GeSn and SiSn are attracting growing attention due to their potential as direct-bandgap semiconductors for optical devices with higher Sn doping. To achieve a higher Sn concentration, thin film growth is carried out using substrates with a larger lattice constant, which imposes tensile stress on the Ge or Si thin films. In this study, we performed density functional theory (DFT) calculations to investigate the effect of Sn and vacancy (V) on the thermal equilibrium concentration of Sn in Ge and Si crystals under isotropic, plane, and uniaxial stresses.
Ozawa et al. (Wed,) studied this question.