Enhanced performance of planar perovskite solar cells using Ce-doped TiO 2 as electron transport layer

Electron transport layer plays a key role in improving charge extraction efficiency and inhibiting electron–hole recombination in perovskite solar cells. In this study, Ce ion was doped into compact TiO 2 layer to improve electron transport performance of TiO 2 thin film. Through UV–Vis and UPS tests, it was found that TiO 2 obtained an appropriate band position after Ce ions doping. Specially speaking, Ce-doped TiO 2 band position facilitates electron transport at the interface. As a result, the device based on 0.009 M Ce-TiO 2 shows the power conversion efficiency is 16.18%, which is 5.75% higher than the device without Ce ions doping. In this work, we provided a new method to improve the electron extraction rate of TiO 2 thin film, which is beneficial for performance of the devices.