Single-molecule rectifiers

Moore's Law has held true with transistor numbers and computing power increasing while prices decrease. However, it's beginning to reach its limits largely due to restrictions imposed by silicon-based electronics. Among the most promising solutions are molecular electronics that use single molecules as rectifiers. Carbon-based nanomaterials are at the forefront of emerging information processing technology. The EU-funded project 'Carbon-based nanoelectronics' (CARBOTRON) used multi-scale modelling to investigate characteristics, a prerequisite to exploitation.

The team studied nano-scale rectification in molecular electronics, the foundation for new computing systems. They identified a novel mechanism for carbon-based spintronics or spin transport electronics, devices exploiting electron (or more generally nuclear) spin instead of or in addition to charge. The findings led to three publications in peer-reviewed scientific journals.

Additional theoretical experiments with carbon-based materials included an investigation of carbon nanobamboo. This is a unique structure made of carbon nanotubes of varying diameters and chiral angles, like long random pieces of bamboo, grown inside larger-diameter carbon nanotubes. The modelling pointed to a mechanism for determining the stable structure.

Finally, researchers used many-body methods to show that predicted values of a band gap measure in 1D carbon molecules agree with published experimental values.

The CARBOTRON project went beyond the original scope, investigating other low-dimensional materials similar to those in the original objectives. Among these were silicene, which is the silicon equivalent of graphene, hydrogenated silicene called silicane, and the germanium equivalent of silicene called germanane. Modelling work demonstrated the tremendous utility of these materials in nano-scale electronics thanks to their excellent physical properties. Seven more papers were published on the topics.

Overall, scientists published 14 articles in esteemed peer-reviewed journals, several of which have been cited many times since. CARBOTRON has placed an important brick in the foundation of future computing systems, demonstrating the potential of molecular electronics to overcome limitations to Moore's Law.