Energy Bandgap of Cd1-xZnxTe, Cd1-xZnxSe and Cd1-xZnxS Semiconductors: A First-Principles Analysis Based on Tran-Blaha-Modified Becke-Johnson Exchange Potential

This paper presents a first-principles investigation of the energy bandgaps of Cd1-xZnxTe, Cd1-xZnxSe and Cd1-xZnxS semiconductor alloys in zinc-blende crystals. The theoretical analysis is based on the full-potential linearized augmented plane wave method within both generalized gradient and local density approximations. Tran-Blaha-modified Becke-Johnson exchange potential was invoked to accurately provide bandgaps and their bowing parameters. A moderate nonlinear dependence with average bowing parameters around b similar to 0.49 eV for Cd1-xZnxTe, b similar to 0.68 eV Cd1-xZnxS, and b similar to 0.63 eV for Cd1-xZnxSe was found. The origin of the nonlinearity is discussed in light of Zunger's approach to conclude that it arises mainly from volume deformation.

Automated summary

This paper presents a first-principles investigation of the energy bandgaps of Cd1-xZnxTe, Cd1-xZnxSe and Cd1-xZnxS semiconductor alloys in zinc-blende crystals. The theoretical analysis is based on the full-potential linearized augmented plane wave method within both generalized gradient and local density approximations. It was found that there is a moderate nonlinear dependence in the bandgaps with average bowing parameters of b ≈ 0.49 eV for Cd1-xZnxTe, b ≈ 0.68 eV for Cd1-xZnxS, and b ≈ 0.63 eV for Cd1-xZnxSe. The nonlinearity mainly arises from volume deformation, as discussed in light of Zunger's approach.