Three-Terminal Single-Molecule Junctions Formed by Mechanically Controllable Break Junctions with Side Gating

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.

A quantum circuit rule for interference effects in single-molecule electrical junctions

“…S tudies of the electrical conductance of single molecules attached to metallic electrodes not only probe the fundamentals of quantum transport but also provide the knowledge needed to develop future molecular-scale devices and functioning circuits [1][2][3][4][5][6][7][8][9] . Owing to their small size (on the scale of Angstroms) and the large energy gaps (on the scale of eV), transport through single molecules can remain phase coherent even at room temperature, and constructive or destructive quantum interference (QI) can be utilized to manipulate their room temperature electrical [10][11][12][13] and thermoelectrical 14,15 properties.…”

Remote control of magnetostriction-based nanocontacts at room temperature

“…The ability to manipulate and remotely control the electronic transport through single-atom or few-atom contacts is currently of great interest due to their potential applications in electronic devices1 and nanoelectromechanical systems (NEMS)2. In particular, mechanically-controlled break junctions34, scanning tunneling microscopy5, and electrochemical methods6 have extensively been used to investigate the electronic transport through monatomic contacts.…”

Research Update: Molecular electronics: The single-molecule switch and transistor

“…[8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] The most popular technique to contact a single molecule is the quantum mechanical break junction technique, where a nanoscopic junction is realized by controllably opening and closing a narrow metallic constriction. 8,9,[21][22][23] As an alternative, molecules are captured between a substrate and the apex of the tip of a scanning tunneling or atomic force microscope. 5, 10-20, 24, 25 a Author to whom correspondence should be addressed.…”