Solvent selection for highly reproducible carbon-based mixed-cation hybrid lead halide perovskite solar cells via adduct approach.

• One step solution-processed Cs 0.1 FA 0.9 PbI 3 deposition method for carbon-based PSCs. • More industrially acceptable eco-friendly solvent, DMSO via adduct approach. • High stability with no discernible decrease in efficiency for 1800 h under ambient. • Cs 0.1 FA 0.9 PbI 3 perovskite in carbon based devices exemplifies great potential of PSC. The major problem identified in carbon-based mixed cation perovskite solar cells (PSCs) is the selection of a suitable solvent for single-step solution-processed perovskite deposition in order to promote their scalable production. Herein we report a detailed study on the selection of appropriate solvent for the one-step deposition of cesium-formamidinium lead iodide (Cs 0.1 FA 0.9 PbI 3) perovskite via Lewis acid-base adduct approach for fully printable mesoporous PSCs with mesoporous TiO 2 /ZrO 2 /C architecture. Highly reproducible Cs 0.1 FA 0.9 PbI 3 solar cells were fabricated via adducts of PbI 2 with eco-friendly dimethyl sulfoxide (DMSO). The best cells fabricated with the above approach yielded a photoconversion efficiency (PCE) of 12.33% for a small area device (active area: 0.09 cm2) and 10.1% for a large area device (active area 0.7cm2). The average power conversion efficiency for 62 PSCs was found to be 10.5% under an AM 1.5G illumination. Finally, the mixed cation perovskite in carbon architecture using the Lewis acid-base adduct approach is remarkably stable, with less than 1% change from the initial PCE after 1800h of storage under dark ambient conditions (25 °C, 60–70% RH). [ABSTRACT FROM AUTHOR]