SnO2 electron transport layer modified with gentian violet for perovskite solar cells with enhanced performance

Interface engineering is a feasible strategy to passivate the defects located at both the surfaces and grain boundaries of the perovskite films. In this work, gentian violet, which is composited of a positive charged amine group and a negative charged Cl− ion, is selected to engineer the MAPbI3/SnO2 interface. The gentian violet modified SnO2 film can enhance the crystallinity of the subsequently deposited MAPbI3 perovskite film, at the same time, due to the effective defect passivation capability of the gentian violent, the trap density of the perovskite film is suppressed. Therefore, the target perovskite solar cell has shown a maximum performance of 20.03% after tuning the concentration of gentian violet.