Molecular valves a step towards nanoscale electronics


SCIENTISTS from the National University of Singapore have worked with Tyndall National Institute at University College Cork to design and fabricate ultra-small devices which will enable energy-efficient electronics.

The work involved gaining insight into the behaviour of the molecules in the devices, allowing the scientists to tweak just one carbon atom to yield a ten-fold increase in switching efficiency.

The scientists designed and created devices based on molecules acting as electrical valves, or diode rectifiers.

The molecules allow current to flow through them when switched ON, and block the current when switched OFF.

Atom-level computer simulations indicated molecules with an add number of carbon atoms stand straighter than molecules with an even number of carbon atoms, allowing them to be packed more closely together.

The assemblies were formed on metal electrode surfaces by the team in Singapore and found to be remarkably free of defects, presenting outstanding suppression of leakage currents and thus operate efficiently and reliably.

The device can be cleanly switched on and off purely on the basis of the charge and shape of the molecules.

Modern electronic devices rely on tiny switches, and this discovery in the molecular scale opens up opportunities for blending molecular properties to be used boost the capabilities of electronics.

To enable the paradigm of nanoscale electronics, molecules need to be used as rectifiers and switches. With the researchers demonstrating the rational design of molecules that rectify current with a large and highly-reproducible ON/OFF ratio, this is a key step forward.