Study on the effects of VO and Hi on the absorption spectrum and conductivity of Ti doped β-Ga2O3

Abstract

β-Ga2O3 has many excellent properties, but poor electrical conductivity limits its application in optoelectronic devices. At present, some progress has been made in the study of Ti doping on the photoelectric properties of β-Ga2O3. However, few studies on the effects of Ti doping and VO-Hi co-existence on photoelectric properties of β-Ga2O3. Defects (VO) and unintentional impurities (Hi) will inevitably exist during the preparation of β-Ga2O3. Given these problems, the effects of Ti doping and VO-Hi co-existence on photoelectric properties of β-Ga2O3 were studied using first-principles GGA+U method. The electronic structure, dielectric function, absorption spectrum, effective mass, mobility, and conductivity of the system were calculated and analyzed. The results indicate that with the increase of Ti doping concentration, the bandgap of the Ti doped β-Ga2O3 system gradually narrows. Ti doping causes a red shift in the peak of the absorption spectrum and effectively improves the conductivity of the system. The O vacancy reduces the conductivity of the system, while the interstitial H increases the conductivity of the system. Thus, Ti-doped β-Ga2O3 material is helpful for preparing new optoelectronic devices.