Evidences of VO, VZn, and Oi defects as the green luminescence origins in ZnO

In this Letter, by employing a combination of typical treatments and sensitive defect characterization, we discriminate between the roles of different kinds of intrinsic defects in ZnO. Thereby, we offer convincing experimental evidence that the green luminescence can originate from VO, VZn, and Oi-related defects, corresponding to the 2.48 eV, 2.35 eV, and 2.26 eV emissions, respectively. The green emission peaks are found to be dependent on the relative concentration of these defect centers.