Location of P and As dopants and p-type doping of ZnO

Although ZnO has long been touted as an excellent material for UV light-emitting diodes and lasers, p-type doping still remains a challenge. In recent reports claiming that p-type doping can be achieved using nitrogen, arsenic and phosphorus, the spatial location of the dopants in the "successful" samples has not been identified. In this work, we present simulation results of x- ray absorption spectra for different locations of p-type dopants and argue that this technique is a powerful tool to experimentally investigate the location of group V dopants and to establish a correlation between the dopant location and corresponding conductivity type.