# Phase diagram of the CulnSe{sub 2}-CuGaSe{sub 2} pseudobinary system studied by combined ab initio density functional theory and thermodynamic calculation

## Abstract

The phase diagram of the CuInSe{sub 2}-CuGaSe{sub 2} pseudobinary system was determined using a combination of special quasirandom structure approach, ab initio density functional theory calculations, and thermodynamic modelling. It is shown that the CuIn{sub 1−x}Ga{sub x}Se{sub 2} solution phase has a tendency to phase separation at low temperature. The calculated consolute temperature is 485 K. It is found that both the binodal and spinodal curves are significantly asymmetric and on both curves there are a local maximum and a local minimum, which have not been reported in the previous studies. Our phase diagram can well explain the finding that the inhomogeneity of CuIn{sub 0.25}Ga{sub 0.75}Se{sub 2} is higher than that of CuIn{sub 0.75}Ga{sub 0.25}Se{sub 2} at the same temperature, while the previous phase diagrams cannot. Hence, our phase diagram should be more reliable and applicable.

- Authors:

- State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Department of Materials Science and Engineering, Lanzhou University of Technology, Lanzhou 730050 (China)
- (China)
- Science and Technology on Surface Engineering Laboratory, Lanzhou Institute of Physics, Lanzhou 730000 (China)

- Publication Date:

- OSTI Identifier:
- 22314540

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ASYMMETRY; DENSITY FUNCTIONAL METHOD; MATHEMATICAL SOLUTIONS; PHASE DIAGRAMS; TEMPERATURE RANGE 0400-1000 K

### Citation Formats

```
Xue, H. T., Tang, F. L., E-mail: tfl03@mails.tsinghua.edu.cn, Science and Technology on Surface Engineering Laboratory, Lanzhou Institute of Physics, Lanzhou 730000, Lu, W. J., Li, X. K., Zhang, Y., and Feng, Y. D.
```*Phase diagram of the CulnSe{sub 2}-CuGaSe{sub 2} pseudobinary system studied by combined ab initio density functional theory and thermodynamic calculation*. United States: N. p., 2014.
Web. doi:10.1063/1.4891829.

```
Xue, H. T., Tang, F. L., E-mail: tfl03@mails.tsinghua.edu.cn, Science and Technology on Surface Engineering Laboratory, Lanzhou Institute of Physics, Lanzhou 730000, Lu, W. J., Li, X. K., Zhang, Y., & Feng, Y. D.
```*Phase diagram of the CulnSe{sub 2}-CuGaSe{sub 2} pseudobinary system studied by combined ab initio density functional theory and thermodynamic calculation*. United States. doi:10.1063/1.4891829.

```
Xue, H. T., Tang, F. L., E-mail: tfl03@mails.tsinghua.edu.cn, Science and Technology on Surface Engineering Laboratory, Lanzhou Institute of Physics, Lanzhou 730000, Lu, W. J., Li, X. K., Zhang, Y., and Feng, Y. D. Thu .
"Phase diagram of the CulnSe{sub 2}-CuGaSe{sub 2} pseudobinary system studied by combined ab initio density functional theory and thermodynamic calculation". United States.
doi:10.1063/1.4891829.
```

```
@article{osti_22314540,
```

title = {Phase diagram of the CulnSe{sub 2}-CuGaSe{sub 2} pseudobinary system studied by combined ab initio density functional theory and thermodynamic calculation},

author = {Xue, H. T. and Tang, F. L., E-mail: tfl03@mails.tsinghua.edu.cn and Science and Technology on Surface Engineering Laboratory, Lanzhou Institute of Physics, Lanzhou 730000 and Lu, W. J. and Li, X. K. and Zhang, Y. and Feng, Y. D.},

abstractNote = {The phase diagram of the CuInSe{sub 2}-CuGaSe{sub 2} pseudobinary system was determined using a combination of special quasirandom structure approach, ab initio density functional theory calculations, and thermodynamic modelling. It is shown that the CuIn{sub 1−x}Ga{sub x}Se{sub 2} solution phase has a tendency to phase separation at low temperature. The calculated consolute temperature is 485 K. It is found that both the binodal and spinodal curves are significantly asymmetric and on both curves there are a local maximum and a local minimum, which have not been reported in the previous studies. Our phase diagram can well explain the finding that the inhomogeneity of CuIn{sub 0.25}Ga{sub 0.75}Se{sub 2} is higher than that of CuIn{sub 0.75}Ga{sub 0.25}Se{sub 2} at the same temperature, while the previous phase diagrams cannot. Hence, our phase diagram should be more reliable and applicable.},

doi = {10.1063/1.4891829},

journal = {Journal of Applied Physics},

number = 5,

volume = 116,

place = {United States},

year = {Thu Aug 07 00:00:00 EDT 2014},

month = {Thu Aug 07 00:00:00 EDT 2014}

}