Orientated crystallization of MAPbI3 using template method for efficient and stable solar cells

The utilization of solar energy has put forward higher requirements for scale application of perovskite solar cells (PSCs), which is subject to the device stability and efficiency. Here, we introduce a pretreatment strategy, spincoating a solution of organic halide salt ethylenediamine dihydroiodide (EDAI2) on MAPbI3 film before annealing, which indicates that EDAI2 can promote the templated growth of MAPbI3 crystals by restraining the number of the complex intermediate phase, and achieved a highly crystallized MAPbI3 film with a preferred orientation along the (110) plane and reduced trap density. Consequently, the EDAI2-treated MAPbI3 PSC achieved an improved efficiency of 20.01 % from an authentic test. Meanwhile, the EDAI2-treated device established excellent stability and maintained over 93 % of the original efficiency for long-term operation both in thermal and humidity conditions.