La2/3Sr1/3VO3 Thin Films: A New p-Type Transparent Conducting Oxide with Very High Figure of Merit

Transparent conducting oxides (TCOs) are a unique series of materials combining electrical conductivity with optical transparency. Most of the commercially available TCOs are of the n-type. The performance of p-type TCOs, however, is far behind their n-type TCO counterparts primarily due to the doping bottleneck and low hole mobility. Herein, a Mott-Hubbard insulator of LaVO3 is proposed as the starting point for exploring p-type TCOs. Substitution of La3+ by Sr2+ can introduce high hole carrier concentration at the top of the valence band to overcome the doping bottleneck. Combining a modest carrier mobility with weak absorption in the visible region, La1-xSrxVO3 compounds can serve as new p-type TCOs and exhibit good balance of the tradeoffs between electrical conductivity and optical transparency. It is demonstrated that La2/3Sr1/3VO3 thin films exhibit a high conductivity of 742.3-872.3 S cm(-1) at room temperature and a high transmission of 53.9-70.1% in the visible region, which leads to the highest figure of merit among p-type TCOs so far.