Design,Synthesis And Performance Study Of Photovoltaic Cells Based On N-Annulated Perylene Bisimides

In recent years,solar cells have attracted widespread attention as clean photovoltaic devices.Among them,organic solar cells have many advantages that inorganic solar cells do not have,such as light weight,flexibility,translucent and the possibility of roll-to-roll large-area fabrication.In the past four decades,the photoelectric conversion mechanism of organic solar cells has been deeply studied,which promotes the continuous progress of organic photovoltaic materials in material design and device preparation.However,compared with inorganic solar cells,organic solar cells still have many factors that restrict their industrial development,such as low device open-circuit voltage caused by energy loss,which makes it difficult for organic photovoltaics to achieve high photoelectric conversion efficiency.To address this problem,this thesis designs new acceptor materials based on structurally improved perylene diimide acceptor units,and applies them to single-component and binary organic solar cells,and explores the potential application value of new perylene diimide acceptors in organic solar cells.The specific research contents are as follows:1.In this work,a novel acceptor unit with a deep LUMO energy level was designed and synthesized,which named N-fused perylene diimide（PNR）and incorporated into double-cable polymers.In terms of molecular design,we connected PNR laterally to the donor backbone PBDB-T-Cl,and synthesized two double-cable single-component polymers with symmetric and asymmetric structural features,respectively named as s-PPNR and as-PPNR.After optimizing the device performance,both polymers achieved high voltages over 1.17 V by reducing V_loss,and compared with s-PPNR,as-PPNR showed an efficiency of 5.05%,which was 3.34%higher.To investigate the reasons for the performance difference of the two wide-bandgap single-component solar cells,we used various physical characterization methods to conduct in-depth analysis.In this study,the voltages of s-PPNR and as-PPNR both exceeded those of the reported double-cable polymer single-component solar cells,providing new insights for the development of single-component solar cells in indoor light and other application fields.2.In this work,the performance of the modified perylene diimide acceptor PNR was further studied.We added PNR and PBI as the third components to the binary solar cells based on PM6 as the donor and BTP-BO-4Cl as the acceptor,constructing novel ternary solar cells.After optimizing the device parameters,we found that the ternary solar cell device with 0.1 ratio of PNR achieved an efficiency of 17.50%,which was higher than that of the binary structure of 17.02%,while the ternary solar cell device with 0.1 ratio of PBI only had an efficiency of 16.39%.To reveal the mechanism of how different perylene diimide acceptors affect the solar cell performance,we used various physical characterization methods to conduct detailed analysis.In this study,the introduction of modified perylene diimide not only provided new ideas for the material design of ternary solar cells,but also offered new pathways for the high-performance development of ternary solar cells.