Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (11): 2597-2604.doi: 10.3866/PKU.WHXB201208272

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

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.

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

MSC2000: 

  • O641