Strain regulation by interface engineering in perovskite solar cells

Abstract Perovskite solar cells (PSCs) have garnered attention for their high efficiency and low production costs. However, long-term operational stability remains a significant challenge due to strain-induced degradation that impacts the structural integrity and performance of the perovskite layer. Strain, arising from factors such as lattice mismatch between layers, thermal expansion during fabrication, and external mechanical forces, can induce structural defects, accelerate ion migration and further reduce the operational lifespan of devices. Research has shown that strategies such as doping, additive engineering, optimization of annealing processes, and interface modification can effectively relieve the residual strain produced in the fabrication process of perovskite film, thereby enhancing the overall performance of the device. Among them, interface engineering has proven to be a key strategy for regulating strain and accordingly enhancing device stability. This article provides a comprehensive overview of recent advances in interface engineering approaches aimed at strain regulation in PSCs. The role of interface design with strain regulation in enhancing crystallinity, reducing defect density, and improving long-term performance is discussed in details, offering insights into future strategies for improving the stability and efficiency of perovskite-based photovoltaic devices.