Application Of Electrospun CuO Nanofibers In Perovskite Solar Cells

In recent years,perovskite materials have attracted more attention due to its high absorption coefficient.In only ten years,the photoelectric conversion efficiency has increased from 3.8%to 25.2%.In order to improve the photoelectric conversion efficiency of perovskite solar cells,most of the researchers focus on the control and optimization of the perovskite film(CH3NH3PbI3),but there is little research about the use of more stable inorganic metal compounds to optimize and modify the hole transport layer.In this paper,the optimal spinning parameters of the electrospun CuO nanofibers(CuO NFs)are discussed firstly,and then the CuO NFs prepared by electrospun is introduced into the hole transport layer as the anode buffer layer to modify the traditional PEDOT:PSS,so as to improve the ability of hole transport layer to extract and transport holes.Finally,Ag doped CuO NFs(Ag/CuO NFs)is introduced to further improve the extraction and transport ability of the composite hole transport layer.Main contents of the paper:(1)Electrospun and calcination of CuO primary fiber.Firstly,the effects of different spinning voltage,spinning speed,receiving distance and other parameters on the morphology of electrospun primary CuO NFs were investigated.The calcined fiber dimension and its substrate were measured by field emission scanning electron microscope(FE-SEM),X-ray diffraction(XRD)and UV-Vis spectrophotometer.It was found that when the spinning voltage was 14 kV,the receiving distance was 15 cm,and the spinning speed was 0.01 ml/min,the morphology of CuO primary fiber was the best.Then,the primary fiber obtained by this parameter is calcined at 450℃ in muffle furnace,and CuO NFs is obtained after annealing.When CuO NFs is used as anode buffer layer,the performance of the device can be improved obviously,and PCE can be increased to 10.4%under the test of 1.5M standard simulated solar light source.(2)Ag/CuO NFs was obtained by doping AgNO3 into the precursor solution of electrospinning and calcining at high temperature.Based on the electrospun CuO primary fiber,the Ag/CuO NFs was obtained by AgNO3 with different doping ratio.Field emission scanning electron microscopy(FE-SEM),X-ray diffraction(XRD)and ultraviolet visible spectro-photometer(UV-Vis)were used to test the calcined fiber and its substrate.The experimental results show that when the amount of AgNO3 is 0.03g,namely,when the mass ratio of CuNO3 to AgNO3 is 10:1,the morphology of the primary Ag/CuO NFs is the best,and the fiber after calcination is uniform in thickness and has good surface morphology.When Ag/CuO NFs is used as anode buffer layer,the performance of the device can be improved obviously.The PCE can be increased to 11.6%under 1.5M standard simulated solar light source test.(3)The cell modified by the above two optimal fibers with the optimal coverage as the anode buffer layer and the standard cell were placed for one month in the environment of 25℃ and 45-65%humidity.The open circuit voltage(Voc),short circuit current(Jsc),filling factor(FF)and photoelectric conversion efficiency(PCE)were measured at a time point of every five days.The conclusion is that compared with the traditional PEDOT:PSS layer modified by pure CuO NFs and unmodified by pure CuO NFs as the hole transport layer,the device using Ag doped CuO NFs as the anode buffer layer has improved the environmental stability,and the Voc,Jsc,FF and PCE have also been improved in different degrees,among which the conversion efficiency of the battery is 33%higher than that of the original perovskite solar cells.