, CaO:D, Ga 2 O 3 :D, La 2 O 3 :D, ThO 2 :D, Y 2 O 3 :D, ZnO:D, (Y,Gd) 2 O 3 :D and (Zn,Cd)O:D.

[0086] Examples of luminescent silicates or halosilicates include: M 2+< SiO 3 :D, M 2+< 2 SiO 4 :D, M 2+< 2 (Si,Ge)O 4 :D, M 2+< 3 SiO 5 :D, M 3+< 2 SiO 5 :D, M 3+< M +< SiO 4 :D, M 2+< Si 2 O 5 :D, M 2+< 2 Si 2 O 6 :D, M 2+< 3 Si 2 O 7 :D, M 2+< 2 M +< 2 Si 2 O 7 :D, M 3+< 2 Si 2 O 7 :D, M 2+< 4 Si 2 O 8 :D, M 2+< 2 Si 3 O 8 :D, M 2+< 3 M 3+< 2 Si 3 O 12 :D, M +< M 3+< M 2+< 4 Si 4 O 10 :D, M +< M 2+< 4 M 3+< Si 4 O 14 :D, M 2+< 3 M 3+< 2 Si 6 O 18 :D, M 3+< SiO 3 X:D, M 2+< 3 SiO 4 X 2 :D, M 2+< 5 SiO 4 X 6 :D, M +< 2 M 2+< 2 Si 4 O 10 X 2 :D, M 2+< 5 Si 4 O 10 X 6 :D, M +< 2 SiX 6 :D, M 2+< 3 SiO 3 X 4 and M 2+< 9 (SiO 4 ) 4 X 2 :D, where M +< is one or more alkali metals, preferably Li, Na and / or K; M 2+< Zn, Fe, Co, Ni, Cd, Cu and / or one or more alkaline earth metals, preferably Be, Mg, Ca, Sr and / or Ba; M 3+< Al, Sc, Y, La and / or one or more rare earth metals selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu;X is one or more halogens, preferably F, Cl, Br and / or I; and D is one or more activators selected from the list consisting of Eu, Ce, Mn, Tb, Sm, Cr, Sn, Pb, Sb, Bi, Cu and Ag.;

[0087] Suggested examples of luminescent silicates and halosilicates are: Ba 2 (Mg,Sr)Si 2 O 7 :D, Ba 2 SiO 4 :D, (Ba,Sr) 2 SiO 4 :D, Ba 5 SiO 4 Br 6 :D, BaSi 2 O 5 :D, BaS 2 Mg, SiO 27 :D :D, Ca 2 MgSi 2 O 7 :D, Ca 3 MgSi 2 O 8 :D, Ca 3 SiO 4 Cl 2 :D, CaMgSi 2 O 6 :D, CaSiO 3 :D, (Ca,Mg)SiO 3 :D, (Ca,Sr) 2 SiO 4 :D, (Ba,Sr) 3 SiO 5 :D, Gd 2 SiO 5 :D, K 2 SiF 6 :D, LaSiO 3 Cl:D, LiCeBa 4 Si 4 O 14 :D, LiCeSrBa 3 Si 4 O 14 :D, LiNa(Mg,Mn) 2 Si 4 O 10 F 2 :D, Lu 2 O 2 :D, Lu 2 O 7 Si :D, (Lu,Gd) 2 SiO 5 :D, Mg 2 SiO 4 :D, Mg 3 SiO 3 F 4 :D, MgBa 3 Si 2 O 8 :D, MgSiO 3 :D, MgSr 3 Si 2 O 8 :D, Sr 2 MgSi 2 O 7 :D, Sr 2 MgSi 2 O 7 :D, Sr 2 SiO 2 36 :Sr O 18 :D, Sr 5 Si 4 O 10 Cl 6 :D, SrBaSiO 4 :D, SrMgSi 2 O 6 :D, Y 2 Si 2 O 7 :D, Y 2 SiO 5 :D, Zn 2 (Si,Ge)O 4 :D, Zn 2 SiO 4 :D and Syn 2 (ZO4 :D)

[0088] Examples of luminescent phosphates or halophosphates include: M 3+< PO 4 :D, M 2+< P 2 O 6 :D, M 2+< 2 P 2 O 7 :D, M +< 2 M 2+< P 2 O 7 :D, M 4+< P 2 O 7 :D, M 2+< B 2 P 2 O 9 :D, M 2+< 6 BP 5 O 20 :D, M 2+< 3 (PO 4 ) 2 :D, M +< 3 M 3+< (PO 4 ) 2 :D, M 2+< 6 (PO 4 ) 4 :D and M 2+< 5 (PO 4 ) 3 X:D, wherein M +< is one or more alkali metals, preferably Li, Na and / or K; M 2+< Zn, Fe, Co, Ni, Cd, Cu and / or one or more alkaline earth metals, preferably Be, Mg, Ca, Sr and / or Ba; M 3+< Al, Sc, Y, La and / or one or more rare earth metals selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; M 4+< Ti, Zr, Ge and / or Sn; X is one or more halogens, preferably F, Cl, Br and / or I; and D is one or more activators selected from the list consisting of Eu, Ce, Mn, Tb, Sm, Cr, Sn, Pb, Sb, Bi, Cu and Ag.

[0089] Bevorzugte Beispiele lumineszenter Phosphate and Halophosphate sind: Ba 3 (PO 4 ) 2 :D, Ca 2 Ba 3 (PO 4 ) 3 Cl:D, Ca 2 P 2 O 7 :D, Ca 3 (PO 4 ) 2 :D, (Ca,Sr) 3 (PO 4 ) 2 :D, (Ca,Zn,Mg) 3 (PO 4 ) 2 :D, Ca 5 (PO 4 ) 3 (F,Cl):D, Ca 5 (PO 4 ) 3 Cl:D, Ca 5 (PO 4 ) 3 F:D, CaB 2 P 2 O 9 :D, CaP 2 O 6 :D, CaSr 2 (PO 4 ) 2 :D, LaPO 4 :D, (La,Ce,Tb)PO 4 :D, Li 2 CaP 2 O 7 :D, LuPO 4 :D, Mg 3 Ca 3 (PO 4 ) 4 :D, MgBa 2 (PO 4 ) 2 :D, MgBaP 2 O 7 :D, MgCaP 2 O 7 :D, MgSr 5 (PO 4 ) 4 :D, MgSrP 2 O 7 :D, Na 3 Ce(PO 4 ) 2 :D, Sr 2 P 2 O 7 :D, Sr 3 (PO 4 ) 2 :D, Sr 5 (PO 4 ) 3 Cl:D, Sr 5 (PO 4 ) 3 F:D, Sr 6 BP 5 O 20 :D, YPO 4 :D, Zn 3 (PO 4 ) 2 :D, Zn 3 (PO 4 ) 2 :D, ZnMg 2 (PO 4 ) 2 :D and (Zn,Mg) 3 (PO 4 ) 2 :D.

[0090] Examples of luminescent borates, haloborates or borosilicates include: M 3+< BO 3 :D, M 2+< B 2 O 4 :D, M 2+< 2 B 2 O 5 :D, M 3+< 2 B 2 O 6 :D, M 3+< B 3 O 6 :D, M 2+< B 6 O 10 :D, M 2+< M 3+< BO 4 :D, M 2+< M 3+< B 3 O 7 :D, M 2+< B 4 O 7 :D, M 2+< 3 M 3+< 2 B 4 O 12 :D, M 3+< 4 B 4 O 12 :D, M 3+< M 2+< B 5 O 10 :D, M 2+< 2 B 6 O 11 :D, M 2+< B 8 O 13 :D, M 2+< 2 B 5 O 9 X:D, M 2+< 2 M 3+< 2 BO 6.5 :D and M 2+< 5 B 2 SiO 10 :D, wherein M 2+< is Zn, Fe, Co, Ni, Cd, Cu and / or one or more alkaline earth metals, preferably Be, Mg, Ca, Sr and / or Ba; M 3+< is Al, Ga, In, Sc, Y, La and / or one or more rare earth metals selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; X is one or more halogens, preferably F, Cl, Br and / or I; and D is one or more activators selected from the list consisting of Eu, Ce, Mn, Tb, Sm, Cr, Sn, Pb, Sb, Bi, Cu and Ag.

[0091] Bevorzugte Beispiele lumineszenter Borate and Borosilikate are: Ca 2 B 2 O 5 :D, Ca 2 B 5 O 9 Br:D, Ca 2 B 5 O 9 Cl:D, Ca 2 La 2 BO 6,5 :D, Ca 5 B 2 SiO 10 :D, CaB 2 O 4 :D, CaLaB 3 O 7 :D, CaLaBO 4 :D, CaYBO 4 :D, Cd 2 B 6 O 11 :D, GdMgB 5 O 10 :D, InBO 3 :D, LaAl 3 B 4 O 12 :D, LaAlB 2 O 6 :D, LaB 3 O 6 :D, LaBO 3 :D, MgB 2 O 4 :D, MgYBO 4 :D, ScBO 3 :D, Sr 2 B 5 O 9 Cl:D, SrB 4 O 7 :D, SrB 8 O 13 :D, YAl 3 B 4 O 12 :D, YBO 3 :D, (Y,Gd)BO 3 :D und ZnB 2 O 4 ,SrO:D·3B 2 O 3 .

[0092] Examples of luminescent aluminates, gallates or aluminosilicates include: M +< AlO 2 :D, M 3+< AlO 3 :D, M 2+< M 3+< AlO 4 :D, M 2+< Al 2 O 4 :D, M 2+< Al 4 O 7 :D, M +< Al 5 O 8 :D, M 3+< 4 Al 2 O 9 :D, M 3+< 3 Al 5 O 12 :D, M +< Al 11 O 17 :D, M 2+< 2 Al 10 O 17 :D, M 3+< 3 Al 5 O 12 :D, M 3+< 3 (Al,Ga) 5 O 12 :D, M 3+< 3 Sc 2 Al 3 O 12 :D, M 2+< 2 Al 6 O 11 :D, M 2+< Al 8 O 13 :D, M 2+< M 3+< Al 11 O 19 :D, M 2+< Al 12 O 19 :D, M 2+< 4 Al 14 O 25 :D, M 2+< 3 Al 16 O 27 :D, M 2+< Ga 2 O 4 :D, M 2+< Ga 4 O 7 :D, M 3+< 3 Ga 5 O 12 :D, M +< Ga 11 O 17 :D, M 2+< Ga 12 O 19 :D, M +< 2 M 2+< 3 Al 2 Si 2 O 10 :D and M 2+< 3 Al 2 Si 3 O 12 :D, wherein M +< one or more alkali metals, preferably Li, Na and / or K; M 2+< Zn, Fe, Co, Ni, Cd, Cu and / or one or more alkaline earth metals, preferably Be, Mg, Ca, Sr and / or Ba; M 3+< Al, Sc, Y, La and / or one or more rare earth metals selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu;and D one or more activators, selected from the list consisting of Eu, Ce, Mn, Tb, Sm, Cr, Sn, Pb, Sb, Bi, Cu and Ag, ist.;

[0093] Suggested examples of luminescent aluminates, gallates and aluminosilicates are: BaAl 12 O 19 :D, BaAl 8 O 13 :D, BaMgAl 10 O 17 :D, CaAl 2 O 4 :D, CaAl 4 O 7 :D, (CaAl 12:19) 2 O 4 :D, CaGa 4 O 7 :D, CeMgAl 11 O 19 :D, Gd 3 Ga 5 O 12 :D, Gd 3 Sc 2 Al 3 O 12 :D, GdAlO 3 :D, KAl 11 O 17 :D, KGa 11 O 17, LagAlA3 :D:D 11 O 19 :D, LiAl 5 O 8 :D, LiAlO 2 :D, LiAlO 2 :D, Lu 3 Al 5 O 12 :D, LuAlO 3 :D, (Lu,Y)AlO 3 :D, MgAl 2 O 4 :D, MgGa Al 6 O 11 :D, Sr 4 Al 14 O 25 :D, SrAl 12 O 19 :D, SrAl 2 O 4 :D, SrAl 4 O 7 :D, SrGa 12 O 19 :D, SrGa 2 O 4 :D, Tb 3 Al 5 O :D, OG, Y 12 :D, (Y,Gd) 3 Al 5 O 12 :D, Y 3 Al 5 O 12 :D, Y 4 Al 2 O 9 :D, YAlO 3 :D, ZnAl 2 O 4 :D und ZnGa 2 O 4 :D.

[0094] Examples of luminescent molybdates or tungstates include: M 2+< MoO 4 :D, M +< M 3+< Mo 2 O 8 :D, M 2+< WO 4 :D, M 2+< 3 WO 6 :D, M 3+< 2 W 3 O 12 :D and M +< M 3+< W 2 O 8 :D, wherein M +< is one or more alkali metals, preferably Li, Na and / or K; M 2+< is Zn, Fe, Co, Ni, Cd, Cu and / or one or more alkaline earth metals, preferably Be, Mg, Ca, Sr and / or Ba; M 3+< is Al, Sc, Y, La and / or one or more rare earth metals selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; and X is one or more halogens, preferably F, Cl, Br and / or I; and D is one or more activators selected from the list consisting of Eu, Ce, Mn, Tb, Sm, Cr, Sn, Pb, Sb, Bi, Cu and Ag.

[0095] Preferred examples of luminescent molybdates and tungstates are: Ba 3 WO 6 :D, Ca 3 WO 6 :D, CaMoO 4 :D, CaWO 4 :D, CdWO 4 :D, La 2 W 3 O 12 :D, LiEuMo 2 O 8 :D, MgWO 4 :D, Sr 3 WO 6 :D, SrMoO 4 :D, Y 2 W 3 O 12 :D and ZnWO 4 :D.

[0096] Examples of luminescent sulfates, sulfides, selenides or tellurides include: M 2+< SO 4 :D, M 2+< 2 (SO 4 ) 2 :D, M 2+< 3 (SO 4 ) 3 :D, M 3+< 2 (SO 4 ) 3 :D, M 2+< S:D, M 2+< (S,Te):D, M 2+< Se:D, M 2+< Te:D, M 2+< Ga 2 S 4 :D, M 2+< Ba 2 S 3 :D and M 2+< Al 2 S 4 :D, wherein M 2+< is Zn, Fe, Co, Ni, Cd, Cu and / or one or more alkaline earth metals, preferably Be, Mg, Ca, Sr and / or Ba; M 3+< Al, Sc, Y, La, and / or one or more rare earth metals selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; and D is one or more activators selected from the list consisting of Eu, Ce, Mn, Tb, Sm, Cr, Sn, Pb, Sb, Bi, Cu and Ag.

[0097] Preferred examples of luminescent sulfates, sulfides, selenides and tellurides are: CaGa 2 S 4 :D, CaS:D, CaSO 4 :D, CdS:D, Mg 2 Ca(SO 4 ) 3 :D, Mg 2 Sr(SO 4 ) 3 :D, MgBa(SO 4 ) 2 :D, MgS:D, MgSO 4 :D, SrAl 2 S 4 :D, SrGa 2 S 4 :D, SrS:D, SrSO 4 :D, Zn(S,Te):D, ZnBa 2 S 3 :D, ZnGa 2 S 4 :D, ZnS:D, (Zn,Cd)S:D and ZnSe:D.

[0098] Examples of luminescent nitrides, oxynitrides or SiAlONs include: M3+<N:D, M2+<Si2O2N2:D, M2+<2Si5N8:D, M3+<3Si6N11:D, M2+<AlSiN3:D, α-SiAlONs:D and β-SiAlONs:D, wherein M2+<Zn, Fe, Co, Ni, Cd, Cu and / or one or more alkaline earth metals, preferably Be, Mg, Ca, Sr and / or Ba; M3+<Al, Ga, Sc, Y, La and / or one or more rare earth metals selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; D is one or more activators selected from the list consisting of Eu, Ce, Mn, Tb, Sm, Cr, Sn, Pb, Sb, Bi, Cu and Ag.

[0099] Preferred examples of luminescent nitrides and oxynitrides are: Ba 2 Si 5 N 8 :D, Ca 2 Si 5 N 8 :D, CaAlSiN 3 :D, (Ca,Sr)AlSiN 3 :D, GaN:D, La 3 Si 6 N 11 :D, Sr 2 Si 5 N 8 :D and (Sr,Ba)Si 2 N 2 O 2 :D.

[0100] Examples of luminescent complex metal-oxygen compounds include: M 3+< AsO 4 :D, M 2+< 13 As 2 O 18 :D, M 2+< GeO 3 :D, M 2+< 2 GeO 4 :D, M 2+< 4 GeO 6 :D, M 2+< 4 (Ge,Sn)O 6 :D, M 2+< 2 Ge 2 O 6 :D, M 3+< 4 Ge 3 O 12 :D, M 2+< 5 GeO 4 X 6 :D, M 2+< 8 Ge 2 O 11 NbO 4 :D, M 2+< Sc 2 O 4 :D, M 2+< 2 SnO 4 :D, M 3+< TaO 4 :D, M 2< +TiO 3 :D, M 2+< 2 TiO 4 :D, M +< 2 M 3+< 2 Ti 3 O 10 :D, M 2+< 5 (VO 4 ) 3 X:D, M 3+< VO 4 :D, M 3+< (V,P)O 4 :D, M +< YO 2 :D, M 2+< ZrO 3 :D, M 2+< 2 ZrO 4 :D and M 2+< M 3+< 2 ZrO 6 :D, wherein M +< is one or more alkali metals, preferably Li, Na and / or K; M 2+< Zn, Fe, Co, Ni, Cd, Cu and / or one or more alkaline earth metals, preferably Be, Mg, Ca, Sr and / or Ba; M 3+< Al, Sc, Y, La, Bi and / or one or more rare earth metals selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu;M 4+< is Ti, Zr, Ge and / or Sn; X is one or more halogens, preferably F, Cl, Br and / or I; and D is one or more activators selected from the list consisting of Sc, Eu, Ce, Mn, Tb, Sm, Cr, Sn, Pb, Sb, Bi, Cu and Ag.;

[0101] Preferred examples of luminescent complex metal-oxygen compounds are: Ba 5 GeO 4 Br 6 :D, Bi 4 Ge 3 O 12 :D, Ca 5 (VO 4 ) 3 Cl:D, CaGeO 3 :D, CaLa 4 O 7 :D, CaSc 2 O 4 :D, CaTiO 3 :D, CaY 2 ZrO 6 :D, GdNbO 4 :D, GdTaO 4 :D, K 2 La 2 Ti 3 O 10 :D, LaAsO 4 :D, LaVO 4 :D, LiInO 2 :D, LiLaO 2 :D, LuTaO 4 :D, Mg 13 As 2 O 18 :D, Mg 2 SnO 4 :D, Mg 2 TiO 4 :D, Mg 4 (Ge,Sn)O 6 :D, Mg 4 GeO 6 :D, Mg 8 Ge 2 O 11 F 2 :D, NaYO 2 :D, SrTiO 3 :D, Y(V,P)O 4 :D, YAsO 4 :D, YTaO 4 :D, YVO 4 :D and Zn 2 GeO 4 :D.

[0102] Examples of luminescent halogen or oxy compounds include: M +< X:D, M 2+< X 2 :D, M 3+< X 3 :D, M +< M 2+< X 3 :D, M +< M 3+< X 4 :D, M 2+< M 3+< 2 X 8 :D, M +< M 3+< 3 X 10 :D, M 3+< OX:D, M 2+< 8 M 4+< 2 O 11 X 2 :D and M 3+< 2 O 2 S:D, wherein M +< is one or more alkali metals, preferably Li, Na and / or K; M 2+< is Zn, Fe, Co, Ni, Cd, Cu and / or one or more alkaline earth metals, preferably Be, Mg, Ca, Sr and / or Ba; M 3+< is Al, Sc, Y, La, and / or one or more rare earth metals selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; X is one or more halogens, preferably F, Cl, Br and / or I; and D is one or more activators selected from the list consisting of Eu, Ce, Mn, Tb, Sm, Cr, Sn, Pb, Sb, Bi, Cu and Ag.

[0103] Suggested examples of luminescent halogen compounds are: BaBr 2 :D, BaCl 2 :D, BaF 2 :D, (Ba,Sr)F 2 :D, BaFBr:D, BaFCl:D, BaY 2 F 8 :D, CaBr 2 in SiO 2 :D, CaCl 2 in SiO 2 :D, CaO CaI 2 in SiO 2 :D, CeF 3 :D, CsF:D, CsI:D, KMgF 3 :D, KY 3F 10 :D, LaBr 3 :D, LaCl 3 :D, LaF 3 :D, LiAlF 4 :D, LiYF 4 :D, MgF 2 :D, NaF, Na RbBr:D, Sr(Cl,Br,I) 2 :D in SiO 2 , SrCl 2 in SiO 2 :D, SrF 2 :D, YF 3 :D, ZnF 2 :D and (Zn,Mg)F 2 :D.

[0104] Suggested examples of luminescent oxygen compounds are oxysulfides and oxyhalides, selected from: Gd 2 O 2 S:D, La 2 O 2 S:D, LaOBr:D, LaOCl:D, LaOF:D, Y

[0105] Preferred luminescent SiAIONs are α- SiAIONs:D and ß- SiAIONs:D.

[0106] Particularly preferred activators D for all of the above-mentioned phosphor compounds are Eu(II), Ce(III), Mn(II), Mn(IV), Eu(III), Tb(III), Sm(III), Cr(III), Sn(II), Pb(II), Sb(III), Bi(III), Cu(I) and Ag(I) and mixtures thereof.

[0107] In a particularly preferred embodiment of the present invention, the luminescent material is an inorganic phosphor selected from the list consisting of M 2+< 2 SiO 4 :D, M 2+< 3 SiO 5 :D, ß-SiAl ions:D, and M 2+< AlSiN 3 :D, where M 2+< is Be, Mg, Ca, Sr and / or Ba and D is Eu(II), and M 3+< 3 (Al,Ga) 5 O 12 :D, where M 3+< is Y, Lu, Tb and / or Gd and D is Ce(III).

[0108] For semiconductor nanoparticles emitting in the green spectral range from 520 to 540 nm, particularly preferred luminescent materials are Eu(II)-activated Ba-Sr orthosilicates with a peak emission in the range from 510 to 530 nm. Such Eu(II)-activated Ba-Sr orthosilicates can be represented by the following molecular formula: (Ba,Sr) 2 SiO 4 :Eu(II). The doping level is typically in the range of 0.5 to 5 atomic %.

[0109] For semiconductor nanoparticles emitting in the orange spectral range from 576 to 600 nm, particularly preferred luminescent materials are Eu(II)-activated Ba-Sr oxyorthosilicates with a peak emission in the range from 585 to 600 nm. Such Eu(II)-activated Ba-Sr oxyorthosilicates can be represented by the following molecular formula: (Ba,Sr) 3 SiO 5 :Eu(II). The doping level is typically in the range of 0.5 to 5 atomic %.

[0110] For semiconductor nanoparticles emitting in the red spectral range from 620 to 640 nm, particularly preferred luminescent materials are Eu(II)-activated Ca-Sr-Al-Si nitrides with a peak emission in the range from 610 to 630 nm. Such Eu(II)-activated Ca-Sr-Al-Si nitrides can be represented by the following molecular formula: (Ca,Sr)AlSiN 3 :Eu(II). The doping level is typically in the range of 0.5 to 5 atomic %.

[0111] The examples of luminescent materials mentioned are for illustrative purposes only and are not to be construed as limiting the scope and scope of the present invention in any way.

[0112] Semiconductor nanoparticles that can be used in the light-converting material of the present invention are submicrometer-sized semiconductor materials capable of emitting light at a specific wavelength when irradiated with optical excitation radiation having a different (shorter) wavelength range. Semiconductor nanoparticles are often referred to as quantum materials. The light emitted by quantum materials is characterized by a very narrow frequency range.

[0113] In a preferred embodiment of the present invention, the semiconductor nanoparticles comprise at least two different semiconductor materials. The semiconductor nanoparticles are preferably present as an alloy or in a core-shell configuration or core-multishell configuration with at least two shells, wherein the core contains either a semiconductor material or an alloy of at least two different semiconductor materials, and the shell(s) independently contain a semiconductor material or an alloy of at least two different semiconductor materials. Optionally, a concentration gradient may exist within the core and / or the shell(s) and / or between the core and / or the shell(s).

[0114] In a particularly preferred embodiment, the semiconductor materials or alloys of at least two different semiconductor materials are different in the core and the adjacent shell and / or in adjacent shells. Due to the toxicity of cadmium, ZnS is preferably used as the shell material. This has the disadvantage that the quantum materials absorb less well in the typical blue LED range around 450 nm. Here, the additional absorption of the emission of the luminescent material of the present invention leads to a particularly significant advantage in the end application.

[0115] As previously described, the semiconductor nanoparticles suitable for the purposes of the present invention are made from semiconductor materials. Possible material compositions of the semiconductor nanoparticles suitable for the present invention are described in WO 2010 / 095140 A3 and WO 2011 / 092646 A2.

[0116] The semiconductor materials are preferably selected from group II-VI semiconductors, group III-V semiconductors, group IV-VI semiconductors, group I-III-VI 2 semiconductors as well as alloys and / or combinations of these semiconductors, wherein the semiconductor materials can optionally be doped with one or more transition metals, such as Mn and / or Cu (cf. MJ Anc, NL Pickett et al., ECS Journal of Solid State Science and Technology, 2013, 2(2), R3071-R3082).

[0117] Examples of group II-VI semiconductor materials are: CdSe, CdS, CdTe, ZnO, ZnSe, ZnS, ZnTe, HgS, HgSe, HgTe, CdZnSe and any combinations thereof.

[0118] Examples of group III-V semiconductor materials are: InAs, InP, InN, GaN, InSb, InAsP, InGaAs, GaAs, GaP, GaSb, AlP, AIN, AlAs, AlSb, CdSeTe, ZnCdSe and any combinations thereof.

[0119] Examples of semiconductor materials of group IV-VI are: PbSe, PbTe, PbS, PbSnTe, Tl 2 SnTe 5 and any combinations thereof.

[0120] Examples of semiconductor materials of group I-III-VI 2 are: CuGaS 2 , CuGaSe 2 , CuInS 2 , CuInSe 2 , Cu 2 (InGa)S 4 , AgInS 2 , AgInSe 2 and any combinations thereof.

[0121] The above-mentioned examples of semiconductor materials for the semiconductor nanoparticles are for illustrative purposes only and are not to be construed as limiting the scope and scope of the present invention in any way. The above-mentioned semiconductor materials can be used either as an alloy or as a core or shell material in a core-shell or core-multishell configuration.

[0122] The external and internal shapes of the semiconductor nanoparticles are not further restricted. Preferably, the semiconductor nanoparticles are in the form of nanodots, nanorods, nanoplatelets, nanotetrapods, nanodots within nanorods, nanorods within nanorods, and / or nanodots within nanoplatelets.

[0123] The length of the nanorods is preferably between 8 and 500 nm and more preferably between 10 and 160 nm. The total diameter of a nanorod is preferably between 1 and 20 nm and more preferably between 1 and 10 nm. A typical nanorod has an aspect ratio (length to diameter) of preferably greater than or equal to 2 and more preferably greater than or equal to 3.

[0124] In a more preferred embodiment, the semiconductor nanoparticles exhibit high absorption in the region of their own emission (self-absorption). This is typically the case for materials with a ZnS shell or very small shell.

[0125] The wavelength of the emitted light (emission color) of the semiconductor nanoparticles in response to the excitation radiation can be suitably selected by adjusting the shape, size, and / or material composition of the nanoparticles. This flexibility with regard to the emission color enables a wide variation in the color of the light-converting material according to the invention. The emission of red light can be achieved, for example, by CdSe nanodots, CdSe nanorods, CdSe nanodots in CdS nanorods, ZnSe nanodots in CdS nanorods, CdSe / ZnS nanorods, InP nanodots, InP nanorods, CdSe / CdS nanorods, ZnSe nanodots in CdS nanorods, and ZnSe / CdS nanorods. Green light emission can be achieved, for example, by CdSe nanodots, CdSe nanorods, CdSe / CdS nanorods, and CdSe / ZnS nanorods.The emission of blue light can be achieved, for example, by core-shell nanodots or core-shell nanorods based on ZnSe, ZnS, ZnSe / ZnS, and / or CdS. This exemplary assignment between specific semiconductor nanoparticles and specific emission colors is not exhaustive and is intended merely for illustrative purposes. Those skilled in the art will be aware that by adjusting the size of the semiconductor nanoparticles, different emission colors can be achieved within certain material-dependent limits.

[0126] Further preferred semiconductor nanoparticles are nanorods having a core-shell configuration with materials selected from CdSe / CdS, CdSeS / CdS, ZnSe / CdS, ZnCdSe / CdS, CdSe / CdZnS, CdTe / CdS, InP / ZnSe, InP / CdS, InP / ZnS and CuInS 2 / ZnS; as well as nanorods having a core-multishell configuration selected from CdSe / CdS / ZnS, CdSe / CdZnS / ZnS, ZnSe / CdS / ZnS, InP / ZnSe / ZnS, InP / CdS / ZnS and InP / CdZnS / ZnS.

[0127] In a preferred embodiment, the semiconductor nanoparticles are applied to the surface of a luminescent material as described above, so that the semiconductor nanoparticles are present in a ratio of 0.01 to 20 wt.%, preferably 0.1 to 5 wt.%, based on the luminescent material.

[0128] In a preferred embodiment, the surface of the semiconductor nanoparticles is coated with one or more ligands. The ligands are not subject to any particular restriction as long as they are suitable for the surface coating of semiconductor nanoparticles. Suitable ligands include, for example, phosphines and phosphine oxides, such as trioctylphosphine oxide (TOPO), trioctylphosphine (TOP), or tributylphosphine (TBP); phosphonic acids, such as dodecylphosphonic acid (DDPA), tridecylphosphonic acid (TBPA), octadecylphosphonic acid (ODPA), or hexylphosphonic acid (HPA); amines, such as dodecylamine (DDA), tetradecylamine (TDA), hexadecylamine (HDA), or octadecylamine (ODA); thiols, such as hexadecanethiol or hexanethiol; mercaptocarboxylic acids, such as mercaptopropionic acid or mercaptoundecanoic acid; and other acids, such as myristic acid, palmitic acid, oleic acid, caproic acid, or adipic acid. The above examples are not intended to be limiting.

[0129] It is further preferred that the surface of the light-converting material of the present invention is coated with one or more coating materials. The coating materials are not particularly limited as long as they are suitable for coating the surface of the light-converting material. Suitable materials include, for example, materials that are also used for coating phosphors, such as inorganic or organic coating materials. The inorganic coating materials may be dielectric insulators, metal oxides (including transparent conductive oxides), metal nitrides, or silicon dioxide-based materials (e.g., glasses). When a metal oxide is used, the metal oxide may be a single metal oxide (i.e., oxide ions combined with a single type of metal ion, such as Al 2 O 3 ) or a mixed metal oxide (i.e.,Oxide ions combined with two or more metal ion types, such as SrTiO 3 , or a doped metal oxide, such as a doped transparent conductive oxide (TCO), such as Al-doped ZnO, Ga-doped ZnO, etc.). The metal ion or metal ions of the (mixed) metal oxide can be selected from any suitable group of the periodic table, such as group 2, 13, 14, or 15, or they can be a d-metal or a lanthanide metal.

[0130] Particular metal oxides include, but are not limited to: Al 2 O 3 , ZnO, HfO 2 , SiO 2 , ZrO 2 and TiO 2 , including combinations, alloys and / or doped species thereof; and / or TCOs, such as Al-doped ZnO, Ga-doped ZnO and In 2 O 3 . The inorganic coatings include silicon dioxide in any suitable form. In some embodiments, one or more of the inorganic coating materials is a metal oxide selected from the group consisting of Al 2 O 3 , ZnO, TiO 2 , In 2 O 3 or combinations and / or doped species thereof. In particular embodiments, the metal oxide is a TCO, e.g., Al-doped ZnO or Ga-doped ZnO.

[0131] Particular metal nitrides include, but are not limited to: AIN, BN, Si 3 N 4 , including combinations, alloys and / or doped species thereof.

[0132] It is also possible to apply an organic coating alternatively and / or in addition to the above-mentioned inorganic coating. The organic coating can also have a beneficial effect on the stability and durability of the light-converting materials, as well as on their dispersibility. Suitable organic materials include (poly)silazanes, such as preferably modified organic polysilazanes (MOPS) or perhydropolysilazanes (PHPS), as well as mixtures thereof, organic silanes, and other organic materials, including polymers.

[0133] Numerous methods for applying coating materials to light-converting materials or phosphors are known in the prior art. For example, WO 2014 / 140936, the content of which is hereby incorporated by reference into the present application, describes methods such as chemical vapor deposition (CVD), physical vapor deposition (PVD) (including magnetron sputtering), Vitex technology, atomic layer deposition (ALD), and molecular layer deposition (MLD). Furthermore, the coating can be carried out using a fluidized bed process. Further coating methods are described in JP 04-304290, WO 91 / 10715, WO 99 / 27033, US 2007 / 0298250, WO 2009 / 065480, and WO 2010 / 075908, the contents of which are hereby incorporated by reference.

[0134] To build up a multilayer coating, different coating materials can be applied one after the other. Numerous coating materials, such as metal oxides such as Al 2 O 3 , SiO 2 , ZnO, TiO 2 and ZrO 2 ; metals such as Pt and Pd; and polymers such as poly(amides) and poly(imides), can be used for coating the light-converting material according to the present invention. Al 2 O 3 is one of the most studied coating materials, which is applied by the atomic layer deposition (ALD) process. Al 2 O 3 can be applied to a substrate by alternately applying trimethylaluminum and water vapor as the respective metal and oxygen sources and purging the ALD chamber between each of these applications with an inert carrier gas such as N 2 or Ar.

[0135] In a particularly preferred embodiment of the present invention, the light-converting material also comprises at least one further type of semiconductor nanoparticles, which are also located on the surface of the luminescent material and whose emission does not lie within the emission range of the luminescent material. This means that the above-mentioned equations (1) to (9) do not have to be satisfied for the at least one further type of semiconductor nanoparticles.

[0136] The light-converting material according to the invention is prepared by (A) providing a suspension of a luminescent material in a solvent; and (B) adding a suspension of semiconductor nanoparticles in a solvent.

[0137] Preferred solvents for the suspension of the luminescent material are water, methanol, ethanol and toluene.

[0138] Preferred solvents for the suspension of the semiconductor nanoparticles are PGMEA (1-methoxy-2-propyl acetate), toluene, methanol, ethanol and water.

[0139] After addition of the semiconductor nanoparticle suspension, the mixture is stirred preferably at room temperature (20 to 25°C) for 0.5 to 5 h before the solvents are subsequently removed at elevated temperature, preferably 40 to 60°C, under vacuum.

[0140] The present invention further provides a light-converting mixture comprising one or more of the light-converting materials according to the invention. It is preferred that the light-converting mixture additionally comprises at least one further luminescent material in addition to the light-converting material.

[0141] It is particularly preferred that the light-converting mixture contains one or more conversion phosphors in addition to the light-converting materials according to the invention. It is preferred that the light-converting materials and the conversion phosphors emit light of different wavelengths that are complementary to one another. If the light-converting material according to the invention is a red-emitting material, it is preferably used in combination with a cyan-emitting conversion phosphor or in combination with blue and green or yellow-emitting conversion phosphors. If the light-converting material according to the invention is a green-emitting material, it is preferably used in combination with a magenta-emitting conversion phosphor or in combination with red and blue-emitting conversion phosphors.It may therefore be preferred that the light-converting material according to the invention is used in combination with one or more further conversion phosphors in the light-converting mixture according to the invention, so that preferably white light is emitted.

[0142] It is preferred that the light-converting mixture comprises the light-converting material according to the invention in a ratio of 1 to 90 wt.%, based on the total weight of the mixture.

[0143] In the context of this application, ultraviolet light is light whose emission maximum lies between 100 and 399 nm, violet light is light whose emission maximum lies between 400 and 430 nm, blue light is light whose emission maximum lies between 431 and 480 nm, cyan light is light whose emission maximum lies between 481 and 510 nm, green light is light whose emission maximum lies between 511 and 565 nm, yellow light is light whose emission maximum lies between 566 and 575 nm, orange light is light whose emission maximum lies between 576 and 600 nm and red light is light whose emission maximum lies between 601 and 750 nm.

[0144] The light-converting material according to the invention is preferably a red- or green-emitting conversion material.

[0145] The conversion phosphors that can be used together with the light-converting material according to the invention and form the light-converting mixture according to the invention are not subject to any particular restriction. Therefore, in general, any possible conversion phosphor can be used. Suitable examples are: Ba 2 SiO 4 :Eu 2+< , Ba 3 SiO 5 :Eu 2+< , (Ba,Ca) 3 SiO 5 :Eu 2+< , BaSi 2 N 2 O 2 :Eu,BaSi 2 O 5 :Pb 2+< , Ba 3 Si 6 O 12 N 2 :Eu, Ba x Sr 1-x F 2 :Eu 2+< (with 0 ≤ x ≤ 1), BaSrMgSi 2 O 7 :Eu 2+< , BaTiP 2 O 7 , (Ba,Ti) 2 P 2 O 7 :Ti, BaY 2 F 8 :Er 3+< ,Yb +< , Be 2 SiO 4 :Mn 2+< , Bi 4 Ge 3 O 12 , CaAl 2 O 4 :Ce 3+< , CaLa 4 O 7 :Ce 3+< , CaAl 2 O 4 :Eu 2+< , CaAl 2 O 4 :Mn 2+< , CaAl 4 O 7 :Pb 2+< ,Mn 2+< , C a Al 2 O 4 :Tb 3+< , Ca 3 Al 2 Si 3 O 12 :Ce 3+< , Ca 3 Al 2 Si 3 O 12 :Ce 3+< , Ca 3 Al 2 Si 3 O 12 :Eu 2+< , Ca 2 B 5 O 9 Br:Eu 2+< , Ca 2 B 5 O 9 Cl:Eu 2+< , Ca 2 B 5 O 9 Cl:Pb 2+< , CaB 2 O 4 :Mn 2+< , Ca 2 B 2 O 5 :Mn 2+< ,CaB 2 O 4 :Pb 2+< , CaB 2 P 2 O 9 :Eu 2+< , Ca 5 B 2 SiO 10 :Eu 3+< , Ca 0.5 Ba 0.5 Al 12 O 19 :Ce 3+< ,Mn 2+< , Ca 2 Ba 3 (PO 4 ) 3 Cl:Eu 2+< , CaBr 2 :Eu 2+< in SiO 2 , CaCl 2 :Eu 2< + in SiO 2 , CaCl 2 :Eu 2+< ,Mn 2+< in SiO 2 , CaF 2 :Ce 3+< , CaF 2 :Ce 3+< ,Mn 2+< , CaF 2 :Ce 3+< ,Tb 3+< , CaF 2 :Eu 2+< , CaF 2 :Mn 2+< , CaGa 2 O 4 :Mn 2+< , CaGa 4 O 7 :Mn 2+< , CaGa 2 S 4 :Ce 3+< , CaGa 2 S 4 :Eu 2+< , CaGa 2 S 4 :Mn 2+< , CaGa 2 S 4 :Pb 2+< , CaGeO 3 :Mn 2+< , CaI 2 :Eu 2+< in SiO 2 , CaI 2 :Eu 2+< ,Mn 2+< in SiO 2 , CaLaBO 4 :Eu 3+< , CaLaB 3 O 7 :Ce 3+< ,Mn 2+< , Ca 2 La 2 BO 6.5 :Pb 2+< , Ca 2 MgSi 2 O 7 , Ca 2 MgSi 2 O 7 :Ce 3+< , CaMgSi 2 O 6 :Eu 2+< , Ca 3 MgSi 2 O 8 :Eu 2+< , Ca 2 MgSi 2 O 7 :Eu 2+< , CaMgSi 2 O 6 :Eu 2+< ,Mn 2+< , Ca 2 MgSi 2 O 7 :Eu 2+< ,Mn 2+< , CaMoO 4 , CaMoO 4 :Eu 3+< , CaO:Bi 3+< , CaO:Cd 2+< , CaO:Cu +< , CaO:Eu 3+< , CaO:Eu 3+< , Na +< , CaO:Mn 2+< , CaO:Pb 2+< , CaO:Sb 3+< , CaO:Sm 3+< , CaO:Tb 3+< , CaO:Tl, CaO:Zn 2+< , Ca 2 P 2 O 7 :Ce 3+< ,α-Ca 3 (PO 4 ) 2 :Ce 3+< , β-Ca 3 (PO 4 ) 2 :Ce 3+< , Ca 5 (PO 4 ) 3 Cl:Eu 2+< , Ca 5 (PO 4 ) 3 Cl:Mn 2+< , Ca 5 (PO 4 ) 3 Cl:Sb 3+< , Ca 5 (PO 4 ) 3 Cl:Sn 2+< , β-Ca 3 (PO 4 ) 2 :Eu 2+< ,Mn 2+< , Ca 5 (PO 4 ) 3 F:Mn 2+< , Ca 5 (PO 4 ) 3 F:Sb 3+< , , Ca 5 (PO 4 ) 3 F:Sn 2+< ,α-Ca 3 (PO 4 ) 2 :Eu 2+< , β-Ca 3 (PO 4 ) 2 :Eu 2+< , Ca 2 P 2 O 7 :Eu 2+< , Ca 2 P 2 O 7 :Eu 2+< ,Mn 2+< , CaP 2 O 6 :Mn 2+< , α-Ca 3 (PO 4 ) 2 :Pb 2+< , α-Ca 3 (PO 4 ) 2 :Sn 2+< , β-Ca 3 (PO 4 ) 2 :Sn 2+< , β-Ca 2 P 2 O 7 :Sn,Mn, α-Ca 3 (PO 4 ) 2 :Tr, CaS:Bi 3+< , CaS:Bi 3+< ,Na, CaS:Ce 3+< , CaS:I 2+< , CaS:Cu +< ,Na +< , CaS:La 3+< , CaS:Mn 2+< , CaSO 4 :Bi, CaSO 4 :Ce 3+< , CaSO 4 :Ce 3+< ,Mn 2+< , CaSO 4 :Eu 2+< , CaSO 4 :Eu 2+< ,Mn 2+< , CaSO 4 :Pb 2+< , CaS:Pb 2+< , CaS:Pb 2+< ,Cl, CaS:Pb 2+< ,Mn 2+< , CaS:Pr 3+< ,Pb 2+< ,Cl, CaS:Sb 3+< , CaS:Sb 3+< ,Na, CaS:Sm 3+< , CaS:Sn 2+< , CaS:Sn 2+< ,F, CaS:Tb 3+< , CaS:Tb 3+< ,Cl, CaS:Y 3+< , CaS:Yb 2+< , CaS:Yb 2+< ,Cl, CaSc 2 O 4 :Ce,Ca 3 (Sc,Mg) 2 Si 3 O 12 :Ce,CaSiO 3 :Ce 3+< , Ca 3 SiO 4 Cl 2 :Eu 2+< , Ca 3 SiO 4 Cl 2 :Pb 2+< , CaSiO 3 :Eu 2+< , Ca 3 SiO 5 :Eu 2+< , (Ca,Sr) 3 SiO 5 :Eu 2+< , (Ca,Sr)3MgSi 2 O 8 :Eu 2+< , (Ca,Sr)3MgSi 2 O 8 :Eu 2+< ,Mn 2+< , CaSiO 3 :Mn 2+< ,Pb, CaSiO 3 :Pb 2+< , CaSiO 3 :Pb 2+< ,Mn 2+< ,CaSiO 3 :Ti 4+< , CaSr 2 (PO 4 ) 2 :Bi 3+< , β-(Ca,Sr) 3 (PO 4 ) 2 :Sn 2+< Mn 2+< , CaTi 0.9 Al 0.1 O 3 :Bi 3+< , CaTiO3 < :Eu 5 (VO 4 ) 3 Cl, CaWO 4 , CaWO 4 :Pb 2+< , CaWO 4 :W, Ca 3 WO 6 :U, CaYAlO 4 :Eu 3+< , CaYBO 4 :Eu 3+< , CaYBO 4 :Eu 3+< , CaYBO 4 :Eu 3+0.< , CaYB 2 ZrO 6 :Eu 3+< , (Ca,Zn,Mg) 3 (Po 4 ) 2 :Sn, (Ce,Mg)BaAl 11 O 13 :Ce, (Ce,Mg)SrAl 11 O 18 :Ce, CeMgAl 11 O 19 , Cd O 21< :Tb CdS:Ag +< ,Cr, CdS:In, CdS:In, CdS:In,Te, CdS:Te, CdWO 4 , CsF, Csl, CsI:Na +< , CsI:TI, (ErCl 3 ) 0.25 (BaCl 2 ) Gad. ON : 3Zn 3+< , Gd 3 Ga 5 O 12 :Cr,Ce, GdNbO 4 :Bi 3+< , Gd 2 O 2 S:Eu 3+< , Gd 2 O 2 Pr 3+< , Gd 2 O 2 S:Pr,Ce,F, Gd< Tb 5 O 2 + S: 3+< , KAl 11 O 17 :Tl +< , KGa 11 O 17 :Mn 2+< , K 2 La 2 Ti 3 O 10 :Eu, KMgF 3 :Eu 2+< , KMgF 3 :Mn 2+< , K 2 , Si O. 4 B :Mn 3+< , LaAlB 2 O 6 :Eu 3+< , LaAlO 3 :Eu 3+< , LaAlO 3 :Sm 3+< , LaAsO 4 :Eu 3+< , LaBr 3 :Ce 3+< , LaBO 3 :Eu 3+< ,LaCl 3 :Ce 3+< , La 2 O 3 :Bi 3+< , LaOBr:Tb 3+< , LaOBr:Tm 3+< , LaOCl:Bi 3+< , LaOCl:Eu 3+< , LaOF:Eu 3+< , La 2 O 3 :Eu 3+< , La 2 O 3 :Pr 3+< , La 2 O 2 S:Tb 3+< , LaPO 4 :Ce 3+< , LaPO 4 :Eu 3+< , LaSiO 3 Cl:Ce 3+< , LaSiO 3 Cl:Ce 3+< ,Tb 3+< , LaVO 4 :Eu 3+< , La 2 W 3 O 12 :Eu 3+< , LiAlF 4 :Mn 2< +, LiAl 5 O 8 :Fe 3+< , LiAlO 2 :Fe 3+< , LiAlO 2 :Mn 2+< , LiAl 5 O 8 :Mn 2+< , Li 2 CaP 2 O 7 :Ce 3+< ,Mn 2+< , LiCeBa 4 Si 4 O 14 :Mn 2+< , LiCeSrBa 3 Si 4 O 14 :Mn 2+< , LiInO 2 :Eu 3+< , LiInO 2 :Sm 3+< , LiLaO 2 :Eu 3+< , LuAlO 3 :Ce 3+< , (Lu,Gd) 2 SiO 5 :Ce 3+< , Lu 2 SiO 5 :Ce 3+< , Lu 2 Si 2 O 7 :Ce 3+< , LuTaO 4 :Nb 5+< , Lu 1-x Y x AlO 3 Ce 3+< (mit 0 ≤ x ≤ 1), (Lu,Y) 3 (Al,Ga,Sc) 5 O 12 :Ce,MgAl 2 O 4 :Mn 2+< , MgSrAl 10 O 17 :Ce, MgB 2 O 4 :Mn 2+< , MgBa 2 (PO 4 ) 2 :Sn 2+< , MgBa 2 (PO 4 ) :U, MgBaP 2 O 7 :Eu 2+< , MgBaP 2 O 7 :Eu 2+< ,Mn 2+< , MgBa 3 Si 2 O 8 :Eu 2+< , MgBa(SO 4 ) 2 :Eu 2+< , Mg 3 Ca 3 (PO 4 ) 4 :Eu 2+< , MgCaP 2 O 7 :Mn 2+< ,Mg 2 Ca(SO 4 ) 3 :Eu 2+< , Mg 2 Ca(SO 4 ) 3 :Eu 2+< ,Mn 2< , MgCeAl n O 19 :Tb 3+< , Mg 4 (F)GeO 6 :Mn 2+< , Mg 4 (F)(Ge,Sn)O 6 :Mn 2+< , MgF 2 :Mn 2+< , MgGa 2 O 4 :Mn 2+< , Mg 8 Ge 2 O 11 F 2 :Mn 4+< , MgS:Eu 2+< , MgSiO 3 :Mn 2+< , Mg 2 SiO 4 :Mn 2+< , Mg 3 SiO 3 F4:Ti 4+< , MgSO 4 :Eu 2+< , MgSO 4 :Pb 2+< , MgSrBa 2 Si 2 O 7 :Eu 2+< , MgSrP 2 O 7 :Eu 2+< , MgSr 5 (PO 4 ) 4 :Sn 2+< , MgSr 3 Si 2 O 8 :Eu 2+< ,Mn 2+< , Mg 2 Sr(SO 4 ) 3 :Eu 2+< , Mg 2 TiO 4 :Mn 4+< , MgWO 4 , MgYBO 4 :Eu 3+< , M 2 MgSi 2 O 7 :Eu 2+< (M = Ca, Sr, and / or Ba), M 2 MgSi 2 O 7 :Eu 2+< ,Mn 2+< (M = Ca, Sr, und / oder Ba), M 2 MgSi 2 O 7 :Eu 2+< ,Zr 4+< (M = Ca, Sr, und / oder Ba), M 2 MgSi 2 O 7 :Eu 2+< ,Mn 2+< ,Zr 4+< (M = Ca, Sr, und / oder Ba), Na 3 Ce(PO 4 ) 2 :Tb 3+< , Na 1.23 K 0.42 Eu 0.12 TiSi 4 O 11 :Eu 3+< , Na 1.23 K 0.42 Eu 0.12 TiSi 5 O 13 xH 2 O:Eu 3+< , Na 1.29 K 0.46 Er 0.08 TiSi 4 O 11 :Eu 3+< , Na 2 Mg 3 Al 2 Si 2 O 10 :Tb, Na(Mg 2-x Mn x )LiSi 4 O 10 F 2 :Mn (mit 0 ≤ x ≤ 2), NaYF 4 :Er 3+< ,Yb 3+< , NaYO 2 :Eu 3+< , P46 (70%) + P47 (30%), β-SiAlON:Eu, SrAl 12 O 19 :Cr 3+< , Mn 2+< , SrAl 2 O 4 :Eu 2+< , SrAl 4 O 7 :Eu 3+< , SrAl 12 O 19 :Eu 2+< , SrAl 2 S 4 :Eu 2+< , Sr 2 B 5 O 9 Cl:Eu 2+< , SrB 4 O 7 :Eu 2+< (F,Cl,Br), SrB 4 O 7 :Pb 2+< , SrB 4 O 7 :Pb 2+< , Mn 2+< , SrB 8 O 13 :Sm 2+< , Sr x Ba y Cl z Al 2 O 4-z / 2 : Mn 2+< , Ce 3+< , SrBaSiO 4 :Eu 2+< , (Sr,Ba) 3 SiO 5 :Eu,(Sr,Ca)Si 2 N 2 O 2 :Eu, Sr(Cl,Br,I) 2 :Eu 2+< in SiO 2 , SrCl 2 :Eu 2+< in SiO 2 , Sr 5 Cl(PO 4 ) 3 :Eu, Sr w F x B 4 O 6,5 :Eu 2+< , Sr w F x B y O z :Eu 2+< ,Sm 2+< , SrF 2 :Eu 2+< , SrGa 12 O 19 :Mn 2+< , SrGa 2 S 4 :Ce 3+< , SrGa 2 S 4 :Eu 2+< , Sr 2 -y Ba y SiO 4 :Eu (wobei 0 ≤ y ≤ 2), SrSi 2 O 2 N 2 :Eu, SrGa 2 S 4 :Pb 2+< , SrIn 2 O 4 :Pr 3+< , Al 3+< , (Sr,Mg) 3 (PO 4 ) 2 :Sn, SrMgSi 2 O 6 :Eu 2+< , Sr 2 MgSi 2 O 7 :Eu 2+< , Sr 3 MgSi 2 O 8 :Eu 2+< , SrMoO 4 :U, SrO 3B 2 O 3 :Eu 2+< ,Cl, β-SrO 3B 2 O 3 :Pb 2+< , β-SrO 3B 2 O 3 :Pb 2+< ,Mn 2+< , α-SrO·3B 2 O 3 :Sm 2+< , Sr 6 P 5 BO 20 :I,Sr 5 (PO 4 ) 3 Cl:Eu 2+< , Sr 5 (PO 4 ) 3 Cl:Eu 2+< ,Pr 3+< , Sr 5 (PO 4 ) 3 Cl:Mn 2+< , Sr 5 (PO 4 ) 3 Cl:Sb 3+< ,Sr 2 P 2 O 7 :Eu 2+< , β-Sr 3 (PO 4 ) 2 :Eu 2+< , Sr 5 (PO 4 ) 3 F:Mn 2+< ,Sr 5 (PO 4 ) 3 F:Sb 3+< ,Sr 5 (PO 4 ) 3 F:Sb 3+< ,Mn 2+< , Sr 5 (PO 4 ) 3 F:Sn 2+< , Sr 2 P 2 O 7 :Sn 2+< , β-Sr 3 (PO 4 ) 2 :Sn 2+< , β-Sr 3 (PO 4 ) 2 :Sn 2+< ,Mn 2+< (Al), SrS:Ce 3+< , SrS:Eu 2+< , SrS:Mn 2+< , SrS:Cu +< ,Na, SrSO 4 :Bi, SrSO 4 :Ce 3+< , SrSO 4 :Eu 2+< , SrSO 4 :Eu 2+< , Mn 2+< , Sr 5 Si 4 O 10 Cl 6 :Eu 2+< , Sr 2 SiO 4 :Eu 2+< , Sr 3 SiO 5 :Eu 2+< , (Sr,Ba) 3 SiO 5 :Eu 2+< , SrTiO 3 :Pr 3+< , SrTiO 3 :Pr 3+< ,Al 3+< ,SrY 2 O 3 :Eu 3+< , ThO 2 :Eu 3+< , ThO 2 :Pr 3+< , ThO 2 :Tb 3+< , YAl 3 B 4 O 12 :Bi 3+< , YAl 3 B 4 O 12 :Ce 3+< , YAl 3 B 4 O 12 :Ce 3+< ,Mn, YAl 3 B 4 O 12 :Ce 3+< ,Tb 3+< , YAl 3 B 4 O 12 :Eu 3+< , YAl 3 B 4 O 12 :Eu 3+< ,Cr 3+< , YAl 3 B 4 O 12 :Th 4+< ,Ce 3+< ,Mn 2+< , YAlO 3 :Ce 3+< , Y 3 Al 5 O 12 :Ce 3+< , Y 3 Al 5 O 12 :Cr 3+< , YAlO 3 :I 3+< ,Y 3 Al 5 O 12 :Eu 3r< , Y 4 Al 2 O 9 :Eu 3+< , Y 3 Al 5 O 12 :Mn 4+< , YALO 3 :Sm 3+< , YALO 3 :Tb 3+< , Y 3 Al 5< O 3 O 13< :T+4 , YBO 3 :Ce 3+< , YBO 3 :Eu 3+< , YF 3 :Er 3+< ,Yb 3+< , YF 3 :Mn 2+< , YF 3 :Mn 2+< ,Th 4+< , YF 3 :Tm, 3+< ,Eb (Y,Gd)BO 3 :Tb, (Y,Gd) 2 O 3 :Eu 3+< , Y 1.34 Gd 0.60 O 3 (Eu,Pr), Y 2 O 3 :Bi 3+< , YOBr:Eu 3+< , Y 2 O 2 :Ceu +3 : O 2, Y 2,Y 3+< , Y 2 O 3 :Ce 3+< ,Tb 3+< , YOCl:Ce 3+< , YOCl:Eu 3+< , YOF:Eu 3+< , YOF:Tb 3+< , Y 2 O 3 :Ho 3+< + 3 , S< Y 2 , Y O 2 3+< , Y 2 O 2 S:Tb 3+< , Y 2 O 3 :Tb 3+< , YPO 4 :Ce 3+< , YPO 4 :Ce 3+< ,Tb 3+< , YPO 4 :Eu 3+< , YPO 4 : ,Mn Y 2+< , Y(P,V)O 4 :Eu, Y 2 SiO 5 :Ce 3+< , YTaO 4 , YTaO 4 :Nb 5+< , YVO 4 :Dy 3+< , YVO 4 :Eu 3+< , ZnAl 2 O 4 :Mn <Mn 2+< , ZnAl 2 O 4 :Mn 2,B Zn O2 , ZnAl 3 :Mn 2+< , (Zn,Be) 2 SiO 4 :Mn 2+< , Zn 0.4 Cd 0.6 S:Ag, Zn 0.6 Cd 0.4 S:Ag, (Zn,Cd)S:Ag,Cl, (Zn,Cd)S:2,Cu 2 :<M , Zn4 ZnF ZnGa 2 O 4 :Mn 2+< ,ZnGa 2 S 4 :Mn 2+< , Zn 2 GeO 4 :Mn 2+< , (Zn,Mg)F 2 :Mn 2+< , ZnMg 2 (PO 4 ) 2 :Mn 2+< , (Zn,Mg) 3 (PO 4 ) 2 :Mn 2+<, AA 3+< , ZnO:Bi 3+< , ZnO:Ga 3+< , ZnO:Ga, ZnO-CdO:Ga, ZnO:S, ZnO:Se, ZnO:Zn, ZnS:Ag +< ,Cl -< , ZnS:Ag,Cu,Cl, ZnO:Ag,Ag,Ag,Zn,In ZnS-CdS (25-75), ZnS-CdS (50-50), ZnS-CdS (75-25), ZnS-CdS:Ag,Br,Ni, ZnS-CdS:Ag +< ,Cl, ZnS-CdS:Cu,Br, ZnS-CdS:CdS:Cu,Br, ZnS-CdS:CdS:Cu, ZnS-CdS:Cl 2+< , ZnS:Cu, ZnS:Cu +< ,Al 3+< , ZnS:Cu +< ,Cl -< , ZnS:Cu,Sn, ZnS:Eu 2+< , ZnS:Mn 2+< , ZnS:Mn,Cu, ZnS:Mn , ZnS:Mn,Cu, ZnS:Mn 2+<P, ZnS:2+<, Te ZnS:P 3-< ,Cl -< , ZnS:Pb 2+< , ZnS:Pb 2+< ,Cl -< , ZnS:Pb,Cu, Zn 3 (PO 4 ) 2 :Mn 2+< , Zn 2 SiO 4 :Mn 2+< , ZnS:Pb 2+< , ZnS:Mn 2+< , A , Zn 2 SiO 4 :Mn,Sb 2 O 2 , Zn 2 SiO 4 :Mn 2+< ,P, Zn 2 SiO 4 :Ti 4+< , ZnS:Sn 2+< , ZnS:Sn,Ag, ZnS:Sn 2+< ,ZnS:Sn,Ag, ZnS:Sn 2+< ,Li +< , ZnS:Mn, Zn:Sn:Te 2+< , ZnSe:Cu +< ,Cl and ZnWO 4 .,

[0146] The light-converting material or the light-converting mixture according to the present invention can be used for the partial or complete conversion of ultraviolet and / or blue light into light with a longer wavelength, such as green or red light. The present invention thus further relates to the use of the light-converting material or the light-converting mixture in a light source. The light source is particularly preferably an LED, in particular a phosphor-converted LED, or pc-LED for short. It is particularly preferred that the light-converting material is mixed with at least one further light-converting material and / or one or more conversion phosphors, thus forming a light-converting mixture that emits, in particular, white light or light with a specific color point (color-on-demand principle).The "color-on-demand principle" refers to the realization of light of a specific color point with a PC-LED using one or more light-emitting materials and / or conversion phosphors.

[0147] The present invention thus further provides a light source comprising a primary light source and at least one light-converting material according to the invention or at least one light-converting mixture according to the invention. Here, too, it is particularly preferred that the light source, in addition to the light-converting material according to the invention, also comprises another light-converting material according to the invention, luminescent material, and / or semiconductor nanoparticles, so that the light source preferably emits white light or light with a specific color point.

[0148] The light source according to the invention is preferably a PC-LED containing a primary light source and a light-converting material or a light-converting mixture. The light-converting material or the light-converting mixture is preferably formed in the form of a layer, wherein the layer may comprise a plurality of sublayers, each of the sublayers containing a different light-converting material or a different light-converting mixture. Thus, the layer may comprise either a single light-converting material or a single light-converting mixture or a plurality of sublayers, each sublayer in turn containing a different light-converting material or a different light-converting mixture.The thickness of the layer can range from a few millimeters to a few micrometers, preferably in the range between 2 mm and 5 µm, depending on the particle size of the light-converting material or the light-converting mixture and the required optical properties.

[0149] In some embodiments for modulating the emission spectrum of an LED, a single layer or a layer comprising sublayers can be formed on the primary light source. The layer or layer comprising sublayers can be disposed either directly on the primary light source or spaced from the primary light source by air, vacuum, or a filler material. The filler material (e.g., silicone or epoxy) can serve as thermal insulation and / or as an optical diffusion layer. Modulating the emission spectrum of the primary light source can serve illumination purposes to produce a light output with a broad color spectrum, e.g., "white" light with a high color rendering index (CRI) and the desired correlated color temperature (CCT).Broad-spectrum light output is achieved by converting a portion of the original light produced by the primary light source into longer-wavelength light. Increasing the intensity of red is important to achieve "warmer" light with a lower CCT (e.g., 2700-3500K), but "smoothing" specific regions in the spectrum, such as the blue-to-green transition, can also improve CRI. Modulation of LED lighting can also be used for visual display purposes.

[0150] The light-converting material or the light-converting mixture according to the invention can be dispersed in a potting material, such as a glass, silicone, silazane, or epoxy resin, or can be formed as a ceramic material. The potting material is a light-transmitting matrix material that encloses the light-converting material or the light-converting mixture according to the invention. Preferred examples of the potting material, which are by no means limiting, are mentioned above. The light-converting material or the light-converting mixture is preferably used in a ratio of 3 to 80 wt. %, based on the potting material, depending on the desired optical properties and the design of the application.

[0151] In a preferred embodiment, the light-converting material or the light-converting mixture according to the invention is arranged directly on the primary light source.

[0152] In an alternative preferred embodiment, the light-converting material according to the invention or the light-converting mixture according to the invention is arranged on a carrier material remote from the primary light source (so-called remote phosphor principle).

[0153] The primary light source of the light source according to the invention can be a semiconductor chip, a luminescent light source, such as ZnO, a so-called TCO (Transparent Conducting Oxide), a ZnSe or SiC-based device, a device based on an organic light-emitting layer (OLED), or a plasma or discharge source, most preferably a semiconductor chip. If the primary light source is a semiconductor chip, it is preferably a luminescent indium aluminum gallium nitride (InAlGaN), as is known in the art. Possible forms of such primary light sources are known to those skilled in the art. Lasers are also suitable as light sources.

[0154] The light-converting material or the light-converting mixture according to the invention can be converted into any desired external shapes, such as spherical particles, platelets, structured materials, and ceramics, for use in light sources, in particular PC LEDs. These shapes are collectively referred to as "shaped bodies." Consequently, the shaped bodies are light-converting shaped bodies.

[0155] Another object of the present invention is a method for producing a light source, wherein the light-converting material or the light-converting mixture is applied in the form of a film by spin coating or spray coating or in the form of a foil as a laminate to the primary light source or the carrier material.

[0156] A further subject matter of the invention is a lighting unit containing at least one light source according to the invention. The use of the lighting unit is not subject to any particular restriction. For example, the lighting unit can be used in optical display devices, in particular liquid crystal displays (LC displays), with a backlight. Therefore, such a display device is also the subject matter of the present invention. In the lighting unit according to the invention, the optical coupling between the light-converting material or the light-converting mixture and the primary light source (in particular semiconductor chips) is preferably achieved by a light-conducting arrangement or device.This makes it possible to install the primary light source at a central location and optically couple it to the light-converting material or mixture by means of light-conducting devices, such as light-conducting fibers. This allows for the creation of luminaires tailored to the lighting requirements, consisting of one or more different light-converting materials or mixtures, which can be arranged to form a luminescent screen, and a light guide coupled to the primary light source. This makes it possible to place a strong primary light source at a location convenient for electrical installation and to install luminaires made of light-converting materials or mixtures coupled to the light guides without additional electrical cabling, simply by laying light guides at any location.

[0157] The following examples and figures are intended to illustrate the present invention. However, they are in no way to be considered limiting. Examples

[0158] All emission spectra were recorded in an integrating sphere combined with an OceanOptics QE Pro spectrometer. A halogen cold light source with a monochromator served as the excitation light source for the powder spectra, and the excitation wavelength-dependent intensity was recorded using a photomultiplier. The tested LEDs were driven by a Keithley sourcemeter (the 5630 LED with a -450 nm chip wavelength at 60 mA was used for the experiments shown here).

[0159] The particle size distributions were measured using a Beckman Coulter Multisizer III in isotonic saline solution. More than 100,000 particles were measured in each sample. Examples of how to produce the light-converting material ORANGE or RED:

[0160] Example 1: 5 g of an orange powdery, Eu 2+< -activated silicate phosphor ((Ba,Sr) 3 SiO 5 with λ em,max = 600 nm) are suspended in 15 ml of toluene in a 100 ml flask. 50 mg of a red nanodot suspension (20 wt. % CdSe / CdS-based nanosemiconductor crystals with a peak emission wavelength of 625 nm in toluene) are added to the suspension. This suspension is stirred for 1 h. The solvent is carefully removed on a rotary evaporator under vacuum at a water bath temperature of 50 °C. The treated silicate powder (QD red 1) is dried for a further 1.5 h under vacuum at a water bath temperature of 50 °C.

[0161] Example 2:5 g of an orange powdery, Eu 2+< -activated silicate phosphor ((Ba,Sr) 3 SiO 5 with λ em,max = 600 nm) are suspended in 15 ml of toluene in a 100 ml flask. 1.74 g of a red nanodot suspension (10 wt. % InP-ZnS-based nanosemiconductor crystals with a peak emission wavelength of 648 nm in toluene) are added to the suspension. This suspension is stirred and mixed for 2.5 h. The solvent is carefully removed on a rotary evaporator under vacuum at a water bath temperature of 50 °C. To completely remove the solvent, the treated silicate (QD red 2) is left on the rotary evaporator for two more hours under vacuum at 50 °C.

[0162] Example 3:2.5 g of a red powdered, Eu 2+< -activated nitride phosphor (CaAlSiN 3 with λ em,max = 613 nm) are suspended in 15 ml of toluene in a 100 ml flask. 250 mg of a red nanodot suspension (20 wt. % CdSe / CdS-based nanosemiconductor crystals with a peak emission wavelength of 625 nm in toluene) are added to the suspension. This suspension is stirred for 1 h. The solvent is carefully removed on a rotary evaporator under vacuum at a water bath temperature of 50 °C. To completely remove the solvent, the treated silicate (QD red 3) is left on the rotary evaporator for two more hours under vacuum at 50 °C.

[0163] Example 4:5 g of an orange powdery, Eu 2+< -activated silicate phosphor ((Ba,Sr) 3 SiO 5 with λ em,max = 585 nm) are suspended in 15 ml of ethanol in a 100 ml flask. 650 mg of a red nanodot suspension (15 wt. % CdSe / CdS-based nanosemiconductor crystals with a peak emission wavelength of 627 nm in PGMEA) are added to the suspension. This suspension is stirred for 2.5 h. The solvent is carefully removed on a rotary evaporator under vacuum at a water bath temperature of 50 °C. The treated silicate powder (QD red 4) is dried for a further 2.5 h under vacuum at a water bath temperature of 50 °C. GREEN:

[0164] Example 5:5 g of a green powdered, Eu 2+< -activated silicate phosphor (Ba,Sr) 2 SiO 4 with λ em,max = 517 nm) is suspended in 15 ml of toluene in a 100 ml flask. 600 mg of a green nanodot suspension (20 wt. % CdSe / CdS / ZnS-based nanosemiconductor crystals with a peak emission wavelength of 525 nm in toluene) is added to the suspension. This suspension is stirred for 2 h. The solvent is carefully removed under vacuum at a 50 °C water bath temperature using a rotary evaporator. The treated silicate powder (QD green 1) is dried for another hour under vacuum at a 50 °C water bath temperature.

[0165] Example 6:5 g of a green powdered, Eu 2+< -activated silicate (Ba,Sr) 2 SiO 4 with λ em,max = 520 nm) is suspended in 15 ml of ethanol in a 100 ml flask. 1.0 g of a green nanodot suspension (10 wt. % CdSe / CdS / ZnS-based nanosemiconductor crystals with a peak emission wavelength of 525 nm in water) is added to the suspension. This suspension is stirred for 4 h. The solvent is carefully removed under vacuum at a water bath temperature of 55 °C on a rotary evaporator. The treated silicate powder (QD green 2) is dried for another hour under vacuum at a water bath temperature of 55 °C.

[0166] Example 7:5 g of a green powdered, Eu 2+< -activated silicate phosphor (Ba,Sr) 2 SiO 4 with λ em,max = 524 nm) is suspended in 15 ml of ethanol in a 100 ml flask. 1.05 g of a green nanodot suspension (10 wt. % CdSe / CdS / ZnS-based nanosemiconductor crystals with a peak emission wavelength of 525 nm in water) is added to the suspension. This suspension is stirred for 3 h. The solvent is carefully removed under vacuum at a 50 °C water bath temperature using a rotary evaporator. The treated silicate powder (QD green 3) is dried for another hour under vacuum at a 50 °C water bath temperature.

[0167] Example 8:5 g of a green powdered, Eu 2+< -activated silicate phosphor (Ba,Sr) 2 SiO 4 with λ em,max = 515 nm) are suspended in 15 ml of ethanol in a 100 ml flask. 1.05 g of a green nanodot suspension (10 wt. % CdSe / CdS / ZnS-based nanosemiconductor crystals with a peak emission wavelength of 525 nm in water) is added to the suspension. This suspension is stirred for 1.5 h. The solvent is carefully removed under vacuum at a water bath temperature of 55 °C on a rotary evaporator. The treated silicate powder (QD green 4) is dried for another hour under vacuum at a water bath temperature of 55 °C.

[0168] Example 9:5 g of a green powdered, Eu 2+< -activated silicate phosphor (Ba,Sr) 2 SiO 4 with λ em,max = 521 nm) are suspended in 15 ml of ethanol in a 100 ml flask. 1.55 g of a green nanodot suspension (10 wt. % CdSe / CdS / ZnS-based nanosemiconductor crystals with a peak emission wavelength of 525 nm in water) is added to the suspension. This suspension is stirred for 1.5 h. The solvent is carefully removed under vacuum at a water bath temperature of 55 °C on a rotary evaporator. The treated silicate powder (QD green 5) is dried for another hour under vacuum at a water bath temperature of 55 °C. GREEN / RED:

[0169] Example 10:5 g of a green powdered, Eu 2+< -activated orthosilicate phosphor ((Sr,Ba) 2 SiO 4 ) with λ em,max = 520 nm) are suspended in 15 ml of toluene in a 100 ml flask. 82 mg of a red nanodot suspension (20 wt. % CdSe / CdS-based nanosemiconductor crystals with a peak emission wavelength of 625 nm in toluene) and 416 mg of a green nanodot suspension (20 wt. % CdSe / CdS / ZnS nanorods with a peak emission wavelength of 525 nm in toluene) are added to the suspension. This suspension is stirred for 1 h. The solvent is carefully removed under vacuum using a rotary evaporator at a water bath temperature of 50 °C. To completely remove the solvent, the treated silicate (QD red / green 1) is left on the rotary evaporator under vacuum at 50 °C for another hour.

[0170] Example 11:5 g of a green powdered, Eu 2+< -activated orthosilicate phosphor ((Sr,Ba) 2 SiO 4 with λ em,max = 520 nm) are suspended in 15 ml of toluene in a 100 ml flask. 71 mg of a red nanodot suspension (20 wt. % CdSe / CdS-based nanosemiconductor crystals with a peak emission wavelength of 625 nm in toluene) are added to the suspension. This suspension is stirred for 1 h. The solvent is carefully removed on a rotary evaporator under vacuum at a water bath temperature of 50 °C. To completely remove the solvent, the treated silicate is left on the rotary evaporator for another hour under vacuum at 50 °C. Subsequently, the treated silicate is suspended in 10 ml of ethanol and 810 mg of a green nanodot suspension (10 wt% CdSe / CdS / ZnS-based nanosemiconductor crystals with 525 nm peak emission wavelength in water) is added.After stirring for one hour at room temperature, the solvent is carefully removed on a rotary evaporator under vacuum at a water bath temperature of 50 °C. To completely remove the solvent, the treated silicate (QD red / green 2) is left on the rotary evaporator for two more hours under vacuum at 50 °C. Reference examples

[0171] Example 12:5 g of a blue powdered Eu 2+< -activated orthosilicate phosphor ((Sr,Ca) 3 MgSi 2 O 8 ) with λ em,max = 466 nm) are suspended in 15 ml of ethanol in a 100 ml flask. 1.05 g of a green nanodot suspension (10 wt. % CdSe / CdS / ZnS-based nanosemiconductor crystals with a peak emission wavelength of 525 nm in water) is added to the suspension. This suspension is stirred for 1.5 h. The solvent is carefully removed under vacuum at a water bath temperature of 55 °C using a rotary evaporator. The treated silicate powder (QD green 6) is dried for another hour under vacuum at a water bath temperature of 55 °C.

[0172] Example 13:5 g of an orange powdered Eu 2+< -activated silicate phosphor ((Ba,Sr) 3 SiO 5 with λ em,max = 585 nm) are suspended in 15 ml of ethanol in a 100 ml flask. 1.05 g of a green nanodot suspension (10 wt. % CdSe / CdS / ZnS-based nanosemiconductor crystals with a peak emission wavelength of 525 nm in water) is added to the suspension. This suspension is stirred for 2.5 h. The solvent is carefully removed under vacuum at a 50 °C water bath temperature using a rotary evaporator. The treated silicate powder (QD green 7) is dried for another 2.5 h under vacuum at a 50 °C water bath temperature.

[0173] Table 1 below shows the luminescent materials and semiconductor nanoparticles (QDs) used in Examples 1 to 13, whereby Examples 2, 4, 10, 11, 12, and 13 are not part of the present invention. The peak wavelength maxima λ em,max of the luminescent materials used, as well as the peak wavelength maxima λ em,max of the semiconductor nanoparticles used, and the peak wavelength maxima λ em,max and half-widths are given. FWHM of the emissions of the prepared light-converting materials. The emission of the semiconductor nanoparticles used was measured in dilute suspension, as described above. The peak wavelength maxima λ em,max and full width at half maximum (FWHM) of the emissions of the prepared light-converting materials were measured in powder and show a long-wavelength shift relative to the pure semiconductor nanoparticle emissions due to reabsorption effects. Table 1 Example λ em,max (luminescence - material) λ em,max (semiconductor nanoparticles) λ max / nm (product) FWHM / nm (product) Nitride (613 nm) - 613 72 Silicate (600 nm) - 600 78 Silicate (585 nm) - 585 67 Silicate (524 nm) - 524 64 Silicate (520 nm) - 520 65 Silicate (517 nm) - 517 63 Silicate (515 nm) - 515 63 1 Silicate (600 nm) Red 1 (625 nm) 625 33 2 Silicate (600 nm) Red 2 (648 nm) 648 75 3 Nitride (613 nm) Red 3 (625 nm) 625 37 4 Silicate (585 nm) Red 4 (627 nm) 627 30 5 Silicate (517 nm) Green 1 (525 nm) 532 40 6 Silicate (520 nm) Green 2 (525 nm) 534 48 7 Silicate (524 nm) Green 3 (525 nm) 535 56 8 Silicate (515 nm) Green 4 (525 nm) 534 50 9 Silicate (521 nm) Green 5 (525 nm) 536 45 10 Silicate (520 nm) Red (625 nm) / Green 1 (525 nm) 530 26 623 38 11 Silicate (520 nm) Red (625 nm) / Green 2 (525 nm) 533 25 621 49 12 Silicate (466 nm) Green 6 (525 nm) 466 44 528 38 13 Silicate (585 nm) Green 7 (525 nm) 585 73 Measurement of the manufactured light-converting materials

[0174] The relative spectral energy distribution of all light-converting materials was measured using a fiber optic spectrometer at an excitation wavelength of 450 nm. The relative spectral energy distribution of all produced materials (emission) is shown in the Figures 1 to 5 shown. LED evaluation

[0175] Empty LEDs are filled with an optical silicone (Dow Corning OE6550) containing precise amounts of red and green particles suspended in a dispenser. The silicone suspension is prepared using a biaxial rotary mixer and subsequently degassed under vacuum. The LEDs are then cured in a drying cabinet at 150°C for 1 hour and measured for the resulting light emission using an integrating sphere with a fiber optic spectrometer. By varying the total amount of powder in the silicone, as well as the individual red, yellow, or green components, virtually any color coordinate in the color triangle can be achieved.

[0176] Instead of silicone, other highly transparent materials can also be used as potting compounds, such as epoxy resins.

[0177] Further useful advantages of the light-converting materials according to the invention are: By reabsorbing the efficient emission of a luminescent material that has a high absorption in the area of ​​the primary light source, an increased efficiency of the LED and a significantly reduced material consumption in the LED are made possible. This is achieved by Figure 7This illustrates the difference between the consumption of a suspension based on an analogously produced unactivated substrate and the narrower emission band, whereby at the same color point, the consumption of a suspension based on an analogously produced unactivated substrate increases by 67% and the efficiency decreases by 22%. Higher color space coverage is possible than with conventional phosphors such as green β-SiAlON or orthosilicate in combination with the red phosphor K2SiF6 due to a narrower emission band. The same sedimentation behavior is achieved across all conversion materials used in the LED, can be specifically adjusted if necessary, and increases the production yield in the LED manufacturing process. Easy to use, as no new production equipment is required at the LED manufacturer. Users have more options for adjusting the LED emission compared to conventional QD films (flexible application, as users do not have to use a different light converter for each color location).Increased LED brightness, as the narrowband red emission eliminates energy waste in the deep, long-wavelength spectral range with low eye sensitivity. Existing phosphor coating technologies can be applied; no additional barrier films are required.

Claims

1. Light-converting material comprising a luminescent material being in a form of macroscopic particles and at least one type of semiconductor nanoparticles, wherein the semiconductor nanoparticles are located on the surface of the luminescent material, wherein the particles include several of the semiconductor nanoparticles, characterized in that the emission from the semiconductor nanoparticles is in the region of the emission from the luminescent material, wherein a maximum of a core exciton absorption band of the semiconductor nanoparticles and an emission maximum of the luminescent material are a maximum of 50 nm apart, wherein an overlap AOL between an emission band of the luminescent material and the core exciton absorption band of the semiconductor nanoparticles being at least 80 %, based on a total area of the core exciton excitation band Aex such that the following equation applies: A OL / A ex * 100 % > 80 % , and wherein the following equation applies for an emission maximum λem,max of the semiconductor nanoparticles and an emission maximum λem,max of the luminescent material: 0 nm ≤ λ em , max semiconductor nanoparticles − λ em , max luminescent material ≤ 30 nm .

2. Light-converting material according to claim 1, wherein the emission band of the semiconductor nanoparticles and the emission band of the luminescent material fully or partly overlap.

3. Light-converting material according to claim 1 or 2, wherein the luminescent material is a phosphor.

4. Light-converting material according to one or more of the claims 1 to 3, characterized in that the luminescent material is an inorganic phosphor activated by Eu(II), Ce(III), Mn(II), Mn(IV), Eu(III), Tb(III), Sm(III), Cr(III), Sn(II), Pb(II), Sb(III), Bi(III), Cu(I) or Ag(I), selected from the list consisting of metal oxides, silicates and halosilicates, phosphates and halophosphates, borates, haloborates and borosilicates, aluminates, gallates and alumosilicates, molybdates and tungstates, sulfates, sulfides, selenides and tellurides, nitrides and oxynitrides, SiAlONs, complex metal-oxygen compounds, halogen compounds and oxy compounds.

5. Light-converting material according to one or more of the claims 1 to 4, characterized in that the semiconductor nanoparticles comprise at least two different semiconductor materials.

6. Light-converting material according to claim 5, characterized in that the semiconductor materials are selected from group II-VI semiconductors, group III-V semiconductors, group IV-VI semiconductors, group I-III-VI2 semiconductors as well as from alloys and / or combinations of these semiconductors, wherein the semiconductor materials may optionally be doped with one or more transition metals.

7. Light-converting material according to one or more of the claims 1 to 6, characterized in that the semiconductor nanoparticles are in the form of nanodots, nanorods, nanoflakes, nanotetrapods, nanodots in nanorods, nanorods in nanorods and / or nanodots in nanoflakes.

8. Light-converting mixture comprising one or more of the light-converting materials according to one or more of the claims 1 to 7.

9. Utilization of a light-converting material according to one of the claims 1 to 7 or a light-converting mixture according to claim 8 for a partial or complete conversion of ultraviolet and / or blue light into light having a longer wavelength.

10. Light source comprising at least one primary light source and at least one light-converting material according to one of the claims 1 to 7 or a light-converting mixture according to claim 8.

11. Light source according to claim 10, characterized in that the light-converting material or the light-converting mixture is arranged directly on the primary light source or is arranged on a support material remote from the primary light source.

12. Method for the production of a light source according to claim 10 or 11, wherein the light-converting material or the light-converting mixture is applied to the primary light source or the support material in the form of a film by spin coating or spray coating or in the form of a sheet as laminate.

13. Lighting unit containing at least one light source according to claim 10 or 11.