A new challenger to graphene has been grown to Southampton scientists

A team of researchers from the University of Southampton’s Optoelectronics Research Centre (ORC) has developed a potential challenger to graphene. The new material − molybdenum di-sulphide (MoS2) − is similar to graphene and it shares many of its properties, including extraordinary current conduction and mechanical strength. However, the difference is that it’s made from metal.

Graphene is formed of carbon atoms, with properties such as very low electrical resistance, high thermal conductivity and mechanical stretchability, yet it is harder than diamond. As such, it is increasingly being used in a new generation of electronic devices − transistors, switches, light sources and others.

The new class of thin metal/sulphide materials that ORC worked with, known as transition metal di-chalcogenides (TMDCs), has become an exciting complementary material to graphene. However, unlike graphene, TMDCs can also emit light, enabling applications such as photodetectors and light emitting devices.

Until recently, fabrication of MoS2 has been diffi cult, as most techniques produce only fl akes, just a few hundred square microns in area. ORC developed a way to manufacture them in larger areas.

“We have been working on the synthesis of chalcogenide materials using a chemical vapour deposition (CVD) process since 2001 and our technology has now achieved the fabrication of large area (> 1000mm2 ) ultra-thin fi lms only a few atoms thick. Being able to manufacture sheets of MoS2 and related materials, rather than just microscopic fl akes as was the case before, greatly expands their promise for nanoelectronic and optoelectronic applications,” said Dr Kevin Huang, from ORC who led the research.

The University is now working with several UK companies and technology centres, as well as MIT and Nanyang Technological University in Singapore, to further expand the scope of MoS2 and its commercialisation.

“Our ability to not only synthesise large uniform thin fi lms but also to transfer these fi lms to virtually any substrate has led to increased demand for our materials,” added Dr Huang.

The work was funded by the Engineering and Physical Sciences Research Council (EPSRC) through the EPSRC Centre for Innovative Manufacturing in Photonics.