Arsenic-doping of ZnO

Arsenic is considered a potential candidate for p-type doping of zinc oxide (ZnO). Most of the publications on this topic discuss the electrical or optical properties. However, it is not always clear whether the formation of secondary phases, e.g. arsenic oxide clusters, might be the source for the observed effects. To gain further insight into this topic, we have studied the incorporation of arsenic into zinc oxide using two different approaches. The first series of samples consisted of zinc oxide single crystals implanted with 75As ions with high doses of 1016cm-2 at an energy of 200 keV. We have investigated the influence of annealing using Rutherford backscattering in channeling geometry (RBS/C), secondary ion mass spectrometry (SIMS), X-ray diffraction (XRD) and X-ray photospectroscopy (XPS). The results discuss the diffusion of the arsenic and of the impurities and the formation of secondary phases. The second series of samples was grown using chemical vapour deposition (CVD), as this method can provide defect-free films of high crystalline quality. The samples were analysed regarding their homogenity and composition