Design,Synthesis And Application Of Wide Band-gap Double-cable Conjugated Polymers

Organic solar cells have the characteristics of light weight,wide material sources,low cost,flexibility,and large-area roll-to-roll production,which have good research value and broad application prospects.Single-component organic solar cells use a single component as a photosensitive layer,which effectively solves the self-aggregation problem of active layer in two-component cells from the perspective of materials.It is conducive to the improvement of the stability of organic photovoltaic devices.At present,the efficiency of single-component solar cells based on double-cable conjugated polymers has exceeded 8%,but there is still a certain gap compared with the two-component cells.Therefore,from the perspective of material structure design and synthesis,this paper seeks a new double-cable conjugated polymer structure that can improve the performance of single-component cells,and further studies the possibility of wide-bandgap double-cable conjugated polymers for indoor applications.The main research results are as follows:1.We designed and synthesized two novel double-cable conjugated polymers P1 and P2 through Click reaction between alkyne and azide groups.They own different chain lengths(C₆H₁₂-triazole and C₁₂H₂₄-triazole)and semi-flexible linker consisting of triazole units and alkyl chain.Compared with fully flexible aliphatic alkyl-linker,the introduction of semi-flexible chains enhances the crystallinity of conjugated polymers,which is favorable for the regular arrangement of polymers.The application of P1 and P2 into single-component organic solar cells showed photoelectric conversion efficiencies of 1.39%and2.03%,respectively.2.We designed and synthesized a new double-cable conjugated polymer PBDBNDI-4Cl by introducing two extra Cl atoms on the donor backbone.Compared with JP02,the introduction of highly electronegative Cl atoms lowered the HOMO energy level of PBDBNDI-4Cl.Applying this double-cable polymer to indoor single-component organic solar cells,a high open circuit voltage of 1 V and a photoelectric conversion efficiency of over 13%were achieved.The high open-circuit voltage proves the feasibility of single-component photovoltaic devices for application in indoor organic photovoltaics,which provides a new idea for the development of single-component indoor organic photovoltaic active layer materials.