Harmonizing Efficiency and Bending Performance in Flexible Perovskite Solar Cells through Annealing Duration Optimization

Abstract

Perovskite materials are promising candidates for flexible photovoltaic applications due to their high light absorption and low-temperature processability. However, achieving high-efficiency flexible perovskite solar cells (FPSCs) typically requires annealing the films for extended periods at elevated temperatures to enhance crystalline quality. This poses a challenge, as prolonged or high-temperature heating can cause deformation or cracking when using conventional flexible substrates for FPSCs. Overcoming the thermal instability of the substrate is essential for ensuring the high performance and stability of FPSCs. To address this issue, a feasible strategy to minimize the annealing duration is explored. The research unveils that a reduced annealing time of only 3 min can yield a perovskite film of comparable high quality to that achieved with conventional 15-minute annealing, leading to an optimized power conversion efficiency of 21.97%. Moreover, the shortened annealing duration significantly enhances the bending performance of FPSCs, enabling them to maintain 90% of the original efficiency even after undergoing 5000 bends with a radius of 5 mm. These findings offer a practical and straightforward pathway to harmonize the exceptional efficiency and resilience properties of FPSCs.