Investigation Of All Inorganic CsPbIBr₂ Perovskite Planar Heterojunction Solar Cells

In recent years,the research on perovskite solar cells has a swift development,the record power conversion efficiency（PCE）of the Organic-inorganic hybrid halide perovskite solar cells has soared to 24.2% in 2019.However,for its further commercialization,the defect is the intrinsic instability of hybrid perovskite.Aiming at this issue,the concept of all-inorganic perovskite has obtained intensive attention.Replacing the organic anions by inorganic anions can improve the inferior stability under enviroment stresses.The investigation for thin film charactristic and the device performance on all-inorganic perovskite solar cells in recent has been more widely and deeply,however,comparing with hybird perovskite and single-crystal silicon solar cells,the difference of power conversion efficiency is still obvious.Meanwhile,the high deposition temperature of all-inorganic perovskite thin films（³00 °C）will induce the extra energy consumption and not be suitable for the commercial application.Therefore,the investigation is focus on the CsPbIBr₂ inorganic pervoskite material employing carbon-based all inorganic planar heterojunction solar cells structure.Through using some facile thin film processing method to improve film quality,a promotion of the performance of solar cells has been realized,and the low temperature device processing has a preliminary exploration.1)The fabrication process of the CsPbIBr₂ inorganic pervoskite thin film was explored,employing the sample one step solution method to prepare stable CsPbIBr₂ pervoskite thin films.The all inorganic planar heterojunction solar cells with the studied films was fabricated in the conventional structure.The performance of CsPbIBr₂ solar cells with no treatment is comparable to the average performance of the cells with same materials at that time.The power conversion efficiency is about 4.85%.2)Furthermore,through intermolecular exchange strategy in one-step solution method to realizing the high quality CsPbIBr₂ thin films,the obtained carbon-based all-inorganic perovskite solar cells fulfiled a PCE improvement over 60%,up to 9.16%.The performance parameters,such as open circuit voltage and fill factor,showed a promotion as well.The power conversion efficiency represents the optimum value for CsPbIBr₂ planer structure when the article was published.3)Light processing method was proposed for the preparation of full-coverage,high crystallinity CsPbIBr₂ thin films which possess excellent photoelectric characteristics.The photovoltage of corresponding devices was remarkly incresaed,thus yields a high open circuit voltage value of 1.283 V.Meanwhile,the short circuit photocurrent density and the fill factor are 11.17 m A/cm2 and 0.66 respectively,resulting in PCE of 8.60%.4)Preliminary study on low temperature preparation of all-Inorganic CsPbIBr₂ Solar Cells has been achieved.After employing the aged precursor solution method,the thin film annealing temperature will reduce to 100 °C,which can reduce the process cost and slightly improve the device performance.