摘要
利用密度泛函理论与非平衡格林函数的第一性原理方法,从理论上研究苝酰二亚胺衍生物PTCDI-[CH2]n(n=0,2,4,6)分子体系的电子输运性质.结果表明:所有的分子结体系结构中都出现了负微分电阻现象,体系的电子输运性质取决于体系中分子的长度.随着CH2数目的增加,分子的长度相应增加,体系的电导呈指数减少;当n≥2时,分子结呈现整流特性;当n=6时,分子结在±2.1 V时整流比高达72.6;这种整流现象归因于分子的非对称结构.
The electronic transport properties of PTCDI-n(n=0,2,4,6) molecular junctions with different molecular lengths were theoretically investigated via the first-principles density functional theory and non-equilibrium Green's function method.Our results showed that the electronic transport properties depend on molecular lengths.The equilibrium conductance of the probed systems decreased exponentially with the increasing length of molecule.With n≥2,rectifying effect had been found.In n=6 case,a significant rectification ratio of 72.6 was achieved at the bias of ±2.1 V in our probed voltage range.The rectification effect resulted from asymmetric molecular structures.Negative differential resistance effect happened in all probe systems.
出处
《安徽大学学报(自然科学版)》
CAS
北大核心
2011年第6期35-40,共6页
Journal of Anhui University(Natural Science Edition)
基金
安徽大学青年基金资助项目(2009QN006A)
安徽大学“211工程”三期校级重点专业基金资助项目(39020012)
安徽大学“211工程”三期校级教育教学改革研究基金资助项目(39030039)
安徽大学“211工程”三期学术创新团队计划基金资助项目(KJTD004B)
安徽大学博士科研启动基金资助项目(02303203)
关键词
第一性原理计算
电子输运
整流
非对称性分子结构
first-principles calculation
electronic transport
rectification
asymmetric molecular configurations