TiO2/Mg-SnO2 nanoparticle composite compact layer for enhancing the performance of perovskite solar cells

Abstract

As an important part of perovskite solar cells (PSCs), the compact electron transport layer largely determines the performance of devices. Titanium dioxide (TiO2) and tin dioxide (SnO2) are very common materials for the electron transport layer (ETL) in PSCs. However, less has been reported regarding the development of high efficiency mesoporous PSCs based on a SnO2 compact layer. Herein, we prepared Mg doped modified SnO2 film at high temperature, combined it with TiO2 to form a composite compact layer, and then applied PSCs with the mesoporous structure. Compared with the pristine SnO2 compact layer, the composite compact layer has excellent interface contact with perovskite and higher electronic extraction capacity. Moreover, the defect free contact between TiO2 and FTO provides stronger hole blocking ability. Devices based on composite compact layers have almost no hysteresis effect. With the composite compact layer, the devices achieved a champion PCE of 13.01%, which is a 9.79% increase compared to the pristine SnO2 compact layer device.