On the possibility of p-type SnO2

Abstract
SnO2 is an abundant, low cost, natively n-type, wide band gap oxide, which can achieve high conductivities due to facile donor doping. Realization of a p-type SnO2 would, however, open up many new avenues in device applications, and has become a major research goal. Previous experimental and theoretical studies have proved inconclusive, with the p-type ability of SnO2 being both supported and questioned in equal measure. In this study we use state of the art hybrid density functional theory to investigate the nature of intrinsic and extrinsic p-type defects in SnO2. We demonstrate that all the p-type defects considered in SnO2 produce localized hole polarons centered on anion sites. We calculate the thermodynamic ionization energies of these defects, and demonstrate that an efficient p-type SnO2 is not achievable.