Achieving high conductivity p-type Ga2O3 through Al-N and In-N co-doping

The lack of p-type Ga2O3 limits its application for optoelectronic devices. Although nitrogen is a common acceptor dopant for oxides, the presence of midgap level, induced by N doping, impairs its p-type conductivity. We propose that Al/In-N co-doping is an effective way to obtain high-conductivity p-type Ga2O3. First-principles calculations reveal that Al-N co-doping exhibits lower defect formation energy and shallower transition level than that of N mono-doping. In-N can further reduce the depth of transition level, corresponding to a higher carrier concentration. More interestingly, enhancing the ratio of N in In-N co-doping, in a greater extent, elevates the p-type conductivity.