4,7-二(5-溴噻吩-2-基)-2,1,3-苯并噻二唑低聚物光伏性能的理论研究  

Theoretical study of the photovoltaic performance for 4,7-bis(5-bromithien-2-yl)-2,1,3-benzothiadiazole oligomers

作　　者：张福兰[1] ZHANG Fu-Lan(Chongqing Key Laboratory of Inorganic Special Functional Materials,College of Chemistry and Chemical Engineering,Yangtze Normal University,Fuling 408100,China)

机构地区：[1]长江师范学院化学化工学院重庆市无机特种功能材料重点实验室,重庆408100

出　　处：《原子与分子物理学报》2021年第3期15-22,共8页Journal of Atomic and Molecular Physics

基　　金：重庆市教委科学技术资助项目(KJ1601215);教育部“春晖计划”(Z2016177)。

摘　　要：采用密度泛函理论中的广义梯度近似方法,在PW91/DNP水平上研究了4,7-二(2-溴代噻吩-5-基)-2,1,3-苯并噻二唑(简称DT(Br) BT)的低聚合物(DT(Br) BT)_(n)(n=1~6)的稳定构型、前线轨道和吸收光谱.结果表明:随着聚合度增加,(DT(Br) BT)_(n)的聚合能增强,前线轨道能隙变窄,而且(DT(Br) BT)_(2)和(DT(Br) BT)_(5)-ring均为平面构型.光谱分析表明:DT(Br) BT单体的最强吸收峰384nm在紫外区;当n=2~6时,(DT(Br) BT)n的吸收峰均发生红移,而且环状聚合物红移程度不如链状聚合物红移程度大;(DT(Br) BT)_(2)最强吸收峰757 nm在可见光区,其余(DT(Br) BT)_(n)(n=3~6)的最强吸收峰都在红外区.通过比较稳定构型、前线轨道和吸收光谱表明,(DT(Br) BT)2和(DT(Br) BT)_(5)-ring具有更好的光伏性能,此研究结果对太阳能电池材料的发展具有潜在的指导意义.The stability structures,front orbitals and absorption spectra of the low polymer(DT(Br) BT)_(n)(n = 1~ 6) for 4,7-di(2-bromothien-5-yl)-2,1,3-benzothiazole(DT(Br) BT for short) are investigated by density functional theory at the GGA/PW91/DNP level. The computational results show that the polymer energy gradually decreases and the energy gap gradually becomes narrow with the increasing polymerization degree. Moreover,the(DT(Br) BT)_(2) and the(DT(Br) BT)_(5)-ring are planar configurations. Spectral analysis shows that the strongest absorption peak of DT(Br) BT monomer is 384 nm in the ultraviolet region. When n = 2 ~ 6,the absorption peaks of the(DT(Br) BT)n are red-shifted,and the red-shifted of cyclic polymer is not as great as that of chain polymer. The strongest absorption peak of(DT(Br) BT)2 is 757 nm in the visible light region,while those of the(DT(Br) BT)_(n)(n = 3 ~ 6) are in the infrared region. The comparison of stable configuration,frontier orbital and absorption spectrum show that the(DT(Br) BT)_(2) and the(DT(Br) BT)_(5)-ring have good photovoltaic performance. The results may prove potential guide for the strategic development of organic solar cell materials.

关 键 词：4 7-二(5-溴噻吩-2-基)-2 1 3-苯并噻二唑 低聚物 光伏性能 密度泛函理论 

分 类 号：O641[理学—物理化学]