Synthesis Of New Cathode Interface Materials For Organic Solar Cells

Organic solar cells?OSCs?had become popular research fields in the field of organic optoelectronics and photovoltaics due to their low cost,good processing performance,diverse material structures,and large-area low-cost printing preparation..In order to achieve low-cost large-scale commercial application of OSCs,further research and exploration in materials?including active layer materials,interface layer materials,electrode materials,etc.?,device industry,and device life were required.In this thesis,a series of different types of water processable organic small molecular materials were designed and synthesized as cathode interfacial layers?CILs?,and their effects on the performance of organic solar cell devices were explored.The specific research content was as follows:?1?Three new non-conjugated organic small-molecule cathode interface materials?HDSID,SPSID,and STSID?containing nitrogen,oxygen,and silicon with zwitterionic components were designed and synthesized.The results shown that the performance of organic solar cells was improved,both in the classic fullerene(PTB7:PC₇₁BM)active layer system and the new non-fullerene?PM6:Y6?active layer system.The optimized device performance was mainly due to the significantly improved charge carrier transport and collection capabilities of the OSCs devices,the work function?WF?of the Al counter electrode was reduced,and the exciton recombination during charge transfer was effectively suppressed.Under 100mW/cm²?AM 1.5G?light,the PCE of the HDSID-modified PTB7:PC₇₁BM-based device was 8.96%,and the efficiency of OSCs based on PM6:Y6 was 15.57%.?2?Three ammonium salt-based ionic compounds SADBS,NDBS,and HSTD were synthesized based on the MSAPBS skeleton structure,and ionic compounds DBS were designed and synthesized based on the SAS skeleton structure.These ionic compounds were used as the cathode interface layer in organic solar cells.It was found that the performance of OSCs devices was improved when ionic compounds were used as the cathode interface modification layer.In particular,in the PTB7:PC₇₁BM system,the PCE of devices with HSTD as the cathode interface can reach 8.33%,the PCE of DBS-based devices can reach 8.48%,and in the PM6:Y6 system,devices with HSTD as the cathode interface the PCE can reach 14.60%,and the PCE of DBS-based devices can reach 14.34%.In this thesis,by studying the synthesis of water/alcohol-soluble organic small molecule cathode interface materials and their performance in organic solar cells,a series of small molecule cathode interface materials that can improve device efficiency and reduce battery manufacturing costs had been developed.It provides a new strategy for the commercialization of OSCs.