PhD Research Project: Single-Molecule Charge Transport in Novel Macromolecular Ring Systems

The field of single-molecule electronics has provided detailed insight into the charge transport properties of individual molecules, how they interact with electrode surfaces and how they can be brought to display wire, diode and transistor function. Experiments have almost exclusively focused on linear molecules, partly because they are relatively easy to make and study. However, branched and in particular ring-shaped molecules display a whole range of interesting properties that make them attractive targets for ‘next generation’ single-molecule devices. This includes quantum interference, a reflection of the wave properties of electrons moving through a molecule, and potentially correlated hopping in multi-centre transition metal complexes.

In collaboration with synthetic chemists, we have recently discovered a new class of macrocyclic ring systems, made of multiple, directly linked ferrocene units. Interestingly, each ferrocene unit communicates quite efficiently with its neighbours, which means that once oxidized, charges can be delocalised efficiently over the entire ring. The charging energy scales inversely with the ring size, which makes them similar to small nanoparticles (‘molecular quantum dots’), except they can be made with atomic precision! All this was established in solution-based studies involving many molecules – virtually nothing is known about their charge transport properties at the single-molecule level.

Hence, the project aims to explore the exciting properties of these novel ring systems, using state-of-the-art electrochemical methods, scanning probe microscopy and other methods. We will try to understand how the unique molecular structure affects charge transport, how to store charge on these structures, and whether they might find application in new types of memory devices. The project is highly interdisciplinary and we will actively collaborate with electronic engineers, synthetic chemists and Machine Learning specialists (in particular Deep Learning).

Please direct any enquires related to this opening to Prof. Tim Albrecht, t.albrecht@bham.ac.uk.