Photovoltaic device

• US 20060065297A1
• Filed: 09/29/2005
• Published: 03/30/2006
• Est. Priority Date: 09/29/2004
• Status: Active Grant

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Terakawa, Akira
• Granted Patent: US 8,049,101 B2
• Time in Patent Office: Days
• US Class Current: 136/255
• CPC Class Codes: H01L 31/0747 comprising a heterojunction of crystalline and amorphous materials, e.g. heterojunction with intrinsic thin layer
• CPC Class Codes: H01L 31/202 including only elements of Group IV of the Periodic Table
• CPC Class Codes: Y02E 10/547 Monocrystalline silicon PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

In the photovoltaic devices comprising a substantially intrinsic amorphous silicon layer containing hydrogen between an n-type single-crystal silicon substrate and a p-type amorphous silicon layer containing hydrogen, the photovoltaic device according to the present invention comprises a trap layer that contains less hydrogen than the intrinsic amorphous silicon layer between the p-type amorphous silicon layer and the intrinsic amorphous silicon layer. The trap layer reduces hydrogen diffusion from the intrinsic amorphous silicon layer to the p-type amorphous silicon layer.

Claims

1. A photovoltaic device comprising:

a crystalline semiconductor substrate;

a substantially intrinsic amorphous semiconductor thin-film layer containing hydrogen and provided on the crystalline semiconductor substrate;

a doped amorphous semiconductor thin-film layer containing hydrogen and provided on the intrinsic amorphous semiconductor thin-film layer; and

a hydrogen-diffusion reducing area provided between the doped amorphous semiconductor thin-film layer and the intrinsic amorphous semiconductor thin-film layer and reducing hydrogen diffusion from the intrinsic amorphous semiconductor thin-film layer to the doped amorphous semiconductor thin-film layer.

2. The photovoltaic device according to claim 1, wherein the hydrogen-diffusion reducing area is an area formed in the vicinity of an interface between the doped amorphous semiconductor thin-film layer and the intrinsic amorphous semiconductor thin-film layer, and containing higher concentrations of hydrogen than the intrinsic amorphous semiconductor thin-film layer does.

3. The photovoltaic device according to claim 1, wherein the hydrogen-diffusion reducing area is an area formed in the vicinity of the interface between the doped amorphous semiconductor thin-film layer and the intrinsic amorphous semiconductor thin-film layer, containing higher concentrations of hydrogen than the intrinsic amorphous semiconductor thin-film layer does, and doped with the same type of impurity as that for the doped amorphous semiconductor thin-film layer.

4. The photovoltaic device according to claim 1, wherein the hydrogen-diffusion reducing area is a trap layer formed in the vicinity of the interface between the doped amorphous semiconductor thin-film layer and the intrinsic amorphous semiconductor thin-film layer and containing lower concentrations of hydrogen than the intrinsic amorphous semiconductor thin-film layer does.

5. The photovoltaic device according to claim 4, wherein the trap layer is a substantially intrinsic amorphous semiconductor thin-film layer.

6. The photovoltaic device according to claim 4, wherein the trap layer is doped with the same type of impurity as that for the doped amorphous semiconductor thin-film layer.

7. A photovoltaic device comprising:

an n-type single-crystal silicon substrate;

a substantially intrinsic amorphous silicon layer containing hydrogen and provided on the single-crystal silicon substrate;

a p-type amorphous silicon layer containing hydrogen and provided on the intrinsic amorphous silicon layer; and

a hydrogen-diffusion reducing area provided between the p-type amorphous silicon layer and the intrinsic amorphous silicon layer and reducing hydrogen diffusion from the intrinsic amorphous silicon layer to the p-type amorphous silicon layer.

8. The photovoltaic device according to claim 7, wherein the hydrogen-diffusion reducing area is an area formed in the vicinity of an interface between the p-type amorphous silicon layer and the intrinsic amorphous silicon layer and containing higher concentrations of hydrogen than the intrinsic amorphous silicon layer does.

9. The photovoltaic device according to claim 7, wherein the hydrogen-diffusion reducing area is an area formed in the vicinity of the interface between the p-type amorphous silicon layer and the intrinsic amorphous silicon layer, containing higher concentrations of hydrogen than the intrinsic amorphous silicon layer does, and doped with a p-type impurity.

10. The photovoltaic device according to claim 7, wherein the hydrogen-diffusion reducing area is a trap layer formed in the vicinity of the interface between the p-type amorphous silicon layer and the intrinsic amorphous silicon layer and containing lower concentrations of hydrogen than the intrinsic amorphous silicon layer does.

11. The photovoltaic device according to claim 10, wherein the trap layer is a substantially intrinsic amorphous silicon layer.

12. The photovoltaic device according to claim 11, wherein the thickness of the trap layer is from 1 nm to 5 nm.

13. The photovoltaic device according to claim 11, wherein the thickness of the trap layer is from 1 nm to 2 nm.

14. The photovoltaic device according to claim 10, wherein the trap layer is an amorphous silicon layer doped with the p-type impurity.

15. The photovoltaic device according to claim 14, wherein the thickness of the trap layer is 0.1 nm or more but less than 3 nm.

16. The photovoltaic device according to claim 14, wherein the thickness of the trap layer is 0.3 nm to 2 nm.