SnO2-Based Interfacial Engineering towards Improved Perovskite Solar Cells

Interfacial engineering is of great concern in photovoltaic devices. Metal halide perovskite solar cells (PSCs) have garnered much attention due to their impressive development in power conversion efficiencies (PCEs). Benefiting from high electron mobility and good energy-level alignment with perovskite, aqueous SnO2 as an electron transport layer has been widely used in n-i-p perovskite solar cells. However, the interfacial engineering of an aqueous SnO2 layer on PSCs is still an obscure and confusing process. Herein, we proposed the preparation of n-i-p perovskite solar cells with different concentrations of SnO2 as electron transport layers and achieved optimized PCE with an efficiency of 20.27%. I Interfacial engineering with regard to the SnO2 layer is investigated by observing the surface morphology, space charge-limited current (SCLC) with the use of an electron-only device, and time-resolved photoluminescence (TRPL) of perovskite films.