Semiconductor light-emitting element
A semiconductor light-emitting element ( 1 ) including: an n-type semiconductor layer ( 140 ); a light-emitting layer ( 150 ); a p-type semiconductor layer ( 160 ); a transparent conductive layer ( 170 ) laminated on the p-type semiconductor layer; a reflective film ( 180 ) which is composed of a material having optical transparency to light emitted from the light-emitting layer and an insulating property and is laminated on the transparent conductive layer; a p-conductive body ( 200 ) which penetrates the reflective film and is electrically connected to the transparent conductive layer; an n-electrode ( 310 ) electrically connected to the n-type semiconductor layer; and a p-electrode ( 300 ) having a p-adhesion layer ( 301 ) which is laminated on the reflective film, is electrically connected to the other end of the p-conductive body, and is composed of the same material as that for the transparent conductive layer and a p-metal reflective layer ( 302 ) which is laminated on the p-adhesion layer.
1. A semiconductor light-emitting element comprising:
a first semiconductor layer that is composed of a group-III nitride semiconductor having a first conductivity type;
a light-emitting layer that is laminated on one surface of the first semiconductor layer to expose a part of the one surface, and that emits light upon conducting an electric power;
a second semiconductor layer that is composed of a group-III nitride semiconductor having a second conductivity type different from the first conductivity type, and that is laminated on the light-emitting layer;
a first transparent conductive layer that is composed of a material having transparency to light emitted from the light-emitting layer and a conductive property, and that is laminated on the second semiconductor layer;
a transparent insulating layer that is composed of a material having transparency to the light emitted from the light-emitting layer and an insulating property, that has a penetration hole in a thickness direction, and that is laminated on the first transparent conductive layer;
a first electrode that is electrically connected to the first semiconductor layer; and
a second electrode that is configured with a second transparent conductive layer and a metal reflective layer, the second transparent conductive layer being composed of a material same as the material of the first transparent conductive layer and laminated to cover the transparent insulating layer and the first transparent conductive layer exposed through the penetration hole, the metal reflective layer being composed of a metal material having reflectance to the light emitted from the light-emitting layer and a conductive property and laminated on the second transparent conductive layer, wherein
at least a part of the second transparent conductive layer contacts the first transparent conductive layer.
2. The semiconductor light-emitting element according to claim 1 , wherein a thickness of the second transparent conductive layer laminated on the first transparent conductive layer exposed through the penetration hole is thinner than a thickness of the transparent insulating layer.
3. The semiconductor light-emitting element according to claim 2 , wherein the first transparent conductive layer and the second transparent conductive layer are composed of a metal oxide.
4. The semiconductor light-emitting element according to claim 3 , wherein the metal oxide is a metal oxide containing indium.
5. The semiconductor light-emitting element according to claim 4 , wherein the metal oxide containing indium is IZO (indium zinc oxide).
6. The semiconductor light-emitting element according to claim 5 , wherein
the first transparent conductive layer is composed of crystallized IZO,
the second transparent conductive layer is composed of uncrystallized IZO, and
the thickness of the second transparent conductive layer laminated on the first transparent conductive layer exposed through the penetration hole is thinner than a thickness of the first transparent conductive layer.
7. The semiconductor light-emitting element according to claim 6 , wherein a sum of the thickness of the second transparent conductive layer laminated on the first transparent conductive layer exposed through the penetration hole and a thickness of the metal reflective layer laminated on the second transparent conductive layer laminated on the first transparent conductive layer is smaller than the thickness of the transparent insulating layer.
8. The semiconductor light-emitting element according to claim 2 , wherein a sum of the thickness of the second transparent conductive layer laminated on the first transparent conductive layer exposed through the penetration hole and a thickness of the metal reflective layer laminated on the second transparent conductive layer laminated on the first transparent conductive layer is smaller than the thickness of the transparent insulating layer.
9. The semiconductor light-emitting element according to claim 8 , wherein the first transparent conductive layer and the second transparent conductive layer are composed of a metal oxide.
10. The semiconductor light-emitting element according to claim 9 , wherein the metal oxide is a metal oxide containing indium.
11. The semiconductor light-emitting element according to claim 10 , wherein the metal oxide containing indium is IZO.
12. The semiconductor light-emitting element according to claim 1 , wherein the first transparent conductive layer and the second transparent conductive layer are composed of a metal oxide.
13. The semiconductor light-emitting element according to claim 12 , wherein the metal oxide is a metal oxide containing indium.
14. The semiconductor light-emitting element according to claim 13 , wherein the metal oxide containing indium is IZO.
15. The semiconductor light-emitting element according to claim 14 , wherein
the first transparent conductive layer is composed of crystallized IZO,
the second transparent conductive layer is composed of uncrystallized IZO, and
a thickness of the second transparent conductive layer laminated on the first transparent conductive layer exposed through the penetration hole is thinner than a thickness of the first transparent conductive layer.
16. The semiconductor light-emitting element according to claim 1 , wherein the transparent insulating layer is composed of a material having a refractive index lower than those of the first transparent conductive layer and the second transparent conductive layer.
17. The semiconductor light-emitting element according to claim 1 , wherein
the first transparent conductive layer is composed of a material having a first refractive index,
the transparent insulating layer is composed of a material having a second refractive index lower than the first refractive index, and
a thickness H of the transparent insulating layer has a relation as (λ/4n)×(B−0.5)≦H≦(λ/4n)×(B+0.5), where the second refractive index is denoted by n, a wavelength of the light emitted from the light-emitting layer is denoted by λ and B is set as an odd number not less than 3.
18. The semiconductor light-emitting element according to claim 1 , wherein the metal reflective layer is composed of silver or a silver alloy.
19. The semiconductor light-emitting element according to claim 1 , wherein the transparent insulating layer is composed of silicon dioxide.
20. The semiconductor light-emitting element according to claim 1 , wherein the transparent insulating layer is laminated on (i) the first transparent conductive layer, (ii) those portions of the second semiconductor layer on which the first transparent conductive layer is not laminated, and (iii) those portions of the first semiconductor layer on which the light-emitting layer is not laminated, and further, wherein the transparent insulating layer is laminated on side surfaces of the light-emitting layer, the second semiconductor layer and the first transparent conductive layer.