Electron-enriched thione enables strong Pb–S interaction for stabilizing high quality CsPbI 3 perovskite films with low-temperature processing

摘要: Cesium lead iodide (CsPbI3) perovskite is a promising photovoltaic material with suitable bandgap and high thermal stability. However, it involves complicated phase transitions, black-phase CsPbI3 mostly formed stabilized at temperatures (200–360 °C), making its practical application challenging. Here, for the first time, we have demonstrated feasible route growing quality thin films under mild conditions by using neutral molecular additive of 4(1H)-pyridinethione (4-PT). The resulting are morphologically uniform stable ambient conditions, consisting micron-sized grains oriented crystal stacking. With range characterization experiments on intermolecular interactions, electron-enriched thione group in 4-PT distinguished to be critical enabling strong Pb–S interaction, which not only influences crystallization paths, but also stabilizes CsPbI3via surface functionalization. based achieves 13.88% power conversion efficiency p–i–n structured device architecture, encapsulated devices can retain over 85% their initial efficiencies after 20 days storage an environment, best results among fully low-temperature processed photovoltaics.