Granted Patent B2

US 12,009,445 · App. 17/800,617 · Granted Jun 11, 2024

Inventors: Shuping Lin (Schwaebisch Hall, DE); Raffael Reineker (Kuenzelsau, DE); Hongqing Shan (Cupertino, CA); Joachim Leopold Ludwig Müller (Fellbach, DE); Bernd Sprecher (Schwaebisch Hall, DE); Kay Ogassa (Leinfelden-Echterdingen, DE)

H01L31/0463H01L31/022425H01L31/0322

Abstract

Claims (51)

1. A method of patterning a thin-film photovoltaic layer stack comprising:

providing a continuous layer stack, the layer stack comprising a substrate, a first electrode layer on the substrate and a photovoltaic layer on the first electrode layer;

immersing the layer stack into an electrically conductive solution;

applying a bias voltage between the electrically conductive solution and the first electrode layer;

selectively removing the photovoltaic layer along a first line and forming a first trench in the photovoltaic layer before or after immersing the layer stack into the electrically conductive solution; and

converting a first material or a first material composition provided in at least a first portion of the layer stack into a first reaction product by an electrochemical reaction, wherein the first reaction product has an electrical conductivity that is lower than an electrical conductivity of the first material or the first material composition,

wherein the first material or the first material composition of the first portion of the layer stack comprises Molybdenum (Mo), and wherein the first reaction product comprises MoO x , with 2.5<x≤3.

2. The method according to claim 1 , wherein selectively removing the photovoltaic layer and forming the first trench comprises:

applying a laser beam onto the layer stack and moving the laser beam along the first line; or

moving a mechanical scribing tool along the first line.

3. The method according to claim 1 , wherein the first portion of the layer stack extends along the first trench.

4. The method according to claim 1 , wherein the layer stack is immersed into a salt solution containing at least one of: Zn, Cd, or Ca, and wherein at least one of the first material, the first material composition, or the first reaction product is transformed into one of: ZnMoO 4 , CaMoO 4 , or CdMoO 4 .

5. The method according to claim 1 , wherein the first portion of the layer stack is a portion of the first electrode layer.

6. The method according to claim 1 , wherein immersing the layer stack in the electrically conductive solution includes immersing the layer stack in a basic solution and thereafter immersing the layer stack in a neutral pH or acidic conductive solution.

7. The method according to claim 1 , wherein a window layer is deposited onto the layer stack and wherein the photovoltaic layer is selectively removed along a second line to form a second trench parallel to the first trench and adjacent to the first trench.

8. The method according to claim 7 , wherein a second electrode layer is deposited onto the layer stack and wherein the photovoltaic layer is selectively removed along a third line to form a third trench parallel to the second trench and adjacent to the second trench.

9. A method of patterning a thin-film photovoltaic layer stack comprising:

providing a continuous layer stack, the layer stack comprising a substrate, a first electrode layer on the substrate, and a photovoltaic layer on the first electrode layer;

immersing the layer stack into an electrically conductive solution;

applying a bias voltage between the electrically conductive solution and the first electrode layer;

selectively removing the photovoltaic layer along a first line and forming a first trench in the photovoltaic layer before or after immersing the layer stack into the electrically conductive solution; and

converting a first material or a first material composition provided in at least a first portion of the layer stack into a first reaction product by an electrochemical reaction,

wherein the first reaction product has an electrical conductivity that is lower than an electrical conductivity of the first material or the first material composition;

wherein the layer stack is immersed into a salt solution containing at least one of: Zn, Cd, or Ca; and

wherein at least one of the first material, the first material composition, or the first reaction product is transformed into one of: ZnMoO 4 , CaMoO 4 , or CdMoO 4 .

10. The method according to claim 9 , wherein selectively removing the photovoltaic layer and forming the first trench comprises:

applying a laser beam onto the layer stack and moving the laser beam along the first line; or

moving a mechanical scribing tool along the first line.

11. The method according to claim 9 , wherein the first portion of the layer stack extends along the first trench.

12. The method according to claim 9 , wherein the first material or the first material composition of the first portion of the layer stack comprises a metal, and wherein the first reaction product comprises one of: a metal oxide, a metal selenide, or a metal sulfide.

13. The method according to claim 9 , wherein the first material or the first material composition of the first portion of the layer stack comprises Molybdenum (Mo), and wherein the first reaction product comprises MoO x , with 2.5<x≤3.

14. The method according to claim 9 , wherein the first portion of the layer stack is a portion of the first electrode layer.

15. The method according to claim 9 , wherein immersing the layer stack in the electrically conductive solution includes immersing the layer stack in a basic solution and thereafter immersing the layer stack in a neutral pH or acidic conductive solution.

16. The method according to claim 9 , wherein a window layer is deposited onto the layer stack, and wherein the photovoltaic layer is selectively removed along a second line to form a second trench parallel to the first trench and adjacent to the first trench.

17. The method according to claim 16 , wherein a second electrode layer is deposited onto the layer stack, and wherein the photovoltaic layer is selectively removed along a third line to form a third trench parallel to the second trench and adjacent to the second trench.

18. A method of patterning a thin-film photovoltaic layer stack comprising:

providing a continuous layer stack, the layer stack comprising a substrate, a first electrode layer on the substrate, and a photovoltaic layer on the first electrode layer;

immersing the layer stack into an electrically conductive solution;

applying a bias voltage between the electrically conductive solution and the first electrode layer;

selectively removing the photovoltaic layer along a first line and forming a first trench in the photovoltaic layer before or after immersing the layer stack into the electrically conductive solution; and

converting a first material or a first material composition provided in at least a first portion of the layer stack into a first reaction product by an electrochemical reaction,

wherein the first reaction product has an electrical conductivity that is lower than an electrical conductivity of the first material or the first material composition;

wherein the first material or the first material composition of the first portion of the layer stack comprises a CIGS semiconductor material with a composition of Cu x (In,Ga) y Se z , with x+3y>2z; and

wherein the first reaction product comprises a CIGS semiconductor material with a composition of Cu x (In,Ga) y Se z ,O w , with x+3y≤2(w+z) and w>0.

19. The method according to claim 18 , wherein selectively removing the photovoltaic layer and forming the first trench comprises:

applying a laser beam onto the layer stack and moving the laser beam along the first line; or

moving a mechanical scribing tool along the first line.

20. The method according to claim 18 , wherein the first portion of the layer stack is a side edge of the photovoltaic layer extending along the first trench.

21. The method according to claim 18 , wherein immersing the layer stack in the electrically conductive solution includes immersing the layer stack in a basic solution and thereafter immersing the layer stack in a neutral pH or acidic conductive solution.

22. The method according to claim 18 , wherein a window layer is deposited onto the layer stack, and wherein the photovoltaic layer is selectively removed along a second line to form a second trench parallel to the first trench and adjacent to the first trench.

23. The method according to claim 22 , wherein a second electrode layer is deposited onto the layer stack, and wherein the photovoltaic layer is selectively removed along a third line to form a third trench parallel to the second trench and adjacent to the second trench.

Assignments (10)

Cited By (1)

US 12,641,890