Dual response of graphene-based ultra-small molecular junctions to defect engineering

作     者：Kunpeng Dou Xiaoxiao Fu Abir De Sarkar Ruiqin Zhang 

作者机构：Department of Physics and Materials Science City University of Hong Kong Hong Kong China Institute of Nano Science and Technology (An Autonomous Institute of Department of Science and Technology Government of India)Habitat Centre (Transit Campus) Phase X Sector-64 Mohali Punjab- 160 062 India 

出 版 物：《Nano Research》 (纳米研究（英文版）)

年 卷 期：2016年第9卷第5期

页      面：1480-1488页

核心收录：

学科分类：080903[工学-微电子学与固体电子学] 0808[工学-电气工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 07[理学] 08[工学] 070203[理学-原子与分子物理] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0702[理学-物理学] 

基　　金：supported by a grant from the Research Grants Council of Hong Kong SAR 

主　　题：graphene defect electron transport molecular electronics single-molecule studies 

摘      要：It has been reported that N and B doping induce a quasi-bound state that suppresses the conduction in graphene nanoribbon （GNR）-based junctions, while an H defect or a pyridine-like N-atom （PN） substitution at the edge of the GNR does not affect the transmission close to the Fermi energy. However, these results may vary when the size of the functional unit of the GNR junction decreases to a molecular level. In this study, a defect is introduced to a test-bed architecture consisting of a polyacene bridging two zigzag GNR electrodes, which changes the molecular state alignment and coupling to the electrode states, and varies the equivalence between two eigen-channels at the Fermi level. It is revealed that B and N atom substitution, and H defects play a dual role in the molecular conductance, whereas the PN substitution acts as an ineffective dopant. The results obtained from density functional theory combined with the non-equilibrium Green＇s function method aid in determining the optimal design for the GNR-based ultra-small molecular devices via defect engineering.