Reduced trap-density and boosted performance of CH₃NH₃PbI₃ solar cells by 1-Pentanethiol enhanced anti-solvent washing route

Abstract

Performance and the stability of the perovskite-based photovoltaic devices are directly linked to existing trap-states or defect profiles at the surface and/or in the bulk of perovskite layers. Hence identification of stemming the defects during perovskite formation is crucial for achieving superior and long-lasting performances. Here, we present the effect of 1-Pentanethiol incorporation into the one-step deposition of perovskite layers. A feasible glove box-free route results in high-quality CH3NH3PbI3 layers under highly humid conditions (RH > 50 %) but at low temperatures (T < 18°C). 1-Pentanethiol addition into the washing solvent leads to the refinement of I/Pb stoichiometry, elimination of the iodide deficiencies, and reduction of the trap-state densities. Consequently, a precise amount 1-Pentanethiol addition enhances photovoltaic performances, resulting in a 54 % PCE improvement for CH3NH3PbI3-based inverted solar cells.