Photovoltaic Device Including a Back Contact and Method of Manufacturing

Patent metadata

Field	Value
Publication number	US-2016126397-A1
Application number	US-201614992304-A
Country	US
Kind code	A1
Filing date	Jan 11, 2016
Priority date	Mar 22, 2013
Publication date	May 5, 2016
Grant date	—

Abstract

A photovoltaic device includes a substrate, a transparent conductive oxide, an n-type window layer, a p-type absorber layer and an electron reflector layer. The electron reflector layer may include zinc telluride doped with copper telluride, zinc telluride alloyed with copper telluride, or a bilayer of multiple layers containing zinc, copper, cadmium and tellurium in various compositions. A process for manufacturing a photovoltaic device includes forming a layer over a substrate by at least one of sputtering, evaporation deposition, CVD, chemical bath deposition process, and vapor transport deposition process. The process includes forming an electron reflector layer over a p-type absorber layer.

First claim

What is claimed:

1 . A photovoltaic structure comprising:
a substrate structure including a base layer, a transparent conductive oxide layer, at least one semiconductor layer; and an electron reflector layer provided over the substrate structure, wherein the electron reflector layer comprises zinc, tellurium, and copper.

2 . The photovoltaic device of claim 1 , wherein the electron reflector layer comprises zinc telluride doped with copper telluride.

3 . The photovoltaic device of claim 2 , wherein the zinc telluride is doped with copper telluride at a concentration between 0.01% and 5%.

4 . The photovoltaic device of claim 2 , wherein the zinc telluride is doped with copper telluride at a concentration between 2% and 5%.

5 . The photovoltaic device of claim 1 , wherein the electron reflector layer comprises zinc telluride alloyed with copper telluride to form (Cu 2 ) x Zn (1-x) Te.

6 . The photovoltaic device of claim 5 , wherein the electron reflector layer comprises (Cu 2 ) x Zn (1-x) Te, where x is between 5% and 60%.

7 . The photovoltaic device of claim 5 , wherein the electron reflector layer comprises (Cu 2 ) x Zn (1-x) Te, where x is between 20% and 35%.

8 . The photovoltaic device of claim 1 , wherein the electron reflector layer comprises a bilayer of two sublayers wherein a first sublayer material is chosen from: zinc telluride doped with copper telluride, and zinc telluride-copper telluride alloy; and where the second sublayer material is chosen from: zinc telluride doped with elemental copper, zinc telluride, cadmium zinc telluride, and copper telluride.

9 . The photovoltaic device of claim 8 , wherein the first sublayer is zinc telluride doped with copper telluride at a concentration of between 0.01% and 5%; and where the second sublayer is zinc telluride.

10 . The photovoltaic device of claim 8 , wherein the first sublayer is zinc telluride alloyed with copper telluride at a concentration of between 5% and 60%; and where the second sublayer is cadmium zinc telluride.

11 . A process for manufacturing a photovoltaic device comprising the steps of:
forming an electron reflector layer over a substrate structure including a base layer, a transparent conductive oxide layer, and at least one semiconductor layer; and activating the photovoltaic device by applying a thermal treatment.

12 . A process for manufacturing a photovoltaic device as in claim 11 , wherein the step of forming an electron reflector layer is performed by depositing a zinc telluride doped with copper telluride at a concentration of between 0.01% and 5% by a vapor deposition process.

13 . A process for manufacturing a photovoltaic device as in claim 11 , wherein the step of forming an electron reflector layer is performed by depositing a zinc telluride doped with copper telluride at a concentration of between 0.01% and 5% by a sputtering process.

14 . A process for manufacturing a photovoltaic device as in claim 11 , wherein the step of forming an electron reflector layer is performed by depositing a zinc telluride alloyed with copper telluride at a concentration of between 5% and 60% by a vapor deposition process.

15 . A process for manufacturing a photovoltaic device as in claim 11 , wherein the step of forming an electron reflector layer is performed by depositing a zinc telluride alloyed with copper telluride at a concentration of between 5% and 60% by a sputtering process.

16 . A process for manufacturing a photovoltaic device as in claim 11 , wherein the step of forming an electron reflector layer is performed by sequentially forming a first sublayer and a second sublayer.

17 . A process for manufacturing a photovoltaic device as in claim 16 , wherein forming at least one of the first sublayer and the second sublayer is performed by depositing a zinc telluride doped with copper telluride at a concentration of between 0.01% and 5% by a vapor deposition process.

18 . A process for manufacturing a photovoltaic device as in claim 16 , wherein forming at least one of the first sublayer and the second sublayer is performed by depositing a zinc telluride doped with copper telluride at a concentration of between 0.01% and 5% by a sputtering process.

19 . A process for manufacturing a photovoltaic device as in claim 16 , wherein forming at least one of the first sublayer and the second sublayer is performed by depositing a zinc telluride alloyed with copper telluride at a concentration of between 5% and 60% by a vapor deposition process.

20 . A process for manufacturing a photovoltaic device as in claim 16 , wherein forming at least one of the first sublayer and the second sublayer is performed by depositing a zinc telluride alloyed with copper telluride at a concentration of between 5% and 60% by a sputtering process.

Assignees

• First Solar Inc

Inventors

• Yu San
• Palaniappagounder Veluchamy
• Addepalli Pratima
• Khan Imran

Classifications

• H10F77/311

  for photovoltaic cells · CPC title

• H10F77/244

  made of transparent conductive layers, e.g. transparent conductive oxide [TCO] layers · CPC title

• H10F77/211

  for photovoltaic cells · CPC title

• H10F71/138

  Manufacture of transparent electrodes, e.g. transparent conductive oxides [TCO] or indium tin oxide [ITO] electrodes · CPC title

• H10F71/128

  Annealing · CPC title