the insertion of a single electron‐deficient B unit into the aromatic backbone strongly affects the LUMO energy level. The insertion of additional B units has only a minor effect on the electronic properties. Cast films of oligomers with two alternated B rings (B–T–B inner core) display crystalline order. Bottom‐contact FETs based on films cast on bare SiO2 show hole‐charge mobilities of 1 × 10−3–5 × 10−3 cm2
据报道,新合成的噻吩(T)和苯并噻二唑(B)的共聚体具有不同的大小,交替基序和烷基取代类型。结合光谱数据,电化学分析和理论计算表明,将单个缺电子的B单元插入芳族主链会强烈影响LUMO能级。插入额外的B单元对电子性能的影响很小。具有两个交替的B环(B–T–B内芯)的低聚物的流延膜显示结晶顺序。基于在裸露的SiO 2上流延的薄膜的底部接触FET的空穴电荷迁移率为1×10 -3 –5×10 -3 cm 2 V -1 s -1和I开/关比例为10 5 –10 6。环己基取代的化合物的溶液浇铸膜是无定形的,没有FET行为。但是,可以通过纳米摩擦和非常规的湿法光刻技术克服这些薄膜中观察不到的有序性,从而可以精细控制薄沉积物中的结构有序性。
Liquid-Crystalline Rigid-Core Semiconductor Oligothiophenes: Influence of Molecular Structure on Phase Behaviour and Thin-Film Properties
The design, synthesis and properties of liquid-crystalline semiconducting oligothiophenes containing dithienothiophene (DTT), benzothiadiazole (BTZ) and carbazole (CBZ) rigid cores are described. The effect of molecular structure (shape, size and substitution) on their thermal behaviour and electrical properties has been investigated. Polarised optical microscopy (POM) and differential scanning calorimetry