Guiding students to understand the nanoscale charge transport by the mechanically controllable break junction technique

Abstract

Fabrication of molecular devices will meet the demands of the miniaturization of traditional electronic devices. Although microfabrication based on the complementary metal-oxide-semiconductor process can fabricate high-quality single-molecule devices, the cost is high, leading to a challenge to provide a hands-on experiment in the teaching practice of charge transport through single-molecule devices. Here, we demonstrate the low cost and simple procedures associated with a mechanically controllable break junction (MCBJ) technique to fabricate single-molecule devices. On the basis of the MCBJ technique, the conductance of gold-gold atomic contacts and single-molecule junctions can be readily characterized. The teaching practice helps students understand charge transport at the single-molecule level, that is, the quantum tunneling mechanisms. Moreover, the MCBJ technique study provides students the opportunity to develop interdisciplinary thinking, which is vital for understanding, designing, and developing single-molecule electronics.