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

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 300 K and 1173 K; however, from 1173 K to 1373 K, 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.