Layer system for thin-film solar cells

Patent metadata

Field	Value
Publication number	US-10134931-B2
Application number	US-201314409653-A
Country	US
Kind code	B2
Filing date	Jun 19, 2013
Priority date	Jun 20, 2012
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

The present invention relates to a layer system ( 1 ) for thin-film solar cells ( 100 ) and solar modules, comprising
an absorber layer ( 4 ), which includes a chalcogenide compound semiconductor, and a buffer layer ( 5 ), which is arranged on the absorber layer ( 4 ) and includes halogen-enriched Zn x In 1-x S y with 0.01≤x≤0.9 and 1≤y≤2,

wherein the buffer layer ( 5 ) consists of a first layer region ( 5.1 ) adjoining the absorber layer ( 4 ) with a halogen mole fraction A 1 and a second layer region ( 5.2 ) adjoining the first layer region ( 5.1 ) with a halogen mole fraction A 2 and the ratio A 1 /A 2 is ≥2 and the layer thickness (d 1 ) of the first layer region ( 5.1 ) is ≤50% of the layer thickness (d) of the buffer layer ( 5 ).

First claim

The invention claimed is:

1. Layer system for thin-film solar cells, comprising:
an absorber layer, which includes a chalcogenide compound semiconductor, and
a buffer layer, which is arranged on the absorber layer and includes halogen-enriched Zn x In 1-x S y with 0.01≤x≤0.9 and 1≤y≤2,
wherein the buffer layer consists of a first layer region adjoining the absorber layer with a halogen mole fraction A 1 and a second layer region adjoining the first layer region with a halogen mole fraction A 2 and a ratio A 1 /A 2 is ≥2 and a layer thickness of the first layer region is ≤20% of a layer thickness of the buffer layer.

2. Layer system according to claim 1 , wherein the ratio A 1 /A 2 is from 2 to 1000.

3. Layer system according to claim 1 , wherein an amount of the halogen in the first layer region amounts to an area concentration of 1·10 13 atoms/cm 2 to 1·10 17 atoms/cm 2 .

4. Layer system according to claim 1 , wherein y is from x+(1−x)*1.3 to x+(1−x)*1.5.

5. Layer system according to claim 1 , wherein the halogen mole fraction in the buffer layer has a gradient that decreases from a surface facing the absorber layer to an interior of the buffer layer.

6. Layer system according to claim 1 , wherein the layer thickness of the buffer layer is from 5 nm to 150 nm.

7. Layer system according to claim 1 , wherein the halogen is chlorine, bromine, or iodine.

8. Layer system according to claim 1 , wherein the chalcogenide compound semiconductor includes Cu(In,Ga,Al)(S,Se) 2 .

9. Thin-film solar cell, comprising:
a substrate,
a rear electrode that is arranged on the substrate,
a layer system according to claim 1 that is arranged on the rear electrode, and
a front electrode that is arranged on the layer system.

10. Method for producing a layer system for thin-film solar cells, comprising:
a) preparing an absorber layer, and
b) arranging a buffer layer, which contains halogen-enriched Zn x In 1-x S y with 0.01≤x≤0.9 and 1≤y≤2 on the absorber layer,
wherein the buffer layer consists of a first layer region adjoining the absorber layer with a halogen mole fraction A 1 and a second layer region adjoining the first layer region with a halogen mole fraction A 2 and a ratio A 1 /A 2 is ≥2, and a layer thickness of the first layer region is ≤20% of a layer thickness of the buffer layer.

11. Method according to claim 10 , comprising:
in the step b), applying a metal-halide compound on the absorber layer and applying zinc indium sulfide on the metal-halide compound.

12. Method according to claim 10 , comprising:
in the step b), applying a metal-halide compound and zinc indium sulfide on the absorber layer.

13. Method according to claim 12 , comprising:
conveying the absorber layer past at least one steam beam of the metal-halide compound and at least one steam beam of indium sulfide and zinc sulfide.

14. Method according to claim 12 , comprising:
applying the metal-halide compound with chlorine, bromine, and/or iodine as halogen and sodium, potassium, aluminum, gallium, indium, zinc, cadmium, and/or mercury as metal.

15. Layer system according to claim 1 , wherein the ratio A 1 /A 2 is from 10 to 100.

16. Layer system according to claim 1 , wherein the amount of the halogen in the first layer region amounts to an area concentration of 2·10 14 atoms/cm 2 to 2·10 16 atoms/cm 2 .

17. Layer system according to claim 1 , wherein the layer thickness of the buffer layer is from 15 nm to 50 nm.

18. Layer system according to claim 1 , wherein the chalcogenide compound semiconductor includes CuInSe 2 , CuInS 2 , Cu(In,Ga)Se 2 , Cu(In,Ga)(S,Se) 2 , or Cu 2 ZnSn(S,Se) 4 .

Assignees

• Saint Gobain
• Bengbu Design & Res Inst Glass Ind

Inventors

• Palm Jörg
• Pohlner Stephan
• Happ Thomas
• Dalibor Thomas
• Dietmüller Roland

Classifications

• H10P14/3436

  being chalcogenide semiconductor materials not being oxides, e.g. ternary compounds · CPC title

• H10P14/3428

  Sulfides · CPC title

• H10P14/3236 Primary

  being chalcogenide semiconducting materials not being oxides, e.g. ternary compounds · CPC title

• H10P14/22

  using physical deposition, e.g. vacuum deposition or sputtering · CPC title

• H01L21/02568

  Electricity · mapped topic