Figure 2
(a) Evolution of the survey scans for, from top to bottom, ()-terminated m-plane ZnO after nitrogen doping, pristine m-plane ZnO, ()-terminated o-plane ZnO after nitrogen doping, and pristine o-plane ZnO. N 1s and Zn 3p core-level XPS spectra of different orientations (b) after and (c) before nitrogen doping. |