Tunable resistivity of correlated VO(A) and VO(B) via tungsten doping.

Applications of correlated vanadium dioxides VO(A) and VO(B) in electrical devices are limited due to the lack of effective methods for tuning their fundamental properties. We find that the resistivity of VO(A) and VO(B) is widely tunable by doping them with tungsten ions. When x < 0.1 in VWO(A), the resistivity decreases drastically by four orders of magnitude with increasing x, while that of VWO(B) shows the opposite behaviour. Using spectroscopic ellipsometry and X-ray photoemission spectroscopy, we propose that correlation effects are modulated by either chemical-strain-induced redistribution of V-V distances or electron-doping-induced band filling in VWO(A), while electron scattering induced by disorder plays a more dominant role in VWO(B). The tunable resistivity makes correlated VO(A) and VO(B) appealing for next-generation electronic devices.