Solution-Processible Organic Semiconductors Based on Selenophene-Containing Heteroarenes, 2,7-Dialkyl[1]benzoselenopheno[3,2-b][1]benzoselenophenes (Cn-BSBSs): Syntheses, Properties, Molecular Arrangements, and Field-Effect Transistor Characteristics
Solution-Processible Organic Semiconductors Based on Selenophene-Containing Heteroarenes, 2,7-Dialkyl[1]benzoselenopheno[3,2-b][1]benzoselenophenes (Cn-BSBSs): Syntheses, Properties, Molecular Arrangements, and Field-Effect Transistor Characteristics
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DOI：
10.1021/cm8030126
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发表时间：
2009-03-10
影响因子：
8.6
通讯作者：
Takimiya, Kazuo
中科院分区：
文献类型：
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作者：
Izawa, Takafumi;Miyazaki, Eigo;Takimiya, Kazuo
合成了一系列2，7-二烷基[1]苯并硒吩并[3，2-B][1]苯并硒吩（C-n-BSBS）。对C-n-BSBS的电化学和光化学研究表明，它们的分子性质与硫对应物2，7-二烷基[1]苯并噻吩[3，2-B][1]苯并噻吩（C-n-BTBT）的分子性质非常相似，其溶液处理的有机场效应晶体管（OFET）显示出优异的场效应迁移率（μ（FET））高于1.0 cm（2）V-1 s（-1）的上级FET特性。C-n-BSBS在Si/SiO2衬底上的薄膜沉积可以通过物理气相沉积或旋涂它们在氯仿中的溶液来容易地实现。原子力显微镜（AFM）表明，薄膜，无论烷基链的长度和沉积方法，由晶粒。另一方面，X射线衍射（XRD）测量表明，衬底上的所有薄膜都具有良好有序的“分子片层”结构，其中C-n-BSBS分子在衬底上具有边缘取向，如在C-n-BTBT薄膜中所观察到的。然而，短的分子间距离（d-间距）的C-n-BSBS薄膜相比，具有相同的烷基链长度的C-n-BTBT薄膜对应于大的倾斜度的分子长轴从基板法线，表明BSBS核心之间的分子间重叠是不太有效的，比观察到的C-n-BTBT薄膜的二维相互作用结构。根据C-n-BSBS薄膜的分子排列和由此产生的较少相互作用的电子结构，C-n-BSBS基OFFET的特性不如C-n-BTBT基OFFET显著，尽管在I-on/off为10（5）的情况下实现了0.23 cm（2）V-1 s（-1）的最大μ（FET）。结果表明，即使是细微的分子修饰，而分子的电子结构没有显着的变化，可以改变分子在固态的排列，这将导致在器件特性的大的差异。为了进一步开发上级有机半导体，不仅要考虑分子的电子结构，而且要考虑固态的电子结构。
A series of 2,7-dialkyl[1]benzoselenopheno[3,2-b][1]benzoselenophenes (C-n-BSBSs) were synthesized as novel soluble organic semiconductors. Electrochemical and photochemical studies on C-n-BSBSs have revealed that their molecular properties are very similar to those of their sulfur counterparts, 2,7-dialkyl[1]benzothieno[3,2-b][1]benzothiophenes (C-n-BTBTs), whose solution-processed organic field-effect transistors (OFETs) show superior FET characteristics with field-effect mobility (mu(FET)) higher than 1.0 cm(2) V-1 s(-1). Thin film deposition of C-n-BSBSs on Si/SiO2 substrates was easily accomplished by physical vapor deposition or spin-coating of their solutions in chloroform. Atomic force microscopy (AFM) showed that the thin films, regardless of the alkyl chain length and the deposition method, consist of crystalline grains. X-ray diffraction (XRD) measurements, on the other hand, indicated that all the thin films on the substrate have a well-ordered "molecular lamella" structure where C-n-BSBS molecules have an edge-on orientation on the substrate, as observed in the thin films of C-n-BTBTs. However, the short intermolecular distances (d-spacings) of C-n-BSBS thin films compared to those of C-n-BTBT thin films with the same alkyl chain length correspond to the large inclination of the molecular long axis from the substrate normal, indicating that the intermolecular overlap between the BSBS cores is less effective than that for the two-dimensional interactive structure observed for C-n-BTBT thin films. In accordance with the molecular arrangement and the resulting less interactive electronic structure of C-n-BSBS thin films, the characteristics of C-n-BSBS-based OFETs were less remarkable than those of C-n-BTBT-based ones, although the maximum mu(FET) of 0.23 cm(2) V-1 s(-1) with I-on/off of 10(5) was achieved. The results indicate that even subtle molecular modifications without significant changes of the molecular electronic structure could alter the molecular arrangement in the solid state, which would result in a large difference in device characteristics. For the further development of superior organic semiconductors, not only the molecular electronic structure but also the electronic structure in the solid state must be taken into account.