The Investigation Of Novel Charge Transport Material And Crystallization Dynamics On Perovskite Solar Cell

One of the most intensively investigated materials in recent years has been organic-inorganic hybrid halogen perovskite.The easily tuned optical properties by ion substitution determine its wild application in different optoelectronic devices.Recently,the organic-inorganic halide lead hybrid perovskite solar cells have been achieved great breakthrough showing the documented power conversion efficiency?PCE?of 22.1%,the certified high efficiency perovskite solar cells are achieved with mesoporous and planar structures.Along with the remarkable performance of perovskite solar cells,researchers commit to promote its industrialization,and the focus of future research hotplots is to explore novel charge transport materials and the perovskite crystallisation dynamics.In this paper,the familiar devices based on TiO₂ mesoporous has been achieved the highest efficiency of 14.3%,by optimizing the preparation process of perovskite film and the thickness of the compact layer.Moreover,the charge recombination behavior in the standard device is analyzed by multi light intensity experiment.A novel hole transport metarial BT-BMeT with 10 thiophenes is applied in mesoporous devices,which can get the efficiency of 7% without doping.The analysises of the rectification and dark current curves show that the performance of the optimized BT-BMeT device has a super hole transport ability than the undoped Spiro-OMeTAD device.Compared with the doped Spiro-OMeTAD,the monochromatic incident photon-to-electron conversion efficiency and electrochemical impedance spectrum elaborate on the results that more internal charge recombination restricts the efficiency of the undoped BT-BMeT device.In addition,as for the representative planar perovskite solar cell,the morphology of perovskite film and the efficiency of related devices were optimized by adjusting the precursor concentration and spinning speed.It shows that the grain size and crystallinity are enhanced by the increase of the concentration and speed.After optimization,the efficiency of the chlorine doped perovskite solar cell prepared by the anti-solvent drenching method was improved from 12% to 16%.Besides,the repeatability is improved effectively with an average efficiency of 15.29±0.62%.The results of X-ray diffraction spectra,as well as the calculation of crystal size and lattice parameters,show that the increase of concentration and speed slow down the crystallisation process of facet?002?/?004?to enlarge the crystal size.The reduction of defect states of perovskite film was detected by the transient absorption spectroscopy and electrochemical impedance spectrum,which leads to the enhancement of device efficiency.