Effect of doping engineering in TiO2 electron transport layer on photovoltaic performance of perovskite solar cells

Abstract

Titanium dioxide (TiO2) is widely applied as an electron transport layer (ETL) in perovskite solar cells (PSCs) due to its remarkable potential ability of electron transfer and long-time stability in PSCs. However, the requirement of high annealing temperature and the existence of hysteresis effect in TiO2-based PSC devices hindered its future applicability in commercial photovoltaic. Recently, various new strategies such as the incorporation of interfacial layer between ETL and absorber, the development of multilayer ETLs, surface passivation, and doping of metal cations in TiO2 have significantly improved the device performance and long-term stability of PSC. Amongst, doping engineering in TiO2 ETL has received more attention due to improved charge transportation ability and elimination of hysteresis. Doping of new ions in ETL materials is the most efficient way to tailor the band structure and modulate the electron mobility. However, in most cases, the basic mechanisms of doping engineering in electron extracting materials are still lacking. The present featured article investigated the scientific requirement and challenges combined with doping engineering in TiO2 ETL.