Synthesizing Li doped TiO2 electron transport layers for highly efficient planar perovskite solar cell

The electron transport layer (ETL) in planar perovskite solar cells (PSC) is a very important layer which extracts photo generated electrons. The performance of this layer depends significantly on its conductance, band energy and electrical trap density. In this study, doping the TiO2 layer is presented as a solution to decrease the solar power loss by increasing the ETL's conductance. The Li-doped TiO2 films have shown significantly improved characteristics by increasing conductivity and providing faster electron transport. The PSC structures were modeled using Solar Cell Capacitance Simulator (SCAPS) to study the effect of various Lithium contents on the efficiency of the PSCs. Key parameters for electrical modeling of planar PSCs were extracted from experimental analysis and reliable sources. A PSC consists of an ETL with 0.3 M Li doped TiO2 resulted a power conversion efficiency of 24.23% which demonstrated 1.97% improvement compared to the one without doping. Pursuant to capacitance-frequency analysis, the doped TiO2 was more conductive and showed lower trap-state density at the ETL/absorber interface compared to the pristine one.