Perovskite Solar Cells Based On Planar Heterojunction Structure

In recent years,perovskite materials based on methylammonium lead iodide CH₃NH₃PbI₃ was investigated enthusiastically due to its excellent optical absorption and charge transfer ability.In this paper,we focus the research on the preparation of perovskite film and planar heterojunction solar cells.The specific contents are as follows.1?The preparation of CH₃NH₃PbI₃ perovskite film.Scanning electron microscopy?SEM?and X-ray diffraction?XRD?methods were used to investigate the spin coating,concentration and spin speed on the morphology of the CH₃NH₃PbI₃ films.It is found that two-step spin-coating method is better than one-step spin-coating method.When the concentration of PbI₂ and CH₃NH₃I solution are 462 mg/mL and 38 mg/mL,the spin speed is controlled to 6000 r/20 s,CH₃NH₃PbI₃ perovskite thin films exhibit the best morphology.2?The research of CH₃NH₃PbI₃ /PCBM planar heterojunction solar cells.We demonstrate the solar cell of ITO/PEDOT:PSS/CH₃NH₃PbI₃ /PCBM/LiF/Al structure.CH₃NH₃PbI₃ thin film was prepared by two step spin coating method and the photoelectric properties of the different thickness PCBM layer and LiF layer were investigated.when PCBM and LiF thickness were 80 nm and 0.6 nm,device demonstrates the best photovoltaic performance with short-circuit current of 10.74 mA/cm²,open-circuit voltage of 0.71 V,fill factor of 0.48 and power conversion efficiency?PCE?of 3.64%.3?The research of CH₃NH₃PbI₃ /P3HT:PCBM structure solar cells.We first choose CH₃NH₃PbI₃ as an additive that added to P3HT: PCBM system to make organic solar cell with a structure of ITO/PEDOT:PSS/P3HT:PCBM:CH₃NH₃PbI₃ /Al.Compared with the traditional solar cell without additives,device with perovskite as the additives demonstrates improved short-circuit current.Besides,an integrated perovskite/organic bulk-heterojunction?BHJ?photovoltaic device for efficient light harvesting and energy conversion was fabracated.The solar cells structure consists of two photovoltaic layers,namely a CH₃NH₃PbI₃ and P3HT: PCBM organic BHJ active layer.PCE of 6.54% was achieved in the integrated device with a Jsc of 19.14 mA/cm2,a Voc of 0.76 V,and an FF of 45.0%.Compared to that of the CH₃NH₃PbI₃ /PCBM planar device,the enhanced performance indicates that the BHJ film absorbs light and contributes to the current density of the device.