Synthesis And Characterization Of Small Molecules And Side Chain Polymer Photovoltaic Materials Containing Porphyrin

With increasing demand for energy from human beings,fossil resources will eventually be exhausted due to inappropriate exploitation,during the process,carbon emissions would fetch environmental pollution.Organic photovoltaic batteries（OPV）have been found considerable with advantages of outstanding flexibility,remarkable plasticity,lighter weight,less environmental side-effect,lower cost.Porphyrin,pyrrolopyrroledione and fluorinated benzotriazole have been widely used in the structure design of photovoltaic materials due to their prominent photoelectric properties.In the second chapter,We synthesized two A-π-D-π-A molecules,SMD1 and SMD2,based on Zn-porphyrin as a donor moiety linked through 4-Octyl-4H-dithieno[3,2-b:2’,3’-d]pyrrole or 4,4-di-2-ethylhexyl-dithieno[3,2-b:2’,3’-d]silole with3-ethyl rhodanine acceptor group.The decomposition temperatures is 388oC and392oC for SMD1 and SMD2,respectively.The onset wavelength in film is 892 and833 nm for SMD1 and SMD2,respectively.The optical band-gap is 1.39 and 1.48 eV for SMD1 and SMD2,respectively.SMD1 has wider and stronger light absorption than SMD2 in the film state.The electrochemical band-gap of the two molecules is1.55 and 1.59 eV for SMD1 and SMD2,respectively.In the third chapter,We synthesized a compound S-Por.The porphyrin side chain polymers（P1 and P2）were synthesized by Still coupling with S-Por,TT and BDT.The decomposition temperatures is 338oC and 400oC for P1 and P2,respectively.The onset wavelength in film is 832 and 788 nm for P1 and P2,respectively.The optical band-gap is 1.49 and 1.57 eV for P1 and P2,respectively.Compared with the absorption of P1,P2 exhibits an absorption peak with a peak value of about 460 nm due to the increase of S-Por.The OSCs based on P1:PC71BM achieved the highest PCE of 5.83%with a V_oc of 0.85 V and a J_sc of 13.25 mAcm^-2.The OSCs based on P1:PC₇₁BM achieved the highest PCE of 5.83%with a V_oc of 0.87 V and a J_sc of12.08 mAcm^-2.In the fourth chapter,We synthesized a molecule SMD3,based on Zn-porphyrin as a donor moiety linked through difluorinated benzotriazole with pyrrolo-pyrroledione acceptor unit.The decomposition temperature of SMD3 is 305℃.It has a broad absorption spectrum reaching the near-infrared region with an optical band-gap of 1.41 eV and an electrochemical band-gap of 1.73 eV.The device based on the SMD3:ITIC only achieved PCE of 0.71%.