Atomically Thin Materials
Atomically thin materials are materials that naturally form in sheets just one or a few atoms thick. The first atomically thin material to be isolated in the laboratory was graphene, a single atom-thick plane of graphite; this discovery resulted in the 2010 Nobel Prize in Physics.
Graphene, like many atomically thin materials, has very strong chemical bonds within a plane, but bonds only very weakly to its neighbouring sheets. This allows graphene to be extracted from graphite, and also makes atomically thin materials higly compatible with a variety of substrates - they can be placed on glass, plastics, or metals without creating any new chemical bonds which might change their properties.
Atomically thin materials are of interest for a wide range of properties: electrical and thermal conduction, mechanical reinforcement of composites, membranes and filters, battery electrodes, biocompatible materials, and more. MCATM researchers are discovering new fundamental properties of atomicaly thin materials, and using these properties for new technological applications.
Novel atomically thin materials currently being studied within MCATM include:
Graphene is a single atom thick plane of carbon arranged in a honeycomb lattice. It is the basic constituent of graphite, which is a stack of graphene layers. The carbon atoms within a layer of graphene are extremely strongly bonded – graphene is the strongest substance known – but very weakly bonded to neighbouring layers. This graphite can be disassembled easily into graphene.
Molybdenum disulphide is a three-atom-thick semiconductor, and can be used to make transistors with comparable performance to silicon, yet transparent and flexible.
Topological insulators are new materials that are insulators (do not conduct electricity) in their interiors, but metallic (conductors of electricity) on their surfaces. In three-dimensional topological insulators, electrical current is carried in an atomically thin two-dimensional layer at the surface of the material. In two-dimensional topological insulators, current is carried along the edges of the material, and in principle can flow without resistance.