A low-cost green mixed antisolvent strategy for strain-release and defect-reduction toward efficient perovskite solar cells

Abstract

Antisolvent engineering is among the most widely used techniques for fabricating high-efficiency perovskite solar cells (PSCs). Recent mixed antisolvent strategies have shown great promise for enhancing the performance of PSCs. These approaches tailor the crystallization kinetics of perovskite films by utilizing solvents with complementary physicochemical properties. In this work, we develop a low-cost and environmentally benign mixed antisolvent system employing ethanol (EtOH) and tert-butanol (TBA). Remarkably, the content of only 5 vol. % TBA in the antisolvent mixture leads to a substantial efficiency improvement, elevating the power conversion efficiency from 21.8% (pure EtOH) to 24.1%, while also significantly enhancing device stability. Further analysis indicates that TBA incorporation effectively mitigates perovskite bulk lattice strain and facilitates pinhole-free grain growth, resulting in enhanced charge carrier mobility and suppressed non-radiative recombination. Our study highlights a simple, cost-effective, and green mixed antisolvent strategy for advancing high-performance PSCs toward practical photovoltaic applications.