Spectroscopic evidence that Li doping creates shallow VZn 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 VZn in ZnO with a luminescence peak around 414 nm (similar to 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.