Antisolvent additive engineering containing green additive for efficient and stable perovskite solar cells

The efficiency of the perovskite layer generally determines the performance of perovskite solar cells (PSCs). Perovskite solar cells (PSCs) depend highly on the layer's morphology, crystalline structure, and surface defect of their power conversion efficiency (PCE), and long-term stability. Introducing appropriate solvent additives to the perovskite precursor solution effectively controls the film structure, defect passivation, and grain boundaries. In this work, alcohols such as isopropyl alcohol (IPA), ethanol, and methanol (a nontoxic, sustainable, and low-cost alcohol) are used as green solvent additives to enhance the quality and morphology of perovskite films and to control nonradiative recombination in the PSCs. The alcohol adducts containing OH groups have interacted with organic cations and Pb ions to produce PbO, which reduces the concentration of halide vacancies, enhances charge transfer, and decreases nonradiative recombination. Alcohol additives can produce homogeneous, highly crystalline perovskite films with improved charge transfer and reduced recombination. Using the best alcohol additive, IPA, provides power conversion efficiency (PCE) of 20.41% and greater ambient air stability, as it keeps more than 82% of its original PCE after 1000 h. Furthermore, IPA additive-based PSCs retain 81% and 80% of their original efficiencies after 500 and 350 h of continuous light irradiation and heating at 85 °C.