Light-emitting device, display, and electronic apparatus

Abstract

To provide a light-emitting device that can improve light extraction efficiency.SOLUTION: A light-emitting device has: a laminate that has a tapered part having a tapered shape whose width is increased from a side of a first electrode toward a side of a second electrode; a first low refractive index part that is provided on a side face of the tapered part and has a lower refractive index than the laminate; a second low refractive index part that is provided on a second electrode on the opposite side of the laminate and has a lower refractive index than the laminate; and a metal part that is provided on a side face of the second low refractive index part. The laminate has a first semiconductor layer having a first conductivity type, a second semiconductor layer provided between the first semiconductor layer and the second electrode and having a second conductivity type different from the first conductivity type, and a luminous layer provided between the first semiconductor layer and the second semiconductor layer. Light generated in the luminous layer is emitted from a side of the second electrode. A surface of the second low refractive index part on the opposite side of the second electrode is a lens surface.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a light-emitting device, a display device, and an electronic device. [Background technology]

[0002] Light emitting elements such as LEDs (Light Emitting Diodes) are used as light sources for display devices and the like.

[0003] For example, Patent Document 1 describes a micro LED element including a nitride semiconductor layer in which an N-type layer, a light-emitting layer, and a P-type layer are stacked in this order when viewed from the light-emitting surface side, a P-side electrode layer formed on the P-type layer, and an N-side electrode layer stacked on the light-emitting surface. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2019 / 038961 Summary of the Invention [Problem to be solved by the invention]

[0005] In the micro LED elements described above, it is desirable to improve the light extraction efficiency. [Means for solving the problem]

[0006] One aspect of the light emitting device according to the present invention is A first electrode; a second electrode disposed opposite the first electrode and having light-transmitting properties; a laminate provided between the first electrode and the second electrode, the laminate having a tapered portion having a tapered shape whose width increases from the first electrode side toward the second electrode side; a first low refractive index portion provided on a side surface of the tapered portion and having a refractive index lower than that of the laminate; a second low refractive index portion provided on the second electrode opposite to the laminate and having a refractive index lower than that of the laminate; A metal portion provided on a side surface of the second low refractive index portion; having The laminate comprises: a first semiconductor layer having a first conductivity type; a second semiconductor layer provided between the first semiconductor layer and the second electrode and having a second conductivity type different from the first conductivity type; a light emitting layer provided between the first semiconductor layer and the second semiconductor layer; having The light generated in the light emitting layer is emitted from the second electrode side, The surface of the second low refractive index portion opposite to the second electrode is a lens surface.

[0007] One aspect of the display device according to the present invention is The present invention has one aspect of the light emitting device.

[0008] One aspect of the electronic device according to the present invention is The present invention has one aspect of the light emitting device. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view illustrating a light emitting device according to an embodiment of the present invention. [Diagram 2] FIG. 1 is a cross-sectional view illustrating a light emitting device according to an embodiment of the present invention. [Diagram 3] FIG. 1 is a cross-sectional view illustrating a light emitting device according to a reference example. [Figure 4] 5A to 5C are cross-sectional views each showing a schematic process for manufacturing the light emitting device according to the embodiment. [Diagram 5] 5A to 5C are cross-sectional views each showing a schematic process for manufacturing the light emitting device according to the embodiment. [Figure 6] FIG. 4 is a cross-sectional view illustrating a light emitting device according to a first modified example of the embodiment. [Figure 7] FIG. 11 is a cross-sectional view illustrating a light emitting device according to a second modified example of the embodiment. [Figure 8]FIG. 11 is a cross-sectional view illustrating a light emitting device according to a second modified example of the embodiment. [Figure 9] FIG. 11 is a cross-sectional view illustrating a light emitting device according to a second modified example of the embodiment. [Figure 10] FIG. 11 is a cross-sectional view illustrating a light emitting device according to a third modified example of the embodiment. [Figure 11] FIG. 11 is a cross-sectional view illustrating a light emitting device according to a third modified example of the embodiment. [Figure 12] FIG. 11 is a cross-sectional view illustrating a light emitting device according to a fourth modified example of the embodiment. [Figure 13] FIG. 11 is a cross-sectional view illustrating a light emitting device according to a fourth modified example of the embodiment. [Figure 14] FIG. 13 is a cross-sectional view illustrating a light emitting device according to a fifth modified example of the embodiment. [Figure 15] FIG. 1 is a diagram illustrating a projector according to an embodiment of the present invention. [Figure 16] FIG. 1 is a plan view illustrating a display according to an embodiment of the present invention. [Figure 17] FIG. 1 is a cross-sectional view illustrating a display according to an embodiment of the present invention. [Figure 18] FIG. 1 is a perspective view showing a schematic diagram of a head mounted display according to an embodiment of the present invention. [Figure 19] FIG. 2 is a diagram illustrating an image forming device and a light guiding device of the head mounted display according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. Note that the embodiments described below do not unduly limit the contents of the present invention described in the claims. In addition, not all of the configurations described below are necessarily essential components of the present invention.

[0011] 1. Light-emitting device Configuration First, the light emitting device according to the present embodiment will be described with reference to the drawings. Fig. 1 is a cross-sectional view that shows a schematic diagram of a light emitting device 100 according to the present embodiment.

[0012] 1, the light emitting device 100 includes, for example, a substrate 10, a laminate 20, a first electrode 30, a second electrode 32, a first light transmitting portion 40, a first metal layer 50, an insulating portion 60, a wiring layer 70, a metal portion 80, a second light transmitting portion 90, and a light transmitting layer 98. The laminate 20, the first electrode 30, the second electrode 32, the first light transmitting portion 40, the first metal layer 50, the second light transmitting portion 90, and the light transmitting layer 98 configure a light emitting element 2. The light emitting element 2 is, for example, an LED. The light emitting element 2 may be a semiconductor laser.

[0013] The substrate 10 is, for example, a silicon substrate. A driving circuit for driving the light emitting element 2 may be provided on the substrate 10.

[0014] A light-emitting element 2 is mounted on the substrate 10. The light-emitting element 2 is mounted in a junction-down manner. Although not shown, a plurality of light-emitting elements 2 may be provided. When viewed from the stacking direction of the first semiconductor layer 22 and the light-emitting layer 24 of the laminate 20 (hereinafter also simply referred to as the "stacking direction"), the plurality of light-emitting elements 2 may be arranged in a matrix.

[0015] The laminate 20 is provided between the first electrode 30 and the second electrode 32. In the illustrated example, the laminate 20 is provided on the first electrode 30. The laminate 20 has a tapered portion 20a having a tapered shape in which the width increases from the first electrode 30 side toward the second electrode 32 side. The width of the tapered portion 20a gradually increases from the first electrode 30 side toward the second electrode 32 side. In the illustrated example, the shape of the tapered portion 20a is a trapezoid. Note that the width is the size in a direction perpendicular to the stacking direction. In the case of a cross-sectional view passing through the center of the laminate 20 in a plan view from the stacking direction and along the stacking direction and a direction perpendicular to the stacking direction, the width is the size in a direction perpendicular to the stacking direction. The side surface 21 of the tapered portion 20a is inclined with respect to the stacking direction. The inclination angle θ1 of the side surface 21 with respect to the stacking direction is, for example, 20° or more and 30° or less. The side surface 21 of the tapered portion 20 a constitutes the side surface of the laminate 20 .

[0016] In this specification, when the light emitting layer 24 is used as the reference in the stacking direction, the direction from the light emitting layer 24 toward the second semiconductor layer 26 of the stack 20 is described as "up," and the direction from the light emitting layer 24 toward the first semiconductor layer 22 is described as "down."

[0017] The laminate 20 includes a first semiconductor layer 22, a light emitting layer 24, and a second semiconductor layer 26. The first semiconductor layer 22, the light emitting layer 24, and the second semiconductor layer 26 form a tapered portion 20a. The first semiconductor layer 22, the light emitting layer 24, and the second semiconductor layer 26 are, for example, Group III nitride semiconductors and have a wurtzite crystal structure.

[0018] The first semiconductor layer 22 is provided on the first electrode 30. In the illustrated example, the first semiconductor layer 22 is in contact with the first electrode 30. The first semiconductor layer 22 is provided between the first electrode 30 and the light emitting layer 24. The first semiconductor layer 22 is provided between the first electrode 30 and the second electrode 32. The first semiconductor layer 22 has a first conductivity type. The first semiconductor layer 22 is, for example, a p-type GaN layer doped with Mg.

[0019] The light emitting layer 24 is provided on the first semiconductor layer 22. The light emitting layer 24 is provided between the first semiconductor layer 22 and the second semiconductor layer 26. In the illustrated example, the light emitting layer 24 constitutes the side surface 21 of the tapered portion 20a. The side surface 21 is constituted by the first semiconductor layer 22, the light emitting layer 24, and the second semiconductor layer 26. Although not illustrated, the light emitting layer 24 may be separated from the side surface 21. The width of the light emitting layer 24 is, for example, 3 μm or less.

[0020] The light emitting layer 24 has an i-type conductivity in which impurities are not intentionally doped. The light emitting layer 24 generates light when a current is injected into it. The light emitting layer 24 has, for example, a well layer and a barrier layer. The well layer and the barrier layer are i-type semiconductor layers. The well layer is, for example, an InGaN layer. The barrier layer is, for example, a GaN layer. The light emitting layer 24 has an MQW (Multiple Quantum Well) structure composed of the well layer and the barrier layer.

[0021] There is no particular limitation on the number of well layers and barrier layers constituting the light emitting layer 24. For example, only one well layer may be provided, in which case the light emitting layer 24 has a SQW (Single Quantum Well) structure.

[0022] The second semiconductor layer 26 is provided on the light emitting layer 24. The second semiconductor layer 26 is provided between the light emitting layer 24 and the second electrode 32. The second semiconductor layer 26 is provided between the first semiconductor layer 22 and the second electrode 32. In the illustrated example, the size of the second semiconductor layer 26 in the stacking direction is larger than the size of the first semiconductor layer 22 in the stacking direction. The second semiconductor layer 26 has a second conductivity type different from the first conductivity type. The second semiconductor layer 26 is, for example, an n-type GaN layer doped with Si.

[0023] The second semiconductor layer 26 has a first contact surface 27 that contacts the second electrode 32. The first contact surface 27 has an uneven structure 28. The first contact surface 27 has an uneven shape. The uneven structure 28 is provided, for example, over the entire surface of the first contact surface 27. The convex portions 29 form the uneven structure 28. A plurality of convex portions 29 are provided. The plurality of convex portions 29 are provided, for example, periodically. The height H of the convex portions 29 is, for example, 400 nm or more. The distance D between the tips of adjacent convex portions 29 is, for example, 230 nm or less. The uneven structure 28 may be a moth-eye structure. Although not shown in the figure, the plurality of convex portions 29 may be arranged randomly.

[0024] In the light emitting device 100, a pin diode is formed by the p-type first semiconductor layer 22, the i-type light emitting layer 24, and the n-type second semiconductor layer 26. In the light emitting device 100, when a forward bias voltage of the pin diode is applied between the first electrode 30 and the second electrode 32, a current is injected into the light emitting layer 24, causing recombination of electrons and holes in the light emitting layer 24. This recombination causes the light emitting layer 24 to generate light.

[0025] The first electrode 30 is provided on the substrate 10. The first electrode 30 is provided between the substrate 10 and the first semiconductor layer 22. The first semiconductor layer 22 may be in ohmic contact with the first electrode 30. The first electrode 30 is electrically connected to the first semiconductor layer 22. The first electrode 30 is bonded to the substrate 10. The first electrode 30 reflects light generated in the light emitting layer 24 to the second electrode 32 side.

[0026] The first electrode 30 is made of, for example, Au. The first electrode 30 is one of the electrodes for injecting a current into the light-emitting layer 24. To the first electrode 30, for example, a potential of a data signal is applied.

[0027] The second electrode 32 is provided on the second semiconductor layer 26. The second electrode 32 is provided between the second semiconductor layer 26 and the second light-transmitting portion 90. The second electrode 32 is disposed opposite to the first electrode 30. The second semiconductor layer 26 may be in ohmic contact with the second electrode 32. The second electrode 32 is electrically connected to the second semiconductor layer 26. The second electrode 32 has light-transmitting properties. The second electrode 32 transmits light generated in the light-emitting layer 24. The light generated in the light-emitting layer 24 is emitted from the second electrode 32 side.

[0028] The material of the second electrode 32 is, for example, ITO (Indium Tin Oxide). The second electrode 32 is the other electrode for injecting a current into the light-emitting layer 24. For example, a constant potential is applied to the second electrode 32. A ground potential may be applied to the second electrode 32. Although not shown, when a plurality of light-emitting elements 2 are provided, the second electrode 32 may be a common electrode for the plurality of light-emitting elements 2.

[0029] The second electrode 32 has a second contact surface 34 in contact with the second semiconductor layer 26. The second contact surface 34 is in contact with the first contact surface 27. The second contact surface 34 has a concave-convex structure 36. The concave-convex structure 36 is provided, for example, over the entire surface of the second contact surface 34. The concave-convex structure 36 has a shape corresponding to the concave-convex structure 28 of the first contact surface 27. The convex portions forming the concave-convex structure 36 are located between adjacent convex portions 29 forming the concave-convex structure 28.

[0030] The refractive index of the second electrode 32 is lower than the refractive index of the second semiconductor layer 26 and higher than the refractive index of the second light transmitting portion 90. When the material of the second electrode 32 is ITO, the refractive index of the second electrode 32 is, for example, 2.1. When the material of the second semiconductor layer 26 is GaN, the refractive index of the second semiconductor layer 26 is, for example, 2.4. When the material of the second light transmitting portion 90 is SiON, the refractive index of the second light transmitting portion 90 is, for example, 1.68.

[0031] The first light transmitting portion 40 is provided on the side surface 21 of the tapered portion 20a. The first light transmitting portion 40 is provided between the laminate 20 and the first metal layer 50. The first light transmitting portion 40 is provided, for example, on the entire surface of the side surface 21. The first light transmitting portion 40 surrounds the laminate 20 when viewed from the stacking direction.

[0032] The first light transmitting section 40 transmits light generated in the light emitting layer 24. The refractive index of the first light transmitting section 40 is lower than the refractive index of the stack 20. Specifically, the refractive index of the first light transmitting section 40 is lower than the refractive index of the first semiconductor layer 22, the refractive index of the light emitting layer 24, and the refractive index of the second semiconductor layer 26. The refractive index of the first light transmitting section 40 is lower than the refractive index of the second light transmitting section 90, for example. The first light transmitting section 40 is, for example, a SiO2 layer.

[0033] The first metal layer 50 is provided on the side surface 21 of the tapered portion 20a via the first light transmitting portion 40. The first metal layer 50 is provided between the first light transmitting portion 40 and the insulating portion 60. The first metal layer 50 surrounds the laminate 20 and the first light transmitting portion 40 when viewed from the stacking direction. The first metal layer 50 extends along the side surface 21. The first metal layer 50 and the first electrode 30 are separated from each other and electrically insulated. An insulating portion 60 is provided between the first metal layer 50 and the first electrode 30. In the illustrated example, the first metal layer 50 and the second electrode 32 are separated from each other and electrically insulated. An insulating portion 60 is provided between the first metal layer 50 and the second electrode 32. The first metal layer 50 overlaps the first semiconductor layer 22, the light emitting layer 24, and the second semiconductor layer 26 when viewed from a direction perpendicular to the stacking direction.

[0034] The first metal layer 50 has a reflective surface 52 that reflects light generated in the light emitting layer 24. The reflective surface 52 faces the side surface 21 of the tapered portion 20a. In the illustrated example, the reflective surface 52 is parallel to the side surface 21. The first metal layer 50 is, for example, an Au layer or an Ag layer.

[0035] The insulating section 60 is provided on a side of the laminate 20. In the illustrated example, the insulating section 60 is provided on a side of the first semiconductor layer 22, the light emitting layer 24, and the second semiconductor layer 26. The insulating section 60 is in contact with, for example, the first light transmitting section 40 and the first metal layer 50. The insulating section 60 surrounds the laminate 20, the first light transmitting section 40, and the first metal layer 50 when viewed from the stacking direction. The insulating section 60 may be provided integrally with the first light transmitting section 40. The material of the insulating section 60 is, for example, the same as the material of the first light transmitting section 40.

[0036] The wiring layer 70 is provided on the insulating section 60. The wiring layer 70 is provided between the insulating section 60 and the metal section 80. The wiring layer 70 is connected to the second electrode 32. The second electrode 32 is electrically connected to a power source (not shown) via the wiring layer 70. The wiring layer 70 may be provided integrally with the second electrode 32. The material of the wiring layer 70 is, for example, the same as the material of the second electrode 32.

[0037] The metal portion 80 is provided on the wiring layer 70. The metal portion 80 is provided on a side surface 91 of the second light transmitting portion 90. The metal portion 80 surrounds the second light transmitting portion 90 when viewed from the stacking direction. The metal portion 80 has a reflective surface 82 that reflects light generated in the light emitting layer 24. The reflective surface 82 is in contact with the side surface 91. In the illustrated example, the reflective surface 82 is parallel to the side surface 91. The sum of the size of the metal portion 80 in the stacking direction, the size of the wiring layer 70 in the stacking direction, and the size of the insulating portion 60 in the stacking direction is, for example, 4 μm or more and 5 μm or less. The material of the metal portion 80 is, for example, Al.

[0038] The second light transmitting portion 90 is provided on the second electrode 32. The second light transmitting portion 90 is provided on the opposite side of the second electrode 32 to the second semiconductor layer 26. The second light transmitting portion 90 is provided on the opposite side of the second electrode 32 to the stacked body 20. The second light transmitting portion 90 transmits light generated in the light emitting layer 24. The refractive index of the second light transmitting portion 90 is lower than the refractive index of the stacked body 20. Specifically, the refractive index of the second light transmitting portion 90 is lower than the refractive index of the first semiconductor layer 22, the refractive index of the light emitting layer 24, and the refractive index of the second semiconductor layer 26. The refractive index of the second light transmitting portion 90 is lower than the refractive index of the second electrode 32. The material of the first light transmitting portion 40 is, for example, SiON.

[0039] The second light transmitting portion 90 has, for example, a tapered portion 92 and a lens portion 94.

[0040] The tapered portion 92 of the second light-transmitting portion 90 is provided between the second electrode 32 and the lens portion 94. The tapered portion 92 is surrounded by the metal portion 80 when viewed from the stacking direction. The tapered portion 92 has a tapered shape in which the width increases from the second electrode 32 side toward the lens portion 94 side. The width of the tapered portion 92 gradually increases from the second electrode 32 to the lens portion 94. In the illustrated example, the shape of the tapered portion 92 is a trapezoid. The width of the upper surface of the tapered portion 92 is, for example, 6.8 μm or less. The tapered portion 92 has a side surface 91. The side surface 91 is inclined with respect to the stacking direction. The inclination angle θ2 of the side surface 91 with respect to the stacking direction is, for example, the same as the inclination angle θ1 of the side surface 21 with respect to the stacking direction. The perpendicular line P2 of the side surface 91 is, for example, parallel to the perpendicular line P1 of the side surface 21. In the illustrated example, the side surface 21 and the side surface 91 are located on the same plane.

[0041] The lens portion 94 of the second light-transmitting portion 90 is provided on the tapered portion 92. The lens portion 94 is, for example, a convex lens. The lens portion 94 may be a microlens. The lens portion 94 has a lens surface 96 that refracts light generated in the light-emitting layer 24. The size of the lens portion 94 in the stacking direction is, for example, 2 μm or more and 3 μm or less. The lens surface 96 is the surface of the second light-transmitting portion 90 on the opposite side to the second electrode 32. The lens surface 96 is, for example, a convex surface. The lens surface 96 collects light generated in the light-emitting layer 24. The lens surface 96 may diffuse the light generated in the light-emitting layer 24.

[0042] The light-transmitting layer 98 is provided on the lens surface 96. The light-transmitting layer 98 transmits light generated in the light-emitting layer 24. The refractive index of the light-transmitting layer 98 is lower than the refractive index of the second light-transmitting portion 90, for example. The light generated in the light-emitting layer 24 is emitted from the light-transmitting layer 98. The light-transmitting layer 98 is, for example, a SiO2 layer.

[0043] Although the above describes an InGaN-based light emitting layer 24, various materials capable of emitting light when a current is injected therein can be used for the light emitting layer 24 depending on the wavelength of the emitted light. For example, semiconductor materials such as AlGaN-based, AlGaAs-based, InGaAs-based, InGaAsP-based, InP-based, GaP-based, and AlGaP-based materials can be used.

[0044] Furthermore, in the above description, the first conductivity type is p-type and the second conductivity type is n-type, but the first conductivity type may be n-type and the second conductivity type may be p-type.

[0045] Although not shown, the laminate 20 may also have a plurality of nanostructures.

[0046] 1.2. Effects The light emitting device 100 includes a first electrode 30, a second electrode 32 that is disposed opposite the first electrode 30 and has light transmissivity, and a laminate 20 that is provided between the first electrode 30 and the second electrode 32 and has a tapered portion 20a that has a tapered shape that increases in width from the first electrode 30 side toward the second electrode 32 side. The light emitting device 100 further includes a first translucent portion 40 that is provided on a side surface 21 of the tapered portion 20a and serves as a first low refractive index portion having a refractive index lower than that of the laminate 20, a second translucent portion 90 that is provided on the side of the second electrode 32 opposite the laminate 20 and serves as a second low refractive index portion having a refractive index lower than that of the laminate 20, and a metal portion 80 that is provided on a side surface 91 of the second translucent portion 90. The laminate 20 has a first semiconductor layer 22 having a first conductivity type, a second semiconductor layer 26 having a second conductivity type different from the first conductivity type and provided between the first semiconductor layer 22 and a second electrode 32, and a light emitting layer 24 provided between the first semiconductor layer 22 and the second semiconductor layer 26. Light generated in the light emitting layer 24 is emitted from the second electrode 32 side, and the surface of the second light transmitting section 90 opposite to the second electrode 32 is a lens surface 96.

[0047] Therefore, in the light emitting device 100, the metal portion 80 can reflect the light generated in the light emitting layer 24, thereby reducing the light leaking from the side surface 91 of the second light transmitting portion 90. For example, the light reflectance can be improved compared to a case where a nonmetallic body made of SiO2 or resin is provided instead of the metal portion and the light is reflected at the interface between the light transmitting portion and the nonmetallic body.

[0048] Furthermore, in the light emitting device 100, the light generated in the light emitting layer 24 can be reflected at the interface between the tapered portion 20a and the first light transmitting portion 40.

[0049] Furthermore, in the light emitting device 100, the lens surface 96 can refract the light generated in the light emitting layer 24. This makes it possible to collect the light generated in the light emitting layer 24, for example, without making the metal section 80 too tall. Therefore, the light generated in the light emitting layer 24 can be refracted while reducing the light loss due to multiple reflections at the metal section 80.

[0050] As a result, the light extraction efficiency of the light emitting device 100 can be improved.

[0051] In the light emitting device 100, the perpendicular line P2 to the side surface 91 of the second light transmitting portion 90 is parallel to the perpendicular line P1 to the side surface 21 of the tapered portion 20a. Therefore, in the light emitting device 100, the light generated in the light emitting layer 24 can be collected more than in a case where, for example, the perpendicular line P2 is not parallel to the perpendicular line P1 and the inclination angle θ2 of the side surface 91 with respect to the stacking direction is larger than the inclination angle θ1 of the side surface 21 with respect to the stacking direction.

[0052] In the light emitting device 100, the refractive index of the first light transmitting section 40 is lower than the refractive index of the second light transmitting section 90. Therefore, in the light emitting device 100, the difference between the refractive index of the first light transmitting section 40 and the refractive index of the laminate 20 can be made larger than when, for example, the refractive index of the first light transmitting section is the same as the refractive index of the second light transmitting section. This allows the light generated in the light emitting layer 24 to be reflected at the interface between the first light transmitting section 40 and the laminate 20.

[0053] In the light emitting device 100, the refractive index of the second light transmitting portion 90 is lower than the refractive index of the second electrode 32. Therefore, in the light emitting device 100, the refractive index of the light emitting element 2 can be decreased from the light emitting layer 24 toward the lens surface 96. This can further improve the light extraction efficiency.

[0054] The light emitting device 100 has a light transmitting layer 98 provided on the lens surface 96. Therefore, in the light emitting device 100, the light transmitting layer 98 can protect the lens surface 96.

[0055] In the light emitting device 100, the refractive index of the light transmitting layer 98 is lower than the refractive index of the second light transmitting portion 90. Therefore, in the light emitting device 100, it is possible to reduce the refractive index difference between the light emitting element 2 and the air layer. This can further improve the light extraction efficiency.

[0056] In the light emitting device 100, the first contact surface 27 of the second semiconductor layer 26 in contact with the second electrode 32 has an uneven structure 28. Therefore, in the light emitting device 100, the uneven structure 28 can make the change in the refractive index at the interface between the second semiconductor layer 26 and the second electrode 32 smooth in the direction from the second semiconductor layer 26 to the second electrode 32. This can reduce the light reflected at the interface between the second semiconductor layer 26 and the second electrode 32. Therefore, the light extraction efficiency can be improved.

[0057] In the light emitting device 100, the second contact surface 34 of the second electrode 32 in contact with the second semiconductor layer 26 has an uneven structure 36. Therefore, in the light emitting device 100, the light extraction efficiency can be improved.

[0058] The light emitting device 100 has a first metal layer 50 provided on the side surface 21 of the tapered portion 20a, and the first metal layer 50 and the first electrode 30 are separated from each other and electrically insulated. Therefore, in the light emitting device 100, the first metal layer 50 can reflect the light generated in the light emitting layer 24, and the light leaking from the side surface 21 can be reduced. This can further improve the light extraction efficiency. For example, when the first metal layer is not provided and light is to be reflected at the interface between the laminate and a non-metallic body such as SiO2, the light incident on the interface at a critical angle or less cannot be reflected, and the light utilization efficiency decreases. The critical angle of SiO2 is, for example, 35° or more and 40° or less.

[0059] Furthermore, in the light emitting device 100, the parasitic capacitance of the first electrode 30 can be reduced compared to when the first metal layer and the first electrode are electrically connected to each other. When the first metal layer and the first electrode are electrically connected to each other, the distance between the metal body made of the first metal layer and the first electrode and the second electrode becomes small, so that the parasitic capacitance of the first electrode becomes large. In particular, when a potential of a data signal is applied to the first electrode 30, it is desirable to reduce the parasitic capacitance.

[0060] In the light emitting device 100, the first metal layer 50 is provided on the side surface 21 of the tapered portion 20a via the first light transmitting portion 40. Therefore, in the light emitting device 100, the first metal layer 50 can reflect the light transmitted through the first light transmitting portion 40 toward the stacked body 20 side.

[0061] In the light emitting device 100, the first metal layer 50 overlaps with the light emitting layer 24 when viewed from a direction perpendicular to the stacking direction. Therefore, in the light emitting device 100, as shown in FIG. 2, the first metal layer 50 can reflect the light L emitted from the side surface of the light emitting layer 24 toward the stacked body 20. This can further improve the light extraction efficiency. As shown in FIG. 3, when the first metal layer is not provided, the light L emitted from the side surface of the light emitting layer 1024 is not reflected at the interface between the stacked body 1020 and the insulating part 1060 depending on the incident angle, but passes through the insulating part 1060. Then, the light L is reflected by the wiring layer 1070 and, for example, enters an adjacent light emitting element (not shown), causing crosstalk.

[0062] Fig. 2 is a cross-sectional view that shows a schematic diagram of the light emitting device 100 according to this embodiment. Fig. 3 is a cross-sectional view that shows a schematic diagram of a light emitting device according to a reference example.

[0063] 2. Manufacturing method of light-emitting device Next, a method for manufacturing the light emitting device 100 according to this embodiment will be described with reference to the drawings. Figures 4 and 5 are cross-sectional views that typically show the manufacturing process of the light emitting device 100 according to this embodiment.

[0064] As shown in Fig. 4, the second semiconductor layer 26, the light emitting layer 24, and the first semiconductor layer 22 are epitaxially grown in this order on the growth substrate 12. Examples of the epitaxial growth method include a metal organic chemical vapor deposition (MOCVD) method and a molecular beam epitaxy (MBE) method. This process forms a stacked body 20. The growth substrate 12 is, for example, a GaN substrate, a sapphire substrate, a silicon substrate, or a SiC substrate. The growth substrate 12 is a substrate for epitaxially growing the stacked body 20.

[0065] Next, the laminate 20 is patterned. The patterning is performed so that the side surface 21 of the tapered portion 20a of the laminate 20 is inclined with respect to the lamination direction. The patterning is performed by, for example, photolithography and etching.

[0066] Next, the first light transmitting portion 40 is formed on the side surface 21 of the tapered portion 20a. The first light transmitting portion 40 is formed by, for example, a chemical vapor deposition (CVD) method or a sputtering method.

[0067] Next, the first metal layer 50 is formed on the side of the first light transmitting portion 40. The first metal layer 50 is formed by, for example, a sputtering method, a CVD method, or a vacuum deposition method.

[0068] Next, the insulating portion 60 is formed on the side of the first metal layer 50 and on the side of the first light transmitting portion 40. The insulating portion 60 is formed by, for example, a CVD method or a sputtering method.

[0069] Next, the first electrode 30 is formed on the second semiconductor layer 26. The first electrode 30 is formed by, for example, a sputtering method, a CVD method, or a vacuum deposition method.

[0070] 5, a structure consisting of the growth substrate 12, the laminate 20, the first electrode 30, the first light-transmitting portion 40, the first metal layer 50, and the insulating portion 60 is bonded to the substrate 10 with the first electrode 30 side facing the substrate 10. The bonding is performed, for example, via solder or silver paste.

[0071] Next, the growth substrate 12 is removed to expose the second semiconductor layer 26. The growth substrate 12 is removed by, for example, a chemical mechanical polisher (CMP).

[0072] Next, the upper surface of the second semiconductor layer 26 is patterned to form the uneven structure 28. The patterning is performed by, for example, photolithography and etching. When forming the uneven structure 28 in which the protrusions 29 are randomly arranged, the uneven structure 28 can be formed by dry etching the entire upper surface of the second semiconductor layer 26 and then wet etching it.

[0073] 1, a second electrode 32 is formed on the second semiconductor layer 26, and a wiring layer 70 is formed on the insulating section 60. The second electrode 32 and the wiring layer 70 are formed by, for example, a sputtering method, a CVD method, or a vacuum deposition method. Since the second electrode 32 is formed on the uneven structure 28, an uneven structure 36 corresponding to the uneven structure 28 is formed in the second electrode 32.

[0074] Next, the metal portion 80 is formed on the wiring layer 70. The metal portion 80 is formed by, for example, a sputtering method, a CVD method, a vacuum deposition method, or a plating method.

[0075] Next, the second light transmitting portion 90 is formed on the second electrode 32. The second light transmitting portion 90 is formed by, for example, a sputtering method or a CVD method.

[0076] Next, the upper surface of the second light-transmitting portion 90 is patterned to form the lens surface 96. The patterning is performed by, for example, photolithography and etching.

[0077] Next, the light-transmitting layer 98 is formed on the lens surface 96. The light-transmitting layer 98 is formed by, for example, a sputtering method or a CVD method.

[0078] Through the above steps, the light emitting device 100 can be manufactured.

[0079] 3. Modifications of the Light Emitting Device 3.1. First variant Next, a light emitting device according to a first modification of this embodiment will be described with reference to the drawings. Fig. 6 is a cross-sectional view that shows a schematic view of a light emitting device 200 according to a first modification of this embodiment.

[0080] Hereinafter, in the light emitting device 200 according to the first modified example of this embodiment, the components having the same functions as the components of the light emitting device 100 according to this embodiment described above are denoted by the same reference numerals, and detailed description thereof will be omitted. This also applies to the light emitting devices according to the second to fifth modified examples of this embodiment described later.

[0081] As shown in FIG. 6, the light emitting device 200 differs from the above-described light emitting device 100 in that an adhesive layer 72 is provided.

[0082] The adhesive layer 72 is provided on the wiring layer 70. The adhesive layer 72 is provided between the wiring layer 70 and the metal portion 80. The adhesive layer 72 bonds the wiring layer 70 and the metal portion 80. The adhesive layer 72 is conductive. The adhesive layer 72 has a reflective surface 74 that reflects light generated in the light emitting layer 24. The reflective surface 74 is in contact with a side surface 91 of the second light transmitting portion 90. In the illustrated example, the reflective surface 74 is parallel to the side surface 91. The adhesive layer 72 is, for example, a TiN layer. The adhesive layer 72 is formed by, for example, a sputtering method or a CVD method.

[0083] The light emitting device 200 has an adhesive layer 72 provided between the wiring layer 70 and the metal section 80. Therefore, in the light emitting device 200, the adhesion between the wiring layer 70 and the metal section 80 can be improved.

[0084] In the light emitting device 200, the adhesive layer 72 has electrical conductivity. Therefore, in the light emitting device 200, the second electrode 32 can be electrically connected to a power source (not shown) not only through the wiring layer 70 but also through the adhesive layer 72 and the metal part 80. This makes it possible to reduce the resistance of the wiring for passing a current to the second electrode 32.

[0085] In the light emitting device 200, the adhesive layer 72 has a reflective surface 74 in contact with the side surface 91 of the second light transmitting portion 90, and the reflective surface 74 reflects the light generated in the light emitting layer 24. Therefore, in the light emitting device 200, the adhesive layer 72 can reflect the light generated in the light emitting layer 24, and the light leaking from the side surface 91 can be reduced. This can further improve the light extraction efficiency.

[0086] 3.2. Second variant Next, a light emitting device according to a second modified example of this embodiment will be described with reference to the drawings. Fig. 7 is a cross-sectional view showing a light emitting device 300 according to a second modified example of this embodiment. For convenience, Fig. 7 shows an enlarged view of the light emitting device 300.

[0087] The light emitting device 300 differs from the above-described light emitting device 100 in that the concave-convex structure 28 of the second semiconductor layer 26 overlaps with the metal portion 80 as shown in FIG.

[0088] In the illustrated example, in the stacking direction, the position of the tip of the convex portion 29 of the unevenness structure 28 is located closer to the second light transmitting portion 90 than the position of the lower surface 84 of the metal portion 80. When viewed from a direction perpendicular to the stacking direction, the lower surface 84 of the metal portion 80 overlaps with a portion of the second semiconductor layer 26 that is not the unevenness structure 28. When viewed from a direction perpendicular to the stacking direction, the unevenness structure 36 of the second electrode 32 overlaps with the metal portion 80. In the illustrated example, the second electrode 32 is separated from the wiring layer 70. The second electrode 32 is connected to the metal portion 80.

[0089] As long as concave-convex structure 28 overlaps metal portion 80 when viewed from a direction perpendicular to the stacking direction, the position of lower surface 84 of metal portion 80 is not particularly limited. When viewed from a direction perpendicular to the stacking direction, lower surface 84 may overlap convex portions 29 of concave-convex structure 28 as shown in Fig. 8, or may overlap tips of convex portions 29 as shown in Fig. 9.

[0090] In the light emitting device 300, the uneven structure 28 overlaps with the metal portion 80 when viewed from a direction perpendicular to the stacking direction. Therefore, in the light emitting device 300, even if light is refracted in a direction intersecting the stacking direction in the uneven structure 28, the light can be reflected by the metal portion 80 toward the second light transmitting portion 90. This can further improve the light extraction efficiency.

[0091] 3.3. Third variant Next, a light emitting device according to a third modified example of this embodiment will be described with reference to the drawings. Fig. 10 is a cross-sectional view that shows a schematic view of a light emitting device 400 according to the third modified example of this embodiment.

[0092] As shown in FIG. 10, the light emitting device 400 differs from the above-described light emitting device 100 in that the first metal layer 50 is electrically connected to the second electrode 32.

[0093] The first metal layer 50 is connected to the wiring layer 70. The first metal layer 50 is electrically connected to the second electrode 32 via the wiring layer 70. A constant potential is applied to the second electrode 32. When viewed from a direction perpendicular to the stacking direction, the entire second semiconductor layer 26 overlaps with the first metal layer 50. When viewed from a direction perpendicular to the stacking direction, the entire light emitting layer 24 overlaps with the first metal layer 50.

[0094] In the light emitting device 400, a constant potential is applied to the second electrode 32, and the first metal layer 50 is electrically connected to the second electrode 32. Therefore, in the light emitting device 400, the first metal layer 50 can reduce electromagnetic wave noise incident on the laminate 20. Furthermore, since the first metal layer 50 is connected to the wiring layer 70, it is possible to suppress light from passing between the first metal layer 50 and the wiring layer 70.

[0095] 11, the first metal layer 50 may be in contact with the side surface 21 of the tapered portion 20a. The first metal layer 50 is in contact with the second semiconductor layer 26. The first metal layer 50 is not in contact with the light emitting layer 24 and the first semiconductor layer 22. In the illustrated example, the first light transmitting portion 40 is not provided. If the first metal layer 50 is in contact with the second semiconductor layer 26, the contact resistance between the metal body having the first metal layer 50 and the second electrode 32 and the second semiconductor layer 26 can be reduced.

[0096] 3.4. Fourth variant Next, a light emitting device according to a fourth modified example of this embodiment will be described with reference to the drawings. Fig. 12 is a cross-sectional view that shows a schematic view of a light emitting device 500 according to the fourth modified example of this embodiment.

[0097] As shown in FIG. 12, the light emitting device 500 differs from the above-described light emitting device 100 in that it has a second metal layer 54.

[0098] The second metal layer 54 is in contact with the side surface 21 of the tapered portion 20a. In the illustrated example, the second metal layer 54 is in contact with the first semiconductor layer 22. The second metal layer 54 is not in contact with the light emitting layer 24 and the second semiconductor layer 26. The second metal layer 54 surrounds the laminate 20 when viewed from the lamination direction. The second metal layer 54 is separated from the first metal layer 50. In the illustrated example, the second metal layer 54 is connected to the first electrode 30. This can reduce the contact resistance between the metal body consisting of the second metal layer 54 and the first electrode 30 and the first semiconductor layer 22. The second metal layer 54 is electrically isolated from the second electrode 32.

[0099] The second metal layer 54 has a reflective surface 56 that reflects light generated in the light emitting layer 24. The reflective surface 56 is in contact with the side surface 21 of the tapered portion 20a. In the illustrated example, the reflective surface 56 is parallel to the side surface 21. The material of the second metal layer 54 is, for example, the same as the material of the first metal layer 50. The second metal layer 54 is formed, for example, by the same method as the first metal layer 50.

[0100] When viewed from a direction perpendicular to the stacking direction, the first metal layer 50 has an overlapping portion 51a that overlaps with the second metal layer 54, and a non-overlapping portion 51b that does not overlap with the second metal layer 54. In the illustrated example, the non-overlapping portion 51b is connected to the wiring layer 70.

[0101] 13, the second metal layer 54 may be connected to the wiring layer 70, and the first metal layer 50 may be separated from the wiring layer 70. In the illustrated example, the second metal layer 54 is in contact with the second semiconductor layer 26. This reduces the contact resistance between the metal body including the second metal layer 54 and the second electrode 32 and the second semiconductor layer 26. The second metal layer 54 is not in contact with the first semiconductor layer 22 or the light emitting layer 24.

[0102] The light emitting device 500 has a second metal layer 54 in contact with the side surface 21 of the tapered portion 20a. Therefore, in the light emitting device 500, the second metal layer 54 can reflect light generated in the light emitting layer 24, and the amount of light leaking from the side surface 21 can be reduced.

[0103] In the light emitting device 500, when viewed from a direction perpendicular to the stacking direction, the first metal layer 50 has an overlapping portion 51a that overlaps with the second metal layer 54, and a non-overlapping portion 51b that does not overlap with the second metal layer 54. Therefore, in the light emitting device 500, it is possible to suppress light from passing between the first metal layer 50 and the second metal layer 54.

[0104] 3.5. Fifth Variant Next, a light emitting device according to a fifth modified example of this embodiment will be described with reference to the drawings. Fig. 14 is a cross-sectional view that shows a schematic view of a light emitting device 600 according to the fifth modified example of this embodiment.

[0105] As shown in FIG. 14, the light emitting device 600 differs from the above-described light emitting device 100 in that the first metal layer 50 is connected to the first electrode 30.

[0106] In the light emitting device 600, the first metal layer 50 is connected to the first electrode 30, and therefore, the passage of light between the first metal layer 50 and the first electrode 30 can be suppressed.

[0107] 4. Projector Next, a projector as a display device according to this embodiment will be described with reference to the drawings. Fig. 15 is a diagram showing a schematic diagram of a projector 700 according to this embodiment.

[0108] The projector 700 includes, for example, a light emitting device 100 as a light source.

[0109] Projector 700 has a housing (not shown), and red light source 100R, green light source 100G, and blue light source 100B that are provided in the housing and emit red light, green light, and blue light, respectively. For convenience, red light source 100R, green light source 100G, and blue light source 100B are illustrated in a simplified form in FIG.

[0110] The projector 700 further includes, for example, a first optical element 702R, a second optical element 702G, a third optical element 702B, a first light modulation device 704R, a second light modulation device 704G, a third light modulation device 704B, and a projection device 708, which are provided in the housing. The first light modulation device 704R, the second light modulation device 704G, and the third light modulation device 704B are, for example, transmissive liquid crystal light valves. The projection device 708 is, for example, a projection lens.

[0111] The light emitted from red light source 100R is incident on first optical element 702R. The light emitted from red light source 100R is collected by first optical element 702R. Note that first optical element 702R may have a function other than collecting light. Second optical element 702G and third optical element 702B may also have a function other than collecting light.

[0112] The light collected by the first optical element 702R is incident on the first light modulation device 704R. The first light modulation device 704R modulates the incident light in accordance with image information. The projection device 708 then enlarges the image formed by the first light modulation device 704R and projects it onto the screen 710.

[0113] The light emitted from green light source 100G is incident on second optical element 702G. The light emitted from green light source 100G is collected by second optical element 702G.

[0114] The light collected by the second optical element 702G is incident on the second light modulation device 704G. The second light modulation device 704G modulates the incident light in accordance with image information. The projection device 708 then enlarges the image formed by the second light modulation device 704G and projects it onto the screen 710.

[0115] The light emitted from blue light source 100B is incident on third optical element 702B. The light emitted from blue light source 100B is collected by third optical element 702B.

[0116] The light collected by the third optical element 702B enters the third light modulation device 704B. The third light modulation device 704B modulates the incident light in accordance with image information. The projection device 708 then enlarges the image formed by the third light modulation device 704B and projects it onto the screen 710.

[0117] The projector 700 further includes a cross dichroic prism 706 that combines the light emitted from the first light modulation device 704R, the second light modulation device 704G, and the third light modulation device 704B, and guides the combined light to a projection device 708.

[0118] The three color lights modulated by the first light modulation device 704R, the second light modulation device 704G, and the third light modulation device 704B enter the cross dichroic prism 706. The cross dichroic prism 706 is formed by bonding four right-angle prisms together, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are disposed on its inner surface. The three color lights are synthesized by these dielectric multilayer films to form light that represents a color image. The synthesized light is then projected by the projection device 708 onto a screen 710, and an enlarged image is displayed.

[0119] Note that red light source 100R, green light source 100G, and blue light source 100B may directly form an image without using first light modulation device 704R, second light modulation device 704G, and third light modulation device 704B, by controlling light emitting device 100 as a pixel of the image according to image information. Then, projection device 708 may enlarge and project the image formed by red light source 100R, green light source 100G, and blue light source 100B onto screen 710.

[0120] In the above example, a transmissive liquid crystal light valve is used as the light modulation device, but a light valve other than liquid crystal may be used, or a reflective light valve may be used. Examples of such light valves include a reflective liquid crystal light valve and a digital micro mirror device. The configuration of the projection device is appropriately changed depending on the type of light valve used.

[0121] The light source can also be applied to a light source device of a scanning type image display device having a scanning means, which is an image forming device that displays an image of a desired size on a display surface by scanning light from the light source on a screen.

[0122] 5. Display Next, a display as a display device according to this embodiment will be described with reference to the drawings. Fig. 16 is a plan view showing a display 800 according to this embodiment. Fig. 17 is a cross-sectional view showing a display 800 according to this embodiment. Note that Fig. 16 shows an X-axis and a Y-axis as two mutually orthogonal axes.

[0123] The display 800 includes, for example, a light emitting device 100 as a light source.

[0124] The display 800 is a display device that displays an image. The image includes an image that displays only text information. The display 800 is a self-luminous display. As shown in Figs. 16 and 17, the display 800 has, for example, a circuit board 810, a lens array 820, and a heat sink 830.

[0125] A driving circuit for driving the light emitting device 100 is mounted on the circuit board 810. The driving circuit is, for example, a circuit including a CMOS (Complementary Metal Oxide Semiconductor) or the like. The driving circuit drives the light emitting device 100 based on, for example, input image information. Although not shown, a light-transmitting substrate for protecting the circuit board 810 is disposed on the circuit board 810.

[0126] The circuit board 810 includes, for example, a display area 812, a data line driving circuit 814, a scanning line driving circuit 816, and a control circuit 818.

[0127] The display area 812 is made up of a plurality of pixels P. In the illustrated example, the pixels P are arranged along the X-axis and the Y-axis.

[0128] Although not shown, a plurality of scanning lines and a plurality of data lines are provided on the circuit board 810. For example, the scanning lines extend along the X-axis, and the data lines extend along the Y-axis. The scanning lines are connected to a scanning line driving circuit 816. The data lines are connected to a data line driving circuit 814. Pixels P are provided at intersections of the scanning lines and the data lines.

[0129] One pixel P has, for example, one light emitting device 100, one lens 822, and a pixel circuit (not shown). The pixel circuit has a switching transistor that functions as a switch for the pixel P. The gate of the switching transistor is connected to a scan line, and one of the source and drain is connected to a data line.

[0130] The data line driving circuit 814 and the scanning line driving circuit 816 are circuits that control the driving of the light emitting device 100 that constitutes the pixel P. The control circuit 818 controls the display of an image.

[0131] Image data is supplied from a higher-level circuit to the control circuit 818. The control circuit 818 supplies various signals based on the image data to the data line driving circuit 814 and the scanning line driving circuit 816.

[0132] When the scanning line driving circuit 816 activates a scanning signal to select a scanning line, the switching transistor of the selected pixel P is turned on. At this time, the data line driving circuit 814 supplies a data signal from the data line to the selected pixel P, causing the light emitting device 100 of the selected pixel P to emit light in response to the data signal.

[0133] The lens array 820 has a plurality of lenses 822. For example, one lens 822 is provided for each light emitting device 100. Light emitted from the light emitting device 100 is incident on one lens 822.

[0134] The heat sink 830 is in contact with the circuit board 810. The material of the heat sink 830 is, for example, a metal such as copper or aluminum. The heat sink 830 dissipates heat generated by the light emitting device 100.

[0135] 6. Head-mounted displays 6.1. Overall structure Next, a head mounted display as an electronic device according to this embodiment will be described with reference to the drawings. Fig. 18 is a perspective view showing a schematic view of a head mounted display 900 according to this embodiment.

[0136] The head mounted display 900 is a head-mounted display having an appearance like glasses, as shown in Fig. 18. The head mounted display 900 is worn on the head of an observer. The observer is a user who uses the head mounted display 900. The head mounted display 900 allows the observer to view image light formed by a virtual image, and also allows the observer to view an external world image in a see-through manner.

[0137] The head mounted display 900 has, for example, a first display unit 910a, a second display unit 910b, a frame 920, a first temple 930a, and a second temple 930b.

[0138] The first display unit 910a and the second display unit 910b display images. Specifically, the first display unit 910a displays a virtual image for the observer's right eye. The second display unit 910b displays a virtual image for the observer's left eye. The display units 910a and 910b each include, for example, an image forming device 911 and a light guide device 915.

[0139] The image forming device 911 forms image light. The image forming device 911 has an optical system, such as a light source and a projection device, and an external member 912. The external member 912 houses the light source and the projection device.

[0140] The light guiding device 915 covers the viewer's eyes. The light guiding device 915 guides the image light formed by the image forming device 911 and allows the viewer to visually recognize the image light overlapping with the outside light. Details of the image forming device 911 and the light guiding device 915 will be described later.

[0141] The frame 920 supports the first display unit 910a and the second display unit 910b. The frame 920, for example, surrounds the display units 910a and 910b. In the illustrated example, the image forming device 911 of the first display unit 910a is attached to one end of the frame 920. The image forming device 911 of the second display unit 910b is attached to the other end of the frame 920.

[0142] A first temple 930a and a second temple 930b extend from the frame 920. In the illustrated example, the first temple 930a extends from one end of the frame 920. The second temple 930b extends from the other end of the frame 920.

[0143] The first temple 930a and the second temple 930b are suspended from the ears of the viewer when the viewer wears the head mounted display 900. The viewer's head is positioned between the temples 930a and 930b.

[0144] 6.2. Image forming and light directing devices 19 is a diagram illustrating an image forming device 911 and a light guide device 915 of a first display unit 910a of a head mounted display 900. The first display unit 910a and the second display unit 910b basically have the same configuration. Therefore, the following description of the first display unit 910a can be applied to the second display unit 910b.

[0145] As shown in FIG. 19, the image forming device 911 includes, for example, a light emitting device 100 as a light source, a light modulation device 913, and a projection device 914 for forming an image.

[0146] The light modulation device 913 modulates the light incident from the light emitting device 100 in accordance with image information, and emits image light. The light modulation device 913 is a transmissive liquid crystal light valve. The light emitting device 100 may be a self-luminous light emitting device that emits light in accordance with input image information. In this case, the light modulation device 913 is not provided.

[0147] The projection device 914 projects the image light emitted from the light modulation device 913 toward the light guide device 915. The projection device 914 is, for example, a projection lens. As a lens constituting the projection device 914, a lens having an axially symmetric surface as a lens surface may be used.

[0148] The light guiding device 915 is precisely positioned with respect to the projection device 914 by, for example, being screwed to the lens barrel of the projection device 914. The light guiding device 915 has, for example, an image light guiding member 916 that guides the image light, and a see-through member 918 for see-through.

[0149] The image light emitted from the projection device 914 is incident on the image light guiding member 916. The image light guiding member 916 is a prism that guides the image light toward the viewer's eye. The image light that enters the image light guiding member 916 is repeatedly reflected on the inner surface of the image light guiding member 916, and is then reflected by the reflective layer 917 and emitted from the image light guiding member 916. The image light that is emitted from the image light guiding member 916 reaches the viewer's eye. The reflective layer 917 is made of, for example, a metal or a dielectric multilayer film. The reflective layer 917 may be a half mirror.

[0150] The transparent member 918 is adjacent to the image light guiding member 916. The transparent member 918 is fixed to the image light guiding member 916. For example, the outer surface of the transparent member 918 is continuous with the outer surface of the image light guiding member 916. The transparent member 918 allows the observer to see outside light through it. The image light guiding member 916 also has a function of allowing the observer to see outside light through it, in addition to the function of guiding the image light. Note that the head mounted display 900 may be configured not to allow the observer to see outside light through it.

[0151] The light emitting device according to the above-described embodiment can be used for applications other than projectors, displays, and head-mounted displays. The light emitting device according to the above-described embodiment can be used for, for example, indoor and outdoor lighting, laser printers, scanners, sensing devices using light, EVFs (Electronic View Finders), wearable displays such as smart watches, in-vehicle lights, and in-vehicle head-up displays.

[0152] The above-described embodiment and modifications are merely examples, and the present invention is not limited to these. For example, the embodiments and modifications can be appropriately combined.

[0153] The present invention includes configurations that are substantially the same as the configurations described in the embodiments, for example, configurations with the same functions, methods, and results, or configurations with the same purpose and effect. The present invention also includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. The present invention also includes configurations that achieve the same effects as the configurations described in the embodiments, or configurations that can achieve the same purpose. The present invention also includes configurations in which publicly known technology is added to the configurations described in the embodiments.

[0154] The following can be derived from the above-described embodiment and modifications.

[0155] One aspect of the light emitting device is A first electrode; a second electrode disposed opposite the first electrode and having light-transmitting properties; a laminate provided between the first electrode and the second electrode, the laminate having a tapered portion having a tapered shape whose width increases from the first electrode side toward the second electrode side; a first low refractive index portion provided on a side surface of the tapered portion and having a refractive index lower than that of the laminate; a second low refractive index portion provided on the second electrode opposite to the laminate and having a refractive index lower than that of the laminate; A metal portion provided on a side surface of the second low refractive index portion; having The laminate comprises: a first semiconductor layer having a first conductivity type; a second semiconductor layer provided between the first semiconductor layer and the second electrode and having a second conductivity type different from the first conductivity type; a light emitting layer provided between the first semiconductor layer and the second semiconductor layer; having The light generated in the light emitting layer is emitted from the second electrode side, The surface of the second low refractive index portion opposite to the second electrode is a lens surface.

[0156] According to this light emitting device, the light extraction efficiency can be improved.

[0157] In one embodiment of the light emitting device, A perpendicular line to a side surface of the second low refractive index portion may be parallel to a perpendicular line to a side surface of the tapered portion.

[0158] According to this light emitting device, for example, it is possible to collect light generated in the light emitting layer.

[0159] In one embodiment of the light emitting device, The refractive index of the first low refractive index portion may be lower than the refractive index of the second low refractive index portion.

[0160] According to this light emitting device, the difference between the refractive index of the first light transmitting portion and the refractive index of the laminate can be made large.

[0161] In one embodiment of the light emitting device, The second electrode may have a lower refractive index than the second semiconductor layer.

[0162] According to this light emitting device, the light extraction efficiency can be further improved.

[0163] In one embodiment of the light emitting device, The refractive index of the second low refractive index portion may be lower than the refractive index of the second electrode.

[0164] According to this light emitting device, the light extraction efficiency can be further improved.

[0165] In one embodiment of the light emitting device, The lens may further include a light-transmitting layer provided on the lens surface.

[0166] According to this light emitting device, the lens surface can be protected by the light transmitting layer.

[0167] In one embodiment of the light emitting device, The refractive index of the light transmitting layer may be lower than the refractive index of the second low refractive index portion.

[0168] According to this light emitting device, the light extraction efficiency can be further improved.

[0169] One aspect of the display device is The present invention has one aspect of the light emitting device.

[0170] One aspect of the electronic device is The present invention has one aspect of the light emitting device. [Explanation of symbols]

[0171] 2...light-emitting element, 10...substrate, 12...growth substrate, 20...laminated body, 20a...tapered portion, 21...side surface, 22...first semiconductor layer, 24...light-emitting layer, 26...second semiconductor layer, 27...first contact surface, 28...uneven structure, 29...convex portion, 30...first electrode, 32...second electrode, 34...second contact surface, 36...uneven structure, 40...first light-transmitting portion, 50...first metal layer, 51a...overlapping portion, 51b...non-overlapping portion, 52...reflective surface, 54...second metal layer, 56...reflective surface, 60...insulating portion, 70...wiring layer, 72...adhesive layer, 74...reflective surface, 80...metal portion, 82...reflective surface, 84...lower surface, 90...second light-transmitting portion, 91...side surface, 92...tapered portion, 94...lens portion, 96...lens surface, 98...light-transmitting layer, 100...light-emitting device, 100R...red light source, 100G...green light source, 100B...blue light source, 200, 300, 400, 500, 600...light-emitting device, 700...projector, 702R...first optical element, 702G ...second optical element, 702B...third optical element, 704R...first optical modulation device, 704G...second optical modulation device, 704B...third optical modulation device, 706...cross dichroic prism, 708...projection device, 710...screen, 800...display, 810...circuit board, 812...display area, 814...data line driving circuit, 816...scanning line driving circuit, 818...control circuit, 820...lens array, 822...lens, 830...heat sink 900...head mounted display, 910a...first display section, 910b...second display section, 911...image forming device, 912...external member, 913...light modulation device, 914...projection device, 915...light guide device, 916...image light guide member, 917...reflective layer, 918...transparent member, 920...frame, 930a...first temple, 930b...second temple, 1020...laminated body, 1024...light emitting layer, 1060...insulating section, 1070...wiring layer

Claims

1. A first electrode; a second electrode disposed opposite the first electrode and having light-transmitting properties; a laminate provided between the first electrode and the second electrode, the laminate having a tapered portion having a tapered shape whose width increases from the first electrode side toward the second electrode side; a first low refractive index portion provided on a side surface of the tapered portion and having a refractive index lower than that of the laminate; a second low refractive index portion provided on a side of the second electrode opposite to the laminate and having a refractive index lower than that of the laminate; A metal portion provided on a side surface of the second low refractive index portion; having The laminate comprises: a first semiconductor layer having a first conductivity type; a second semiconductor layer provided between the first semiconductor layer and the second electrode and having a second conductivity type different from the first conductivity type; a light emitting layer provided between the first semiconductor layer and the second semiconductor layer; having The light generated in the light emitting layer is emitted from the second electrode side, a surface of the second low refractive index portion opposite to the second electrode is a lens surface.

2. In claim 1, A light emitting device, wherein a perpendicular line to a side surface of the second low refractive index portion is parallel to a perpendicular line to a side surface of the tapered portion.

3. In claim 1, A light emitting device, wherein the refractive index of the first low refractive index portion is lower than the refractive index of the second low refractive index portion.

4. In claim 1, A light emitting device, wherein the second electrode has a refractive index lower than a refractive index of the second semiconductor layer.

5. In claim 4, A light emitting device, wherein the refractive index of the second low refractive index portion is lower than the refractive index of the second electrode.

6. In claim 1, A light emitting device having a light transmitting layer provided on the lens surface.

7. In claim 6, A light emitting device, wherein the refractive index of the light transmitting layer is lower than the refractive index of the second low refractive index portion.

8. A display device comprising the light emitting device according to claim 1 .

9. An electronic device comprising the light emitting device according to claim 1 .

Images