Synthesis And Performance Research Of Polymer And Porphyrin Small Molecule Donor Materials Based On BDT

The development of human society is accompanied by a large amount of energy consumption.In order to solve the current energy crisis,mankind urgently needs to develop a clean energy to replace traditional fossil energy.As an ideal clean energy,solar energy has huge development prospects.How to efficiently use solar energy has become one of the global research hotspots.Organic solar cell is a device that converts solar energy into electric energy through photovoltaic materials.Because of its light weight,flexible material,easy processing,and low cost,it has attracted widespread attention from related researchers in academia and industry.Active layer materials include donor materials and acceptor materials.Which are a key component of organic solar cells,they play an important role in improving the photoelectric performance of organic solar cells(OSCs).This article mainly focuses on the synthesis and performance research of organic solar cell donor materials.The main contents are as follows:(1)Three D-?-A polymer donor materials(J52Cl-H,J52Cl-Cl and J52Cl-F)were designed and synthesized using BDT as electron donor unit,3-chlorothiophene as?bridge and BTz as acceptor unit.We explored the effects of introducing chlorine atoms on the?bridge and the substitution of different heteroatoms in the side chain on the molecular photophysical properties,thermal stability properties,electrochemical properties,surface morphology,and photovoltaic performance.Studies have shown that the introduction of chlorine atoms into the polymer backbone can reduce the HOMO energy level of the molecule,thereby helping to increase the V_ocof the photovoltaic device.We have obtained the optimal device test conditions by changing the mixing ratio of the acceptor material,the type of additives,the spin coating speed and the thermal annealing conditions,etc.The reverse photovoltaic device based on J52Cl-H:IT4F PCE reached 10.41%and the corresponding V_oc,J_scand FF are 0.97 V,18.13 m A cm^-2,59.45%,respectively.The reverse photovoltaic device based on J52Cl-F:ITIC has the PCE of 5.90%and the corresponding V_oc,J_scand FF are 0.87 V,12.80 m A cm^-2,52.94%,respectively.The reverse photovoltaic device based on J52Cl-Cl:IT4F reached the PCE of 6.72%and the corresponding V_oc,J_scand FF are 0.88V,13.85 m A cm^-2and 54.92%,respectively.(2)The organic small molecule solar cell donor material was designed and synthesized with triarylamine porphyrin as the donor unit and diketopyrrolopyrrole(DPP)as the acceptor unit.The main work includes introducing Zn into the triarylamine porphyrin through zinc acetate as the central metal,and then introducing an alkyne bond to the triarylamine zinc porphyrin.The purpose is to improve the degree of molecular planarization and at the same time improve the charge transport.Then we tested the photophysical properties,electrochemical properties and photovoltaic properties of the target products.The work in this chapter provides relevant experience and ideas for subsequent researchers to design high-performance photovoltaic materials based on this type of compound.According to the photovoltaic performance test,the device based on the target molecule has J_sc=1.72 m A cm^-2,V_oc=0.21 V,FF=34%,and PCE=0.13%.(3)Two DPP acceptor units modified by halogen and two cyanoketone acceptor units modified by thienyl were designed and synthesized.Finally,we carried out structural characterization of the molecules to provide some experience and ideas for further enriching solar cell materials.