Photovoltaic device with a zinc magnesium oxide window layer

Patent metadata

Field	Value
Publication number	US-10056507-B2
Application number	US-201514740501-A
Country	US
Kind code	B2
Filing date	Jun 16, 2015
Priority date	Sep 22, 2010
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

Methods and devices are described for a photovoltaic device and substrate structure. In one embodiment, a photovoltaic device includes a substrate structure and a CdTe absorber layer, the substrate structure including a Zn1-xMgxO window layer and a low conductivity buffer layer. Another embodiment is directed to a process for manufacturing a photovoltaic device including forming a Zn1-xMgxO window layer over a substrate by at least one of sputtering, evaporation deposition, CVD, chemical bath deposition process and vapor transport deposition process. The process including forming a CdTe absorber layer above the Zn1-xMgxO window layer.

First claim

What is claimed is:

1. A photovoltaic device comprising:
a transparent glass substrate;
a transparent conductive oxide layer;
a Zn 1-x Mg x O semiconductor window layer, wherein 0<x<1 and the transparent conductive oxide layer is between the transparent glass substrate and the Zn 1-x Mg x O semiconductor window layer;
a buffer layer between the transparent conductive oxide layer and the Zn 1-x Mg x O semiconductor window layer; and
a semiconductor absorber layer on the Zn 1-x Mg x O semiconductor window layer, wherein the semiconductor absorber layer comprises cadmium and tellurium, and wherein x is tuned such that the conduction band offset of the Zn 1-x Mg x O semiconductor window layer with respect to the semiconductor absorber layer that comprises cadmium and tellurium is in the range of 0 to +0.4 eV;
wherein the Zn 1-x Mg x O semiconductor window layer is doped with Mn, Nb, N, F or by introducing oxygen vacancies.

2. The photovoltaic device of claim 1 , wherein the Zn 1-x Mg x O semiconductor window layer is on the buffer layer.

3. The photovoltaic device of claim 1 , wherein the thickness of the Zn 1-x Mg x O semiconductor window layer ranges from about 2 nm to about 2000 nm.

4. The photovoltaic device of claim 1 , wherein the conductivity of the Zn 1-x Mg x O semiconductor window layer is within a range of about 1 mOhm per cm to about 10 Ohm per cm.

5. The photovoltaic device of claim 1 , further comprising a barrier layer between the glass substrate and the transparent conductive oxide layer.

6. The photovoltaic device of claim 1 , wherein the Zn 1-x Mg x O semiconductor window layer has a dopant concentration of between about 1×10 14 cm −3 and about 1×10 19 cm −3 .

7. The photovoltaic device of claim 1 , wherein the Zn 1-x Mg x O semiconductor window layer has a dopant concentration of between about 1×10 17 cm −3 and about 1×10 18 cm −3 .

8. A method of forming a photovoltaic device, the method comprising:
forming a transparent conductive oxide layer over a transparent glass substrate;
forming a Zn 1-x M x O semiconductor window layer over the transparent conduct oxide layer, wherein 0<x<1 and the transparent conductive oxide layer is between the transparent glass substrate and the Zn 1-x Mg x O semiconductor window layer;
forming a buffer layer between the transparent conductive oxide layer and the Zn 1-x Mg x O semiconductor window layer; and
forming a semiconductor absorber layer over the Zn 1-x Mg x O semiconductor window layer, wherein the semiconductor absorber layer comprises cadmium and tellurium, and wherein x is tuned such that the conduction band offset of the Zn 1-x Mg x O semiconductor window layer with respect to the semiconductor absorber layer that comprises cadmium and tellurium is in the range of 0 to +0.4 eV; and
doping the Zn 1-x Mg x O semiconductor window layer with Mn, Nb, N, F or by introducing oxygen vacancies.

9. The method of claim 8 further comprising forming a second semiconductor window layer between the Zn 1-x Mg x O semiconductor window layer and the semiconductor absorber layer, wherein the second semiconductor window layer comprises cadmium sulfide.

10. The method of claim 8 , wherein the semiconductor absorber layer is on the Zn 1-x Mg x O semiconductor window layer.

11. The method of claim 8 , wherein the Zn 1-x Mg x O semiconductor window layer has a dopant concentration of between about 1×10 14 cm −3 and about 1×10 19 cm −3 .

12. The method of claim 8 , wherein the Zn 1-x Mg x O semiconductor window layer has a dopant concentration of between about 1×10 17 cm −3 and about 1×10 18 cm −3 .

13. The method of claim 8 , wherein the Zn 1-x Mg x O semiconductor window layer is formed by at least one of sputtering, evaporation deposition, CVD, chemical bath deposition process and vapor transport deposition process.

14. The method of claim 8 , wherein the Zn 1-x Mg x O semiconductor window layer is formed such that its conductivity is within a range of about 1 mOhm per cm to about 10 Ohm per cm.

Assignees

• First Solar Inc
• Frist Solar Inc

Inventors

• Shao Rui
• Gloeckler Markus

Classifications

• H01L31/022483

  Electricity · mapped topic

• Y02E10/543

  Solar cells from Group II-VI materials · CPC title

• H01L31/18

  Electricity · mapped topic

• H01L31/022466 Primary

  Electricity · mapped topic

• H01L31/1884

  Electricity · mapped topic