Design Of Cathode Interface Modification Materials For Organic Solar Cells And Study Of Doping Mechanis

Organic solar cells have attracted more and more attention due to a series of advantages such as light weight,solution processing and flexible translucent devices.However,there are still many problems to be solved to achieve the commercial application of organic solar cells.For example,printable and flexible large-scale preparation remain unresolved issues.Based on water/alcohol-soluble cathode interface material(CIM),n-doped modified CIM with high conductivity was developed and studied in this thesis,and its influence on the performance of photovoltaic devices was also studied:1.The high conductivity material graphene was dispersed into two water/alcohol soluble cathode interface material to study the modification mechanism and device performance of such doping.The device performance was studied by J-V curve,the conductivity was studied by space-charge limited current method,and the work function was studied by Kelvin probe.The characterization ESR and XPS results confirmed the n-doping of graphene by PDIN and NDIN.Using PM6:Y6 as active layer,PDIN-G and NDIN-G as cathode interface layer,the power conversion efficiency were improved to 16.56% and 14.4%,respectively.2.The graphene material was replaced with single-walled carbon nanotube(SWCNT)material.The doping modification of PDIN-CNT and NDIN-CNT was carried out,and proving that this doping mechanism have certain universality.SWCNT can be thought of as being made of graphene in curls and thus similar in properties to graphene.It was found that the PDIN-CNT and NDIN-CNT CIMs could optimize the device performance,and the power conversion efficiency were 17.19% and 14.84%,respectively.Moreover,n-doped PDIN-CNT and NDIN-CNT interface layers had high conductivity through characterization.