# US 2013/0157406 A1 · Low- cost solution approach to deposit selenium and sulfur for cu(in,ga)(se,s)2 formation

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2013/0157406 A1
- Document ID: US20130157406A1
- Status: Published application
- Kind: A1
- Application number: 13/330,836
- Filed: 2011-12-20
- Published: 2013-06-20
- Earliest claimed: 2011-12-20
- Assignees: Intermolecular, Inc.
- Inventors: Wei Liu
- Web page: https://patentgrep.com/patent/US20130157406A1

## CPC

- H10F 77/126: {comprising only Group I-III-VI chalcopyrite materials, e.g. CuInSe2, CuGaSe2 or CuInGaSe2 [CIGS]}
- H10F 77/169: Thin semiconductor films on metallic or insulating substrates
- H10F 77/1694: {the films including Group I-III-VI materials, e.g. CIS or CIGS}
- H10F 77/1696: {the films including Group II-VI materials, e.g. CdTe or CdS}
- H10F 77/1698: {the metallic or insulating substrates being flexible}
- H10P 14/203: {using transformation of metal, e.g. oxidation or nitridation}
- H10P 14/265: {using solutions}
- H10P 14/2901: {Materials}
- H10P 14/3436: {being chalcogenide semiconductor materials not being oxides, e.g. ternary compounds}
- Y02E 10/541: CuInSe2 material PV cells
- H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

Methods of forming copper indium gallium diselenide (CIGS) layers for photovoltaic devices are disclosed. In one aspect, a solution based selenization method in the formation of CIGS is provided. In some embodiments a substrate containing elemental copper (Cu), indium (In) and gallium (Ga) is coated with a solution comprising a source of selenium (Se) dissolved in a solvent. After coating with the selenium based solution, the substrate is heated to form the CIGS layer. Coating of the substrate with the selenium based solution may be carried out by dip coating, slit casting, gap coating, ink-jet type coating, among other techniques. The solution based selenization method disclosed herein provides high material utilization and low cost, unlike vacuum based processes.

## Claims

### Claim 1

A method of selenization in the formation of a copper indium gallium diselenide (CIGS) layer in a photovoltaic device, comprising:
coating a substrate containing elemental Cu, In and Ga with a solution comprising a source of selenium (Se) dissolved in a solvent to form a layer comprising Se on the substrate, and wherein a thickness or composition of the Se layer is determined during the coating step by measuring any one or more of: thickness of the solution, concentration of Se in the solution, viscosity of the solution, or speed of coating the solution on the substrate; and
heating the coated substrate.

### Claim 2 (depends on 1)

The method of claim 1 wherein the step of coating is performed by any one or more of: spin coating, dip coating, curtain coating, blade coating, ink-jet type coating, slit casting, or gap coating.

### Claim 3 (depends on 1)

The method of claim 1 wherein the step of coating is performed by spraying.

### Claim 4 (depends on 1)

The method of claim 1 wherein the step of coating is performed by ink jet coating or ink-jet printing.

### Claim 5 (depends on 1)

The method of claim 1 wherein the solution is comprised of selenium dissolved in a solvent.

### Claim 6 (depends on 5)

The method of claim 5 wherein the solvent is comprised of any one or more of: hydrazine, hydrous hydrazine, ethanolamine, ethylenediamine (EDA), propylenediamine (PDA), dimethyl sulfoxide (DMSO) or mixtures thereof

### Claim 7 (depends on 5)

The method of claim 5 wherein the concentration of selenium in the solvent is up to about 10 M.

### Claim 8 (depends on 5)

The method of claim 5 wherein the concentration of selenium in the solvent is in the range of about 0.1 M to about 5 M.

### Claim 9 (depends on 1)

The method of claim 1 wherein the heating step is carried out in an inert environment at a temperature in the range of about 200 to about 650 C.

### Claim 10 (depends on 9)

The method of claim 9 wherein the heating step is carried out for a duration in the range of about 1 to about 300 minutes.

### Claim 11

A method of forming a copper indium gallium diselenide (CIGS) layer on a substrate, comprising:
depositing elemental copper, indium and gallium onto the substrate;
then coating the substrate with a solution comprising a source of selenium (Se) dissolved in a solvent; and
heating the coated substrate to form the CIGS layer.

### Claim 12 (depends on 11)

The method of claim 11 wherein the step of depositing is comprised of any one or more of: electrodeposition, electroless deposition, evaporation, physical vapor deposition, sputter deposition or chemical vapor deposition.

### Claim 13 (depends on 11)

The method of claim 11 wherein the step of coating is carried out by any one or more of: spin-coating, dip coating, curtain coating, blade coating, ink-jet type coating, slit casting, gap coating or spraying.

### Claim 14 (depends on 11)

The method of claim 11 wherein the step of coating is carried out by ink jet coating or ink-jet printing.

### Claim 15 (depends on 11)

The method of claim 11 wherein the solution is comprised of selenium dissolved in a solvent.

### Claim 16 (depends on 15)

The method of claim 15 wherein the solvent is comprised of any one or more of: hydrazine, hydrous hydrazine, ethanolamine, ethylenediamine (EDA), propylenediamine (PDA), dimethyl sulfoxide (DMSO) or mixtures thereof.

### Claim 17 (depends on 15)

The method of claim 15 wherein the concentration of selenium metal in the solvent is in the range of about 0.1 M to about 5 M.

### Claim 18 (depends on 11)

The method of claim 11 wherein the heating step is carried out in an inert environment at a temperature in the range of about 200 to about 650 C. and for a duration in the range of about 1 to about 300 minutes.

### Claim 19 (depends on 11)

The method of claim 11 wherein the Se layer is formed having a desired thickness by varying during the coating step, any one or more of: thickness of the solution, concentration of Se in the solution, viscosity of the solution, or speed of coating the solution on the substrate.