Study On Optimization And Mechanism Of High-Performance Perovskite Solar Cells Based On Doping Technique

With the rapid rise of third-generation solar cells,perovskite solar cells have become one of the brightest new stars.Since 2009,its conversion efficiency has increased from 3.9%to22.1%in a short period of several years,and it has achieved a feat that other batteries cannot accomplish.But it still has a lot of room for improvement.Therefore,how to improve the preparation conditions and optimize the cell structure to improve its photoelectric conversion efficiency is still an important issue in the research field of perovskite solar cells.In this paper,the basic perovskite solar cell is firstly prepared by optimizing the basic preparation conditions,which provides a reference for its optimization.Secondly,the perovskite layer is optimized by introducing NMP into the perovskite precursor solution.And analyzed its influence mechanism from various aspects.Finally,the use of Bphen:Cs₂CO₃:BCP layer as the cathode interface modification layer of the PSCs effectively reduced the charge recombination and improved the electron extraction,thereby improving the device performance.In the second chapter,using ITO/PEDOT:PSS/CH₃NH₃PbI₃/PCBM/BCP/Ag as the PSCs structure,the basic perovskite solar cells were effectively obtained by optimizing the preparation conditions.the PEC of the device reaches 10.29%with a open circuit voltage(V_OC)0.856V,short circuit current density(J_SC)16.52mA.cm² and fill factor?FF?72.8%.Whereafter a simple and effective method was adopted to improve the quality of perovskite films by adding N-methyl-2-pyrrolidone?NMP?to perovskite precursors solution.Comparison and analysis of the effect of different ratios of NMP on film formation performance.It has been found that the optimal addition amount of NMP can help to form a more uniform and dense perovskite layer which can effectively improve the light absorption capacity of the perovskite layer and reduce the charge recombination and perovskite layer defects.It is beneficial to create a more optimized planar structure perovskite solar cell.Compared with the untreated perovskite solar cell,the conversion efficiency is increased by 27.11%.In the third chapter,we used the Bphen:Cs₂CO₃:BCP layer as an interfacial modification layer for perovskite?CH₃NH₃Pb I₃?/PCBM and Ag electrodes.The energy level of Bphen film can be modified by effective doping of Cs₂CO₃ and BCP,which can effectively improve electron extraction and reduce carrier recombination,and further obtain higher V_OC.The optimized planar structure perovskite solar cell has a power conversion efficiency?PCE?of16.93%,which is higher than that of the undoped Bphen?12.97%?reference device.