Barium acetate as an additive for high performance perovskite solar cells

摘要

Defects within the halide perovskite films limit the efficiency and stability of perovskite solar cells (PSCs). Here, barium acetate (BaAc2) is employed as an additive in MAPbI(3) for high performance PSCs. The BaAc2 can control the crystallization and thus produce high-quality perovskite films, which is attributed to interaction between the acetate ions and perovskite precursor. Both low defect density and the movement of energy levels contribute to a significant increase in open circuit voltage (V-oc). Consequently, an efficiency up to 19.82% with a high V-oc of 1.13 V is obtained based on the optimized BaAc2 concentration device. Moreover, the compact perovskite crystal with suppression of ion migration endows the BaAc2 doped PSCs with obviously enhanced thermal stability. The device with BaAc2 additive maintained over 90% of its original power conversion efficiency (PCE) after thermal aging at 90 degrees C for 400 hours.