High temperature dehydrogenation for realization of nitrogen-doped p-type ZnO

In this letter, we report on the realization of the p-type ZnO film by in situ nitrogen doping and subsequent thermal activation, as well as the discussions on the doping mechanism. Through the high temperature activation, a conversion of conductivity from n- to p-type with a hole concentration of ∼1019/cm3 has been observed by Hall measurements, accompanied with the formation and dissociation of N–H complex investigated by Raman spectra. These observations provide probability on the passivation effect of N–H complex and dehydrogenation process at high temperature, as confirmed by the variation of N and H atomic concentration in the secondary ion mass spectra. The dehydrogenation process in oxygen ambient at 900 °C led to the dissociation of NO–H complexes, resulting in the formation of isolated NO acceptors and compensation to the intrinsic donor-like defects. The N-related acceptor bound exciton in photoluminescence with a small binding energy of 100 meV and high p-type conductivity in activated ZnO:N film imply the important role of dehydrogenation effect to the realization of p-type ZnO.