Low-temperature and facile solution-processed two-dimensional TiS2 as an effective electron transport layer for UV-stable planar perovskite solar cells

摘要

Charge transport layers (CTLs) play a great role in achieving highly efficient and stable perovskite solar cells (PSCs). Recently, two-dimensional (2D) materials with high mobility have been proved to be good candidates for CTLs in PSCs. Here, 2D-TiS2 nanosheets are prepared by a simple solution exfoliation method. It is demonstrated that 2D-TiS2 can be applied as an effective electron transport layer in planar PSCs for the first time. Using TiS2 films prepared from solution with an optimized concentration, PSCs show a high power conversion efficiency (PCE) of 17.37%. Benefiting from the merits of solution processability, low temperature, high mobility and suitable energy level, the proposed TiS2 fabrication method could aid the scalable production of PSCs with high efficiency and excellent UV stability. Moreover, such a facile and low-temperature film retreatment approach guarantees the application of TiS2 as an ETL in flexible devices.