单端吸附碳链双分子结电子输运性质的理论研究  

Theoretical Studies of Electron Transport Properties in Bimolecular Junctions Based on Monothiol-anchored Carbon Chains

作　　者：袁顺东[1,2] 梅群波[1] 凌启淡[1,3] 汪联辉[1] 黄维[1] 

机构地区：[1]南京邮电大学有机电子与信息显示国家重点实验室培育基地,江苏南京210023 [2]中国石油大学(华东)理学院,山东青岛2665803 [3]福建师范大学福建省高分子材料重点实验室,福建福州350108

出　　处：《南京邮电大学学报（自然科学版）》2013年第5期88-96,共9页Journal of Nanjing University of Posts and Telecommunications：Natural Science Edition

基　　金：国家重点基础研究发展计划(973计划)(2009CB930601);国家自然科学基金(60976019;90813010;60907041);新世纪优秀人才支持计划(NCET-07-0446);高等学校博士学科点专项科研基金(20093223110002);江苏省"高校优秀科技创新团队"基金(TJ207035;TJ208027)资助项目

摘　　要：设计了几个由不等长、单巯基吸附的碳链构成的双分子结模型,并利用密度泛函理论和非平衡格林函数方法对其电子输运性质进行了系统的理论研究。结果显示,两分子中较短的分子对分子结电导性质有比较大的贡献。比较不同双分子结之间的传输性质发现,两分子长度的差异对分子结的整流效应有着较大的影响,体现了较短分子的调制作用。每个分子结都表现出了负微分电阻效应。针对这些整流和负微分电阻等现象,利用分子结的透射谱以及分子投影自洽哈密顿量对其进行了系统的分析。Several models of bimolecular junctions were designed based on two different-lengthed and monothiol-anchored carbon chains,and their electron-transport properties were investigated systematically using density functional theory （DFr） combined with the first-principles nonequilibrium Green＇s function （NEGF）.Computational results show that the shorter carbon chain moiety makes more contribution to the conductance of molecular junctions.The comparisons of transport properties among these junctions show that the difference in lengths of two molecules can influence the rectification effect significantly.It indicates the modulation from the shorter carbon chain moiety.Negative differential resistance （NDR） behaviors occur in all of the bimolecular junctions.The rectification and NDR characteristics were discussed emphatically through analyzing the transmission spectra and molecular projected self-consistent Hamiltonian （MPSH）.

关 键 词：碳链 双分子结 电子输运 密度泛函理论 非平衡格林函数 

分 类 号：O469[理学—凝聚态物理]