Strategic Optimization of Annealing Parameters for Efficient and Low Hysteresis Triple Cation Perovskite Solar Cell

Abstract The highly efficient perovskite solar cells (PSCs) are often developed with a hybrid metal halide perovskite material as the absorber layer. Particularly, cesium (Cs) containing triple cation perovskites (CsFAMA) have emerged as prospective absorber materials owing to their high reproducibility and superior reliability. Mostly, the perovskite thin films preparation involves thermal annealing as a post‐treatment technique strongly dependent on the perovskite materials. By optimizing the parameters for thermal annealing temperature and annealing time, the fabrication of economical perovskite devices is achievable. Herein, we strategically investigated the influence of annealing time by keeping a constant annealing temperature on the growth of triple‐cation perovskite thin films and solar cells. We observed the formation of highly crystallized perovskite thin films with efficient photovoltaic performance for the heating time of just 10 min at 120 °C. Further, the perovskite devices with optimized annealing temperature and time exhibited low hysteresis index might be attributed to reduced trap states owing to improved grain size and crystallinity of CsFAMA thin films. Reduced heating time is desirable and beneficial in the industrial fabrication of photovoltaic devices.