Effects of imidazole additive on the performance of perovskite solar cells
To passivate the defects in perovskite films and improve the quality of the films,imidazole(IM)was added to the perovskite precursor.The perovskite films were prepared by spin-coating method.The morphology,structure and properties of the perovskite films were characterized by X-ray photoelectron spectrometer,scanning electron microscope,X-ray diffractometer,ultraviolet-visible spectrophotometer and steady-transient fluorescence lifetime spectrometer.The results show that IM is both Lewis acidic and Lewis basic,can effectively regulate the growth of perovskite crystals,increase the grain size of perovskite,and improve the quality of perovskite films.IM can also simultaneously form complexation with uncoordinated Pb2+and I-in perovskite,and collaboratively passivate Pb2+and I??defects at the film surface and grain boundaries.The photoelectric conversion efficiency(PCE)of the IM-modified cell device increases from 15.43%to 17.02%.The high-quality perovskite films with large grain size and low density of defect states effectively block the invasion of water molecules and improve the stability of the battery device.The successful preparation of high quality perovskite films with low defects based on the IM additive provides theoretical guidance for the commercial production of perovskite solar cells.
imidazoleadditiveperovskite solar celldefect passivationphotoelectric performanceperovskite films