Tailoring methyl-ammonium lead bromide nanostructure by solvent engineering and their application to high open circuit voltage solar cells

Methyl-ammonium lead bromide (MAPbBr3) perovskite films were fabricated by two-step deposition process. We used two common organic solvents, N, N-Dimethylformamide and Dimethyl sulfoxide (DMSO), which is commonly used to fabricate lead halide films. In this work, we used these solvents in both steps of the spin coating process to fabricate nanostructured MAPbBr3 perovskite films. When DMF was employed; a uniform, dense, compact sub-micron size perovskite nanocube arrays perovskite film was observed. However, when DMSO was employed; nanorod and microplate perovskite films were observed. In contrast to conventional two-step spinning processing, this process has better well organized and submicron size nanocrystals. The best performing device employing MAPbBr3 micro/nano-cubes active layer (using DMF) has a power conversion efficiency of (PCE) of 5.88% and the best performing device employing MAPbBr3 nanorods/microplates active layer (using DMSO) has a PCE of 4.22%. This finding will help the researcher to fabricate well-organized nanocube/nanorods/microplate-array based perovskite solar cells.