Understanding the dopability of As in selenium-alloyed cadmium telluride solar cells

Cadmium telluride (CdTe) and its alloy CdTeSe are widely used in optoelectronic devices, such as radiation detectors and solar cells, due to their superior electrical properties. However, the formation of defects and defect complexes in these materials can significantly affect their performance. As a result, understanding the defect formation and recombination processes in CdTe and CdTeSe alloy is of great importance. In recent years, density functional theory (DFT) calculations have emerged as a powerful tool for investigating the properties of defects in semiconductors. In this paper, we use DFT calculations to study the properties of arsenic extrinsic defects in CdTeSe alloy, providing insights into the effects of these defects on the electrical properties of the material. We found that AX centers formation is more favorable in the alloy, which can potentially reduce the dopability of As in CdTeSe alloy. Our findings not only provide new insights into the mechanisms of As extrinsic defects in CdTeSe but also have implications for the development of high-performance solar cells.