Density Functional Theory Study on Defect Feature of AsGaGaAs in Gallium Arsenide

Abstract

We investigate the defect feature of AsGaGaAs defect in gallium arsenide clusters in detail by using first‐principles calculations based on the density functional theory (DFT). Our calculations reveal that the lowest donor level of AsGaGaAs defect on the gallium arsenide crystal surface is 0.85 eV below the conduction band minimum, while the lowest donor level of the AsGaGaAs defect inside the gallium arsenide bulk is 0.83 eV below the bottom of the conduction band, consistent with gallium arsenide EL2 defect level of experimental value (Ec‐0.82 eV). This suggests that AsGaGaAs defect is one of the possible gallium arsenide EL2 deep‐level defects. Moreover, our results also indicate that the formation energies of internal AsGaGaAs and surface AsGaGaAs defects are predicted to be around 2.36 eV and 5.54 eV, respectively. This implies that formation of AsGaGaAs defect within the crystal is easier than that of surface. Our results offer assistance in discussing the structure of gallium arsenide deep‐level defect and its effect on the material.