摘要:本实验以2,7-双（4,4,5,5-四甲基-1,3,2-二氧杂硼烷-二基）-9,9-二辛基芴、4,7-二溴-2,1,3-苯并噻二唑、端基为溴的聚合度为7的己基噻吩齐聚物等原料，通过Suzuki偶合反应合成了D-A型嵌段共聚物。所得共聚物的数均分子量在5000-10000之间。通过紫外吸收光谱对共聚物进行表征，发现共聚物的最大吸收峰在波长为400-500nm，同时随着苯并噻二唑的比例的增加，最大吸收峰逐渐红移。由循环伏安曲线可以发现共聚物的能带隙较窄，且随着苯并噻二唑比例的增加，共聚物从既有空穴传输又有电子传输逐渐变为电子传输。在热稳定性方面，聚合物的最大分解区间为400-500°C，在此区间内，共聚物失重为40%-50%，且随着苯并噻二唑比例增大，其热稳定性有所降低。同时，我们探究共聚物在太阳能电池中的应用，发现共聚物薄膜在光照下产生了明显的光电流。
关键词：噻吩苯并噻二唑嵌段共聚物，D-A型推拉电子结构的有机半导体，窄能带隙的聚合物太阳能电池
Abstract:The thiophene benzothiadiazole block copolymers were synthesized by using 2,7-bis(4,4,5,5-tetramethyl-1,3,2-dioxoborane-diyl)-9,9-diotylfluorene,4,7-dibromo-2,1,3-benzothiadiazole and 3-hexylthiophene oligomers with the degree of 7. The block copolymers were prepared by Suzuki coupling reaction. The number average molecular weights of the copolymers were between 5000-10000. The copolymers were characterized by ultraviolet and visible spectrophotometer. The maximum absorption peaks were at the wavelength of about 400-500nm. With the increase in the propotion of benzothiadiazole , the maximum absorption peaks were redshifted. The bandgaps of the polymers calculated via the cyclic voltammetry curves of the copolymers were narrow. With the increase in the propotion of benzothiadiazole , the copolymers gradually turned from both hole transportion and electron transportion into electron transportion. The maximum decompositions in the thermal stability of the copolymers ranged from 400°C to 500°C. In this range, the weight loss of the copolymers were from 40%-50%. With the increase in the propotion of benzothiadiazole , the thermal stabilities of the polymers were decreased. The application in solar cells was explored and the photo current was found when the copolymer material film was irradiated.
Keywords：Thiophene benzothiadiazole block copolymer, D-A organic semiconductors, Polymer solar cells of narrow bandgap
