Perovskite solar cells with a performance exceeding 20% with benzoic acid-assisted green anti-solvent

Emerging solar cells, perovskite solar cells (PSCs), promises the world community green energy at a reasonable price. However, more research is needed to improve their efficiency and sustainability. Improving carrier mobilities of the formamidinium triiodide (FAPbI3) perovskite layer is one of the state-of-the-art strategies to increase the photovoltaic performance of PSCs. Here, we employed this strategy thanks to the benzoic acid additive for anisole anti-solvent. Our findings indicate that the benzoic acid improves the crystalline properties of the FAPbI3 photoactive layer, and consequently, the nonradiative recombination is effectively suppressed. The benzoic acid-based PSCs show improved carrier mobilities due to improved interfacial charge extraction and facilitated charge transfer. The acid-treated devices record a maximum efficiency of 22.44% with a reduced hysteresis, while the control devices obtain an efficiency of 19.34%. moreover, the acid-modified PSCs show improved stability behavior against humidity and sun illumination, which paves the way for the PSCs' commercialization.