Abstract
Recently, reported perovskite solar cells (PSCs) with high power conversion efficiency (PCE) are mostly based on mesoporous structures containing mesoporous titanium oxide (TiO 2 ) which is the main factor to reduce the overall hysteresis. However, existing fabrication approaches for mesoporous TiO 2 generally require a high temperature (>450 °C) annealing process. Moreover, there is still plenty of scope for improvement in terms of increasing the electron conductivity and reducing the carrier recombination. Herein, a facile one-step, in situ and low-temperature method was developed to prepare an Nb:TiO 2 compact-mesoporous layer to serve as both a scaffold and an electron transport layer (ETL) in PSCs. The Nb:TiO 2 compact-mesoporous layer based PSCs exhibit suppressed hysteresis, which is attributed to the synergistic effect of the large interface surface area caused by nano-pin morphology on the surface and the improved carrier transportation caused by the presence of Nb. Such a high-quality compact-mesoporous layer allows the PSC achieve a remarkable PCE of 19.74%. This work promises an effective approach for creating hysteresis-less and high-efficiency PSCs based on compact-mesoporous structures with lower energy consumption and cost.
In-situ formed and low-temperature deposited Nb: TiO2 compact-mesoporous layer for hysteresis-less perovskite solar cells with high performance
