The N-doped ZnO nanowires were synthesized, at the relatively low growth temperature of 500C, by directly heating zinc powder using NH3 as the dopant. The incorporation of N into the ZnO nanowires was experimentally confirmed by X-ray photo-electron spectroscopy, Raman spectra and photoluminescence measurements. By combining post annealing experiments after growth with first-principles calculations, the detailed migration mechanism of N and compensation mechanism in N-doped ZnO nanowires were systematically studied. The larger aspect ratio of nanowires favours the formation of oxygen vacancy and out-diffusion of substitutional N (NO), making NO in ZnO nanowires always compensated by hydrogen interstitials (HI). The results could help to explain the challenge in getting p-type ZnO and shed new light on the possible realization of p-type doping of ZnO in the future.

Compensation Mechanism in N-Doped ZnO Nanowires. J.Gao, X.Zhang, Y.Sun, Q.Zhao, D.Yu: Nanotechnology, 2010, 21[24], 245703