Design,Synthesis And Properties Of Photoactive Additives Based On Divinylthiophene

In recent years,with serious energy shortage and environmental pollution,it is urgent to develop new energy.Organic solar cells（OSCs）have become an important direction in development and utilization of new energy due to their advantages,such as cleanliness,low cost,available raw materials,and flexibility for large-area preparation.This dissertation mainly introduces the development of fullerence-OSCs and non-fullerence-OSCs,as well as the additions used in photoactive layer and their application in OSCs.In order to solve the key problems about power conversion efficiency（PCE）and stability of OSCs,a series of solid additives based on divinyl-thiophene were designed and synthesized.Their molecular structures were characterized well.And their opto-physical,electrochemical and thermal properties,charge mobilities were studied.The effects of hydronge bond andπ-πstacking on photoelectric performance were futher studied.The main research contents are as follows:（1）A series of A_H-D-A_H-type solid additives with double N-H bonds,2H-TR、2H-TC6R、2H-TCi8R and 2H-TOC8R,using divinyl-thiophene or its derivatives as donor（D）unit,and rhodanine as acceptor（A_H）unit,were designed and synthesized.The effect of solid additives with double N-H bonds on active layer morphology was systematically investigated.The polymer solar cells（PSCs）were made using poly[4,8-bis（5-（2-ethylhexyl）thiophene-2-yl）benzo[1,2-b;4,5-b’]dithiophene-2,6-diyl-alt-（4-（2-ethylhexyl）-3-fluorothieno[3,4-b]thiophene）-2-carboxylate2-6-diyl]（PTB7-T h）as donor material and[6,6]-phenyl-C₆₀-butyricacid methyl ester(PC₆₀BM)as acceptor material.The effect of solid additives with double N-H bonds on photovoltaic performance was studied.It is found that adding 1.0 wt%solid additives into PTB7-Th/PC₆₀BM blends can increase external quantum efficiency（EQE）for the resulting blends.Different types of solid additives are added and different effects of improving EQE could be achieved.The PTB7-Th/PC₆₀BM/2H-TOC8R based device exhibited the best photoelectric properties.The highest PCE is 7.18%with an open circuit voltage(V_oc)of 0.80 V,short-circuit current(J_sc)of 12.94 m A cm^-2 and a fill factor（FF）of 69.55%.The PCE value is enhanced by 19.9%in comparison with that in the device without solid additives.（2）A series of A_H-D-A-type solid additives of H-TRC6,H-TRC8 with a single N-H bond and A-D-A-type solid additives of 2C-TRC6,2C-TRC8 without N-H bond based on divinyl-thiophene unit（D）and rhodanine unit（A_H）,were designed and synthesized.The effect of solid additives on active-layer morphology was systematically investigated.The PSC_S were made using poly[（2,6-（4,8-bis（5-（2-ethylh exyl）thiophen-2-yl）benzo[1,2-b:4,5-b’]dithiophene））-alt-（5,5-（1’,3’-di-2-thienyl-5’,7’bis（2-ethylhexyl）benzo[1’,2’-c:4’,5’-c’]dithiophene-4,8-dione））]（PBDB-T）as donor material and PC₆₀BM as acceptor material.It was found that PBDB-T/PC₆₀BM/H-TR C8 based device exhibited better photoelectric properties.And the PCE is 8.06%with V_oc of 0.87 V,J_sc of 12.78 m A cm^-2and FF of 72.23%.The PCE value is enhanced by20.6%in comparison with that in the device without solid additives.（3）A series of A-D-A-type solid additives of 2C-TD,2C-TO and 2C-TO8 using divinyl-thiophene or its derivatives as donor（D）unit,5-methoxy-1,3-indandione as acceptor（A）units,were designed and synthesized.The effect of this type of additives on the morphology were systematically investigated.The PSCs were made using PBDB-T as donor material and 3,9-bis（2-methylene（3-（1,1-dicyanomethylene）-indano ne））-5,5,11,11-tetrakis（4hexylphenyl）-dithieno[2,3-d:2’,3’-d’]-s-indaceno[1,2-b:5,6-b]dithiophene)（ITIC）as acceptor material.It was found that PBDB-T/ITIC/2C-TO based device exhibited a higher FF of 68.71%,which is enhanced by 6.9%in comparison with that in the device without solid additives.