Preparation And Modification Of Inverted Structured Perovskite Solar Cell Devices

Perovskite materials have attracted much attention in recent years as optical absorption layer of perovskite solar cells due to their wide optical absorption range,long carrier migration distance,low exciton binding energy and bipolarity,CH3NH3PbI3(MAPbI3)has been widely studied as an optical absorrption layer because of its excellent photoelectric properties and carrier migration properti.es.In this study,lead acetate(Pb(CH3COO)2)was used as raw material to prepare MAPbI3 perovskite layer with excellent performance,and perovskite solar cell devices with glass/ITO/PEDOT:PSS/MAPbI3PCBM/BCP/Al structure were further prepared.By testing the photoelectric properties of the devices,the optimal parameters of preparation process were obtained.On this basis,the perovskite solar cell devices were modified from the perspective of improving the efficiency and stability of the device.Urea was added to perovskite precursor solution,and the effects of different urea content on device performance and the effects of urea addition on film growth mechanism were studied.Secondly,the Cul buffer layer is inserted between the hole transport layer and perovskite layer to study the effect of Cul buffer layer insertion on the device performance.The results are as follows:(1)Perovskite thin film,s were prepared by using lead acetate as aw material,and perovskite solar cell devices were further prepared.Tthe best parameters of preparation process were obtained,the optimal lead excess molar ratio of perovskite precursor solution is 5%,and the optimal annealing temperature is 80?.Under this condition,the device prepared has achieved photoelectric conversion efficiency(PCE)of more than p15%.(2)Urea additives with different molar ratios were added into perovskite precursor solution,and the optimal preparation process of perovskite layer with urea addition was studied.The test results show that t.he optimal annealing time of perovskite layer inereases with the increase of urea content.The results show that the orientation of characteristic peaks of perovskite phase is enhanced by the addition of urea.Moreover,the addition of urea forms a intermediate phase with the precursor solution,which slows the crystallization of perovskite phase,promotes its uniform nucleation and improves the quality of the film.Therefore,the PCE of samples with urea addition is improved.When the molar ratio of urea is 0.5%,the PCE of the device reached 16.91%,which is 13%higher than that of the sample without urea.(3)The properties of CuI film prepared with different concentration of CuI precursor solution were studied.When the concentration of CuI precursor solution was 20mg/mL,the prepared Cul films had better film-forming properties.Perovskite solar cell devices with Cul buffer layer also achieved good performance with PCE of 16.77%,and the PCE maintained 80%of the maximum value after two hours of illumination.It indicated that the stability of perovskite solar cell devices with CuI buffer layer is obviously improved.