Reducing the acceptor levels of p-type β-Ga2O3 by (metal, N) co-doping approach

Fabricating p-type β-Ga2O3 with shallow acceptor levels is vital to the application of β-Ga2O3 based devices. Herein, we propose a potential approach, (electron-poor metal, N) co-doping, to effectively decrease the acceptor levels. The (electron-poor metal, N) co-doping is easier to be realized compared to the pure N doping for β-Ga2O3. Moreover, partial co-doping further shifts up the Ga–O bonding orbitals and down the dopant-O anti-bonding orbitals and the unoccupied p orbitals of N and O ions, thus the acceptor levels can be significantly decreased when the pure metal doping is replaced by the co-doping method. The acceptor levels of (Mg, N) and (Zn, N) co-doped β-Ga2O3 are as low as 0.16, and 0.01 eV, respectively. More importantly, (metal dopant with p orbitals, N) co-doping hinders the formation of O-vacancy which limits the formation of p-type β-Ga2O3. These results suggest that (metal, N) co-doping might be a potential way to achieve an effective p-type β-Ga2O3.