Three-terminal single molecule junctions formed by mechanically controllable break junctions with side gating

본 논문은 기계적인 방법으로 나노갭 크기의 분자접합(mechanically controllable break junction; MCBJ)을 형성하고 side 게이트 전극을 사용하여 단분자 트랜지스터 구조를 만들어 전기적 특성을 측정 분석한 연구결과이다. 분자접합(molecular junction) 중심에서 수 나노미터 정도 떨어진 side 게이트 전극에서 걸어주는 전압으로 분자의 오비털 에너지가 조절되고, 따라서 분자 트랜지스터 현상 측정이 가능하였다. 본 연구는 MCBJ 기법으로 기계적으로 안정된 단분자 트랜지스터 접합구조를 이용하는 분자전자소자 연구방향을 제시할 것이다.

Abstract: Molecules are promising candidates for electronic device components because of their small size, chemical tunability, and ability to self-assemble. A major challenge when building molecule-based electronic devices is forming reliable molecular junctions and controlling the electrical current through the junctions. Here, we report a three-terminal junction that combines both the ability to form a stable single-molecule junction via the mechanically controllable break junction (MCBJ) technique and the ability to shift the energy levels of the molecule by gating. Using a noncontact side-gate electrode located a few nanometers away from the molecular junction, the conductance of the molecule could be dramatically modulated because the electrical field applied to the molecular junction from the side gate changed the molecular electronic structure, as confirmed by the ab initio calculations. Our study will provide a new design for mechanically stable single-molecule transistor junctions fabricated by the MCBJ method.

Authors: Dong Xiang(서울대), Hyunhak Jeong(서울대), Dongku Kim(서울대),
Takhee Lee*(서울대), Yongjin Cheng, Qingling Wang, and Dirk Mayer*; 교신저자*

Nano Lett., Article ASAP
DOI: 10.1021/nl401067x
Publication Date (Web): May 23, 2013