Research On Photoanode And Photoelectric Properties Of Flexible Perovskite Solar Cells At Low Temperature

Due to the wide application prospect for wearable devices and flexible electronics and rapid development of perovskite solar cells（PSCs）,flexible PSCs have been attracting more and more attention in recent years.Today,the flexible PSCs still have a very big gap compared with the rigid PSCs,it’s the poor ability of tolerance temperature of flexible polymer substrate that limit compact layer needing a high temperature process to applying in flexible device and hinder the improvement of photovoltaic conversion efficiency（PCE）.To obtain high efficient flexible PSCs,most researchers focus on the research of high performance compact layer,studying kinds of preparation methods and new materials,but bringing high cost.Thus,this paper pays attention to low cost for high efficient flexible PSCs at low temperature,firstly,ionic liquid interface modifying ZnO in a low temperature is used to regulate the performance of flexible PSCs;then the effect of SnS₂ prepared by vacuum room temperature deposition on flexible device was studied,and the detailed analysis:IL-BF₄ ionic liquid were used to modified the interface of ZnO,It can be seen in water contact angle and AFM that the surface wettability of the ZnO increases and the roughness decreases due to IL-BF₄ modification,which is favorable to the high quality and uniform growth of PbI₂ films.There are higher conversion rate for PbI₂ to MAPbI₃ with more crystalline,observed in the XRD results.After modification,the SEM exhibits larger MAPbI₃ grain size,so the absorbance of MAPbI₃ gets stronger and devices have a higher light capture efficiency;Carrier transport capacity of ZnO increased significantly,it can be verified from carriers mobility and transient fluorescence spectra measuring carrier lifetime;Carrier recombination rate of the device is reduced,as shown in the steady state PL（Photoluminescence）and EIS;Based on PET/ITO/ZnO/IL-BF₄ layer/MAPbI₃/Spiro-OMeTAD/Au structure,the flexible devices showed optimal photoelectric performance,average PCE increased to 12.1%from 8.59%,and the forward and reverse scan curve show a lower hysteresis effect,and a good durability of flexible device is displayed in the resistance to bending experiments.SnS₂ thin film was deposited on the PEN/ITO substrate by room temperature vacuum deposition technology,and MAPbI₃ layer was prepared used one step method,this paper study the influence of thickness SnS₂ thin film on photoelectric performance of the flexible PSCs.The band structure of SnS₂ was determined by ultraviolet visible absorption spectrum and ultraviolet photoelectron spectroscopy,the results indicate SnS₂ as compact layer has a good energy level matching in the flexible PSC.The room temperature vacuum deposition realizes a high crystalline SnS₂,it can be seen from XRD and XPS test results;SEM demonstrates that SnS₂ have a dense and uniform surface.flexible devices based on 60 nm SnS₂ show an highest photovoltaic efficiency 13.2%,FF is 0.601,J_SC is 21.7 mA cm^-2,V_OCC is 1.011 V.