CsPbI2.69Br0.31 solar cells from low-temperature fabrication
A low-temperature one-step solution process for the preparation of cesium lead iodide perovskite solar cells (PSCs) was developed by adding hydrobromic acid (HBr) into the precursor solution. CsPbI2.69Br0.31 was confirmed as the best structure, with a bandgap of 1.75 eV. A 9.58% power conversion efficiency (PCE) was achieved, which is the highest for PEDOT:PSS-based inorganic perovskite solar cells. The device efficiency decreased by 4% after being stored in N2 for 1200 hours.