萘二酰亚胺类电子受体材料分子设计与开路电压的理论调控  

Molecular design of the NDI derivatives electron acceptors and theoretical adjustment of the open-circuit voltage

作　　者：邵绒 王文亮[1,2] 杨鑫博 尹世伟[1,2] 

机构地区：[1]陕西省大分子科学重点实验室 [2]陕西师范大学化学化工学院,西安710119

出　　处：《中国科学：化学》2016年第7期699-706,共8页SCIENTIA SINICA Chimica

基　　金：国家自然科学基金(编号:21173139;21173138;21473108);陕西省重点科技创新团队基金(编号:2013KCT-17)资助项目

摘　　要：采用密度泛函理论预测了6个萘二酰亚胺(NDI)衍生物电子受体分子An(n=1~6)的几何构型、前线轨道特征及吸收光谱,并分别与选定的3个给体分子Dm(m=1~3)组合,构建给-受体(D-A)界面,从单分子尺度评估了不同D-A界面载流子的复合程度.结果表明,引入N、O、S等杂原子可以改变分子间氢键位点及强度,调节D-A界面分子间的距离与位移,以降低界面载流子复合,通过减小光电压损失获得高的开路电压V_(oc);此外,通过计算给体HOMO^D与受体LUMO^A之间的电子耦合V_(if)发现,平面性均较好的D-A分子组合V_(if)较大,界面载流子易于复合,会引起较大的光电压损失,不利于获得高的V_(oc).将平面性好的受体与非平面型给体材料搭配作为有机太阳能电池光活性层有可能获得高的V_(oc).综合考虑ΔE_L、V_(if)、D-A分子的平面性和光吸收效率等因素,认为D3-A5组合有望成为电子迁移率高、可见光和近红外区吸收宽、界面激子能有效分离且不易复合的理想给-受体分子组合对.Based on naphthalene diimide （NDI） unit, 6 electron acceptor molecules An （n=1-6） have been designed, and their geometric configurations, the characteristics of frontier molecular orbital and optical properties have been investigated by density functional theory. Furthermore, the donor-acceptor （D-A） interfaces are respectively simulated by combining the 6 acceptors with the selected three donors Dm （m=1-3）. Then the degree of interface recombination is evaluated from the single molecule scale. The results provide an efficient way to adjust the recombination that is through strong H-bond interaction to change the distance and displacements of D-A interface by introducing N, O, S heteroatoms. The fine-tuning of D-A interfacial stacking, reducing interface recombination, can enhance the open-circuit voltage （Voc）. In addition, the proper calculated results of electronic coupling between HOMO of donors and LUMO of acceptors showing the donor and acceptor materials both with good planar combined can lead to serious recombination against high open-circuit voltage. While in organic solar cell, acceptor with good planar combined with non-planar donor materials, to form optical active layer, is an effective approach to obtain high Voc. Considering AEL, Vif, the planarity of donor and acceptor molecules and light absorption efficiency, D3-A5 combination is the most promising candidate of optical active layer materials in organic solar cell.

关 键 词：萘二酰亚胺 给-受体界面 电子耦合 开路电压 能量转换效率 

分 类 号：O621.23[理学—有机化学]