Light-emitting device, projector, and display

Abstract

To provide a light emitting device that can block light emitted from a portion of a laminate overlapping an outer edge of a first electrode in plan view.SOLUTION: A light emitting device has: a substrate; a laminate that is provided on the substrate and has a luminous layer; a first electrode that is in contact with the laminate on a side of the laminate opposite to the substrate and injects current to the luminous layer; and a wiring layer that is electrically connected with the first electrode and has light shielding properties against light generated in the luminous layer. The wiring layer is provided with a first opening through which light emitted from the laminate passes. In plan view, the first opening is located inside an outer edge of the first electrode.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a light-emitting device, a projector, and a display.

Background Art

[0002] Semiconductor lasers are expected as high-brightness next-generation light sources. In particular, semiconductor lasers applying nanocolumns are expected to achieve high-output light emission with a narrow emission angle due to the effect of photonic crystals by the nanocolumns.

[0003] For example, Patent Document 1 describes a semiconductor optical element array including a plurality of nanocolumns including an n-type clad layer such as n-type AlGaN, an active layer, and a p-type semiconductor layer including a p-type clad layer such as p-type AlGaN. A p-side electrode is provided on the plurality of nanocolumns.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a semiconductor optical element array having a plurality of nanocolumns, there are nanocolumns that overlap with the outer edge of the p-side electrode in a plan view. Such nanocolumns may be cut, for example, by overetching when forming the p-side electrode.

Means for Solving the Problems

[0006] One aspect of the light-emitting device according to the present invention is a substrate, a laminate provided on the substrate and having a light-emitting layer, A first electrode that contacts the laminate on the side opposite to the substrate of the laminate and injects current into the light-emitting layer; A wiring layer that is electrically connected to the first electrode and has light-shielding properties with respect to the light generated in the light-emitting layer; having The wiring layer is provided with a first opening through which the light emitted from the laminate passes; In plan view, the first opening is located inside the outer edge of the first electrode.

[0007] One aspect of the projector according to the present invention is having one aspect of the light-emitting device.

[0008] One aspect of the display according to the present invention is having one aspect of the light-emitting device.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0010] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Note that the embodiments described below do not unduly limit the content of the present invention described in the claims. Also, not all of the configurations described below are essential constituent elements of the present invention.

[0011] 1. Light-emitting device 1.1. Overall 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 schematically showing the light-emitting device 100 according to the present embodiment. FIG. 2 is a plan view schematically showing the light-emitting device 100 according to the present embodiment. Note that FIG. 1 is a cross-sectional view taken along line I-I of FIG. 2.

[0012] As shown in FIGS. 1 and 2, the light-emitting device 100 has, for example, a substrate 10, a laminate 20, an insulating layer 40, a first electrode 50, a second electrode 60, a third electrode 70, and a wiring layer 80. For convenience, in FIG. 2, the illustration of the second electrode 60 is omitted. The light-emitting device 100 is, for example, a semiconductor laser.

[0013] The substrate 10 is, for example, a Si substrate, a GaN substrate, a sapphire substrate, a SiC substrate, or the like.

[0014] The laminate 20 is provided on the substrate 10. In the example shown in FIG. 1, the laminate 20 is provided on the substrate 10. The laminate 20 has, for example, a buffer layer 22 and columnar portions 30.

[0015] In this specification, in the stacking direction of the laminate 20 (hereinafter, also simply referred to as the "stacking direction"), when the light-emitting layer 34 is used as a reference, the direction from the light-emitting layer 34 toward the second semiconductor layer 36 is referred to as "upward", and the direction from the light-emitting layer 34 toward the first semiconductor layer 32 is referred to as "downward" for description. Further, the direction orthogonal to the stacking direction is also referred to as the "in-plane direction". Further, the "stacking direction of the laminate 20" refers to the stacking direction of the first semiconductor layer 32 and the light-emitting layer 34 of the columnar portion 30. Further, "in plan view" refers to the case when viewed from the stacking direction.

[0016] The buffer layer 22 is provided on the substrate 10. The buffer layer 22 is a semiconductor layer of a first conductivity type. The buffer layer 22 is, for example, an n-type GaN layer doped with Si. Although not shown, a mask layer for forming the columnar portion 30 is provided on the buffer layer 22. The mask layer is, for example, a silicon oxide layer, a titanium layer, a titanium oxide layer, an aluminum oxide layer, or the like.

[0017] The columnar portion 30 is provided on the buffer layer 22. The columnar portion 30 has a columnar shape protruding upward from the buffer layer 22. In other words, the columnar portion 30 protrudes upward from the substrate 10 via the buffer layer 22. The columnar portion 30 is also referred to as, for example, a nanocolumn, a nanowire, a nanorod, or a nanopillar. The planar shape of the columnar portion 30 is, for example, a polygon or a circle.

[0018] The diameter of the columnar portion 30 is, for example, 50 nm or more and 500 nm or less. By setting the diameter of the columnar portion 30 to 500 nm or less, a high-quality crystal light-emitting layer 34 can be obtained, and the strain inherent in the light-emitting layer 34 can be reduced. Thereby, the light generated in the light-emitting layer 34 can be amplified with high efficiency.

[0019] Note that the "diameter of the columnar portion" refers to the diameter when the planar shape of the columnar portion 30 is a circle, and refers to the diameter of the minimum circumscribed circle when the planar shape of the columnar portion 30 is not a circular shape. For example, when the planar shape of the columnar portion 30 is a polygon, the diameter of the columnar portion 30 is the diameter of the smallest circle that includes the polygon inside; when the planar shape of the columnar portion 30 is an ellipse, the diameter of the columnar portion 30 is the diameter of the smallest circle that includes the ellipse inside.

[0020] A plurality of columnar portions 30 are provided. The interval between adjacent columnar portions 30 is, for example, 1 nm or more and 500 nm or less. The plurality of columnar portions 30 are arranged at a predetermined pitch in a predetermined direction in a plan view. The plurality of columnar portions 30 are arranged, for example, in a triangular lattice pattern or a square lattice pattern. The plurality of columnar portions 30 can exhibit the effect of a photonic crystal.

[0021] Note that the "pitch of the columnar portion" is the distance between the centers of adjacent columnar portions 30 along a predetermined direction. The "center of the columnar portion" refers to the center of the circle when the planar shape of the columnar portion 30 is a circle, and refers to the center of the minimum circumscribed circle when the planar shape of the columnar portion 30 is not a circular shape. For example, when the planar shape of the columnar portion 30 is a polygon, the center of the columnar portion 30 is the center of the smallest circle that includes the polygon inside; when the planar shape of the columnar portion 30 is an ellipse, the center of the columnar portion 30 is the center of the smallest circle that includes the ellipse inside.

[0022] The columnar portion 30 has a first semiconductor layer 32, a light-emitting layer 34, and a second semiconductor layer 36.

[0023] The first semiconductor layer 32 is provided on the buffer layer 22. The first semiconductor layer 32 is provided between the substrate 10 and the light-emitting layer 34. The first semiconductor layer 32 is a semiconductor layer of a first conductivity type. The first semiconductor layer 32 is, for example, an n-type GaN layer doped with Si.

[0024] The light-emitting layer 34 is provided on the first semiconductor layer 32. The light-emitting layer 34 is provided between the first semiconductor layer 32 and the second semiconductor layer 36. The light-emitting layer 34 generates light when current is injected. The light-emitting layer 34 has, for example, a well layer and a barrier layer. The well layer and the barrier layer are i-type semiconductor layers that are not intentionally doped with impurities. The well layer is, for example, an InGaN layer. The barrier layer is, for example, a GaN layer. The light-emitting layer 34 has a MQW (Multiple Quantum Well) structure composed of a well layer and a barrier layer.

[0025] Note that the number of well layers and barrier layers constituting the light-emitting layer 34 is not particularly limited. For example, only one well layer may be provided, and in this case, the light-emitting layer 34 has a SQW (Single Quantum Well) structure.

[0026] The second semiconductor layer 36 is provided on the light-emitting layer 34. The second semiconductor layer 36 is a semiconductor layer of a second conductivity type different from the first conductivity type. The second semiconductor layer 36 is, for example, a p-type GaN layer doped with Mg. The first semiconductor layer 32 and the second semiconductor layer 36 are cladding layers having a function of confining light in the light-emitting layer 34.

[0027] Although not shown, an OCL (Optical Confinement Layer) composed of an i-type InGaN layer and a GaN layer may be provided between at least one of the first semiconductor layer 32 and the light-emitting layer 34 and between the light-emitting layer 34 and the second semiconductor layer 36. Further, the second semiconductor layer 36 may have an EBL (Electron Blocking Layer) composed of a p-type AlGaN layer.

[0028] In the light-emitting device 100, a pin diode is formed by a p-type second semiconductor layer 36, an i-type light-emitting layer 34, and an n-type first semiconductor layer 32. In the light-emitting device 100, when a forward bias voltage of the pin diode is applied between the first electrode 50 and the third electrode 70, current is injected into the light-emitting layer 34, and recombination of electrons and holes occurs in the light-emitting layer 34. Light emission is caused by this recombination. The light generated in the light-emitting layer 34 propagates in the in-plane direction, forms a standing wave due to the effect of the photonic crystal by the plurality of columnar portions 30, gains in the light-emitting layer 34, and laser oscillation occurs. Then, the light-emitting device 100 emits +1st order diffracted light and -1st order diffracted light as laser light in the stacking direction.

[0029] Although not shown, a reflective layer may be provided between the substrate 10 and the buffer layer 22 or under the substrate 10. The reflective layer is, for example, a DBR (Distributed Bragg Reflector) layer. By the reflective layer, the light generated in the light-emitting layer 34 can be reflected, and the light-emitting device 100 can emit light only from the side of the first electrode 50.

[0030] The insulating layer 40 covers the laminate 20. In the illustrated example, the insulating layer 40 covers a part of the buffer layer 22, a part of the plurality of columnar portions 30, and a part of the first electrode 50. The thickness of the insulating layer 40 is, for example, 1 μm or more. The insulating layer 40 is, for example, a polyimide layer, a silicon oxide layer, or the like.

[0031] The first electrode 50 is provided on the second semiconductor layer 36. The first electrode 50 is electrically connected to the second semiconductor layer 36. The second semiconductor layer 36 may be in ohmic contact with the first electrode 50.

[0032] The second electrode 60 is provided on the first electrode 50 and the insulating layer 40. The first electrode 50 and the second electrode 60 are one of the electrodes for injecting current into the light-emitting layer 34. Details of the first electrode 50 and the second electrode 60 will be described later.

[0033] The third electrode 70 is provided on the buffer layer 22. The buffer layer 22 may be in ohmic contact with the third electrode 70. The third electrode 70 is electrically connected to the first semiconductor layer 32. In the illustrated example, the third electrode 70 is electrically connected to the first semiconductor layer 32 via the buffer layer 22. The third electrode 70 is the other electrode for injecting current into the light-emitting layer 34. The third electrode 70 is, for example, a laminate in which a Cr layer and a Ni layer are laminated from the buffer layer 22 side.

[0034] The wiring layer 80 is provided on the second electrode 60 and on the insulating layer 40. The wiring layer 80 is electrically connected to the first electrode 50 via the second electrode 60. Details of the wiring layer 80 will be described later.

[0035] In the above description, the InGaN-based light-emitting layer 34 has been described. However, as the light-emitting layer 34, various material systems capable of emitting light by injecting current can be used according to 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 can be used.

[0036] Also, in the above description, a gap was provided between adjacent columnar portions 30. However, the laminate 20 may have a light propagation layer for propagating the light generated in the light-emitting layer 34 between adjacent columnar portions 30. The light propagation layer is, for example, a silicon oxide layer, an aluminum oxide layer, or a titanium oxide layer.

[0037] Also, in the above description, an example in which the laminate 20 has a plurality of columnar portions 30 has been described. However, the laminate 20 may be composed of a film-like first semiconductor layer 32, a film-like light-emitting layer 34, and a film-like second semiconductor layer 36 without having a plurality of columnar portions 30.

[0038] Also, the light-emitting device 100 may be an LED (Light Emitting Diode) instead of being limited to a laser.

[0039] 1.2. Wiring Layer and Electrodes, etc. The wiring layer 80 is provided with a first opening 82. In the example shown in FIG. 2, the shape of the first opening 82 is a circle. The first opening 82 is defined by the side surface 84 of the wiring layer 80. The first opening 82 penetrates through the wiring layer 80. The first opening 82 is an opening through which the light emitted from the laminate 20 passes. In the illustrated example, the wiring layer 80 has a ring-shaped portion 86 having a ring shape and an extending portion 88 extending outward from the ring-shaped portion 86. Although not shown, the extending portion 88 is connected to, for example, wire bonding or FPC (Flexible Printed Circuits).

[0040] The wiring layer 80 has a light-shielding property with respect to the light generated in the light-emitting layer 34. Therefore, the wiring layer 80 shields the light emitted from the laminate 20. The wiring layer 80 does not transmit the light emitted from the laminate 20. The transmittance of the wiring layer 80 with respect to the light generated in the light-emitting layer 34 is lower than the transmittance of the first electrode 50 with respect to the light generated in the light-emitting layer 34.

[0041] The resistivity of the wiring layer 80 is lower than the resistivity of the second electrode 60. The wiring layer 80 is a metal wiring layer. The wiring layer 80 is, for example, a laminate in which a Cr layer, a Ni layer, and an Au layer are laminated from the side of the insulating layer 40. The thickness of the Cr layer is, for example, 20 nm. The thickness of the Ni layer is, for example, 30 nm. The thickness of the Au layer is, for example, 200 nm. If the thickness of the wiring layer 80 is 200 nm or more, the light emitted from the laminate 20 can be more reliably shielded.

[0042] The insulating layer 40 is provided with a second opening 42. In the example shown in FIG. 2, the shape of the second opening 42 is a circle. The second opening 42 penetrates the insulating layer 40. The second opening 42 is defined by the side surface 44 of the insulating layer 40. Further, the bottom surface of the second opening 42 is defined by the upper surface of the first electrode 50. A second electrode 60 is provided on the side surface 44. In the illustrated example, the wiring layer 80 is not provided in the second opening 42. In a plan view, the area of the second opening 42 is smaller than the area of the first opening 82, and all of the second opening 42 overlaps with the first opening 82.

[0043] The first electrode 50 is provided on the side opposite to the substrate 10 of the laminate 20. The first electrode 50 is in contact with the laminate 20. The first electrode 50 is provided between the laminate 20 and the second electrode 60.

[0044] Here, FIG. 3 is a cross-sectional view schematically showing the vicinity of the side surface 52 of the first electrode 50. For the sake of convenience, in FIG. 3, the illustration of members other than the columnar portion 30 and the first electrode 50 is omitted. As shown in FIG. 3, the first columnar portion 30a among the plurality of columnar portions 30 has a portion covered by the first electrode 50 and a portion not covered by the first electrode 50. The first columnar portion 30a is provided under the side surface 52 of the first electrode 50. In a plan view, the first columnar portion 30a overlaps with the outer edge 54 of the first electrode 50. All of the first columnar portion 30a overlaps with the wiring layer 80 in a plan view. The first opening 82 and the second opening 42 are located inside the outer edge 54 in a plan view as shown in FIG. 2. The outer edge 54 overlaps with the wiring layer 80 in a plan view. In the illustrated example, all of the outer edge 54 overlaps with the wiring layer 80 in a plan view. The side surface 52 of the first electrode 50 constitutes, for example, the outer edge 54.

[0045] The resistivity of the first electrode 50 is lower than that of the second electrode 60. The first electrode 50 transmits the light emitted from the laminate 20. The thickness of the first electrode 50 is, for example, 5 nm or more and 50 nm or less, preferably 10 nm or more and 30 nm or less. If the thickness of the first electrode 50 is 5 nm or more, the resistance can be lowered. If the thickness of the first electrode 50 is 50 nm or less, the transmittance for the light generated in the light-emitting layer 34 can be increased.

[0046] The first electrode 50 is, for example, a laminate in which a Pd layer, a Pt layer, and an Au layer are laminated from the side of the second semiconductor layer 36. The thickness of the Pd layer is, for example, 5 nm. The thickness of the Pt layer is, for example, 5 nm. The thickness of the Au layer is, for example, 10 nm. Note that the first electrode 50 may be a laminate in which a Ni layer and an Au layer are laminated from the side of the second semiconductor layer 36.

[0047] The second electrode 60 is in contact with the first electrode 50. The second electrode 60 is not in contact with the laminate 20. The second electrode 60 is provided in the second opening 42. In the illustrated example, the second electrode 60 is provided on the upper surface of the insulating layer 40, the side surface 44 of the insulating layer 40 that defines the second opening 42, and the upper surface of the first electrode 50. The second electrode 60 is connected to the first electrode 50 exposed by the second opening 42. The planar shape of the second electrode 60 is, for example, a circle.

[0048] The transmittance of the second electrode 60 for the light generated in the light-emitting layer 34 is higher than the transmittance of the first electrode 50 for the light generated in the light-emitting layer 34. The second electrode 60 is, for example, transparent to the light generated in the light-emitting layer 34. The thickness of the second electrode 60 is, for example, 100 nm or more and 500 nm or less, preferably 250 nm or more and 350 nm or less. If the thickness of the second electrode 60 is 100 nm or more, the resistance can be lowered. If the thickness of the second electrode 60 is 500 nm or less, the transmittance for the light generated in the light-emitting layer 34 can be increased. The material of the second electrode 60 is, for example, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide).

[0049] 1.3. Effects In the light-emitting device 100, there are a laminate 20 provided on a substrate 10 and having a light-emitting layer 34, a first electrode 50 that is in contact with the laminate 20 on the side opposite to the substrate 10 of the laminate 20 and injects current into the light-emitting layer 34, and a wiring layer 80 that is electrically connected to the first electrode 50 and has light-shielding properties with respect to the light generated in the light-emitting layer 34. The wiring layer 80 is provided with a first opening 82 through which the light emitted from the laminate 20 passes, and the first opening 82 is located inside the outer edge 54 of the first electrode 50 in a plan view.

[0050] Therefore, in the light-emitting device 100, the wiring layer 80 can block the light emitted from the portion (the first columnar portion 30a in the illustrated example) that overlaps the outer edge 54 in the plan view of the laminate 20. The portion that overlaps the outer edge 54 in the plan view of the laminate 20 may be cut away, for example, by over-etching when forming the first electrode 50. Therefore, the light emitted from the portion that overlaps the outer edge 54 in the plan view of the laminate 20 may have, for example, a shifted wavelength or a reduced emission intensity. In the light-emitting device 100, since such light can be blocked by the wiring layer 80 and the light emitted from the light-emitting device 100 can be defined by the first opening 82, it is possible to reduce the possibility of wavelength shift and emission intensity reduction.

[0051] In the light-emitting device 100, the laminate 20 has a plurality of columnar portions 30, and each of the plurality of columnar portions 30 has a first semiconductor layer 32 of a first conductivity type, a second semiconductor layer 36 of a second conductivity type different from the first conductivity type, and a light-emitting layer 34 provided between the first semiconductor layer 32 and the second semiconductor layer 36. Therefore, in the light-emitting device 100, compared with the case where the laminate does not have a plurality of columnar portions and has a film-shaped light-emitting layer, the strain inherent in the light-emitting layer 34 can be reduced.

[0052] In the light-emitting device 100, among the plurality of columnar portions 30, the first columnar portion 30a overlaps with the outer edge 54 of the first electrode 50 in plan view. In the light-emitting device 100, for example, even if the first columnar portion 30a is cut by overetching when the first electrode 50 is formed, the wiring layer 80 can block the light emitted from the first columnar portion 30a.

[0053] The light-emitting device 100 has a second electrode 60 provided on the first electrode 50. The wiring layer 80 is electrically connected to the first electrode 50 via the second electrode 60. The resistivity of the first electrode 50 is lower than that of the second electrode 60, and the transmittance of the second electrode 60 with respect to the light generated in the light-emitting layer 34 is higher than the transmittance of the first electrode 50 with respect to the light generated in the light-emitting layer 34. Therefore, in the light-emitting device 100, it is possible to increase the transmittance of the electrode structure formed of the first electrode 50 and the second electrode 60 with respect to the light generated in the light-emitting layer 34 while reducing the contact resistance between the electrode structure and the laminate 20.

[0054] 2. Manufacturing method of light-emitting device Next, a method for manufacturing the light-emitting device 100 according to the present embodiment will be described with reference to the drawings. FIGS. 4 to 6 are cross-sectional views schematically showing the manufacturing process of the light-emitting device 100 according to the present embodiment.

[0055] As shown in FIG. 4, a buffer layer 22 is epitaxially grown on the substrate 10. Examples of the epitaxial growth method include the MOCVD (Metal Organic Chemical Vapor Deposition) method and the MBE (Molecular Beam Epitaxy) method.

[0056] Next, a mask layer (not shown) is formed on the buffer layer 22. The mask layer is formed, for example, by electron beam evaporation or sputtering.

[0057] Next, using the mask layer as a mask, the first semiconductor layer 32, the light-emitting layer 34, and the second semiconductor layer 36 are epitaxially grown on the buffer layer 22 in this order. Examples of the method of epitaxial growth include the MOCVD method and the MBE method. By this step, a laminate 20 having a plurality of columnar portions 30 can be formed.

[0058] As shown in FIG. 5, a first electrode 50 is formed on the laminate 20. The first electrode 50 is formed, for example, by a CVD (Chemical Vapor Deposition) method or a sputtering method. Next, a resist layer 90 having a predetermined shape is formed on the first electrode 50. The resist layer 90 is formed by photolithography. Next, using the resist layer 90 as a mask, the first electrode 50 not covered by the resist layer 90 is etched. The etching in this step is, for example, dry etching. In this step, over-etching is performed to completely remove the first electrode 50 not covered by the resist layer 90. Therefore, a part of the columnar portion 30 not covered by the resist layer 90 is etched.

[0059] As shown in FIG. 6, after removing the resist layer 90, an insulating layer 40 is formed so as to cover the laminate 20 and the first electrode 50. The insulating layer 40 is formed, for example, by a CVD method or a spin coating method. Next, the insulating layer 40 is patterned to form a second opening 42. The patterning is performed, for example, by photolithography and etching.

[0060] As shown in FIG. 1, a second electrode 60 is formed on the first electrode 50 and on the insulating layer 40. The second electrode 60 is formed, for example, by a CVD method or a sputtering method.

[0061] Next, a wiring layer 80 is formed on the second electrode 60 and on the insulating layer 40. The wiring layer 80 is formed, for example, by a CVD method or a sputtering method. Next, the wiring layer 80 is patterned to form a first opening 82. The patterning is performed, for example, by photolithography and etching.

[0062] Next, a third electrode 70 is formed on the buffer layer 22. The third electrode 70 is formed, for example, by a CVD method or a sputtering method. Note that the formation order of the second electrode 60 and the third electrode 70 is not particularly limited. Also, the formation order of the third electrode 70 and the wiring layer 80 is not particularly limited.

[0063] Through the above steps, the light-emitting device 100 can be manufactured.

[0064] In the above description, an example in which the first electrode 50 is formed by photolithography and etching has been described. However, the first electrode 50 may be formed by a lift-off method. When the first electrode 50 is formed by the lift-off method, the thickness in the vicinity of the outer edge 54 of the first electrode 50 may be small. Therefore, even when the first electrode 50 is formed by the lift-off method, it is preferable that the light emitted from the portion overlapping the outer edge 54 in the plan view of the laminate 20 is blocked by the wiring layer 80.

[0065] 3. Modification Example of Light-Emitting Device Next, a light-emitting device according to a modification example of the present embodiment will be described with reference to the drawings. FIG. 7 is a cross-sectional view schematically showing a light-emitting device 200 according to a modification example of the present embodiment. FIG. 8 is a plan view schematically showing the light-emitting device 200 according to a modification example of the present embodiment. Note that FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. 8. Also, for convenience, in FIG. 8, the illustration of the second electrode 60 is omitted.

[0066] Hereinafter, in the light-emitting device 200 according to the modification example of the present embodiment, members having the same functions as those of the members of the light-emitting device 100 according to the above-described present embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0067] In the above-described light-emitting device 100, as shown in FIG. 1, the wiring layer 80 was not provided in the second opening 42. In contrast, in the light-emitting device 200, as shown in FIG. 7, the wiring layer 80 is provided in the second opening 42.

[0068] In the light-emitting device 200, the wiring layer 80 is provided on the side surface 44 of the insulating layer 40 via the second electrode 60. As shown in FIG. 8, in a plan view, the area of the first opening 82 is smaller than the area of the second opening 42, and all of the first opening 82 overlaps with the second opening 42.

[0069] The light-emitting device 200 has an insulating layer 40 covering the laminate 20. The insulating layer 40 is provided with a second opening 42. The second opening 42 is provided inside the outer edge 54 of the first electrode 50 in a plan view. The second electrode 60 is provided on the side surface 44 of the insulating layer 40 that defines the second opening 42. The wiring layer 80 is provided on the side surface 44 via the second electrode 60. The resistivity of the wiring layer 80 is lower than the resistivity of the second electrode 60. Therefore, in the light-emitting device 200, the distance between the wiring layer 80 with a low resistivity and the first electrode 50 can be made smaller than in the case where the wiring layer is not provided on the side surface of the insulating layer via the second electrode. Thereby, current can be efficiently injected into the light-emitting layer 34.

[0070] 4. Projector Next, the projector according to the present embodiment will be described with reference to the drawings. FIG. 9 is a diagram schematically showing a projector 800 according to the present embodiment.

[0071] The projector 800 has, for example, the light-emitting device 100 as a light source.

[0072] The projector 800 has a housing (not shown) and a red light source 100R, a green light source 100G, and a blue light source 100B that respectively emit red light, green light, and blue light provided in the housing. For convenience, in FIG. 9, the red light source 100R, the green light source 100G, and the blue light source 100B are simplified.

[0073] The projector 800 further includes a first optical element 802R, a second optical element 802G, a third optical element 802B, a first light modulation device 804R, a second light modulation device 804G, a third light modulation device 804B, and a projection device 808, which are provided inside the housing. The first light modulation device 804R, the second light modulation device 804G, and the third light modulation device 804B are, for example, transmissive liquid crystal light valves. The projection device 808 is, for example, a projection lens.

[0074] The light emitted from the red light source 100R enters the first optical element 802R. The light emitted from the red light source 100R is condensed by the first optical element 802R. Note that the first optical element 802R may have functions other than light condensation. The same applies to the second optical element 802G and the third optical element 802B described later.

[0075] The light condensed by the first optical element 802R enters the first light modulation device 804R. The first light modulation device 804R modulates the incident light according to the image information. Then, the projection device 808 enlarges the image formed by the first light modulation device 804R and projects it onto the screen 810.

[0076] The light emitted from the green light source 100G enters the second optical element 802G. The light emitted from the green light source 100G is condensed by the second optical element 802G.

[0077] The light condensed by the second optical element 802G enters the second light modulation device 804G. The second light modulation device 804G modulates the incident light according to the image information. Then, the projection device 808 enlarges the image formed by the second light modulation device 804G and projects it onto the screen 810.

[0078] The light emitted from the blue light source 100B enters the third optical element 802B. The light emitted from the blue light source 100B is condensed by the third optical element 802B.

[0079] The light collected by the third optical element 802B is incident on the third light modulation device 804B. The third light modulation device 804B modulates the incident light according to the image information. Then, the projection device 808 enlarges the image formed by the third light modulation device 804B and projects it onto the screen 810.

[0080] Also, the projector 800 can have a cross-dichroic prism 806 that combines the light emitted from the first light modulation device 804R, the second light modulation device 804G, and the third light modulation device 804B and guides it to the projection device 808.

[0081] The three color lights modulated by the first light modulation device 804R, the second light modulation device 804G, and the third light modulation device 804B are incident on the cross-dichroic prism 806. The cross-dichroic prism 806 is formed by bonding four right-angled prisms, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are arranged on its inner surface. These dielectric multilayer films combine the three color lights to form light representing a color image. Then, the combined light is projected onto the screen 810 by the projection device 808, and an enlarged image is displayed.

[0082] Note that the red light source 100R, the green light source 100G, and the blue light source 100B may directly form an image without using the first light modulation device 804R, the second light modulation device 804G, and the third light modulation device 804B by controlling the light emitting device 100 as pixels of the video according to the image information. Then, the projection device 808 may enlarge the video formed by the red light source 100R, the green light source 100G, and the blue light source 100B and project it onto the screen 810.

[0083] 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 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 according to the type of light valve used.

[0084] Furthermore, the present invention can also be applied to a light source device of a scanning type image display device having a scanning means such that the light source scans the light from the light source on a screen to display an image of a desired size on the display surface.

[0085] 5. Display Next, the display according to the present embodiment will be described with reference to the drawings. FIG. 10 is a plan view schematically showing the display 900 according to the present embodiment. FIG. 11 is a cross-sectional view schematically showing the display 900 according to the present embodiment. For convenience, in FIG. 10, the X-axis and the Y-axis are illustrated as two axes orthogonal to each other.

[0086] The display 900 has, for example, a light emitting device 100 as a light source.

[0087] The display 900 is a display device that displays an image. The image includes those that display only character information. The display 900 is a self-emitting type display. As shown in FIGS. 10 and 11, the display 900 has a circuit board 910, a lens array 920, and a heat sink 930.

[0088] The circuit board 910 is equipped with a drive circuit for driving the light-emitting device 100. The drive circuit is a circuit including, for example, CMOS (Complementary Metal Oxide Semiconductor). The drive circuit drives the light-emitting device 100 based on, for example, the input image information. Although not shown in the figure, a translucent substrate for protecting the circuit board 910 is disposed on the circuit board 910.

[0089] The circuit board 910 has a display area 912, a data line drive circuit 914, a scan line drive circuit 916, and a control circuit 918.

[0090] The display area 912 is composed of a plurality of pixels P. In the illustrated example, the pixels P are arranged along the X-axis and the Y-axis.

[0091] Although not shown in the figure, the circuit board 910 is provided with a plurality of scan lines and a plurality of data lines. For example, the scan lines extend along the X-axis, and the data lines extend along the Y-axis. The scan lines are connected to the scan line drive circuit 916. The data lines are connected to the data line drive circuit 914. Pixels P are provided corresponding to the intersections of the scan lines and the data lines.

[0092] One pixel P has, for example, one light-emitting device 100, one lens 922, and a pixel circuit (not shown). The pixel circuit includes a switching transistor that functions as a switch for the pixel P. The gate of the switching transistor is connected to the scan line, and one of the source or drain is connected to the data line.

[0093] The data line drive circuit 914 and the scan line drive circuit 916 are circuits that control the driving of the light-emitting device 100 constituting the pixel P. The control circuit 918 controls the display of the image.

[0094] Image data is supplied to the control circuit 918 from a higher-level circuit. The control circuit 918 supplies various signals based on the image data to the data line drive circuit 914 and the scan line drive circuit 916.

[0095] When the scanning line driving circuit 916 activates the scanning signal to select the scanning line, the switching transistor of the selected pixel P is turned on. At this time, the data line driving circuit 914 supplies a data signal from the data line to the selected pixel P, so that the light emitting device 100 of the selected pixel P emits light according to the data signal.

[0096] The lens array 920 has a plurality of lenses 922. For example, one lens 922 is provided for one light emitting device 100. The light emitted from the light emitting device 100 enters one lens 922.

[0097] The heat sink 930 is in contact with the circuit board 910. The material of the heat sink 930 is, for example, a metal such as copper or aluminum. The heat sink 930 dissipates the heat generated by the light emitting device 100.

[0098] The light emitting device according to the above-described embodiment can be used not only for projectors and displays. For applications other than projectors and displays, there are light sources such as indoor and outdoor lighting, laser printers, scanners, in-vehicle lights, sensing devices using light, and communication devices.

[0099] The above-described embodiments and modifications are examples and are not limited thereto. For example, it is also possible to appropriately combine each embodiment and each modification.

[0100] The present invention includes configurations that are substantially the same as the configurations described in the embodiments, for example, configurations having the same functions, methods, and results, or configurations having the same objectives and effects. 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 exhibit the same operational effects as the configurations described in the embodiments or configurations that can achieve the same objectives. The present invention also includes configurations in which known technologies are added to the configurations described in the embodiments.

[0101] The following content is derived from the above-described embodiments and modified examples.

[0102] One aspect of the light-emitting device is a substrate, a laminate provided on the substrate and having a light-emitting layer, a first electrode that is in contact with the laminate on the side opposite to the substrate of the laminate and injects current into the light-emitting layer, a wiring layer that is electrically connected to the first electrode and has light-shielding properties with respect to the light generated in the light-emitting layer, and has a first opening through which the light emitted from the laminate passes is provided in the wiring layer, in plan view, the first opening is located inside the outer edge of the first electrode.

[0103] According to this light-emitting device, it is possible to block the light emitted from the portion of the laminate that overlaps the outer edge of the first electrode in plan view.

[0104] In one aspect of the light-emitting device, the laminate has a plurality of columnar portions, each of the plurality of columnar portions has a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type different from the first conductivity type, and the light-emitting layer provided between the first semiconductor layer and the second semiconductor layer, and may have.

[0105] According to this light-emitting device, it is possible to reduce the strain inherent in the light-emitting layer.

[0106] In one aspect of the light-emitting device, a first columnar portion among the plurality of columnar portions may overlap the outer edge of the first electrode in plan view.

[0107] According to this light-emitting device, it is possible to block the light emitted from the first columnar portion by the wiring layer.

[0108] In one aspect of the light-emitting device, it has a second electrode provided on the first electrode, the wiring layer is electrically connected to the first electrode via the second electrode, the resistivity of the first electrode is lower than that of the second electrode, the transmittance of the second electrode with respect to the light generated in the light-emitting layer may be higher than the transmittance of the first electrode with respect to the light generated in the light-emitting layer.

[0109] According to this light-emitting device, it is possible to increase the transmittance of the electrode structure with respect to the light generated in the light-emitting layer while reducing the contact resistance between the electrode structure composed of the first electrode and the second electrode and the laminate.

[0110] In one aspect of the light-emitting device, it has an insulating layer covering the laminate, a second opening is provided in the insulating layer, the second opening is provided inside the outer edge of the first electrode in a plan view, the second electrode is provided on the side surface of the insulating layer defining the second opening, the wiring layer is provided on the side surface via the second electrode, the resistivity of the wiring layer may be lower than that of the second electrode.

[0111] According to this light-emitting device, the distance between the wiring layer and the first electrode can be reduced. Thereby, current can be efficiently injected into the light-emitting layer.

[0112] One aspect of the projector is, having one aspect of the light-emitting device.

[0113] One aspect of the display is, having one aspect of the light-emitting device.

Description of Reference Numerals

[0114] 10… Substrate, 20… Laminate, 22… Buffer layer, 30… Columnar part, 30a… First columnar part, 32… First semiconductor layer, 34… Light-emitting layer, 36… Second semiconductor layer, 40… Insulating layer, 42… Second opening, 44… Side surface, 50… First electrode, 52… Side surface, 54… Outer edge, 60… Second electrode, 70… Third electrode, 80… Wiring layer, 82… First opening, 84… Side surface, 86… Ring-shaped part, 88… Extension part, 90… Resist layer, 100… Light-emitting device, 100R… Red light source, 100G… Green light source, 100B… Blue light source, 200… Light-emitting device, 800… Projector, 802R… First optical element, 802G… Second optical element, 802B… Third optical element, 804R… First light modulation device, 804G… Second light modulation device, 804B… Third light modulation device, 806… Cross-dichroic prism, 808… Projection device, 810… Screen, 900… Display, 910… Circuit board, 912… Display area, 914… Data line drive circuit, 916… Scan line drive circuit, 918… Control circuit, 920… Lens array, 922… Lens, 930… Heat sink

Claims

1. A substrate, a laminate provided on the substrate and having a light-emitting layer, a first electrode that contacts the laminate on the side opposite to the substrate of the laminate and injects current into the light-emitting layer, a wiring layer that is electrically connected to the first electrode and has light-shielding properties with respect to the light generated in the light-emitting layer, a second electrode provided on the first electrode, an insulating layer that covers the laminate, wherein the wiring layer is provided with a first opening through which the light emitted from the laminate passes, the first opening is located inside the outer edge of the first electrode in plan view, the laminate has a plurality of columnar portions, each of the plurality of columnar portions has a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type different from the first conductivity type, and the light-emitting layer provided between the first semiconductor layer and the second semiconductor layer, a first columnar portion among the plurality of columnar portions has a first portion that overlaps the first electrode in plan view and a second portion that does not overlap the first electrode in plan view, the wiring layer overlaps the first portion and the second portion of the first columnar portion in plan view, the wiring layer is electrically connected to the first electrode via the second electrode, the resistivity of the first electrode is lower than the resistivity of the second electrode, the transmittance of the second electrode with respect to the light generated in the light-emitting layer is higher than the transmittance of the first electrode with respect to the light generated in the light-emitting layer, the insulating layer is provided with a second opening, the second opening is provided inside the outer edge of the first electrode in plan view, the second electrode is provided on the side surface of the insulating layer that defines the second opening, the wiring layer is provided on the side surface via the second electrode, the resistivity of the wiring layer is lower than the resistivity of the second electrode, a light-emitting device.

2. A projector having the light-emitting device according to Claim 1.

3. A display having the light-emitting device according to Claim 1. ​ ​ ​ ​ ​ ​ ​ ​

Images