Atom-thick materials materialise in Oxford

Scientists have developed a method of splitting materials similar to graphite into atom-thin sheets, leading to applications for new electronic technologies.

The  team led by scientists at Oxford University and Trinity College have found a way to create such nano-sheets in a quick and inexpensive manner, which can be scaled up to work on an industrial level – threatening to steal the thunder from the nation’s favourite two dimensional material, graphene.

The team used mild ultrasonic pulses and common solvents to separate the materials into incredibly thin sheets, in the same way that the graphite has recently made the headlines for being split into layers of ultra-strong graphene.

It is said that a one-millimetre-thick layer of graphite could be broken into three million layers of graphene that measure just one atom in thickness.

According to the researchers there are over 150 layered materials such as Boron Nitride, Molybdenum disulfide, and Tungsten disulfide that can potentially be metallic, semi-metallic or semiconducting depending on their chemical composition and how their atoms are arranged.

“Because of its extraordinary electronic properties graphene has been getting all the attention, including a recent Nobel Prize, as physicists hope that it might, one day, compete with silicon in electronics,” said Dr Valeria Nicolosi of Oxford University’s Department of Materials.

“But in fact there are hundreds of other layered materials that could enable us to create powerful new technologies.”

According to Professor Coleman, of Trinity College Dublin, the nano-materials have chemical and electronic properties which are well suited for applications in new electronic devices, as well as super-strong composite materials and energy generation and storage.

Previous attempts have been made to create nano-sheets from other types of materials, but until now it has proved impractical as the methods were considered too time consuming, and resulted in materials that were too fragile to be realistically be used.

However the scientists believe they have a new method which allows low cost, high yield results, claiming that with only one milligram of material, many billions of atom-thick sheets can be made at the same time from a wide variety of exotic layered materials.

The nanosheets created through this method can then be sprayed onto the surface of other materials like silicon to produce hybrid films which can potentially allow their abilities to be integrated with conventional technologies.

Dr Nicolosi told TechEye that the uses for the new method are manifold, with applications dependent on the specific material that is being used.

“There are a range of possibilities for this, as it means that we are able to produce a wide range of effects in terms of electronic properties,” she said.

“One of the main functions that are possible is in thermoelectronics, where for example the heat waste of a car can be absorbed by the material and converted into electricity.

“Also materials could be used easily for superconducting, with the ability to store massive amounts of energy, as well as being released very efficiently.

“For laptop batteries this could mean that, rather than your battery dying after a year, it could operate like brand new for a much longer time.

“This is because the battery’s material is essentially destroyed while charging, however the new materials are vastly more robust.”