Fabrication of high efficiency perovskite solar cells based on mesoporous TiO2 nanofibrous film under high humidity conditions

Highlights: • 1D TiO₂ nanofibrous film was prepared by electrospinning technique as mesoporous of PSCs. • PSCs were fabricated under ambient conditions even with a high humidity condition more than 40%. • The 1D TiO₂ nanofiber-based PSCs achieved a power conversion efficiency (PCE) about 11.6% compared with 7.5% whereas the 0D TiO₂ nanoparticle-based PSCs only has 7.5%. - Abstract: One-dimensional (1D) TiO₂ nanofibrous film with good morphology and electrical characteristics was prepared by electrospinning technique. And then perovskite solar cells (PSCs) were fabricated based on 2-μm-thick mesoporous TiO₂ nanofibrous film under ambient conditions even with a high humidity condition more than 40%. The devices show high power conversion efficiency (PCE) due to high porosity that is beneficial to the loading of CH₃NH₃PbI₃ perovskite layer. This high-porosity 1D TiO₂ nanofibrous film also acts as a protection layer which can enhance the moisture stability of CH₃NH₃PbI₃. As a result, conversion efficiency of 11.6% and short-circuit current density (J_sc) of 17.3 mA were achieved under 100 mW cm⁻² AM 1.5 G solar illumination. These two values are both higher than those of zero-dimensional (0D) TiO₂ nanoparticulate film-based devices.