Spectroscopic evidence that Li doping creates shallow V_Zn in ZnO

The simultaneous introduction of shallow acceptors and elimination of donor compensation is the key issue toward achieving p-type ZnO. Herein, through accurate control of the Li dopant configuration and systematic spectroscopy characterization, we obtain direct evidence that Li doping creates isolated V_Zn in ZnO with a luminescence peak around 414 nm (∼3.0 eV), and at the same time, removes donors. Interestingly, the same defect emission is also created by simple H₂O₂ treatment and appeared in a ZnO single crystal with abundant metal vacancies, unambiguously demonstrating its shallow acceptor characteristic.