Thieno[3,2-b]thiophene oligomers and their applications as p-type organic semiconductors
作者:Moawia O. Ahmed、Chunmei Wang、Peisi Keg、Wojciech Pisula、Yeng-Meng Lam、Beng S. Ong、Siu-Choon Ng、Zhi-Kuan Chen、Subodh G. Mhaisalkar
DOI:10.1039/b900979e
日期:——
This study describes the synthesis, characterization and electronic properties of a novel series of soluble thieno[3,2-b]thiophene oligomers (1a and b and 2a and b) for thin film transistor (TFT) applications. All the compounds were synthesized in high yield using Pd-catalyzed Stille or Suzuki coupling reactions and were substituted by two dodecyl groups at the 3- or 4-position of the thiophene unit to ensure the solubility for facile device fabrication. Aryl units such as phenyl and naphthyl were used for ‘end-capping’ to provide stability against oxidation. The design of these materials has focused on their self-assembly and solution processability. All the compounds have been characterized by 1H, 13C NMR, and elemental analysis. Their electronic and optical properties were investigated using UV-Vis and photoluminescence spectroscopy, cyclic voltammetry, thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC). High-resolution STM images of 1a and 2a adsorbed on HOPG revealed highly ordered self-organized domains. Two-dimensional wide-angle X-ray scattering (2D-WAXS) was used to study the solid state packing of 1a and 2a. Top-contact OTFT devices from 1a were prepared by spin coating and showed promising behaviour with mobilities up to 3.11 × 10−2 cm2V−1 s−1 and on/off ratios up to 104.
本研究描述了薄膜晶体管(TFT)应用中一系列新型可溶性噻吩[3,2-b]噻吩低聚物(1a和b以及2a和b)的合成、表征和电子特性。所有化合物均采用钯催化的斯蒂尔或铃木偶联反应合成,并在噻吩单元的3或4位上被两个十二烷基取代,以确保在简易器件制造中的可溶性。苯基和萘基等芳基单元用于“端封”,以提供抗氧化稳定性。这些材料的设计侧重于其自组装和溶液可加工性。所有化合物均通过1H、13C NMR和元素分析进行了表征。利用紫外-可见光和光致发光光谱、循环伏安法、热重分析(TGA)和差示扫描量热法(DSC)研究了它们的电子和光学特性。吸附在HOPG上的1a和2a的高分辨率STM图像揭示了高度有序的自组织域。二维广角X射线散射(2D-WAXS)用于研究1a和2a的固态堆积。通过旋涂制备了1a的顶部接触OTFT器件,并显示出良好的性能,迁移率高达3.11×10-2 cm2V-1 s-1,开/关比高达104。