Optimizating TiO2 electron transport layer for MAPbBr3 perovskite solar cells by way of Ga doping

The exceptional electron transport performance and high stability of titanium dioxide (TiO 2 ) make it widely used in the electron transport layer (ETL). However, the presence of numerous surface defects in TiO 2 layer can lead to unnecessary non-radiative recombination, which reduces carrier mobility and affects the photoelectric conversion efficiency (PCE) of perovskite solar cells (PSCs). Therefore, tremendous researches have been focused on reducing surface defects and improving carrier mobility in TiO 2 layer. In this study, we adopted metal gallium (Ga) with high conductivity at room temperature as an optimization strategy to enhance the performance of TiO 2 layer. By incorporating metal Ga into the TiO 2 precursor solution, we successfully fabricated a TiO 2 -Ga layer that exhibits reduced surface defects and optimized energy level structure. This provides an efficient pathway for electron transport in perovskite layer. Experimental results demonstrate that (methyl ammonium lead tribromide) MAPbBr 3 perovskite solar cell devices based on TiO 2 -Ga layer achieve nearly 24% higher PCE compared to those based on pure TiO 2 layer. This successful optimization strategy utilizing metal Ga offers novel insights and approaches for enhancing the performance of PSCs.