Luminescence behavior and compensation effect of N-doped ZnO films deposited by rf magnetron sputtering under various gas-flow ratios of O2/N2

The photoluminescent and electrical properties of N-doped ZnO films fabricated by rf magnetron sputtering under various gas-flow ratios of O2/N2 were examined in this study. The dependence of conduction type on the gas-flow rate of O2/N2 was found. The authors identified a direct correlation between the defect spectral feature and conduction type of N-doped ZnO samples and provided a physical model for producing p-type ZnO. According to these observed results, the authors suggested that p-type conversion of N-doped ZnO may be due to a combined effect of the increased acceptor (substitutional nitrogen in oxygen site, zinc vacancy and interstitial oxygen) density and the decreased donor (oxygen vacancy) density. In addition, synthesis of p-type N-doped ZnO was repeated, suggesting that p-type ZnO can be fabricated with excellent reproducibility by rf magnetron sputtering a ZnO target doped with nitrogen. -- Highlights: • The electrical property of sputtered ZnO under various O2/N2 ratios was examined. • The dependence of photoluminescent properties on the O2/N2 rate was found. • A correlation between the defect spectral feature and conductivity was identified. • Compensation of residual donors and conduction type conversion were observed