Doping Modification Of Polymer Electrodes And Its Application In Photovoltaic Devices

Perovskite/organic solar cells(PVSCs/OSCs)have become a hot research field due to its low cost,light weight,rich raw materials and other advantages.Transparent conductive electrodes are one of the key components in solar cells,which have a significant impact on energy conversion efficiency,mechanical performance,and cost.Indium tin oxide(ITO)is a traditional transparent conductive electrode with good conductivity and transparency.However,ITO has problems such as high cost,complex preparation,and poor mechanical flexibility,which limit its application in flexible solar cells.The conductive polymer poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate(PEDOT:PSS)can be prepared in solution,and after doping treatment,it can achieve high conductivity,becoming one of the ideal transparent conductive electrodes for preparing PVSCs/OSCs.Although traditional acid treatment methods can improve the conductivity of PEDOT:PSS electrodes,they are difficult to penetrate into the bottom layer of the electrodes,affecting the overall conductivity.In addition,strong acid treatments such as sulfuric acid immersion can corrode plastic substrates,making it difficult to prepare flexible PEDOT:PSS electrodes,thereby affecting the photovoltaic and mechanical properties of devices.In this paper,layer-by-layer(LBL)codoping method,acid atomization method and high work function molecular surface modification method are mainly used to improve the conductivity,work function and stability of polymer electrodes,and the high efficient PVSCs/OSCs based on PEDOT:PSS electrodes are successfully prepared.The specific research ideas and results are as follows:1.The PVSCs with a structure of PEDOT:PSS/P3CTN/CH3NH3PbI3/PCBM/C60/BCP/Ag have been fabricated by immersing the PEDOT:PSS electrodes in a diluted methanesulfonic acid.Using poly(3-(4methylaminocarboxyl)thiophene)(P3CT-N)instead of conventional PEDOT:PSS as the anode buffer layers can improve hole transport and reduce interface energy losses,thereby improving the photovoltaic performance of PVSCs.It is found that the sheet resistance of the modified PEDOT:PSS electrodes is 62 Ω sq-1,and their transmittance exceeded 88%in the wavelength range of 380-800 nm by experiments.In addition,the surface work function of the modified PEDOT:PSS electrodes is-5.11 eV,which improves the energy level adaptation between the electrodes and the calcium titanium layers.Finally,the developed PVSCs display a power conversion efficiency(PCE)of 13.13%.2.The inverted OSCs with a structure of PEDOT:PSS/ZnO/PM6:Y6/MoO3/Ag have been fabricated using PEDOT:PSS as the anodes,the conductivity of which is improved by treating PEDOT:PSS films with trifluoromethanesulfonic acid vapor at low temperature.The performances of the OSCs are enhanced by substituting acid vapor treatment for conventional acid dipping treatment,which avoids corrosion of the plastic substrates,improves the smoothness and uniformity of PEDOT:PSS thin films and promotes charge carrier transfer and collection.Thus,the optimized OSCs display a PCE of 11.49%.3.The normal OSCs with a structure of PEDOT:PSS/PEDOT:PSS(P VP AI4083)/PM6:Y6/ZnO/PEDOT:PSS have been fabricated by using PEDOT:PSS as the upper and lower electrodes.We first develop a unique LBL H2SO4/EG co-doping method to make the high-merit PEDOT:PSS anodes.The polymeric anodes exhibit a record-high FoM of 100 and an electrical conductivity of 4200 S cm-1,due to the large removal of insulating PSS in the whole matrices(involving the rear sides)and the fine phase separation without large-domain aggregates.The vacuum-free,all-solution and all-air processed OSCs yield 11.12%efficiency with a fill factor of 72.5%and most(≈91%)of the initial efficiency are maintained after the storage for 30 days.