A-site FA+engineering boosting photoluminescence efficiency and stability of cesium copper iodine (Cs3Cu2I5) perovskites

Here, we firstly propose an A-site engineering strategy to improve the luminescence performance of Cs 3 Cu 2 I 5 . Through the incorporation of FA + , the lattice defects in Cs 3 Cu 2 I 5 can be reduced and the PLQY of the optimized sample is increased to 95%.