Surface light-emission element using zinc oxide substrate

1. A surface light-emitting device comprising:

a substrate composed of an oriented polycrystalline zinc oxide sintered body in a plate shape;

a light emitting functional layer provided on the substrate; and

an electrode provided on the light emitting functional layer;

wherein zinc oxide single crystal grains constituting the oriented polycrystalline zinc oxide sintered body have an average grain diameter of 1 to 100 μm, and

wherein the oriented polycrystalline zinc oxide sintered body has an orientation in the (002) plane, (110) plane, or (101) plane.

2. The surface light-emitting device according to claim 1 , wherein the light emitting functional layer has a structure epitaxially grown in conformity with an orientation of the oriented polycrystalline zinc oxide sintered body, and thereby has a crystal orientation aligned in a normal direction.

3. The surface light-emitting device according to claim 1 , further comprising a buffer layer between the light emitting functional layer and the substrate.

4. The surface light-emitting device according to claim 1 , wherein the oriented polycrystalline zinc oxide sintered body has a degree of orientation of 50% or greater to 100% or less.

5. The surface light-emitting device according to claim 1 , wherein the oriented polycrystalline zinc oxide sintered body has a degree of orientation of 65% or greater to 100% or less.

6. The surface light-emitting device according to claim 1 , wherein the oriented polycrystalline zinc oxide sintered body has a degree of orientation of 75% or greater to 100% or less.

7. The surface light-emitting device according to claim 1 , wherein the oriented polycrystalline zinc oxide sintered body is doped with an n-type dopant.

8. The surface light-emitting device according to claim 7 , wherein the n-type dopant comprises one or more selected from the group consisting of aluminum (Al), gallium (Ga), indium (In), boron (B), fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and silicon (Si).

9. The surface light-emitting device according to claim 1 , wherein the oriented polycrystalline zinc oxide sintered body is doped with a p-type dopant.

10. The surface light-emitting device according to claim 9 , wherein the p-type dopant comprises one or more selected from the group consisting of nitrogen (N), phosphorus (P), arsenic (As), carbon (C), lithium (Li), sodium (Na), potassium (K), silver (Ag), and copper (Cu).

11. The surface light-emitting device according to claim 1 , wherein the oriented polycrystalline zinc oxide sintered body has a resistivity of 8×10 −4 Ωcm or greater to 1×10 −2 Ωcm or less.

12. The surface light-emitting device according to claim 1 , wherein the oriented polycrystalline zinc oxide sintered body has a resistivity of 8×10 −4 Ωcm or greater to 1×10 −3 Ωcm or less.

13. The surface light-emitting device according to claim 1 , wherein the light emitting functional layer has a light emitting function based on a p-n junction.

14. The surface light-emitting device according to claim 1 , wherein the light emitting functional layer is composed of at least one selected from zinc oxide-based materials, gallium nitride-based materials, aluminum nitride-based materials, copper oxide-based materials, nickel oxide-based materials, zinc telluride-based materials, and zinc sulfide-based materials.

15. The surface light-emitting device according to claim 1 , wherein the substrate has an area of 25 cm 2 or greater to 400 cm 2 or less.

16. The surface light-emitting device according to claim 1 , wherein the oriented polycrystalline zinc oxide sintered body has a resistivity of 8×10 −4 Ωcm or greater to 1×10 −1 Ωcm or less.