Tailoring electrical property of the low-temperature processed SnO2 for high-performance perovskite solar cells

Herein, we for the first time doped NW5+ into the low-temperature (<100 degrees C) SnO2 sol-gel route to tailor the electrical property of SnO2 layers and the band alignment between SnO2 and the normally used mixed perovskites. The results revealed that proper NW5+ doping increased the conductivity of the SnO2 electron transport layer (ETL), and the conduction band (CB) level of the SnO2 ETL was shifted down to approach the CB level of perovskites, which facilitated the electron injection from perovskite to SnO2, accelerated the charge transport, and reduced the non-radiative recombination, leading to improved power conversion efficiency from 18.06% to 19.38%. The NW5+ doping process provided an efficient route for fabricating high-efficiency perovskite solar cells (PSCs) at a temperature lower than 100 degrees C, and promoted the commercialization progress of PSCs.