Electron transport improvement of perovskite solar cells via intercalation of Na doped TiO2 from metal-organic framework MIL-125(Ti)

Abstract In this study, Na doped TiO2 (Na-TiO2) was successfully prepared using metal–organic framework (MIL-125(Ti)) as precursor. Then, the as-prepared Na-TiO2 was inserted into the interlayer between the electron transport layers and perovskite layer. As a result, the interface contact between layers has been improved effectively, leading to the enhancement of optoelectronic performance of perovskite solar cells. Compared with the traditional device, the Na-TiO2 decorated device exhibited higher quality perovskite layer with lower trap state density, higher conductivity, and better electron’s extraction and transmission. Power conversion efficiency of solar cell increased form pristine device of 17.21 % to 20.49 % with excellent reproducibility under 100 mW·cm2 illumination. The result illustrated a novel and facile method for promoting the performance of PSCs.