Interplay of Charged States and Oxygen Dissociation Induced by Vacancies in Phosphorene

Vacancies in phosphorene play important roles on understanding of fundamental properties and further applications in nanoelectronics and optoelectronics. In this paper, we have systematically investigated charged states and related surface oxidation induced by the single and double vacancies in phosphorene using first-principles calculations. We find that these defects can both achieve stable −1 charge states, which significantly affect the geometries and electronic properties. The reaction pathway calculations reveal that vacancy defects can remarkably lower the reaction barrier for O2 dissociation. More importantly, we propose a unique bioxidation mechanism in the presence of the double vacancy, resulting in the ultralow reaction barrier only 0.26 eV, which matches the rapid degradation of phosphorene in experiments. In addition, oxidation reaction can also impact on charged vacancy defects, providing a possible mechanism to explain the decrease of p-type doping and modest increased band gap. This work ...