Al concentration dependence of electrical and photoluminescent properties of co-doped ZnO films

This study reports on the electrical and photoluminescent properties of Al–N co-doped ZnO films with different Al contents. The results suggest that N solubility in ZnO is limited even by the co-doping method. Intermediate Al contents were found to be most important for achieving high-hole-concentration p-type ZnO. Carrier mobility was found to decrease with increasing Al content. Low temperature photoluminescence spectra revealed a dominant emission band at 3.13 eV, which was attributed to a DAP transition. The observed broadened and red-shifted DAP band in the high-Al-containing co-doped samples could relate to rather potential fluctuations.