Effect of doping concentration on point defect structure in As-implanted ZnO

The effect of doping concentration on the point defect structure of As-implanted ZnO single crystal was investigated using diffuse x-ray scattering and photoluminescence spectroscopy. Based on the assumption that the low-dose ion implantation did not shift the phonon dispersion of the lattice, Huang diffuse scattering signals were obtained by subtracting thermal diffuse scattering intensities. We found that the point defects aggregate into defect clusters after annealing, and their average size decreases and concentration increases with increasing the doping concentration. The underlying mechanisms of this counter-intuition result were suggested.