Synergistic Interface Layer Optimization and Surface Passivation with Fluorocarbon Molecules toward Efficient and Stable Inverted Planar Perovskite Solar Cells

摘要

Large-size organic halide passivation has been considered an efficient approach to enhance the perovskite solar cell (PSC) efficiency and stability.Herein,a facile posttreatment strategy was demonstrated,wherein trifluoromethyl-phenethylamine hydrobromide(CF3-PEABr) is firstly used to passivate the perovskite film surface.The CF3-PEABr surface posttreatment could coordinate with halide dangling bonds that exist at the perovskite crystal surface.Moreover,the surface treatment with CF3-PEABr could efficiently passivate the defects in the perovskite film and suppress the nonradiative carrier recombination.As a result,a high efficiency of 21.3％ is obtained,and an increment of 80 mV in Voc (a large Voc of 1.15 V,with a 0.42 V voltage deficit) occurs,compared to the control device.To relieve the hydrophobic nature properties of the-CF3 functional group and the dewetting problem of PCBM layer deposition,a surfactant Triton X-100 is used to modify the PCBM layer.Furthermore,the devices with CF3-PEABr posttreatment exhibit better operational,thermal (85℃),and long storage stabilities without any encapsulation.