Determination of nitrogen-related defects in N-implanted ZnO films by dynamic cathodoluminescence

Visible bands arising from N-related defects are investigated by dynamic cathodoluminescence (CL) and Gaussian deconvolution. The intensity of the red band increases while that of the ultraviolet (UV) band decreases. The intensity of the yellow band also decreases but only slightly as a function of the electron bombardment cycle. The CL behavior of N-doped ZnO after post-annealing in N2 at high temperature reveals that the N-related defects cannot be easily compensated. The results also confirm the assignment of the N-related defects and are in agreement with the theoretical prediction about Zn-N bonding. Our data provide some clues to the mechanism of the conversion of ZnO into p-type by nitrogen doping.