The Synthesis And Research On Structure-activity Relationship Of Triphenylamine-conjugated Bridge-rhodanine Small Molecule Donor Materials

In this thesis,using triphenylamine?DPTA?as donor?D?moiety and rhodanine?RD?as acceptor?A?unit,we keep the structure of the electron donor unit and the electron acceptor unit constant.A series of D-?-A small molecule donor materials were synthesized by introducing different types of conjugated?-bridges.The solar cell device was prepared by the structure of ITO/ZnO/Small Molecule:PC₆₁BM(or PC₇₁BM)/MoO₃/Ag.The photovoltaic performance of the device was characterized.According to the experimental results,the structure-activity relationship between donor molecules and photovoltaic devices constructed with D-?-A module is pointed out.The main contents include the followings:In chapter 2,one thiophene group,two thiophene group and three thiophene group were used as conjugated?-bridges,which were introduced between the DPTA unit and the RD unit.Three kinds of organic small molecule donor materials were designed and synthesized,namely 1T,2T and 3T.The 1T has the E_g of 2.06 eV and the E_HOMO/E_LUMOUMO of-5.13 eV/-3.07 eV.The theoretical calculation shows that the intramolecular charge transfer?ICT?state exciton binding energy?E_b?is 0.32 eV.The device(1T:PC₇₁BM=1:3)shows the PCE of1.21%,with the V_OCC of 0.73 V,J_SCC of 4.48 mA·cm^-22 and FF of 37.22%.The 2T shows the E_g of 1.93 eV,whose E_HOMO/E_LUMOUMO are-3.14 eV/-5.07 eV.The E_b is 0.29 eV.The device(2T:PC₇₁BM=1:3)PCE of 1.57%was obtained with the V_OCC of 0.69 V,J_SCC of 5.54 mA·cm^-2and FF of 41.09%.The 3T has the E_g of 1.85 eV,the E_HOMO/E_LUMOUMO of-5.05 eV/-3.20 eV and the E_b of 0.33 eV.The device(3T:PC₇₁BM=1:3)PCE is 0.98%with the V_OCC of 0.62 V,J_SCC of 3.82 mA·cm^-22 and FF of 41.72%.When the two thiophene groups are introduced into the molecule as the?-bridge,We have found that the separation of intramolecular exciton is the most advantageous and the photovoltaic performance of the molecule is optimal.In chapter 3,the thieno[3,2-b]thiophene?TT?group and thiophene?T?group positions were exchanged with each other funct as conjugate?-bridges,which were introduced between the DPTA unit and the RD unit.Two kinds of small organic molecules were obtained,namely T-RD and TT-RD,whose E_g are 1.92 eV and 1.88 eV,the E_HOMOOMO values are-5.26 eV and-5.19 eV,the E_LUMOUMO values are-3.34 eV and-3.31 eV,the E_b values are 0.33 eV and 0.32 eV,respectively.When the mass ratio of photoactive layer T-RD:PC₇₁BM is 1:3,the solar cell device has a PCE with a value of 1.40%,the V_OCC of 0.72 V,the J_SCC of 5.01 mA·cm^-22 and FF of 38.83%.When the mass ratio of TT-RD:PC₇₁BM is 1:3,the PCE value of the solar cell device is 1.70%,the V_OCC of 0.63 V,the J_SCC of 6.36 mA·cm^-22 and FF of 41.96%.By comparative analysis,when the TT group with a larger conjugate plane is closer to the electron acceptor unit,it was found that the photovoltaic performance of the molecule is better.In chapter 4,using different types of carbon single bond,thiophene group?T?and alkynyl?A?as conjugated?-bridges,three kinds of organic small molecule donor materials were designed and synthesized,namely DPR,TDPR and ADPR.The DPR has the E_g of 1.63 eV,the E_HOMO/E_LUMOUMO of-4.99 eV/-3.36 eV,the E_b of 0.20 eV.The device(DPR:PC₆₁BM=1:2)whose PCE was obtained with a value of 1.21%,the V_OCC of 0.72 V,J_SCC of 4.51 mA·cm^-2and FF of 32.81%.The TDPR has the E_g of 1.58 eV,the E_HOMO/E_LUMOUMO of-5.01 eV/-3.34 eV,the E_b of 0.17 eV.The device(TDPR:PC₆₁BM=1:2)whose PCE was obtained with a value of 1.29%,the V_OCC of 0.72 V,J_SCC of 5.24 mA·cm^-22 and FF of 34.13%.The ADPR has the E_g of 1.67 eV,the E_HOMO/E_LUMOUMO of-5.09 eV/-3.42 eV,the E_b of 0.18 eV.The device(ADPR:PC₆₁BM=1:1.5)shows the PCE of 1.20%,the V_OCC of 0.75 V,J_SCC of 4.81 mA·cm^-2and FF of 33.25%.Comparing the experimental data,when the thiophene group is introduced into the molecule as a conjugated?-bridge,it is found that the photovoltaic performance of the molecule is relatively good.In chapter 5,the anthracene?A?and[9,9']bianthracenyl?BA?were introduced between DPTA unit and RD unit,respectively.Two kinds of organic small molecules were designed and synthesized,namely AR and BAR.The values of E_g are 2.51 eV and 2.52 eV,the E_HOMOOMO are-5.15 eV and-5.12 eV,the E_LUMOUMO are-2.64 eV and-2.60 eV,respectively.The performance of photovoltaic devices based on two small molecules AR and BAR is for further study.