A research team led by University of Warwick and EMPA have found a way past a catch 22 issue of stability and reproducibility that meant that graphene-based junctions were either mechanically or electrically stable but not both at the same time.
Graphene and graphene-like molecules are attractive choice as an electronic component in molecular devices but until now have proven very challenging to use in large-scale production of such devices that will be operational and robust at room temperatures.
Simple mechanically-stable structures such as graphene-like molecules are easy to produce by chemical synthesis but at a very small scale are limited when forming an electronic device. The researchers overcome these limits by separating the requirements for mechanical and electronic stability at the molecular level. They produced an electrically-effective structure by building a graphene-like molecule stack to form an electron path through the graphene-like molecules P orbitals (these are dumbbell shaped electron clouds within which an electron can be found, within a certain degree of probability).
The development could lead to new opportunities for using molecular properties such as quantum interference which occurs at such a small scale provided a sufficiently mechanical robust structures are achieved.
“Our approach represents a simple but powerful strategy for the future integration of molecule-based functions into stable and controllable nanoelectronic devices,” said Dr Hatef Sadeghi from the University of Warwick’s School of Engineering who led the theoretical modelling of this work.
The conductivity of graphene has made it a target for many researchers seeking to exploit it to create molecular-scale devices. This work was undertaken by the University of Warwick, EMPA, and Lancaster and Bern Universities.