The Influence Of Fullerene Interlayer For Interface Engineering On Photovoltaic Performance Of Perovskite Solar Cells

Perovskite solar cells(PSCs)have been developed for high-efficiency,low cost and simply manufacturing of large-area.Various solution-processed interfaces have been developed to improve the photovoltaic performance of PSCs,which relying on development,rational design and optimization of abundant interface materials.The paper analyzed the key issues in flexible n-i-p PSCs based on related literature.Facile interfaces engineering for making TiO2/fullerene(C60 or C70)layers and influence of interfaces engineering on photoelectric properties of PSCs were reported,as follows:1.Herein,the C70 interlayer between TiO2 and(HC(NH2)2PbI3)x(CH3NH3PbC13)1-x is prepared by spin-coating and low-temperature annealing for planar n-i-p PSCs.The resultant TiO2/C70 ETLs shows good surface morphology,efficient electron extraction and facilitation of high-quality perovskite film formation,which can be attributed to the suitable nano-size and the superior electronic property of C70 molecules.In comparison with pristine TiO2-based PSCs,the efficiency and hysteresis index are respectively enhanced 28%and reduced 76%by adding C70 interlayer between TiO2 and perovskite on the basis of statistical data of more than 50 cells.With the main advantages of low-temperature process and optimized interface,the champion efficiency of PSCs on flexible substrates could exceed 12%in contrast with above 18%on rigid substrate.2.The facible interface engineering for making all-solution-processed TiO2/C60 layers in flexible n-i-p PSCs is reported.Due to the improvement of the perovskite grain quality,promotion of interfacial charge transfer and suppression of interfacial charge recombination,the stabilized PCE for the flexible PSCs reached as high as 16%with high bending resistance retention(～80 after 1500 cycles)and high light-soaking retention(～100%after 100 min).In addition,the stabilized PCE was over 19%for rigid the TiO2/C60-based PSCs.The facile low-temperature solution process renders the practicability for high-performance flexible PSCs applied to wearable devices and portable equipment.