On the Chemical Origin of the Gap Bowing in (GaAs)1−x Ge2x Alloys: A Combined DFT–QSGW Study

Nanoscale Research Letters

关键词: Photovoltaics;    III–;    V IV-doped alloys;    Bandgap bowing;    Order–;    disorder phase transition;    DFT;    Quasiparticle Self-consistent GW;   

DOI  :  

来源: DOAJ

【 摘 要 】

Abstract

Motivated by the research and analysis of new materials for photovoltaics and by the possibility of tailoring their optical properties for improved solar energy conversion, we have focused our attention on the (GaAs)_{1− x} Ge_2x series of alloys. We have investigated the structural properties of some (GaAs)_{1− x} Ge_2x compounds within the local-density approximation to density-functional theory, and their optical properties within the Quasiparticle Self-consistent GW approximation. The QSGW results confirm the experimental evidence of asymmetric bandgap bowing. It is explained in terms of violations of the octet rule, as well as in terms of the order–disorder phase transition.

【 授权许可】

Unknown