Light-emitting member and method for manufacturing the same, optical member, light-emitting device

Abstract

To reduce unevenness in color and / or brightness of light exiting from a light exit surface.SOLUTION: A light-emitting member comprises a light-emitting unit with a first surface configured to emit light, and a film formed on the first surface. The film has a refractive index that differs from that of the light-emitting unit by 0.3 or more, contains a particular substance, and has a thickness in a range of 10 to 70 nm, inclusive.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a light-emitting member, a method for manufacturing the same, an optical member, and a light-emitting device.

Background Art

[0002] As disclosed in Patent Document 1, an optical member having an optical thin film formed thereon is known. As the optical thin film, for example, a metal oxide film is used. By using a metal oxide film, an antireflection film, a reflection film, a filter film, a retardation film, a surface protection film, etc. can be realized. In such an optical member, various optical characteristics are required depending on the usage state.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] <从 The present disclosure aims to reduce color unevenness and / or luminance unevenness of light emitted from a light-emitting surface.

Means for Solving the Problems

[0005] A light-emitting member according to an embodiment of the present disclosure has a first surface, a light-emitting portion from which light is emitted, and a film formed on the first surface. The film has a refractive index difference between the film and the light-emitting portion of 0.3 or more, contains particulate substances, and has a film thickness of 10 nm or more and 70 nm or less.

[0006] Furthermore, an emitting member according to one embodiment of the present disclosure comprises a emitting portion having a first surface from which light is emitted, and a film formed on the first surface, wherein the film has a refractive index difference of 0.3 or more between the film and the emitting portion, contains particulate matter, and within the region where the film is formed, the proportion of the particulate matter to the area of ​​the region is 30% or more and 80% or less.

[0007] Furthermore, an optical member according to one embodiment of the present disclosure comprises a light-emitting member according to one embodiment of the present disclosure and a translucent plate-like member disposed on the second surface side, which is the opposite surface of the first surface of the light-emitting portion.

[0008] Furthermore, a light-emitting device according to one embodiment of the present disclosure includes a base having a bottom surface and a frame surrounding the bottom surface, a light-emitting element disposed on the bottom surface, and a light-emitting member according to one embodiment of the present disclosure, or an optical member according to one embodiment of the present disclosure, which seals the space in which the light-emitting element is disposed.

[0009] Furthermore, a method for manufacturing a light-emitting member according to one embodiment of the present disclosure comprises the steps of: preparing a light-emitting part having a first surface and emitting light; forming a film on the first surface; and heating the film, wherein in the step of forming the film, a film is formed containing a substance having a refractive index difference of 0.3 or more with respect to the light-emitting part, and having a film thickness of 10 nm to 70 nm, and in the step of heating the film, the substance is atomized.

[0010] Furthermore, a method for manufacturing a light-emitting member according to one embodiment of the present disclosure comprises the steps of: preparing a light-emitting part having a first surface and emitting light; forming a film on the first surface; and heating the film, wherein in the step of forming the film, a film is formed containing a substance having a refractive index difference of 0.3 or more with respect to the light-emitting part, and in the step of heating the film, the substance is atomized so that in the region where the film is formed, the proportion of particulate matter to the area of ​​the region is 30% or more and 80% or less. [Effects of the Invention]

[0011] According to one embodiment of the present disclosure, color unevenness and / or brightness unevenness of light emitted from a light-emitting surface can be reduced. [Brief explanation of the drawing]

[0012] [Figure 1] This is a perspective view illustrating a light-emitting member according to the first embodiment. [Figure 2] This is a cross-sectional view taken along line II-II in Figure 1, illustrating a light-emitting member according to the first embodiment. [Figure 3] This is a diagram (part 1) illustrating a method for manufacturing a light-emitting member according to the first embodiment. [Figure 4] This is a diagram (part 2) illustrating a method for manufacturing a light-emitting member according to the first embodiment. [Figure 5] This is an SEM image of a niobium oxide film before heating. [Figure 6] This is an SEM image of a niobium oxide film after heating at 800°C for 1 hour under atmospheric pressure. [Figure 7] This is an SEM image of a niobium oxide film after heating at 850°C for 1 hour under atmospheric pressure. [Figure 8] This is an SEM image of a niobium oxide film after heating at 900°C for 1 hour under atmospheric pressure. [Figure 9] This is an SEM image of a niobium oxide film after heating at 950°C for 1 hour under atmospheric pressure. [Figure 10] This is an SEM image of a niobium oxide film after heating at 1000°C for 1 hour under atmospheric pressure. [Figure 11] This is an SEM image of a niobium oxide film with a thickness of 5 nm after heating at 950°C for 1 hour under atmospheric pressure. [Figure 12] This is an SEM image of a niobium oxide film with a thickness of 10 nm after heating at 950°C for 1 hour under atmospheric pressure. [Figure 13] This is an SEM image of a niobium oxide film with a thickness of 30 nm after heating at 950°C for 1 hour under atmospheric pressure. [Figure 14] This is an SEM image of a niobium oxide film with a thickness of 50 nm after heating at 950°C for 1 hour under atmospheric pressure. [Figure 15]SEM photograph of a niobium oxide film with a film thickness of 70 [nm] after heating at 950 °C for 1 h under atmospheric pressure. [Figure 16] SEM photograph of a niobium oxide film with a film thickness of 100 [nm] after heating at 950 °C for 1 h under atmospheric pressure. [Figure 17] Figure illustrating the change in linear transmittance of a niobium oxide film with a film thickness of 10 [nm] before and after heating. [Figure 18] Figure illustrating the change in linear transmittance of a niobium oxide film with a film thickness of 30 [nm] before and after heating. [Figure 19] Figure illustrating the change in linear transmittance of a niobium oxide film with a film thickness of 50 [nm] before and after heating. [Figure 20] Figure illustrating the change in linear transmittance of a niobium oxide film with a film thickness of 70 [nm] before and after heating. [Figure 21] Figure illustrating the relationship between the output of the laser light input to the light-emitting member and the luminous efficiency. [Figure 22] Perspective view illustrating the optical member according to the second embodiment. [Figure 23] Cross-sectional view taken along line XXIII-XXIII of FIG. 22 illustrating the optical member according to the second embodiment. [Figure 24] Perspective view illustrating the light-emitting device according to the third embodiment. [Figure 25] Cross-sectional view taken along line XXV-XXV of FIG. 24 illustrating the light-emitting device according to the third embodiment. [Figure 26] Perspective view of the state in which the optical member is further removed from the light-emitting device according to the third embodiment [Figure 27] Plan view of the state in which the optical member is further removed from the light-emitting device according to the third embodiment.

Embodiments for Carrying Out the Invention

[0013] The following description will explain embodiments for carrying out the invention with reference to the drawings. In the following description, terms indicating specific directions or positions (for example, "up," "down," and other terms including these terms) will be used as needed. The use of these terms is for the purpose of facilitating the understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present invention. Also, parts with the same reference numerals appearing in multiple drawings indicate the same or equivalent parts or components.

[0014] Furthermore, in this disclosure, the term "polygon" refers to polygons such as triangles and quadrilaterals, including shapes where the corners of the polygon have been rounded, chamfered, or otherwise modified. Similarly, shapes where modifications have been made not only to the corners (ends of the sides) but also to the middle parts of the sides will also be referred to as polygons. In other words, shapes that retain the shape of a polygon but have been partially modified are included in the interpretation of "polygon" as described in this disclosure.

[0015] Furthermore, the same applies not only to polygons, but also to words describing specific shapes such as trapezoids, circles, and concave shapes. The same also applies when dealing with each side that forms such a shape. In other words, even if a side has been processed at a corner or in the middle, the interpretation of "side" includes the processed part. When distinguishing a "polygon" or "side" without partial processing from a processed shape, the term "strictly" should be added, for example, "strictly quadrilateral."

[0016] Furthermore, the embodiments shown below are illustrative examples of light-emitting members and the like for embodying the technical concept of the present invention, and do not limit the present invention to the following. Also, the dimensions, materials, shapes, relative arrangements, etc. of the components described below are intended to be illustrative, and not to limit the scope of the present invention unless otherwise specified. In addition, the content described in one embodiment is applicable to other embodiments and modifications. Furthermore, the size and positional relationships of the components shown in the drawings may be exaggerated for clarity of explanation. In addition, in order to avoid the drawings becoming excessively complex, schematic diagrams that omit the illustration of some elements may be used, or end view diagrams that show only the cross-section may be used as cross-sectional views.

[0017] <First Embodiment> Figure 1 is a perspective view illustrating a light-emitting member according to the first embodiment. Figure 2 is a cross-sectional view taken along line II-II in Figure 1, illustrating a light-emitting member according to the first embodiment.

[0018] As shown in Figures 1 and 2, the light-emitting member 10 has a composite member 13 and a film 15.

[0019] The individual components of the light-emitting member 10 will now be described.

[0020] (Composite member 13) The composite member 13 has a light-emitting portion 11 and a light-reflecting portion 12. However, the light-reflecting portion 12 is not an essential component and is provided as needed.

[0021] The light-emitting section 11 has an upper surface 11a, a lower surface 11b which is the opposite surface of the upper surface 11a, and a side surface 11c which intersects with the upper surface 11a and the lower surface 11b. The upper surface of the light-emitting section 11 may be referred to as the first surface, and the lower surface as the second surface. The side surface 11c connects the outer edge of the upper surface 11a and the outer edge of the lower surface 11b. The light-emitting section 11 is, for example, a rectangular parallelepiped or a cube. In this case, both the upper surface 11a and the lower surface 11b of the light-emitting section 11 are rectangular, and the light-emitting section 11 has four rectangular side surfaces 11c. Here, a rectangle refers to a rectangle or a square.

[0022] However, the light-emitting part 11 is not limited to a rectangular prism or a cube. That is, the planar shape of the light-emitting part 11 is not limited to a rectangle, and can be any shape such as a circle, ellipse, or polygon. Note that viewing an object from the direction normal to the top surface 11a of the light-emitting part 11 is sometimes referred to as a planar view, and the shape of the object when viewed from the direction normal to the top surface 11a of the light-emitting part 11 is sometimes referred to as the planar shape.

[0023] The light-emitting part 11 can, for example, emit light from the upper surface 11a after it is incident from the lower surface 11b. That is, the upper surface 11a is the light-emitting surface from which light is emitted. The light-emitting part 11 may also have light-transmitting properties. In this application, light-transmitting properties refer to a transmittance of 80% or more for light.

[0024] Since the light-emitting part 11 is irradiated with light, it is preferable that the base material of the light-emitting part 11 be formed using an inorganic material that is not easily decomposed by light irradiation as the main material. The main material is, for example, ceramics. Examples of ceramics that can be used as the main material include aluminum oxide, aluminum nitride, silicon oxide, yttrium oxide, zirconium oxide, or magnesium oxide. For the ceramic main material, it is preferable to select a material with a melting point of 1300°C to 2500°C so that the light-emitting part 11 does not undergo deformation or discoloration due to heat. The light-emitting part 11 is, for example, a sintered body formed with ceramics as the main material.

[0025] The light-emitting unit 11 may be a wavelength conversion unit having a phosphor. When the light-emitting unit 11 is a wavelength conversion unit, it can, for example, convert light incident from the lower surface 11b into light of a different wavelength and emit the converted light from the upper surface 11a. The light-emitting unit 11 may emit only a portion of the incident light. The light-emitting unit 11 may convert all of the incident light into light of a different wavelength. In this case, the light incident on the light-emitting unit 11 is not emitted from the light-emitting unit 11.

[0026] If the light-emitting section 11 is a wavelength conversion section, the light-emitting section 11 can be formed, for example, by sintering a phosphor with a translucent material such as aluminum oxide. The phosphor content can be 0.05% to 50% by volume relative to the total volume of the ceramics. Alternatively, for example, ceramics consisting substantially only of phosphor, obtained by sintering phosphor powder, may be used. Furthermore, the light-emitting section 11 may be formed from a single crystal of phosphor.

[0027] Examples of phosphors include cerium-activated yttrium aluminum garnet (YAG), cerium-activated lutetium aluminum garnet (LAG), europium-activated silicate ((Sr,Ba)2SiO4), α-sialon phosphors, and β-sialon phosphors. Among these, garnet-based phosphors such as YAG and LAG phosphors exhibit good heat resistance.

[0028] For example, if the light-emitting part 11 has a YAG phosphor, when blue excitation light is incident from the lower surface 11b, the blue excitation light and fluorescence are combined to emit white light from the upper surface 11a.

[0029] The light-reflecting portion 12 is, for example, a frame-shaped member having a rectangular opening. The light-reflecting portion 12 has an upper surface 12a, a lower surface 12b which is the opposite surface of the upper surface 12a, an inner surface 12c connecting the inner edge of the upper surface 12a and the inner edge of the lower surface 12b, and an outer surface 12d connecting the outer edge of the upper surface 12a and the outer edge of the lower surface 12b. The outer and inner edges of the upper surface 12a and the outer and inner edges of the lower surface 12b are, for example, rectangles. In this case, the light-reflecting portion 12 has four rectangular inner surfaces 12c and four rectangular outer surfaces 12d. However, the outer and inner edges of the upper surface 12a and the outer and inner edges of the lower surface 12b are not limited to rectangles, but can be any shape such as circles, ellipses, polygons, etc.

[0030] The light-reflecting portion 12 is, for example, a sintered body formed primarily from ceramics. Examples of ceramics that can be used as the main material include aluminum oxide, aluminum nitride, silicon oxide, yttrium oxide, zirconium oxide, and magnesium oxide. Among these, aluminum oxide is preferred because of its high reflectivity. However, the light-reflecting portion 12 does not have to be primarily made of ceramics. The light-reflecting portion 12 may be formed using, for example, metal or a composite of ceramics and metal.

[0031] In the composite member 13, the inner surface 12c of the light-reflecting portion 12 is connected to the side surface 11c of the light-emitting portion 11. The composite member 13 is flat in shape, for example, a rectangular parallelepiped.

[0032] The upper surface 11a of the light-emitting portion 11 and the upper surface 12a of the light-reflecting portion 12 may, for example, form a single continuous plane. Similarly, the lower surface 11b of the light-emitting portion 11 and the lower surface 12b of the light-reflecting portion 12 may, for example, form a single continuous plane. The composite member 13 may have a shape in which the upper surface 11a and / or lower surface 11b of the light-emitting portion 11 protrude more than the upper surface 12a and / or lower surface 12b of the light-reflecting portion 12. In this case, a part of the side surface 11c of the light-emitting portion 11 connects to the inner surface surface 12c of the light-reflecting portion 12.

[0033] The light-emitting part 11 and the light-reflecting part 12 may be formed by joining separate parts, or they may be formed integrally. The light-emitting part 11 and the light-reflecting part 12 may be formed integrally, for example, by a sintered body. It is also possible to adjust the porosity in the light-emitting part 11 and the light-reflecting part 12. The porosity can be adjusted by sintering conditions (sintering temperature, sintering time, heating rate), particle size of the material, concentration of sintering aid, etc.

[0034] For example, when forming the light-emitting part 11 and the light-reflecting part 12 using the same ceramic as the main material, the porosity of the light-reflecting part 12 is made greater than that of the light-emitting part 11. In other words, the composite member 13 is formed such that the light-reflecting part 12 contains more voids than the light-emitting part 11. In this case, it is preferable to adjust the sintering conditions so that the porosity of the light-reflecting part 12 is about 10%. This creates a reflective region due to air at the boundary between the side surface 11c of the light-emitting part 11 and the inner surface 12c of the light-reflecting part 12, allowing light that strikes the inner surface 12c of the light-reflecting part 12 from the light-emitting part 11 side to be reflected back to the light-emitting part 11 side.

[0035] (Membrane 15) The film 15 is a light-scattering film containing particulate matter. The film 15 can mainly scatter light with wavelengths in the range of 320 nm to 530 nm. Here, "particulate" means that the film 15 does not have to be formed continuously, but contains independent particles. However, some particles may be connected to each other. The shape of the particles may be any shape, including spherical, flattened, star-shaped, or irregular shapes.

[0036] Preferably, within the region where the film 15 is formed, the proportion of particulate matter to the area of ​​that region is 30% or more and 80% or less. By satisfying this proportion, a sufficient effect of scattering incident light can be obtained. The proportion of particulate matter to the area of ​​the region where the film 15 is formed can be measured by image processing of an SEM (scanning electron microscope) image of the film 15.

[0037] The film thickness of the film 15 is preferably 10 nm to 70 nm, and more preferably 30 nm to 50 nm. If the film thickness becomes too thick, the luminescence efficiency will decrease, so it is required that the film 15 be deposited with an appropriate thickness. Furthermore, if the film thickness of the film 15 is 10 nm to 70 nm, the substance contained in the film 15 is sufficiently atomized, and a sufficient scattering effect of incident light is obtained. If the film thickness of the film 15 is 30 nm to 50 nm, the number of independent particles of the substance contained in the film 15 increases, and the scattering effect of incident light becomes even greater.

[0038] The particulate matter contained in the film 15 preferably has a high refractive index in order to obtain a scattering effect. The refractive index of the particulate matter contained in the film 15 is, for example, 2 or higher. The particulate matter contained in the film 15 is, for example, niobium oxide. Furthermore, the material forming the film 15 does not contain any material other than the particulate matter. The refractive index of niobium oxide is approximately 2.3 to 2.4. It is preferable to use a material with a high refractive index for the particulate matter contained in the film 15. Specifically, niobium oxide (Nb2O5) can be given as an example of niobium oxide. Other materials with a high refractive index include tantalum oxide, zirconium oxide, and titanium oxide.

[0039] (Light-emitting member 10) The film 15 is formed on at least the upper surface 11a of the light-emitting portion 11. The film 15 may extend from the upper surface 11a of the light-emitting portion 11 to the upper surface 12a of the light-reflecting portion 12. The film 15 may be formed on the entire surface of the upper surface 11a of the light-emitting portion 11 and the upper surface 12a of the light-reflecting portion 12 (i.e., the entire upper surface of the composite member 13).

[0040] The refractive index difference between the film 15 and the light-emitting part 11 is 0.3 or greater. If the refractive index difference between the film 15 and the light-emitting part 11 is 0.3 or greater, a sufficient scattering effect of incident light can be obtained. The larger the refractive index difference between the film 15 and the light-emitting part 11, the greater the scattering effect of incident light, which is preferable.

[0041] When the main material of the light-emitting part 11 is aluminum oxide, the refractive index of the light-emitting part 11 is approximately 1.6 to 1.8. On the other hand, when the particulate matter contained in the film 15 is niobium oxide, as mentioned above, the refractive index of the film 15 is approximately 2.3 to 2.4. In this case, the refractive index difference between the film 15 and the light-emitting part 11 is 0.3 or more. Furthermore, a refractive index difference of 0.8 between the film 15 and the light-emitting part 11 can be achieved. One example of how the refractive index difference can be determined is from the refractive index of the main material in the film 15 and the light-emitting part 11, respectively. In this case, the main material accounts for 50% or more of the constituent elements.

[0042] In the light-emitting member 10, the upper surface 11a of the light-emitting portion 11, where the film 15 is formed, is the light-emitting side, and the lower surface 11b of the light-emitting portion 11 is the light-incoming side. That is, light incident on the light-emitting portion 11 is emitted via the film 15. In addition, some of the light may also be incident on the lower surface 12b of the light-reflecting portion 12.

[0043] The light-reflecting portion 12 reflects light from the light-emitting portion 11 toward the light-reflecting portion 12 with its inner surface 12c. The light from the light-emitting portion 11 toward the light-reflecting portion 12 is the light incident on the light-emitting portion 11. If the light-emitting portion 11 is a wavelength conversion portion having a phosphor, the light-reflecting portion 12 reflects light incident on the light-emitting portion 11, or light whose wavelength has been converted by the light-emitting portion 11, with its inner surface 12c. It is preferable that the light-reflecting portion 12 be formed of a material with high thermal conductivity that dissipates heat from the light-emitting portion 11. For example, the light-reflecting portion 12 can be formed of aluminum oxide (Al2O3), which is a ceramic material with high thermal conductivity.

[0044] The light-emitting member 10 may have a film other than the film 15. For example, a light-shielding film made of metal or the like may be formed on the film 15 formed on the upper surface 12a of the light-reflecting portion 12. The light-shielding film can be formed with a thickness in the range of 50 nm to 500 nm, for example. By providing a light-shielding film, light leakage from sources other than the film 15 formed on the upper surface 11a of the light-emitting portion 11, which is the light-emitting surface, can be suppressed. Alternatively, the film 15 may be provided on top of the light-shielding film.

[0045] (Method for manufacturing the light-emitting member 10) Figure 3 illustrates a method for manufacturing a light-emitting member according to the first embodiment. First, as shown in Figure 3, a composite member 13 is prepared. The composite member 13 can be prepared, for example, by manufacturing a light-emitting part 11 and a light-reflecting part 12. Alternatively, instead of manufacturing the composite member 13, it may be prepared by procuring a composite member 13.

[0046] When manufacturing the composite member 13, for example, the composite member 13 can be manufactured by joining the side surface 11c of the light-emitting part 11 and the inner surface 12c of the light-reflecting part 12 with an adhesive. Alternatively, the composite member 13 can be formed by integrally sintering the light-emitting part 11 and the light-reflecting part 12. In this case, for example, the powder material forming the light-emitting part 11 and the light-reflecting part 12 of the sintered body can be integrally molded and sintered. For sintering, for example, atmospheric pressure sintering, discharge plasma sintering (SPS method), hot press sintering (HP method), etc. can be used.

[0047] Next, as shown in Figure 4, a film 15 is formed on at least the upper surface 11a of the light-emitting portion 11. The film 15 is, for example, a film containing niobium oxide. The film 15 may be formed over the entire surface of the upper surface 11a of the light-emitting portion 11 and the upper surface 12a of the light-reflecting portion 12. The film 15 can be formed, for example, by sputtering. At this point, the film 15 is formed continuously, not in particulate form. After the film 15 is formed, the film 15 is heated. The heating process causes the substances contained in the film 15 to become particulate. In other words, the heating process creates a film 15 containing particulate substances. The heating process causes the substances contained in the film 15 to become particulate, so that, for example, in the region where the film 15 is formed, the proportion of particulate substances to the area of ​​that region is 30% to 80%. This completes the light-emitting member 10. Furthermore, in the process of forming the film 15, the film 15 does not necessarily have to contain niobium oxide; it may be elemental niobium or niobium nitride. If the heating atmosphere in the process of heating the film 15 is an oxidizing atmosphere, the same particle formation can be achieved even if a niobium or niobium nitride film is formed.

[0048] From the viewpoint of atomizing the substances contained in the film 15, the film thickness of the film 15 is preferably 10 nm to 70 nm, and more preferably 30 nm to 50 nm. Furthermore, from the viewpoint of atomizing the substances contained in the film 15, it is preferable to heat the film 15 at a temperature of 850°C to 1000°C, and more preferably at a temperature of 900°C to 950°C. In addition, it is preferable to perform the heat treatment in an atmospheric atmosphere for about 1 hour. Furthermore, it is preferable that the heat treatment in an atmospheric atmosphere does not exceed 10 hours. This makes it possible to create a good state of particle formation. Note that the heating temperatures mentioned here are temperature conditions at atmospheric pressure.

[0049] Alternatively, the process may involve preparing only the light-emitting part 11 in the step shown in Figure 3, forming a film 15 on the upper surface 11a of the light-emitting part 11 in the step shown in Figure 4, and then heating the film 15. In this case, a light-emitting member 10 is produced that has the light-emitting part 11 and the film 15, but does not have the light-reflecting part 12.

[0050] (Light scattering properties of film 15) Figures 5 to 10 are SEM images related to the particle formation of niobium oxide. Figure 5 is an SEM image of the niobium oxide film before heating. Figure 6 is an SEM image of the niobium oxide film after heating at 800°C for 1 hour under atmospheric pressure. Figure 7 is an SEM image of the niobium oxide film after heating at 850°C for 1 hour under atmospheric pressure. Figure 8 is an SEM image of the niobium oxide film after heating at 900°C for 1 hour under atmospheric pressure. Figure 9 is an SEM image of the niobium oxide film after heating at 950°C for 1 hour under atmospheric pressure. Figure 10 is an SEM image of the niobium oxide film after heating at 1000°C for 1 hour under atmospheric pressure.

[0051] Figure 5 shows that the niobium oxide film before heating is formed continuously, not in particulate form. Furthermore, as shown in Figures 6 to 10, the degree of particle formation of the niobium oxide changes with heating temperature. At 800°C, particle formation occurs, but the degree of particle formation is low and there are many continuous parts. Therefore, it is preferable to heat the film at a temperature of 850°C to 1000°C for particle formation. Moreover, a heating temperature of 900°C to 950°C is more preferable as it results in a higher proportion of particles.

[0052] Figures 11 to 16 are SEM images showing the differences in the particle formation of niobium oxide depending on the film thickness (heating conditions: 950°C for 1 hour under atmospheric pressure). Figure 11 is an SEM image of a niobium oxide film with a thickness of 5 nm after heating at 950°C for 1 hour under atmospheric pressure. Figure 12 is an SEM image of a niobium oxide film with a thickness of 10 nm after heating at 950°C for 1 hour under atmospheric pressure. Figure 13 is an SEM image of a niobium oxide film with a thickness of 30 nm after heating at 950°C for 1 hour under atmospheric pressure. Figure 14 is an SEM image of a niobium oxide film with a thickness of 50 nm after heating at 950°C for 1 hour under atmospheric pressure. Figure 15 is an SEM image of a niobium oxide film with a thickness of 70 nm after heating at 950°C for 1 hour under atmospheric pressure. Figure 16 is an SEM image of a niobium oxide film with a thickness of 100 nm that was heated at 950°C for 1 hour under atmospheric pressure.

[0053] Figures 11 to 16 show that, in order to atomize a niobium oxide film, the film thickness should not be too thin or too thick; there is an optimal film thickness range. Specifically, in terms of the degree of atomization, a niobium oxide film thickness of 10 nm to 70 nm is preferable, and a thickness of 30 nm to 50 nm is even preferable, as this increases the number of independent particles. Furthermore, the more independent particles there are, the greater the scattering effect.

[0054] Considering the results in Figures 11-16 together with those in Figures 5-10, it can be said that in order to atomize the niobium oxide film, it is preferable to deposit the niobium oxide film with a thickness of 10 nm to 70 nm and heat it at a temperature of 850°C to 1000°C. Furthermore, more preferable conditions for atomizing the niobium oxide film are to deposit the niobium oxide film with a thickness of 30 nm to 50 nm and heat it at a temperature of 900°C to 950°C. Note that the heating temperatures mentioned here are under atmospheric pressure conditions.

[0055] Figures 17 to 20 illustrate the change in linear transmittance before and after heating of niobium oxide films with different thicknesses. Figure 17 illustrates the change in linear transmittance before and after heating of a niobium oxide film with a thickness of 10 nm. Figure 18 illustrates the change in linear transmittance before and after heating of a niobium oxide film with a thickness of 30 nm. Figure 19 illustrates the change in linear transmittance before and after heating of a niobium oxide film with a thickness of 50 nm. Figure 20 illustrates the change in linear transmittance before and after heating of an oxidized niobium film with a thickness of 70 nm.

[0056] In Figures 17 to 20, the measurement samples consisted of a plate-shaped sapphire, approximately 400 μm thick, with both sides mirror-finished, and a niobium oxide film of predetermined thickness (10 nm, 30 nm, 50 nm, 70 nm) formed on one side. Samples with different film thicknesses and heating temperatures were then prepared, and the linear transmittance of each sample before and after heating of the niobium oxide film was measured and is shown in Figures 17 to 20.

[0057] Here, linear transmittance is the ratio of light emitted perpendicularly from the niobium oxide film to light incident perpendicularly on the plane of a plate-shaped sapphire. In Figures 17 to 20, "Sapphire" indicates the linear transmittance of sapphire without a niobium oxide film, and "After Film Formation" indicates the linear transmittance before heating.

[0058] As shown in Figures 17-20, for all film thicknesses of 10 nm, 30 nm, 50 nm, and 70 nm, the linear transmittance of the heated niobium oxide film decreases in the wavelength range of 400 nm to 800 nm compared to the niobium oxide film before heating. Furthermore, in the range of 800°C to 950°C, the decrease in linear transmittance on the short-wave side increases as the heating temperature rises, and the difference with the long-wave side tends to widen. In contrast, at 1000°C, the linear transmittance on the short-wave side tends to be higher than at 950°C.

[0059] The reason why the linear transmittance on the short-wave side decreases in the heating temperature range of 800°C to 950°C is that heating causes the niobium oxide film to granulate, scattering the incident light. This is considered to be a phenomenon similar to Rayleigh scattering. From the results in Figures 5 to 16 above, it is preferable to deposit the niobium oxide film with a thickness of 30 nm to 50 nm and heat it at a temperature of 900°C to 950°C under atmospheric pressure in order to granulate the niobium oxide film. In Figures 17 to 20, the linear transmittance on the short-wave side decreases over a wide wavelength range when heated at 950°C, indicating that heating at 950°C causes the niobium oxide film to granulate appropriately, resulting in ideal scattering.

[0060] In Figures 17-20, the linear transmittance on the short-wave side is reduced to some extent even in the film before heating. This is not because scattering increased due to particle formation, but because the amount of light transmitted through the film decreased due to the refractive index of the niobium oxide film.

[0061] Thus, by heating the niobium oxide film to form particles, light scattering by the niobium oxide particles increases, reducing the linear transmittance on the short-wave side and widening the difference with the long-wave side. By utilizing this property, it is possible to reduce color unevenness and / or brightness unevenness of the light emitted from the light-emitting surface of the light-emitting member 10, as described below.

[0062] For example, in the light-emitting member 10 shown in Figure 1, etc., if the film 15 is a niobium oxide film after heating, and light in the short-wave wavelength range shown in Figures 17-20 is incident from the lower surface 11b of the light-emitting part 11, the incident light can be scattered. For example, if laser light with an emission peak wavelength in the range of 320 nm to 530 nm is incident from the lower surface 11b of the light-emitting part 11, the laser light will diffuse, and the difference in intensity between the center and the outer edge of the light-emitting surface will decrease. Therefore, color unevenness and / or brightness unevenness of the light emitted from the light-emitting surface of the light-emitting member 10 can be reduced.

[0063] Furthermore, in the light-emitting member 10 shown in Figure 1, etc., the light-emitting part 11 is a wavelength conversion part having YAG as a phosphor, and the film 15 is a heated niobium oxide film. For example, when laser light with an emission peak wavelength in the range of 420 nm to 480 nm is incident from the lower surface 11b side of the light-emitting part 11, white light is emitted from the light-emitting surface of the light-emitting member 10. In this case as well, the same effect as described above can be obtained. That is, because the laser light is diffused and the difference in intensity between the center and the outer periphery of the light-emitting surface of the light-emitting member 10 becomes smaller, the color unevenness and / or brightness unevenness of the white light emitted from the light-emitting surface of the light-emitting member 10 can be reduced.

[0064] Furthermore, the diffusion of the laser light allows the scattered laser light to be excited by the phosphor in the light-emitting unit 11 and converted into fluorescence. This reduces the concentration (volume) of the phosphor and improves the temperature characteristics of the light-emitting unit 11 (wavelength conversion unit).

[0065] Figure 21 illustrates the relationship between the output of the laser light input to the light-emitting element and its luminous efficiency, showing representative data for a film thickness of 30 nm. The sample is a light-emitting element 10 in which the light-emitting part 11 is a wavelength conversion part with YAG as the phosphor, and the film 15 is a niobium oxide film with a thickness of 30 nm. An integrating sphere was used for the measurement. In addition, measurements were also performed on a sample without a niobium oxide film as a reference.

[0066] As shown in Figure 21, it can be seen that the luminescence efficiency is improved when the light-emitting unit 11 has a niobium oxide film 15 after heating. This is thought to be because a portion of the laser light incident from the lower surface 11b side of the light-emitting unit 11 is backscattered to the lower surface 11b side by the film 15, and the phosphor is re-excited by the backscattering, increasing the amount of phosphor light emitted from the light-emitting surface of the light-emitting member 10. The increase in phosphor light is also advantageous in reducing color unevenness and / or brightness unevenness.

[0067] <Second Embodiment> In the second embodiment, an example of an optical component using the light-emitting member according to the first embodiment is shown. Note that in the second embodiment, descriptions of components that are the same as those described in the previously described embodiments may be omitted.

[0068] Figure 22 is a perspective view illustrating an optical member according to the second embodiment. Figure 23 is a cross-sectional view taken along line XXIII-XXIII in Figure 22, illustrating an optical member according to the second embodiment. As shown in Figures 22 and 23, the optical member 20 includes a light-emitting member 10 and a plate-shaped member 21.

[0069] The individual components of the optical element 20 will now be described.

[0070] (Plate-shaped member 21) The plate-like member 21 is a translucent member. The plate-like member 21 has an upper surface 21a, a lower surface 21b which is the opposite surface of the upper surface 21a, and a side surface 21c which intersects with the upper surface 21a and the lower surface 21b. The side surface 21c connects the outer edge of the upper surface 21a and the outer edge of the lower surface 21b. The plate-like member 21 is, for example, a rectangular parallelepiped or a cube. In this case, both the upper surface 21a and the lower surface 21b of the plate-like member 21 are rectangular, and the plate-like member 21 has four rectangular side surfaces 21c.

[0071] However, the plate-like member 21 is not limited to a rectangular parallelepiped or a cube. In other words, the planar shape of the plate-like member 21 is not limited to a rectangle, but can be any shape such as a circle, ellipse, or polygon.

[0072] The plate-like member 21 has a base material that is composed of a flat plate shape such as a rectangular parallelepiped. The base material of the plate-like member 21 can be formed using, for example, sapphire as the main material. Sapphire is a material with relatively high transmittance and relatively high strength. In addition to sapphire, other translucent materials such as quartz, silicon carbide, or glass may be used as the main material. It can be used.

[0073] (Optical component 20) In the optical member 20, the side of the plate-shaped member 21 on which the film 15 of the light-emitting member 10 is not formed is joined to the upper surface 21a of the plate-shaped member 21. In other words, the plate-shaped member 21 is positioned on the lower surface 11b side of the light-emitting portion 11 and the lower surface 12b side of the light-reflecting portion 12. The light-emitting member 10 can be joined to the plate-shaped member 21 by forming a metallized film on a part of the area on the upper surface 21a of the plate-shaped member 21 where the light-emitting member 10 is positioned, and on a part of the lower surface 12b of the light-reflecting portion 12, and fixing the metallized films together using solder such as Au-Sn. If the base material of the plate-shaped member 21 is sapphire, sapphire is a material with relatively high thermal conductivity, so it can dissipate the heat generated in the light-emitting member 10.

[0074] Since the plate-shaped member 21 is translucent, light incident from the lower surface 21b side of the plate-shaped member 21 passes through the light-emitting part 11 to the film 15 and is emitted from the film 15 side. Therefore, scattering due to the particle nature of the film 15 provides the same effect as the light-emitting member 10.

[0075] A destructive detection mechanism may be provided between the light-emitting member 10 and the plate-shaped member 21. The destructive detection mechanism can be realized, for example, by joining a wiring pattern provided on the lower surface side of the light-emitting member 10 and a wiring pattern provided on the upper surface 21a side of the plate-shaped member 21 using solder such as Au-Sn.

[0076] For example, a wiring pattern provided between the light-emitting member 10 and the plate-shaped member 21 is electrically connected to a detection circuit located outside the optical member 20. The detection circuit then monitors changes in the resistance value of the wiring pattern, and when the resistance value changes beyond a predetermined threshold, it can detect damage to the light-emitting member 10 and / or the plate-shaped member 21.

[0077] Since the plate-shaped member 21 is translucent, the destructive detection mechanism provided between the light-emitting member 10 and the plate-shaped member 21 is visible from the lower surface 21b of the plate-shaped member 21. Therefore, it is possible to confirm whether the destructive detection mechanism is properly joined during the manufacturing process of the optical member 20, thereby ensuring stable quality.

[0078] <Third Embodiment> The third embodiment shows an example of a light-emitting device using the optical component according to the second embodiment. In the third embodiment, descriptions of components that are the same as those described in the previously described embodiments may be omitted.

[0079] Figure 24 is a perspective view illustrating a light-emitting device according to the third embodiment. Figure 25 is a cross-sectional view taken along the line XXV-XXV in Figure 24, illustrating the light-emitting device according to the third embodiment. Figure 26 is a perspective view of the light-emitting device according to the third embodiment with the optical components further removed. Figure 27 is a plan view of the light-emitting device according to the third embodiment with the optical components further removed.

[0080] As shown in Figures 24 to 27, the light-emitting device 200 includes an optical member 20, a base 210, a light-emitting element 220, a submount 230, a light-reflecting member 240, a protective element 250, a temperature measuring element 260, wiring 270, and a light-shielding member 280. The light-emitting device 200 only needs to have at least the optical member 20, the base 210, and the light-emitting element 220. Alternatively, the light-emitting device 200 may have a light-emitting member 10 instead of the optical member 20.

[0081] The components of the light-emitting device 200 will now be described.

[0082] (base 210) The base portion 210 has an upper surface 210a, a lower surface 210b, a plurality of inner surfaces 210c, one or more outer surfaces 210d, and a bottom surface 210e. The base portion 210 has a concave shape that is recessed from the upper surface 210a to the lower surface 210b. In addition, the base portion 210 has a rectangular outer shape in plan view, and the recess is formed inside this outer shape.

[0083] Furthermore, in a plan view, a frame is formed by one or more inner surfaces 210c that intersect the upper surface 210a. That is, the base 210 has a frame that forms a bottom surface 210e and inner surfaces 210c that extend above the bottom surface 210e. The recess of the base 210, including the bottom surface 210e, is surrounded by this frame.

[0084] Furthermore, the base portion 210 has one or more stepped portions 216 on the inside of the frame. The stepped portion 216 consists only of an upper surface and a side surface that intersects with the upper surface and extends downward. The one or more inner surfaces 210c include the side surface that intersects with the upper surface 210a of the base portion 210 and the side surface of the stepped portion 216.

[0085] The base portion 210 can be formed using, for example, ceramics as the main material. For example, aluminum nitride, silicon nitride, aluminum oxide, or silicon carbide can be used as the ceramic material. However, the base portion 210 is not limited to ceramics; it may also be formed using other insulating materials as the main material.

[0086] Furthermore, one or more metal films are provided on the bottom surface 210e of the base portion 210. Also, one or more metal films are provided on the top surface 210a of the base portion 210. The one or more metal films provided on the bottom surface 210e include metal films that are electrically connected to the metal films provided on the top surface 210a.

[0087] Furthermore, the frame of the base 210 does not have to be provided on the same plane as the bottom surface 210e. For example, the frame of the base 210 may be provided on a plane that is recessed below the bottom surface 210e. Also, the base 210 does not have to be formed integrally, but may be, for example, a frame joined to a plate-like member.

[0088] (Light-emitting element 220) The light-emitting element 220 is not particularly limited as long as it is a light-emitting element, and for example, a semiconductor laser element, a light-emitting diode (LED), or an organic light-emitting diode (OLED) can be used. In this embodiment, as an example, an example in which a semiconductor laser element is used as the light-emitting element 220 is shown. In other words, the light-emitting element 220 in the following description is a semiconductor laser element.

[0089] The light-emitting element 220 has, for example, a rectangular shape in plan view. The side where it intersects with one of the two shorter sides of the rectangle becomes the light-emitting end face from which light is emitted. The top and bottom surfaces of the light-emitting element 220 have a larger area than the light-emitting end face.

[0090] Furthermore, the light (laser light) emitted from the light-emitting element 220 has a broadened shape and forms an elliptical far-field pattern (hereinafter referred to as "FFP") on a plane parallel to the light-emitting end face. Here, FFP refers to the shape and light intensity distribution of the emitted light at a position away from the light-emitting end face.

[0091] Light emitted from the light-emitting element 220 forms an elliptical FFP in a plane parallel to the light-emitting end face, where the layer direction of the multiple semiconductor layers including the active layer is the minor axis, and the stacking direction perpendicular to it is the major axis. The layer direction corresponding to the minor axis is called the horizontal direction of the FFP, and the stacking direction corresponding to the major axis is called the vertical direction of the FFP.

[0092] Furthermore, based on the light intensity distribution of the FFP of the light-emitting element 220, 1 / e of the peak intensity value 2 Light with the above intensity shall be called the main portion of the light. The angle corresponding to the full width at half maximum of this light intensity distribution shall be called the divergence angle. The divergence angle of the FFP in the vertical direction shall be called the vertical divergence angle, and the divergence angle of the FFP in the horizontal direction shall be called the horizontal divergence angle.

[0093] The light-emitting element 220 can be one in which the emission peak wavelength of the light emitted from the light-emitting element 220 is in the range of 320 nm to 530 nm, typically in the range of 430 nm to 480 nm. Examples of such light-emitting elements 220 include semiconductor laser elements containing nitride semiconductors. Examples of nitride semiconductors that can be used include GaN, InGaN, or AlGaN. However, the wavelength of the light emitted from the light-emitting element 220 is not limited to these.

[0094] (Submount 230) The submount 230 is, for example, constructed in the shape of a rectangular parallelepiped and has a bottom surface, a top surface, and sides. The submount 230 has the smallest width in the vertical direction. Note that the shape is not limited to a rectangular parallelepiped. The submount 230 is formed using, for example, aluminum nitride or silicon carbide, but other materials may be used. A metal film is provided on the top surface of the submount 230.

[0095] (Light-reflecting member 240) The light-reflecting member 240 has a light-reflecting surface 241 that reflects light. The light-reflecting surface is provided with a surface that, for example, has a light reflectance of 90% or more with respect to the peak wavelength of the irradiated light. The light reflectance here may be 100% or less than 100%.

[0096] Furthermore, the light-reflecting member 240 has a plurality of light-reflecting surfaces 241. The plurality of light-reflecting surfaces 241 are all planar inclined with respect to the lower surface, and each includes two light-reflecting surfaces 241 with different inclination angles relative to the lower surface. Neither of these two light-reflecting surfaces 241 are positioned perpendicularly or parallel to the lower surface. Also, the two light-reflecting surfaces 241 are continuously connected, forming a single integrated reflective region. Note that the shape of the light-reflecting surfaces 241 is not limited to a planar shape; for example, it may be a curved shape.

[0097] The light-reflecting member 240 preferably uses a heat-resistant material as its main material. For example, glass such as quartz or BK7 (borosilicate glass), metals such as aluminum, or Si can be used. The light-reflecting surface can be formed using, for example, metals such as Ag or Al, or dielectric multilayer films of Ta2O5 / SiO2, TiO2 / SiO2, or Nb2O5 / SiO2. Note that A / B indicates a multilayer film in which film A and film B are stacked in order.

[0098] (Protection element 250) The protection element 250 is designed to prevent excessive current from flowing through and damaging specific elements, such as light-emitting elements. For example, a Zener diode made of Si can be used as the protection element 250.

[0099] (Temperature measuring element 260) The temperature measuring element 260 is an element used as a temperature sensor to measure the ambient temperature. For example, a thermistor can be used as the temperature measuring element 260.

[0100] (Wiring 270) The wiring 270 is used for electrical connection between the two components. For example, metal wire can be used as the wiring 270.

[0101] (Light-shielding member 280) The light-shielding member 280 can be formed, for example, from a resin having light-shielding properties. Here, light-shielding properties refer to the property of not transmitting light, and in addition to the property of blocking light, light-absorbing properties or reflective properties may also be used to achieve light-shielding. The light-shielding member 280 can be formed, for example, by incorporating fillers such as light-diffusing materials and / or light-absorbing materials into a resin.

[0102] Examples of resins used to form the light-shielding member 280 include epoxy resin, silicone resin, acrylate resin, urethane resin, phenolic resin, and BT resin. Examples of light-absorbing fillers contained in the light-shielding member 280 include dark-colored pigments such as carbon black.

[0103] (Light-emitting device 200) In the light-emitting device 200, two light-reflecting members 240 are arranged on the bottom surface 210e of the base 210. The two light-reflecting members 240 are each placed on different metal films, and their lower surfaces are joined to the bottom surface 210e of the base 210. Furthermore, the two light-reflecting members 240 are arranged point-symmetrically with respect to a point SP (see Figure 27), for example. In a plan view, the upper ends of the light-reflecting surfaces 241 of the two light-reflecting members 240 are parallel or perpendicular to the inner surface 210c or outer surface 210d of the base 210. Note that the difference between parallel and perpendicular here is allowed to be within ±5 degrees.

[0104] A protective element 250 and a temperature measuring element 260 are arranged on the bottom surface 210e of the base portion 210. The protective element 250 is placed on and bonded to a metal film on which one of the two light-reflecting members 240 is placed. The temperature measuring element 260 is placed on and bonded to a metal film different from the metal film on which the two light-reflecting members 240 are placed.

[0105] Two submounts 230 are positioned on the bottom surface 210e of the base 210. Each of the two submounts 230 is positioned on a different metal film, and its lower surface is joined to the bottom surface 210e of the base 210. Furthermore, each of the two submounts 230 is positioned on a metal film on which a light-reflecting member 240 is positioned. Note that the submounts 230 and the light-reflecting member 240 may be positioned on different metal films.

[0106] The light-emitting element 220 is positioned on the bottom surface 210e of the base 210. Specifically, the light-emitting element 220 is positioned on the submount 230. In the illustrated example of the light-emitting device 200, two light-emitting elements 220 are positioned on the upper surfaces of different submounts 230, and the lower surfaces of the submounts 230 are joined to the bottom surface 210e of the base 210. Furthermore, the two light-emitting elements 220 are positioned symmetrically with respect to point SP. That is, the point at which the two light-emitting elements 220 are symmetrical and the point at which the two light-reflecting members 240 are symmetrical are at the same location. In the following description, this point SP will be referred to as the point of symmetry.

[0107] In a plan view, the two light-emitting elements 220 have their exit end faces that are neither parallel nor perpendicular to the inner surface 210c or outer surface 210d of the base 210. Therefore, their exit end faces are not parallel or perpendicular to the upper end of the light-reflecting surface 241. In other words, in a plan view, the light-emitting elements 220 are positioned so that their exit end faces are oblique to the inner surface 210c and outer surface 210d of the base 210, or to the upper end of the light-reflecting surface 241.

[0108] Alternatively, instead of positioning the light-emitting element 220 diagonally, the light-reflecting member 240 may be positioned diagonally. In other words, the light-emitting element 220 may be positioned parallel or perpendicular to the inner surface 210c or outer surface 210d of the base 210, while the light-reflecting member 240 may not be positioned parallel or perpendicular. Here, a difference of ±5 degrees is permitted for parallel or perpendicular.

[0109] In each of the two light-emitting elements 220, the light emitted from the exit end face is directed onto the corresponding light-reflecting member 240. The corresponding light-reflecting member 240 is a light-reflecting member 240 located on the same metal film. The light-emitting elements 220 are positioned such that at least the main portion of the light is directed onto the light-reflecting surface 241.

[0110] Furthermore, between the corresponding light-emitting element 220 and the light-reflecting member 240, the light-emitting element 220 is located further from the point of symmetry than the light-reflecting member 240. Therefore, the light emitted from the light-emitting element 220 travels in a direction approaching the point of symmetry. In addition, at least one of the two light-emitting elements 220 is positioned close to the temperature measuring element 260. This allows for accurate measurement of the temperature of the light-emitting element 220.

[0111] The submount 230 on which the light-emitting element 220 is located serves as a heat dissipation component in the light-emitting device 200, releasing the heat generated from the light-emitting element 220. To make the submount 230 function as a heat dissipation component, it should be formed from a material with better thermal conductivity than the light-emitting element 220. Furthermore, forming it from a material with better thermal conductivity than the bottom surface 210e of the base 210 will provide an even greater heat dissipation effect.

[0112] Furthermore, the submount 230 can play a role in adjusting the light emission position of the light-emitting element 220 in the light-emitting device 200. For example, if it is desired that the light passing through the optical axis be horizontal to the bottom surface 210e and that it be directed onto a predetermined position on the light-reflecting surface 241, the submount 230 can be used as an adjustment member.

[0113] The light-emitting element 220, the protective element 250, and the temperature measuring element 260 are electrically connected to a metal film provided on the bottom surface 210e of the base 210 via corresponding wiring 270. The metal film provided on the bottom surface 210e of the base 210 is used for the electrical connection between these elements and the external power supply. This allows these elements to be electrically connected to the external power supply via the metal film on the top surface 210a of the base 210.

[0114] The plate-shaped member 21 of the optical element 20 is positioned on the upper side of the base 210. More specifically, the outer periphery of the lower surface 21b of the plate-shaped member 21 is joined to the upper surface of the stepped portion 216 of the base 210. By joining the plate-shaped member 21 to the base 210, a closed space in which the light-emitting element 220 is arranged is formed. In this way, the plate-shaped member 21 can function as a lid member in the light-emitting device 200. Furthermore, this closed space is formed in an hermetically sealed state. Hermetically sealed, it is possible to suppress the accumulation of organic matter and other dust on the light-emitting end face of the light-emitting element 220.

[0115] If the light-emitting member 10 is used instead of the optical member 20, for example, the light-reflecting portion 12 of the light-emitting member 10 can be made to an appropriate size, and the outer periphery of the lower surface 12b of the light-reflecting portion 12 can be joined to the upper surface of the stepped portion 216 of the base 210.

[0116] The main portion of the light emitted by the light-emitting element 220 is reflected by the light-reflecting surface 241 of the light-reflecting member 240 and incident on the plate-shaped member 21. The plate-shaped member 21 is translucent to the light emitted by the light-emitting element 220. The main portion of the light, after passing through the plate-shaped member 21, is incident on the light-emitting portion 11 of the light-emitting member 10 that constitutes the optical member 20.

[0117] The light-emitting member 10 has a light-incident region on its lower surface where light from the main portion is incident, and a peripheral region thereof. In the light-emitting member 10, the light-emitting part 11 forms the light-incident region. In the light-emitting member 10, if the light-emitting part 11 is a wavelength conversion part having a phosphor, the light-emitting part 11 emits second light obtained by converting the first light emitted from the light-emitting element 220 into light of a different wavelength.

[0118] The first light emitted from the light-emitting element 220, or the second light whose wavelength has been converted by the light-emitting section 11, is emitted to the outside of the light-emitting device 200 via the film 15 formed on the upper surface 11a of the light-emitting section 11. In other words, the upper surface of the film 15 formed on the upper surface 11a of the light-emitting section 11 becomes the light-emitting surface of the light-emitting device 200. In the light-emitting member 10, if the light-emitting section 11 is a wavelength conversion section having a phosphor, the film 15 reduces the amount of first light emitted and increases the amount of second light emitted compared to a state in which the film 15 is not formed.

[0119] Furthermore, if the heat generated by wavelength conversion concentrates in a specific location, the light conversion efficiency of the light-emitting unit 11 tends to decrease. Therefore, it is preferable that the distribution of light incident on the light-emitting unit 11 be diffused. For example, it is preferable to ensure that the high-intensity portions of the laser light emitted from each of the two light-emitting elements 220 do not overlap. For example, this control can be achieved by adjusting the light-reflecting surface 241 of the light-reflecting member 240.

[0120] The light-shielding member 280 is formed inside the frame created by the upper surface 210a of the base 210. The light-shielding member 280 is formed to fill the gap between the base 210 and the light-emitting member 10. The light-shielding member 280 can be formed, for example, by pouring in a thermosetting resin and curing it with heat. By providing the light-shielding member 280, light leakage is suppressed.

[0121] The light-shielding member 280 is in contact with the inner surface 210c that intersects with the upper surface 210a of the base 210, the upper surface of the stepped portion 216 of the base 210, the side surface of the plate-shaped member 21, the upper surface of the plate-shaped member 21, and the side surface of the light-emitting member 10. It does not reach the upper surface of the light-emitting member 10. Alternatively, even if it reaches the upper surface of the light-reflecting portion 12, it does not reach the upper surface of the light-emitting portion 11. If it is difficult to achieve high-precision light shielding up to the boundary between the light-emitting portion 11 and the light-reflecting portion 12 with the light-shielding member 280, as described above, it is preferable to form a light-shielding film on the film 15 formed on the upper surface 12a of the light-reflecting portion 12 of the light-emitting member 10. This makes it possible to suppress light leakage from surfaces other than the light-emitting surface with high precision in the light-emitting device 200.

[0122] Since the light-emitting device 200 is equipped with a light-emitting member 10 having a light-scattering film 15 containing particulate matter, the laser light from the light-emitting element 220 reaches the film 15 and diffuses, reducing the intensity difference between the center and the outer edge of the light-emitting surface. Therefore, the color unevenness and / or brightness unevenness of the light emitted from the light-emitting surface can be reduced in the light-emitting device 200. When the light-emitting element 220 is a semiconductor laser element, light with a small spot diameter is emitted, so a high effect can be expected by reducing the color unevenness and / or brightness unevenness of the light due to scattering.

[0123] If the light-emitting portion 11 of the light-emitting member 10 has a YAG phosphor and the light-emitting element 220 is a semiconductor laser element that emits blue light in the range of emission peak wavelength 420 nm to 480 nm, then if the film 15 is not formed, the emitted light is likely to have areas with strong blue light that are highly directional and areas with strong phosphor color.

[0124] In contrast, the light-emitting device 200 is equipped with a light-emitting member 10 having a light-scattering film 15 containing particulate matter, so that highly directional blue light is scattered. As a result, the parts with a strong blue color in the emitted light are weakened, and the color unevenness and / or brightness unevenness of the light emitted from the light-emitting surface is reduced. As a result, good white light can be obtained from the light-emitting surface.

[0125] The light-emitting device 200 can be used, for example, in a vehicle's headlight. However, the light-emitting device 200 is not limited to this and can be used as a light source for lighting, projectors, head-mounted displays, and other displays such as backlights.

[0126] Although preferred embodiments have been described in detail above, the invention is not limited to the embodiments described above, and various modifications and substitutions can be made to the embodiments described above without departing from the scope of the claims. [Explanation of symbols]

[0127] 10 Light-emitting element 11 Light-emitting part 11a, 12a, 21a, 210a top surface 11b, 12b, 21b, 210b bottom side 11c, 21c side 12 Light reflecting part 12c, 210c inner surface 12d, 210d outer surface 13 Composite Members 15 membrane 20 Optical components 21 Plate-shaped member 200 Light-emitting devices 210 base 216 Stepped section 220 light-emitting elements 230 Submount 240 Light-reflecting member 241 Light reflective surface 250 protective elements 260 Temperature measurement buttons 270 Wiring 280 Light-shielding material

Claims

1. A light-emitting part having a first surface from which light is emitted, The material comprises a film formed on the first surface by depositing a film with a thickness of 10 nm to 70 nm and then heating it at a temperature of 800°C to 1000°C for particle formation, The aforementioned film is a light-emitting member having a refractive index difference of 0.3 or more between the film and the light-emitting portion, and containing particulate matter.

2. It has a first surface and a light-emitting part from which light is emitted, The film formed on the first surface, The aforementioned film has a refractive index difference of 0.3 or more between the film and the light-emitting portion, contains particulate matter, and has a film thickness within the range of 10 nm to 70 nm. The aforementioned film is formed in such a state that it contains particles independent of the continuously formed portion, and is a light-emitting member.

3. It has a first surface and a light-emitting part from which light is emitted, The film formed on the first surface, The light-emitting member wherein the film has a refractive index difference of 0.3 or more between the film and the light-emitting portion, contains particulate matter, and within the region where the film is formed, the proportion of the particulate matter to the area of ​​the region is 30% or more and 80% or less.

4. The light-emitting member according to any one of claims 1 to 3, wherein the light-emitting part is a wavelength conversion part having a phosphor.

5. The light-emitting member according to any one of claims 1 to 4, wherein the refractive index of the substance is 2 or more.

6. The light-emitting member according to any one of claims 1 to 5, wherein the substance is niobium oxide.

7. The light-emitting member according to any one of claims 1 to 6, having a light-reflecting portion connected to a side surface that intersects with the first surface of the light-emitting portion.

8. A light-emitting member according to any one of claims 1 to 7, An optical member having a translucent plate-like member disposed on the second surface side, which is the opposite side of the first surface of the light-emitting portion.

9. A base comprising a bottom surface and a frame surrounding the bottom surface, A light-emitting element arranged on the bottom surface, A light-emitting member according to any one of claims 1 to 7, or an optical member according to claim 8, It has, A light-emitting device that seals the space in which the light-emitting element is arranged.

10. The light-emitting element is a semiconductor laser element that emits a first light, The light-emitting device according to claim 9, wherein the light-emitting unit emits a second light obtained by converting the light emitted from the semiconductor laser element into light of a different wavelength.

11. The semiconductor laser element emits the first light having an emission peak wavelength in the range of 320 nm to 530 nm. The light-emitting device according to claim 10, wherein the film reduces the amount of first light emitted from the light-emitting unit and increases the amount of second light emitted from the light-emitting unit compared to a state in which the film is not formed.

12. A step of preparing a light-emitting part having a first surface and emitting light, A step of forming a film on the aforementioned first surface, The process includes a step of heating the aforementioned film, In the step of forming the aforementioned film, a film is formed that contains a substance having a refractive index difference of 0.3 or more with respect to the light-emitting portion, and has a film thickness of 10 nm or more and 70 nm or less. A method for manufacturing a light-emitting member, comprising the step of heating the aforementioned film to form the film containing the particleized substance.

13. A step of preparing a light-emitting part having a first surface and emitting light, A step of forming a film on the aforementioned first surface, The process includes a step of heating the aforementioned film, In the step of forming the aforementioned film, a film is formed that contains a substance having a refractive index difference of 0.3 or more with respect to the light-emitting portion. A method for manufacturing a light-emitting member, wherein in the step of heating the film, the substance is atomized so that in the region where the film is formed, the proportion of the particulate substance to the area of ​​that region is 30% or more and 80% or less.

14. The method for manufacturing a light-emitting member according to claim 12 or 13, wherein in the step of heating the film, the film is heated at a temperature of 850°C or more and 1000°C or less.

15. The method for manufacturing a light-emitting member according to any one of claims 12 to 14, wherein the substance is niobium oxide.

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