Preparation Of Organolead Halide Perovskite Films And Studies On Photoelectric Properties

Solar energy as a clean and new energy has been widely concerned,becoming the best alternative to fossil fuels.Photovoltaic power generation technology represented by solar cells has been commercialized.In recent years,the organic-inorganic hybrid perovskite solar cells in the third generation solar cells have been made a breakthrough progress.However,the research on perovskite solar cells is still in the initial stage,the film preparation repeatability rate is not high,the preparation process is not perfect,which will limit the development of photovoltaic industry to some extent.In this paper,the preparation methods and process parameters control of perovskite materials in solar cells are studied.The main research progress is as follows:Firstly,Pure iodine perovskite film materials were prepared by adjusting spin coating speed,adding antisolvent and two-step spin coating method.And the influence law of methylamine iodine solution with different concentrations on the film quality in the two-step method was discussed.CH₃NH₃PbI₃ perovskite films with higher crystallinity,higher absorption strength and fewer defects were obtained,and the photoelectric conversion efficiency was increased from 5.99%to 6.86%.The problem of aggregation and contraction of the perovskite film in the traditional preparation method is effectively solved,So that the preparation repeatability of the pure iodine perovskite film is improved.Secondly,a stable CH₃NH₃PbI_3-xBr_x doped perovskite film was prepared by introducing methylbromide into the precursor solution of pure iodine perovskite.The physical and chemical changes of CH₃NH₃PbI_3-xBr_x perovskite films were studied with the molar ratio of CH₃NH₃I to CH₃NH₃Br changing.With the increase of CH₃NH₃Br content,the quality of perovskite doped films increases gradually and the diffraction peak shifts to some extent.The effects of different doping perovskite materials on the photoelectric properties were discussed.The photoelectric conversion efficiency of the perovskite-type doped films prepared under the proper proportion reaches 8.6%.At the same time,the stability of CH₃NH₃PbI₃ and CH₃NH₃PbI_3-xBr_x in battery performance was compared.The results show that the efficiency of perovskite-type batteries doped with bromine can be reduced to less than 1%after a longer time,which proving that the stability of perovskite doped with bromine is better than that of pure iodine perovskite.