Interfacial Dipoles Boost Open-Circuit Voltage of Tin Halide Perovskite Solar Cells

Tin halide perovskites are promising materials for real-world photovoltaic applications, and there is large room for their performance to grow. We improved energy-level alignment between the perovskite and electron transport layers by introducing 4-fluorophenethylamine hydrobromide as an interfacial dipole. Thus, the open-circuit voltage of FASnI(3) solar cells increased to 0.974 V and their power conversion efficiency reached 15.7%, representing a significant advance in this field.