Hydrophobic β-Carotene Passivation toward Efficient and Stable Perovskite Solar Cells
Abstract
Perovskite, as a synthetic functional material, has garnered significant research attention in recent years due to its exceptional optoelectronic properties and cost-effectiveness in photovoltaic applications. However, one of the most prominent challenges in practical applications remains the inadequate environmental stability of perovskite materials. This study aims to identify a natural, low-cost additive that can simultaneously enhance operational stability and passivate internal crystal defects, thereby improving photoelectric conversion efficiency. We successfully achieved this objective by utilizing β-carotene molecule. As a highly abundant and stable natural pigment, it offers notable cost advantages, exhibiting potent antioxidant effects and regulate perovskite energy level. Incorporation studies of β-carotene in tri-cation perovskite systems demonstrate its efficacy as a long-chain passivator, reducing crystalline defects and enhancing grain compactness. Current-voltage measurements reveal that β-carotene incorporation boosts the champion power conversion efficiency (PCE) of (CsFAMA)Pb(I/Br)3 perovskite solar cells from 20.49% to 23.38%, corresponding to a 14.1% relative enhancement. Moreover, its excellent antioxidant and moisture resistance properties ensure that the PCE remains above 89% of the initial value after exposure to environmental humidity for 500 hours. We report a natural pigment-based molecular modulator that concurrently addresses defect passivation and environmental protection, achieving simultaneously enhanced PCE and stability in high-performance perovskite photovoltaics.