Optoelectronic Component and Method for Producing an Optoelectronic Component

Abstract

An optoelectronic component and a method for producing an optoelectronic component are disclosed. In an embodiment an optoelectronic component includes at least one laser source configured to emit at least one laser beam during operation and a self-supporting conversion element arranged in a beam path of the laser beam, wherein the self-supporting conversion element comprises a substrate followed by a first layer, the first layer being directly bonded to the substrate and comprising at least one conversion material embedded in a glass matrix, wherein the glass matrix has a proportion of 50 vol % to 80 vol % inclusive in the first layer, wherein the substrate is free of the glass matrix and of the conversion material and mechanically stabilize the first layer, and wherein the first layer has a layer thickness of less than 200 m.

Claims

1-18. (canceled)

19. An optoelectronic component comprising: at least one laser source configured to emit at least one laser beam with primary radiation; and a self-supporting conversion element arranged in a beam path of the laser beam, wherein the self-supporting conversion element comprises a substrate followed by a first layer, the first layer being directly bonded to the substrate and comprising at least one conversion material embedded in a glass matrix, wherein the glass matrix has a proportion of 50 vol % to 80 vol % inclusive in the first layer, wherein the substrate is free of the glass matrix and of the conversion material and mechanically stabilize the first layer, and wherein the first layer has a layer thickness of less than 200 m.

20. The optoelectronic component according to claim 19, wherein the laser beam is dynamically arranged with respect to the conversion element.

21. The optoelectronic component according to claim 19, wherein the laser beam is statically arranged with respect to the conversion element.

22. The optoelectronic component according to claim 19, further comprising a dichroic layer stack disposed between substrate and the glass matrix, wherein the dichroic layer stack is transmissive for the primary radiation, wherein the conversion material is configured to at least partially convert the primary radiation into secondary radiation with a longer wavelength, and wherein the dichroic layer stack is configured to at least partially reflected the secondary radiation.

23. The optoelectronic component according to claim 19, wherein the laser beam strikes the conversion material and at least partially converts the primary radiation of the laser beam into secondary radiation with a longer wavelength, wherein the primary and secondary radiation are reflected on the substrate or on the substrate with a reflective layer and/or a dichroic layer stack located between the substrate and the glass matrix, and wherein the reflected radiation emerges again via the conversion material.

24. The optoelectronic component according to claim 19, wherein the substrate is glass, ceramic, glass-ceramic, metal or sapphire.

25. The optoelectronic component according to claim 19, wherein the substrate has a higher softening temperature than the glass matrix.

26. The optoelectronic component according to claim 19, wherein the substrate is arranged between the laser source and the first layer in a transmissive arrangement, or wherein the first layer is arranged between the laser source and the substrate in a reflective arrangement.

27. The optoelectronic component according to claim 19, wherein the first layer has a surface facing away from the substrate which is structured.

28. The optoelectronic component according to claim 19, wherein the glass matrix is oxidic and comprises lead oxide, bismuth oxide, boron oxide, silicon dioxide, tellurium oxide, phosphorus pentoxide, aluminum oxide or zinc oxide.

29. The optoelectronic component according to claim 19, wherein the glass matrix comprises ZnO, B.sub.2O.sub.3 and SiO.sub.2.

30. The optoelectronic component according to claim 19, wherein the glass matrix comprises ZnO, at least one glass former and a network converter or an intermediate oxide comprising at least one of the following materials: alkaline earth oxide, alkali oxide, aluminum oxide, zirconium oxide, niobium oxide, tantalum oxide, tellurium oxide, tungsten oxide, molybdenum oxide, antimony oxide, silver oxide, tin oxide, or rare earth oxide.

31. The optoelectronic component according to claim 19, wherein the glass matrix is a tellurite glass, a silicate glass, an aluminosilicate glass, a borate glass, a borosilicate glass or a phosphate glass.

32. The optoelectronic component according to claim 19, wherein the glass matrix has a content of at most 75 vol % in the first layer.

33. The optoelectronic component according to claim 19, wherein the at least one conversion material is selected from the group consisting of (Y,Gd,Tb,Lu).sub.3(Al,Ga).sub.5O.sub.12:Ce.sup.3+, (Sr,Ca)AlSiN.sub.3:Eu.sup.2+, (Sr,Ba,Ca,Mg).sub.2Si.sub.5N.sub.8:Eu.sup.2+, (Ca,Sr,Ba).sub.2SiO.sub.4:Eu.sup.2+, -SiAlON:Eu.sup.2+, -SiAlON:Eu.sup.2+, (Sr,Ca)S:Eu.sup.2, (Sr,Ba,Ca).sub.2(Si,Al).sub.5(N,O).sub.8:Eu.sup.2+, (Ca,Sr).sub.8Mg(SiO.sub.4).sub.4Cl.sub.2:Eu.sup.2+, and (Sr,Ba)Si.sub.2N.sub.2O.sub.2:Eu.sup.2+.

34. The optoelectronic component according to claim 19, wherein at least two different conversion materials are embedded in the glass matrix.

35. A method for manufacturing an optoelectronic component according to claim 19 the method comprising: providing the self-supporting conversion element at least into the beam path of the laser beam, wherein the self-supporting conversion element is manufactured by: mixing of at least one conversion material and a glass powder which, after a subsequent glazing step, produces the glass matrix, and optionally further substances for producing a paste; applying the paste directly onto the substrate to form the first layer; drying the first layer at not less than 75 C.; heating the substrate and the first layer to a temperature at least as high as a temperature at which the glass matrix material of the first layer has a viscosity of 10.sup.5 dP a*s, the temperature being greater than 350 C.; and optionally smoothing or roughening a surface of the first layer facing away from the substrate.

36. The method according to claim 35, wherein applying the paste comprises doctoring, screen printing, stencil printing, dispensing or spray coating.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0123] Further advantages, advantageous embodiment and further developments result from the following exemplary embodiments described in connection with the figures.

[0124] It is shown in:

[0125] FIGS. 1A to 2F show optoelectronic components according to an embodiment;

[0126] FIG. 3 shows an electron microscope image of a conversion element according to an embodiment;

[0127] FIG. 4A shows the produced conversion element of exemplary embodiment 2 in plan view according to an embodiment; and

[0128] FIG. 4B shows the color location homogeneity of exemplary embodiment 2 over the coated surface.

[0129] In the exemplary embodiment and figures, identical, similar or similarly acting elements can each be provided with the same reference signs. The elements shown and their proportions are not to be regarded as true to scale. Rather, individual elements such as layers, devices, components and regions can be displayed too large for better visualization and/or better understanding.

[0130] For example, FIGS. 1A and 1B show the substrate 2, which is illustrated thinner than the layer thickness of the first layer 10, although the layer thickness of substrate 2 (approx. 500 m) is preferably greater than the layer thickness of the first layer 10 (maximum 200 m).

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0131] FIG. 1A shows a schematic cross-sectional representation of a conversion element 100 according to an embodiment. The conversion element 100 has a substrate 2 on which a glass matrix 3 is arranged. The conversion material 4, which is configured for wavelength conversion, is introduced into the glass matrix 3. The conversion material 4 and the glass matrix 3 form the first layer 10. In this example, the conversion material 4 is homogeneously distributed in the glass matrix 3.

[0132] FIG. 1B shows the distribution of the conversion material 4 in the glass matrix 3 by means of a concentration gradient or grain size gradient. Larger particles of the conversion material 4 are arranged towards substrate 2, smaller particles towards the opposite side of substrate 1. The glass matrix 3, for example, can be a tellurite glass. A garnet such as YAG:Ce can be used as conversion material 4.

[0133] FIGS. 2A to 2F each show a side view of an optoelectronic component 1000, each with a conversion element 100 according to an embodiment, each arranged as a LARP arrangement. The distance between the laser source and conversion element may be several cm.

[0134] FIG. 2A shows a laser source 1 which is configured to emit a primary radiation (also called first radiation, laser beam or laser radiation) 5. The first radiation 5 strikes directly onto substrate 2, which is, for example, sapphire and which is transmissively shaped. The glass matrix 3 and the conversion material 4 are arranged downstream of the substrate 2. The conversion material 4 at least partially absorbs the primary radiation 5 and emits a secondary radiation 6. The conversion element 100 can be designed for full conversion or partial conversion. Preferably the conversion element 100 is adhesive-free here or in the other exemplary embodiments.

[0135] The conversion element 100 as shown in FIG. 2B shows a substrate 2 that is reflective. The substrate 2 extends over the base side of the first layer 10 with glass matrix 3, in which the conversion material 4 is embedded, and to a side surface of the first layer 10. The primary radiation 5 emitted by the laser source 1 thus impinges directly on the glass matrix 3, is converted by the conversion material 4 at least partially into radiation with changed wavelength and is reflected at the substrate 2. The laser source 1 can be arranged on a heat sink 8. The laser source 1 as well as the glass matrix 3 and the substrate 2 can also be arranged on a carrier 7. The carrier 7 can, for example, be a printed circuit board. Here, the laser beam 5 can irradiate vertically and/or at a certain angle to the conversion element 100.

[0136] In the embodiments of FIGS. 2A and 2B, the conversion element 100 can also be mounted mechanically immovable in relation to the laser source 1. The laser beam 5 of laser source 1 may be capable of scanning or moving (dynamically) on the surface of conversion element 100. This does not exclude the possibility that when the laser beam 5 moves, the laser source 1 is mounted mechanically immovable with respect to the conversion element 100.

[0137] Alternatively, the laser beam 5 can be arranged statically to the conversion element 100. The laser beam 5 of the laser source 1 is thus arranged on a fixed position of the surface of the conversion element 100.

[0138] FIG. 2C shows the arrangement of the laser source 1 at an angle to the substrate 2 and the glass matrix 3. The same applies to the conversion element 100 according to FIG. 2D. With the conversion element 100 of FIG. 2D, the laser source 1 is integrated into a light guide. The first layer 10, the glass matrix 3, the conversion material 4 and the substrate 2 can be designed in the same way as the previous embodiments. In FIG. 2C the laser source 1 and the substrate 2 with the glass matrix 3 are not arranged on a common carrier 7. As shown in FIG. 2C or FIG. 2D, the primary radiation 5 can reach the substrate 2 or the glass matrix 3 via a light guide in a freely moving manner. In both cases the substrate 2 is transmissive. For a reflective application the substrate 2 is formed reflective and arranged under the glass matrix 3. This means that the primary radiation 5 first hits the glass matrix 3 and then the reflective substrate 2 (not shown).

[0139] Between laser source 1 and the conversion element 100, optical elements 9, such as lens or collimator or mirror, can be arranged (see FIG. 2F).

[0140] FIG. 2E essentially corresponds to the embodiment of FIG. 2A. Unlike FIG. 2A, the embodiment of FIG. 2E has a dichroic coating 21 and/or an anti-reflective coating 22 as part of substrate 2. The dichroic coating 21 is arranged directly on the first layer 10. The anti-reflection coating 22 is arranged on the side of substrate 2 facing away from the first layer 10.

[0141] Exemplary embodiment 1: ZnOB.sub.2O.sub.3-SiO2 as glass matrix 221 (refractive index about 1.6).

[0142] A paste produced with a powder of a glass consisting of zinc oxide, boron oxide, silicon dioxide and aluminum oxide, garnet as a conversion material powder and a conventional screen printing medium consisting of a binder and a solvent is applied to the substrate by one of the usual coating methods. Application can, for example, be carried out by means of doctoring with a layer thickness in the wet state between 30 and 200 m, preferably 50 to 150 m, in particular between 60 and 130 m. After drying, the conversion element can be tempered at a temperature of, for example, 600 C. After tempering, the first layer 10 of the conversion element 100 may contain a conversion material 4 with a proportion of 25 vol %.

[0143] FIG. 3 shows an example of an electron microscope image (SEM) of a conversion element 100 according to an embodiment. The layer thickness of the first layer 10 is about 85 m after a tempering temperature of about 600 C. for thirty minutes. The conversion material 4 has a proportion of approximately 22 vol % in the first layer 10. A borosilicate glass with good chemical resistance was used as substrate 2.

[0144] The measured quantum efficiency of the example of FIG. 3 is about 98% (absolute value). The measured absorption was 1.8% in a wavelength range from 680 to 720 nm. Both values show that the conversion elements 100 described here have excellent properties in the optoelectronic components 1000 described here. Quantum efficiency and absorption were measured with a Hamamatsu-Quantaurus arrangement.

[0145] Exemplary embodiment 2: ZnOB.sub.2O.sub.3-SiO.sub.2 as glass matrix (refractive index about 1.6).

[0146] A paste was produced from a glass powder consisting of zinc oxide, boron oxide, silicon dioxide and aluminum oxide, YAGaG as a conversion material in powder form and a conventional screen printing medium and then applied to a sapphire substrate with a dichroic coating. The application was done by doctoring. The gap height of the doctor blade was 60 m. The thickness of the substrate was about 500 m. After drying at 80, the conversion element was tempered at 600 C. for one minute at a heating rate of 10 K/min. After the tempering step, the first layer 10 of the conversion element 100 contained a conversion material proportion of 28 vol % (calculated without pores) and a layer thickness of approximately 20 m of the first layer 10.

[0147] FIG. 4A shows the manufactured conversion element 100 of exemplary embodiment 2 in plan view. The width of the coating, here marked with an arrow, is approximately 1 cm.

[0148] FIG. 4B shows the color location distribution of the exemplary embodiment 2 over the coated area (asnumber of steps; Sstep size).

[0149] A small proportion of the aluminum oxide is contained in the glass powder of exemplary embodiments 1 and 2 in particular. Therefore, this was not taken into account in the formula of exemplary embodiments 1 and 2.

[0150] Exemplary embodiment 3: ZnOB.sub.2O.sub.3-SiO.sub.2 as glass matrix (refractive index about 1.6).

[0151] Exemplary embodiment 3 was manufactured like exemplary embodiment 2 and tempered at a temperature of 600 C. for thirty minutes. The thickness of the tempered first layer is approximately 20 m.

[0152] Exemplary embodiment 4: ZnOB.sub.2O.sub.3-SiO.sub.2 as glass matrix (refractive index approx. 1.6).

[0153] Exemplary embodiment 4 was manufactured like exemplary embodiment 3, but with a gap height of 60 m. The thickness of the tempered first layer is approximately 13 m.

[0154] The exemplary embodiments described in connection with the figures and their features can also be combined with each other according to further exemplary embodiments, even if such combinations are not explicitly shown in the figures. Furthermore, the exemplary embodiments described in connection with the figures may have additional or alternative features as described in the general part.

[0155] The invention is not limited by the description in connection with the exemplary embodiments to these. Rather, the invention includes any new feature as well as any combination of features, which in particular includes any combination of features in the patent claims, even if that feature or combination itself is not explicitly mentioned in the patent claims or exemplary embodiments.