On-Chip Break Junctions and Period-Adjustable Grating Driven by Thermal Stress

Abstract

The investigation of the electron transport through single molecule needs an efficient method to generate stable molecular junctions. There are various techniques, such as mechanically controllable break junction (MCBJ) technique and electromigration technique, to generate stable nanogaps and stable molecular junctions. However, it is a great challenge for MCBJ technique to obtain on-chip molecular junctions because of the constraint of the push rod components, which do not make it facile to fabricate highly integrated molecular devices. Meanwhile, the gap size between electrodes is nonadjustable for the electromigration method, which leads to a low yield of molecular junctions. In this report, a thermally controllable break junction method, which can overcome the above problem, is proposed for the first time. The device is based on a double-V-shaped symmetrical structure and mechanically driven by thermal expansion, thus the push rod is not needed. Furthermore, we proposed that the thermally controlled double-V-shaped structure can be employed to precisely adjust the period of the metal grating with nanometer accuracy, which is unavailable in other methods.