Perovskite Oxide SrTiO₃ as an Efficient Electron Transporter for Hybrid Perovskite Solar Cells

In this work, we explored perovskite oxide SrTiO 3 (STO) for the first time as the electron-transporting layer in organolead trihalide perovskite solar cells. The steady-state photoluminescence (PL) quenching and transient absorption experiments revealed efficient photoelectron transfer from CH 3 NH 3 PbI 3– x Cl x to STO. Perovskite solar cells with meso -STO exhibit an open circuit voltage of 1.01 V, which is 25% higher than the value of 0.81 V achieved in the control device with the conventional meso -TiO 2 . In addition, an increase of 17% in the fill factor was achieved by tailoring the thickness of the meso -STO layer. We found that the application of STO leads to uniform perovskite layers with large grains and complete surface coverage, leading to a high shunt resistance and improved performance. These findings suggest STO as a competitive candidate as electron transport material in organometal perovskite solar cells.