Quantum engineering of energy-efficient molecular materials (QMol)

QMol will realise a new generation of switchable organic/organometallic compounds, with the potential to fulfil societal needs for flexible energy harvesting materials, low-power neuromorphic computing, smart textiles and self-powered patches for healthcare. The possibility of creating these exciting materials derives from a series of world firsts by the investigators, demonstrating that advantageous room-temperature quantum interference effects can be scaled up from single molecules to self-assembled monolayers, new strategies for controlling molecular conformation and energy levels, and new methods of molecular assembly, which can be deployed in printed scalable architectures.

The demand for wearable electronic devices has increased enormously in recent years and integration of these devices into textiles is highly desirable. A key problem is the need for a power supply, typically in the form of a battery or supercapacitor, which need to be recharged. To overcome this problem, QMol will develop flexible thermoelectric materials that can covert waste heat from the body and other sources into electricity. Progress in this direction has been made using disordered, doped polymer composites [eg ACS Appl. Mater. Interfaces 2020, 12, 41, 46348], but there is a need to develop higher-performance, inexpensive, easily processable, flexible thermoelectric materials. The best inorganic materials cannot fulfil these requirements and therefore QMol will focus on the development of high-performance, thin-film, organic/organometallic materials.

In parallel with these developments, it is widely recognised that dendritic-synaptic interconnections among neurons in the brain embed intricate logic structures enabling decision-making that vastly outperforms any artificial electronic analogues, with extremely low power requirements. Moreover, the network in a brain is dynamically reconfigurable, which provides flexibility and adaptability to changing environments. To build artificial neural networks, which mimic this behaviour, QMol will develop thin-film, organic/organometallic materials, which embed complex logic possibilities in the material properties of a single circuit element and outperform recent realisations of such logic elements. The resultant current-voltage characteristic of these molecular memristors will exhibit history-dependent, non-volatile switching transitions between different conductance levels.

As demonstrators of the wide potential of these new materials, by the end of the Programme, we shall deliver

(i) smart textiles with in-built thermal management,

(ii) cross-plane, memristive devices, which are a fundamental building block of a neuromorphic computer

(iii) flexible organic thermoelectric energy generators (TEGs) and self-powered patches for healthcare.

We have demonstrated that room-temperature quantum interference effects in monolayer molecular films can be used to enhance memristive switching, energy harvesting and thermal control. Since transport is perpendicular to the plane of such films, long-range order within the films is not required.

QMol recognises that although monolayer films are of fundamental scientific interest, they are not technologically useful, because for example, in a device, it is not possible to create a significant thermal gradient across a monolayer in a perpendicular direction. Therefore the new materials envisaged by QMol will be finite-thickness multi-layers, which move the above functionalities into the third dimension.

The team comprises nine academics, with track records at the forefront of their fields. They are supported by twenty world leaders from industry and academia, comprising the six-member QMol Advisory Board and fourteen external partners. Eight postdoctoral researchers (PDRAs) will be employed by QMol and will be joined by eight PhD students, an industry-funded CASE student and an industry-funded PDRA.