Synthesis And Photovoltaic Performance Of Organic Donor Materials Based On Porphyrin

Porphyrin-based compounds often have strong absorption capacity,excellent thermal stability and high electron mobility,which make small molecules or polymers based on porphyrin attract more and more attention in organic solar cells(OSCs).This dissertation briefly reviews the research progress of porphyrin compounds in OSCs for many years,as well as the design ideas in molecular structure.By considering the solubility,absorption spectra,energy level matching,carrier mobility and the morphology of the blend films,we designed and synthesized two small molecule donors and a polymer donor based on porphyrin.The synthesized intermediate compounds and the final target molecules were characterized by nuclear magnetic resonance spectroscopy,time of flight mass spectrometry and gel permeation chromatography.The main contents of this dissertation are as follows:(1)Designed and synthesized two A-?-D-?-A type small molecule donors based on porphyrin(name as Por-RD and Por-EC),which with zinc porphyrin as the core,thiophene as the?-bridge,and 3-ethylrhodanine or 2-ehylhexyl cyanoacetate as the terminal groups,respectively.The effects of two different terminal groups on optical properties,electrochemical properties,carrier mobility,blend film morphology and photovoltaic performance were systematically studied.The research results show that the Por-RD with rhodanine end group exhibits wider and stronger absorption,more suitable energy level,higher and more balanced mobility and good phase morphology.After adding 1%pyridine and annealing with THF,the device based on Por-RD:PC₇₁BM showed the best PCE value of 4.87%,J_sc of 11.53 m A cm^-2,V_oc of0.90 V,and FF of 46.85%.(2)Designed and synthesized a polymer donor P(Por-BDD)based on porphyrin and benzodithiophene dione(BDD),and systematically studied its optical properties,electrochemical properties and photovoltaic performance.The research results showed that P(Por-BDD)had good absorption in the 400-850 nm.After being prepared into a binary organic solar cell with PC₇₁BM,it exhibited a PCE of 5.53%.Subsequently,we added the P(Por-BDD)as the third component to the PM6:PC71BM system to supplement the spectrum and increase the J_sc.Finally,after adding 1%DIO,the PCE value was 7.89%,and the J_sc value was effectively increased.