The roles of the temperature on the structural and electronic properties of deep-level VAsVGa defects in gallium arsenide

Abstract

The roles of temperature on the structural and electronic properties of VAsVGa defects in gallium arsenide have been studied by using ab-initio molecular dynamic (MD) simulation. Our calculated results show that the relatively stable quaternary complex defect of GaAsAsGaVAsVGa can be converted from the VAsVGa complex clusters defect between 300K and 1173K; however, from 1173K to 1373K, the decomposition of the complex defect GaAsAsGaVAsVGa occurs, turning into a deep-level VAsVGa cluster defect and an isolated AsGa antisite defect, and relevant defect of GaAs is recovered. The properties of GaAsAsGaVAsVGa defect has been studied by first-principles calculations based on hybrid density functional theory. Our calculated results show that the GaAsAsGaVAsVGa belongs to EL2 deep-level defect in GaAs. Thus, we reveal that the temperature has an important effect on the microstructure of deep-level defects and defect energy level in gallium arsenide that EL2 and EL6 deep-level defects have a certain correlation, which means they could transform into each other. Controlling temperature in the growth process of GaAs could change the microstructure of deep-level defects and defect energy levels in gallium arsenide materials, whereby affects the electron transport properties of materials.