电子受体强度对基于Thieno[3,2-b]thiophene的共轭聚合物电子性质的影响  

The effects of electron-acceptor strength on the electronic properties of thieno[3,2-b] thiophene-based donor-acceptor copolymers

作　　者：傅杨武 陈明君 周胡来 张洁 冉娟 FU Yang-Wu;CHEN Ming-Jun;ZHOU Hu-Lai;ZHANG Jie;RAN Juan(School of Environmental ＆ Chemisty Engineering,Chongqing Three Gorges University,Chongqing 404020,China)

机构地区：[1]重庆三峡学院环境与化学工程学院,重庆404020

出　　处：《四川大学学报（自然科学版）》2018年第6期1275-1281,共7页Journal of Sichuan University(Natural Science Edition)

基　　金：国家自然科学基金(21073144)

摘　　要：采用杂化的密度泛函方法(DFT/B3LYP),在6-31G(d)理论水平下研究了基于噻吩并[3,2-b]噻吩(Thieno[3,2-b]thiophene,TT))的D-A型共轭聚合物的几何结构、电子结构和性质.研究发现,在以TT为电子供体的D-A型共轭聚合物中,电子受体强度是影响其几何结构、电子结构和性质的重要因素.对基于TT的电子受体与电子供体交替排列的D-A型共轭聚合物,在一定范围内,电子受体强度增加,有利于减小共轭聚合物的键长交替,降低聚合物的能隙,并使其能带变宽,电子离域程度增大,载流子有效质量减小,载流子迁移能力增强.但受体强度过大,键长交替反而增大,能带和能隙均变窄,载流子迁移能力减弱.The donor-acceptor（D-A） conjugated copolymer were designed by choosing Thieno[3,2-b]thiophene（TT） as the electron donor and quinoxaline（Q）, Benzo[c][1,2,5]thiadiazole（BT）, pyrazino[2,3-g]quinoxaline（PQ）, [1,2,5]thiadiazolo[3,4-g]quinoxaline （TQ） or Benzobis[1,2,5]thiadiazole （BBT） as the electron acceptor unit. The DFT/B3LYP method is employed to investigate the electronic structures and properties of the donor-acceptor alternating copolymers. The theoretical results suggest that electron-acceptor strength contribute significantly to the geometrical structures and electronic properties of the alternating donor-acceptor copolymers. The geometrical and electronic properties of the TT-based copolymers exhibit a systematic trend with the electron-acceptor strength within a certain range. The bond length alternation, band gap （ Eg ） and hole effective mass decrease, the bandwidth （both valence and conduction band） increases systematically with an increase in the electron-withdrawing ability of the acceptor moiety within a certain range of the electron-acceptor strength.

关 键 词：噻吩并[3 2-b]噻吩 电子受体强度 电子结构与性质 

分 类 号：O641[理学—物理化学]