### 星型多支化p-n结构窄带隙共轭分子的设计合成与性能研究

1. 有机电子与信息显示国家重点实验室培育基地 南京邮电大学信息材料与纳米技术研究院 南京 210023
• 投稿日期:2013-04-24 发布日期:2013-06-27
• 通讯作者: 赖文勇,E-mail:iamwylai@njupt.edu.cn;黄维,E-mail:iamwhuang@njupt.edu.cn E-mail:iamwylai@njupt.edu.cn;iamwhuang@njupt.edu.cn
• 基金资助:

项目受受国家重大基础研究发展计划项目(No. 2009CB930601)、国家自然科学基金(Nos. 20904024, 51173081, 61136003, 61106036, 61204048)、江苏省自然科学基金(No. BK2011760)、南京邮电大学攀登计划(Nos. NY210016, NY212072)、江苏高校优势学科建设工程资助项目、江苏省“青蓝工程”项目和江苏省普通高校研究生科研创新计划项目(No. CXLX11_0399)资助.

### Synthesis and Characterization of Starburst Conjugated Molecules with Multiple p-n Branches for Narrow Band Gap Modulation

Zhao Lingling, Jiu Yuanda, Wang Jianyun, Zhang Xinwen, Lai Wenyong, Huang Wei

1. Key Laboratory for Organic Electronics & Information Displays (KLOEID) and Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023
• Received:2013-04-24 Published:2013-06-27
• Supported by:

Project supported by the National Basic Research Program of China (973 Program, No. 2009CB930601), the National Natural Science Foundation of China (Nos. 20904024, 51173081, 61136003, 61106036, 61204048), the Natural Science Foundation of Jiangsu Province (No. BK2011760), the NUPT Scientific Foundation (Nos. NY210016, NY212072), the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), the Qing Lan Project of Jiangsu Province and the Research Fund for Graduate Innovation Project of Jiangsu Province (No. CXLX11_0399).

Well-defined π conjugated molecules have attracted much attention in the field of organic electronics, due to their promising optoelectronic properties, good monodispersity, high purity, excellent reproducibility and facile functionalization. Here, a series of starburst molecules (P1, P2 and P3) with truxene as the core, thiophene unit as p-type electron donating segments, and benzothiadiazole chromophore as the n-type electron accepting segments, have been designed and synthesized. The aim of the systematic investigation of these structural variations was to provide insight into the relationship between the effective conjugation length and the photophysical properties, the intramolecular energy transfer process, which would shed light for the rational design of novel optoelectronic materials for organic electronic devices. The resulting molecules, P1, P2, and P3, possess a series of advantages, including high solubility, broad absorption, low band gap and good thermal stability, etc. The chemical structures of the intermediates and resulting molecules were confirmed by 1H NMR, 13C NMR, GC-MS/MALDI-TOF. P1, P2, and P3 exhibited good thermal stability according to thermogravimetric analysis (TGA) and low-lying HOMO and LUMO energy levels as well as narrow band gaps according to cyclic voltammetry (CV). P1 and P3 possessed amorphous properties, while P2 exhibited crystalline properties as revealed by differential scanning calorimetry (DSC). The electronic properties have also been investigated by DFT calculation. The HOMO/LUMO energy levels and band gaps could be fine tuned by varying the content of p and/or n type moieties. Compared to P1 and P2, the maximum absorption and emission of P3 were obviously red-shifted due to increased effective conjugation with introducing additional thiophene units into the p-n branches and modulating the substituted position of the alkyl group. To investigate the primarily optoelectronic properties of these molecules, OLEDs were fabricated using the following configuration: ITO/PEDOT: PSS (50 nm)/EML (74 nm)/TPBi (30 nm)/LiF (1.3 nm)/Al (80 nm). Maximum luminance of 2908, 4683, 1085 and 4730 cd/m2 were demonstrated with maximum current efficiency of 1.18, 0.50, 0.16 and 2.50 cd/A, respectively.