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.