溶液酸碱性对低聚苯亚乙炔基分子结电输运性质的影响  

Electronic transport properties of oligophenyleneethynylene molecular junctions in alkaline and acid solutions

作　　者：林晓那 张广平[1] 任俊峰[1] 原晓波[1] 胡贵超[1] 

机构地区：[1]山东师范大学物理与电子科学学院,济南250014

出　　处：《物理学报》2014年第6期334-340,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10904083;10904084);山东省高等学校科技计划(批准号:J13LA05)资助的课题~~

摘　　要：结合密度泛函理论和非平衡格林函数方法计算了溶液酸碱性对低聚苯亚乙炔基分子结电输运性质的影响,此低聚苯亚乙炔基分子中两个不同位置的H原子被氨基和羧基取代.通过质子化和去质子化模拟酸性溶液和碱性溶液对分子结构的影响.计算结果表明:中性环境下分子器件具有良好的导电性和微弱的整流效应;碱性溶液中羧基去质子化后,分子器件电流值增长近一倍,但整流效应变化不明显;酸性溶液中氨基质子化后,分子器件正向偏压导电性能略微降低,但整流方向发生明显反转,且与中性环境下的情况相比,整流比提高了近三倍.提出了一种利用化学手段控制分子结导电能力和整流性能的方法.Using nonequilibrium Green’s function method combined with density functional theory, we theoretically investigate the influences of alkaline and acid solutions on electronic transport properties in oligophenyleneethynylene molecular junctions with amino and carboxylic groups. The numerical results show that comparing with the case of neutral state, the conductance of the molecular junction is double improved and the rectifying direction is inverted when carboxylic group is deprotonated in the alkaline environment. On the other hand, the rectification ratio is enhanced trebly and the rectifying direction is inverted similarly when amino group is protonated in the acid environment. This theoretical work presents a chemically controllable method of manipulating conductance and rectification of molecular junctions.

关 键 词：分子电子器件 电输运特性 整流 

分 类 号：O631.3[理学—高分子化学]