(July 14, 2015) An
international team of physicists has used a scanning tunneling microscope to
create a minute transistor consisting of a single molecule and a small number
of atoms. The observed transistor action is markedly different from the
conventionally expected behavior and could be important for future device
technologies as well as for fundamental studies of electron transport in
molecular nanostructures. The physicists represent the Paul-Drude-Institut für
Festkörperelektronik (PDI) and the Freie Universität Berlin (FUB), Germany, the
NTT Basic Research Laboratories (NTT-BRL), Japan, and the U.S. Naval Research Laboratory
(NRL). Their complete findings are published in the 13 July 2015 issue of the
journal Nature Physics.
Transistors have a channel region between two external
contacts and an electrical gate electrode to modulate the current flow through
the channel. In atomic-scale transistors, this current is extremely sensitive
to single electrons hopping via discrete energy levels. In earlier studies, researchers
have examined single-electron transport in molecular transistors using top-down
approaches, such as lithography and break junctions. But atomically precise
control of the gate—which is crucial to transistor action at the smallest size
scales—is not possible with these approaches.