含5,5′-连噻吩二硫醇的三元混合膜结构与性质研究

Investigation of structure and properties of ternary mixed self-assembled monolayers containing bithiophene-5,5′-dithiol

在烷基硫醇混合膜的基础上,制备出由5,5′-连噻吩二硫醇(BT),戊硫醇(C5T)和癸硫醇(C10T)组成的三元混合膜,并对其结构及性质进行了详细的研究。BT和C10T插入到C5T分子形成的基底中。BT分布在组装膜的内部而C10T则分布在组装膜的缺陷处以及BT分子周围。BT和C10T形成各自独立的相区,但是将两种分子的浓度降低5倍后,二者在组装膜中的分布变得均匀,而且相分离的现象明显减轻。三种分子的隧穿电阻分别为BT:26 MΩ、C5T:47 MΩ、C10T:350 MΩ。研究表明,在较低浓度下,分子在该混合膜表面的分布较烷基硫醇混合膜更均匀,且电子传输能力也强于后者。

Based on alkanethiolate mixed self-assembled monolayers,ternary mixed self-assembled monolayers composed of pentanethiols（C5T）,decanethiols（C10T）and bithiophene-5,5′-dithiol（BT）were prepared.Their structure and electron transport properties were studied.BT and C10T were inserted in the C5T matrix.BT dispersed at the center of the domains while C10T dispersed in the domain boundaries or appeared around BT.Both of them formed pahased-seperated regions.However,phase-separated domains became smaller and uniformed SAMs formed after the concentration ratios of BT and C10T in the solution decreased five times.The resistances of three molecules were 26 MΩ for BT,47 MΩ for C5T and 350 MΩ for C10T,respectively.This investigation revealed that at a lower concentration ratio,the distribution of molecules in SAMs containing BT is more uniform than that in alkanethiolate SAMs.Besides,in terms of electron transport properties,the former is better than the latter.