Green solvents processed all functional layers for efficient perovskite solar cells

Screening green solvents to prepare the functional layers in perovskite solar cells (PSCs) is important for the safety of manufacturers and the environment in the upcoming large-scale industrialization. The all-green solvent engineering of perovskite films aims to eliminate the toxicity that is caused by the traditional host solvent and anti-solvent. However, it still needs the highly toxic solvent of chlorobenzene (CB) to prepare the hole transportation layer (HTL) of spiro-OMeTAD films to achieve high-performance solar cells. In this work, we screened the green solvent of anisole to replace the highly toxic CB to prepare the spiro-OMeTAD films in typical solar cells. As a result, we achieved fully green solvents for the fabrication of all functional layers in the most attractive PSCs with a configuration of FTO/SnO2/(FAPbI3)0.95(MAPbBr3)0.05/spiro-OMeTAD/Au. The best solar cell delivers a power conversion efficiency (PCE) of 19.0%, which is comparable to the toxic CB processed HTL layer in PSCs. This work provides a candidate of choice to achieve fully green solvents for all functional layers in high-performance PSCs. Green solvent processing of all the functional layers in efficient solar cells.