Density Functional Theory Study on the Elastic Properties of GaAs/Si Semiconductor Heterostructures

Abstract

Semiconductor heterostructures, such as GaAs/Si, have the potential to exhibit unique electrical and optical properties at their interfaces, making them promising candidates for high-performance photocatalysts, solar cells, and semiconductor devices. In this study, density functional theory (DFT) calculation was utilized to investigate the elastic properties of GaAs/Si semiconductor heterostructures. The Bulk modulus, Young's modulus, Poisson's ratio, and Shear modulus of six distinct GaAs/Si heterostructures were calculated and analyzed. It was revealed that the bulk modulus and Young's modulus closely aligned with the predictions of the Rule of Mixtures (ROM), thereby validating the reliability of the DFT calculation methodology employed in this study. However, the Poisson's ratio and shear modulus deviated from the ROM predictions, with the shear modulus being notably lower. Further analysis of the electron distribution within the GaAs/Si heterostructures indicated a reduction in the electrons contributing to bonding at the interface, leading to weakened bonds and a consequent decrease in shear modulus. Additionally, the presence of metallicity at the interfaces was identified. These specific characteristics of the GaAs/Si heterostructures will provide valuable insights for future applications of this material.