Improvement of The Performance of Planar Heterojunction Perovskite Solar Cells by Using Pyridine as Additive

An efficient one-step solution method was demonstrated to prepare CH3NH3PbI3 perovskite solar cells by adding pyridine to the precursor solution. The film morphology, crystallinity, and optical properties of CH3NH3PbI3 perovskite films were investigated by SEM, AFM, XRD, UV-Vis and PL. The results show that the perovskite film properties (coverage of perovskite films and surface morphology) can be manipulated by incorporating a small amount of pyridine. The adding of pyridine is helpful to obtain a smooth, continuous and dense morphology. With the optimized pyridine volume fraction of 1%, the power conversion efficiency of 7.33% with Jsc of 14.64 mA/cm2, Voc of 0.82 V, and FF of 0.61 is obtained for the planar device structure. By contrast, the power conversion efficiency of the device without pyridine is only 1.01%. However, the further increase of the content of pyridine can result in the decomposition of perovskite, because the pyridine can easily form complexes with perovskite and induce the perovskite dissociation. © 2017, Science Press. All right reserved.