物理化学学报 >> 2012, Vol. 28 >> Issue (11): 2597-2604.doi: 10.3866/PKU.WHXB201208272

理论与计算化学 上一篇    下一篇

以主族元素为桥的梯形化合物的光电性质

刘淑娟, 马廷春, 许文娟, 刘湘梅, 赵强, 黄艳琴, 黄维   

  1. 有机电子与信息显示国家重点实验室培养基地, 南京邮电大学信息材料与纳米技术研究院, 南京 210046
  • 收稿日期:2012-06-25 修回日期:2012-08-27 发布日期:2012-10-17
  • 通讯作者: 赵强 E-mail:iamqzhao@njupt.edu.cn
  • 基金资助:

    国家重点基础研究发展计划(2009CB930601, 2012CB933301); 国家自然科学基金(21174064, 21171098); 教育部创新团队(IRT1148); 江苏省国际合作计划-重点国别和地区研发合作项目(BZ2010043); 南京邮电大学基金(NY210029)和江苏高校优势学科建设工程资助项目资助

Optoelectronic Properties for Main Group Element-Bridged Ladder Compounds

LIU Shu-Juan, MA Ting-Chun, XU Wen-Juan, LIU Xiang-Mei, ZHAO Qiang, HUANG Yan-Qin, HUANG Wei   

  1. Key Laboratory for Organic Electronics & Information Displays and Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, Nanjing 210046, P. R. China
  • Received:2012-06-25 Revised:2012-08-27 Published:2012-10-17
  • Supported by:

    The project was supported by the National Key Basic Research Program of China (973) (2009CB930601, 2012CB933301), National Natural Science Foundation of China (21174064, 21171098), the Ministry of Education of China (IRT1148), Key Projects in Jiangsu Province for International Cooperation, China (BZ2010043), Nanjing University of Posts and Telecommunications, China (NY210029), and Priority Academic Program Development of Jiangsu Higher Education Institutions, China.

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摘要：

梯形化合物具有大的平面π共轭结构, 不会产生构象扭曲, 可以有效增加π共轭长度, 因而表现出非常好的光电性质. 将主族元素引入到梯形化合物骨架中作为桥接单元不仅可以固定其结构而且由于主族元素和π共轭骨架之间的轨道相互作用, 可以实现对这类化合物光电性质的调节. 采用密度泛函理论对一系列主族元素桥的梯形化合物的结构和光电性质进行了理论研究, 从而可更好地理解和预测这类化合物的性质. 研究发现, 这类化合物的电子结构可以通过引入主族元素进行调节. 由于具有更大的π共轭程度, 四主族元素桥化合物的吸收与双主族元素桥化合物相比有明显的红移, 而且荧光寿命较短. 另外, 通过计算离子化势(IPs)、电子亲和能(EAs)和重组能(λ)考察了这类化合物的电子和空穴注入及传输性质. 研究发现, 四主族元素桥化合物表现出更强的电子和空穴注入能力.

关键词: 密度泛函理论, 电子性质, 梯形化合物, 主族元素, 光物理性质

Abstract:

Ladder-type π-conjugated molecules with fully ring-fused structures have fascinating optoelectronic properties because the flattened π-conjugated framework can eliminate conformational disorder and effectively enhance π-conjugation. Their optoelectronic properties can be modified by incorporating main group elements into the ladder skeleton. Heteroatom-bridges not only stiffen the skeleton but also contribute to the electronic structure through orbital interaction between the main group elements and the π-conjugated skeleton. Herein, the structural, electronic, and optical properties of bisand tetrakis-bridged (C, Si or P-bridged) stilbene derivatives were investigated by density functional theory (DFT) and time-dependent DFT (TDDFT) to provide theoretical understanding and predictions for these compounds. The electronic structures of these π-conjugated skeletons could be tuned by the incorporated elements. Compared with bis-bridged analogs, tetrakis-bridged derivatives exhibited substantial red shifts in the absorption and shorter radiative lifetimes because of extended π-conjugation. In addition, the energy barrier for the injection and transport rates of the holes and electrons was evaluated using ionization potentials, electronic affinities, and reorganization energies (λ). Compared to bis-bridged analogs, tetrakis-bridged derivatives exhibit higher accepting abilities for both holes and electrons.

Key words: Density functional theory, Electronic properties, Ladder-type molecules, Main group element, Photophysical property