Doping-induced bandgap tuning of α-Ga2O3 for ultraviolet lighting

We propose the novel strategy for indirect-to-direct band gap transition of gallium oxide-based semiconductors for ultraviolet lighting device through first-principles calculations using a screened hybrid functional. Our calculations show that the tuning of electronic band gap of α-Ga2O3 is straightforward by adding dopants, which mimics alloy-like system. In order to put the band gap in the energy range of ultraviolet light, Group-III (In, Tl) at the Ga site and Group-V (N, P) or Group-VI (S, Se) at the O site are examined. We find that the most of doped Ga2O3 possess direct or nearly direct band gaps lying in the ultraviolet energy that is essential for optoelectronic devices.