Strain engineering improves the photovoltaic performance of carbon-based hole-transport-material free CsPbIBr₂ perovskite solar cells

Alkylamines with different chain lengths including n-butylamine, n-hexylamine, and n-octylamine, are applied to regulate the CsPbIBr2 perovskite film quality by strain engineering. The status of residual strains is controllably modulated, resulting in improved efficiency and stability of carbon-based hole-transport-material free CsPbIBr2 perovskite solar cells.