A sintering-free, nanocrystalline tin oxide electron selective layer for organometal perovskite solar cells

Effective electron selective layer (ESL) is critical for the power conversion efficiency in organometal halide-based perovskite solar cells (PSCs). In this work, a spincoating process has been developed to fabricate high quality nanocrystalline SnO2 film at 100 degrees C without further sintering at higher temperature. When used as ESL in PSCs, such SnO2 film shows greater electron extraction ability and higher efficiency than TiO2 film processed under similar condition, as evidenced by the efficient time-resolved photoluminescence (TRPL) quenching SnO2/CH3NH3PbI3 film. As a result, the SnO2-based PSCs possess higher open circuit voltage of 0.91 V, short circuit current density of 20.73 mA cm(-2), and fill factor of 64.25%, corresponding to a conversion efficiency of 12.10%, compared with 7.16% of TiO2-based PSCs. This demonstrates the great potential of applying spin-coating sintering-free process for the low-cost and large-scale manufacturing of PSCs.