An efficient post-treatment strategy with acetylacetone for low temperature CsPbI2Br solar cells

All inorganic perovskite solar cells (PSCs) have been demonstrated to get tremendous interest recently owing to their better thermal stability. Nevertheless, some CsPbI 2 Br films prepared at low temperature have lower quality compared to those annealing at high temperature. Herein, to obtain high performance PSCs, a simple post-treatment strategy is presented by spin coating acetylacetone (AA) solution on the CsPbI 2 Br films. The AA treatment can reduce the density traps on the CsPbI 2 Br films surface and enlarge the size of grains, resulting in enhanced performance PSCs. After optimizing surface treatment, the devices based on low-temperature-processed CsPbI 2 Br with AA treatment achieved a power conversion efficiency (PCE) of 14.43%. The better CsPbI 2 Br films quality and interface contact of hole transport layer (HTL)/CsPbI 2 Br result in better device stability. Therefore, it could be a promising post treatment method for enhancing the performance of PSCs by introducing AA on the perovskite surface.