Polycrystalline CDTE thin film semiconductor photovoltaic cell structures for use in solar electricity generation
A reverse p-n junction solar cell device and methods for forming the reverse p-n junction solar cell device are described. A variety of n-p junction and reverse p-n junction solar cell devices and related methods of manufacturing are provided. N-intrinsic-p junction and reverse p-intrinsic-n junction solar cell devices are also described.
1. A photovoltaic device, comprising:
(a) a non-crystalline substrate or superstrate;
(b) a first layer adjacent to said superstrate or substrate, the first layer comprising
(i) tellurium (Te) and cadmium (Cd) or zinc (Zn), or
(ii) Te, Cd and Zn;
(c) a second layer adjacent to the first layer, the second layer comprising Cd and Te; and
(d) a third layer adjacent to the second layer, the third layer comprising Cd and Te, wherein:
(i) the first layer is chemically doped n-type, the second layer is chemically doped p-type, and the third layer is chemically doped p-type; or
(ii) the first layer is chemically doped p-type, the second layer is chemically doped p-type, and the third layer is chemically doped n-type.
2. The photovoltaic device of claim 1 , further comprising a layer comprising Zn and Te between said substrate or superstrate and said first layer.
3. The photovoltaic device of claim 1 , further comprising a fourth layer adjacent to the third layer, the fourth layer comprising Cd and Te.
4. The photovoltaic device of claim 1 , wherein one or more of said first layer, second layer and third layer comprise Te, Cd and Zn.
5. The photovoltaic device of claim 1 , wherein
(a) said first layer and second layer comprise Te, Cd and Zn;
(b) said first layer and third layer comprise Te, Cd and Zn;
(c) said second layer and third layer comprise Te, Cd and Zn; or
(d) said first layer, second layer and third layer comprise Te, Cd and Zn.
6. The photovoltaic device of claim 5 , wherein said first layer, second layer and third layer comprise Te, Cd and Zn.
7. The photovoltaic device of claim 1 , wherein said first layer, second layer and/or said third layers are compositionally graded in Cd and Zn.
8. The photovoltaic device of claim 1 , wherein said first layer is chemically doped n-type, the second layer is chemically doped p-type, and the third layer is chemically doped p-type.
9. The photovoltaic device of claim 1 , wherein said first layer is chemically doped p-type, the second layer is chemically doped p-type, and the third layer is chemically doped n-type.
10. A photovoltaic device, comprising:
(a) a substrate or superstrate;
(b) a first layer adjacent to said substrate or superstrate, said first layer comprising:
(i) tellurium (Te) and cadmium (Cd) or zinc (Zn), or
(ii) Te, Cd and Zn, wherein said first layer comprises a p-type chemical dopant;
(c) a second layer adjacent to the first layer, the second layer comprising Cd and Te, wherein said second layer comprises a p-type chemical dopant; and
(d) a third layer adjacent to the second layer, the third layer comprising Cd and Te, wherein said third layer comprises an n-type chemical dopant.
11. The photovoltaic device of claim 10 , further comprising a layer comprising Zn and Te between said substrate or superstrate and said first layer.
12. The photovoltaic device of claim 10 , further comprising a fourth layer adjacent to the third layer, the fourth layer comprising Cd and Te.
13. The photovoltaic device of claim 10 , wherein one or more of said first layer, second layer and third layer comprise Te, Cd and Zn.
14. The photovoltaic device of claim 10 , wherein
(a) said first layer and second layer comprise Te, Cd and Zn;
(b) said first layer and third layer comprise Te, Cd and Zn;
(c) said second layer and third layer comprise Te, Cd and Zn; or
(d) said first layer, second layer and third layer comprise Te, Cd and Zn.
15. The photovoltaic device of claim 14 , wherein said first layer, second layer and third layer comprise Te, Cd and Zn.
16. The photovoltaic device of claim 10 , wherein said first layer, second layer and/or said third layers are compositionally graded in Cd and Zn.
17. The photovoltaic device of claim 10 , wherein said first layer comprises tellurium (Te) and cadmium (Cd) or zinc (Zn).
18. The photovoltaic device of claim 10 , wherein said first layer comprises Te, Cd and Zn, and wherein said first layer comprises a p-type chemical dopant.
19. A photovoltaic device, comprising:
(a) a low ohmic ZnTe contact layer adjacent to a superstrate or substrate, wherein the low ohmic ZnTe contact layer comprises a p-type dopant;
(b) a p-n heterojunction or homojunction adjacent to said low ohmic ZnTe contact layer, said p-n heterojunction or homojunction comprising:
(i) a p-type layer comprising cadmium (Cd) and tellurium (Te);
(ii) an n-type layer comprising Cd and Te adjacent to the p-type layer; and
(c) a low ohmic contact layer comprising Cd and Te adjacent to said p-n heterojunction or homojunction.
20. The photovoltaic device of claim 19 , wherein the superstrate or substrate is non-crystalline.
21. The photovoltaic device of claim 19 , wherein said p-type layer further comprises Zn.
22. The photovoltaic device of claim 19 , wherein said n-type layer further comprises Zn.
23. A photovoltaic device, comprising:
(a) a substrate or superstrate;
(b) a low ohmic contact layer comprising cadmium (Cd) and tellurium (Te) adjacent to said superstrate or substrate, wherein the low ohmic contact layer comprises an n-type dopant;
(c) an n-type layer comprising Cd and Te adjacent to the low ohmic CdTe layer;
(d) a p-type CdZnTe layer adjacent to the n-type layer; and
(e) a low ohmic p-type CdZnTe contact layer adjacent to the p-type CdZnTe layer.
24. The photovoltaic device of claim 23 , wherein the superstrate or substrate is non-crystalline.
25. The photovoltaic device of claim 23 , wherein said p-type CdZnTe layer and/or said low ohmic p-type CdZnTe layer are compositionally graded in Cd and Zn.
26. The photovoltaic device of claim 23 , wherein said n-type layer further comprises Zn.