Large-Area Organic-Free Perovskite Solar Cells with High Thermal Stability

Abstract

Organic-free perovskite solar cells (PSCs) with all inorganic functional layers have been considered as the most promising candidate for achieving long-term stability. Here, we demonstrate the first organic-free PSC consisted of inorganic CsPbI2Br perovskite, nickel oxide hole transport layer, and niobium oxide electron transport layer. The as-fabricated organic-free PSC exhibits a maximum PCE of 11.20% with a large active area of 5 cm2. The PCE is increased to 14.11% with smaller area and retains above 98% of its initial value after being stored in nitrogen atmosphere for 30 days. More importantly, the organic-free PSCs show excellent thermal stability with PCE remained above 98% of its initial value after being heated at 100 °C for 150 min. The high thermal stability of the device makes it possible to conduct post-annealing to further increase its maximum PCE to 14.45%, which is the highest among any reported all-inorganic PSCs with p-i-n structure. The enhanced performance of the post-annealed device is ascribed to the decreased trap-state density and improved interface charge transfer properties of the device. These results demonstrated that this novel organic-free device architecture can be employed to fabricate efficient and stable PSCs for large-scale manufacturing.