Morphology controlled (CH3NH3)3Bi2Cl9 thin film for lead free perovskite solar cell

Traditional perovskite solar cells have made tremendous progress in terms of efficiency in the past few years but the presence of toxic lead (Pb) has restricted their commercialization. We report here a process to fabricate MABiCl perovskite thin film based solar cell. The process shows some intriguing outcomes like uniform surface morphology of the perovskite layer, high open-circuit voltage and good fill-factor. The film shows improved uniform morphology and surface coverage with flakes (dimension 570 nm x 360 nm, thickness similar to 100-200 nm. The solar cell device shows an open-circuit voltage of about 496 mV and a fill factor 0.55. The improved morphology of the perovskite layer with reduced number of defects and charge traps possibly decreases the probability of recombination of photoexcited charge carriers. The result indicates that the process can be a good alternative to prepare lead free perovskite solar cells with improved performance.