Graphene quantum dots to help create single electron transistors

Scientists from Manchester University, the Ulsan National Institute of Science & Technology and the Korea Institute of Science and Technology have developed a novel technology, which combines the fabrication procedures of planar and vertical heterostructures in order to assemble graphene-based single-electron transistors.

Graphene quantum dots to help create single electron transistorsThe schematic structure of the devices

In the study, it was demonstrated that high-quality graphene quantum dots (GQDs), regardless of whether they were ordered or randomly distributed, could be successfully synthesized in a matrix of monolayer hexagonal boron nitride (hBN). Here, the growth of GQDs within the layer of hBN was shown to be catalytically supported by the platinum (Pt) nanoparticles distributed in-between the hBN and supporting oxidised silicon (SiO2) wafer, when the whole structure was treated by the heat in the methane gas (CH4). It was also shown, that due to the same lattice structure (hexagonal) and small lattice mismatch (~1.5%) of graphene and hBN, graphene islands grow in the hBN with passivated edge states, thereby giving rise to the formation of defect-less quantum dots embedded in the hBN monolayer.

Grolltex announces graphene plant expansion in San Diego to 30,000 eight Inch wafer equivalents

Grolltex logo imageGraphene and 2D materials producer Grolltex has announced the completion of its recent capacity expansion and released production for 30,000 eight-inch wafer equivalents per year at its CVD monolayer fabrication facility in San Diego, California.

“This is the only commercial CVD monolayer graphene production facility in California and in fact it is the largest capacity plant of its kind in the U.S.”, said CEO, Jeff Draa. “Demand for our electronics grade graphene has never been better. Our production lines are capable of producing single layer graphene or single layer hexagonal Boron Nitride”.

DTU team protects graphene with hBN for future electronics

Graphene Flagship researchers at DTU, Denmark, solved the problem of graphene's accumulation of defects and impurities due to environmental exposure by protecting it with insulating layers of hexagonal boron nitride, another two-dimensional material with insulating properties.

DTU team protects graphene with hBN for future electronics image

Peter Bøggild, researcher at Graphene Flagship partner DTU and coauthor of the paper, explains that although 'graphene is a fantastic material that could play a crucial role in making new nano-sized electronics, it is still extremely difficult to control its electrical properties.' Since 2010, scientists at DTU have tried to tailor the electrical properties of graphene, by making a very fine pattern of holes, so that channels through which an electric power can flow freely are formed. 'Creating nanostructured graphene turned out to be amazingly difficult, since even small errors wash out all the properties we designed it to have,' comments Bøggild.

Korean researchers fabricate ordered graphene quantum dot arrays

A new study led by the Ulsan National Institute of Science and Technology in South Korea reveals a technology capable of fabricating highly ordered arrays of graphene quantum dots.

Korean researchers fabricate ordered graphene quantum dot arrays imageGraphene quantum dots of various sizes in a stable, ordered array

The research team demonstrated a novel way of synthesizing GQDs, embedded inside a hexagonal boron nitride (hBN) matrix. Thus, they demonstrated simultaneous use of in-plane and van der Waals heterostructures to build vertical single-electron tunneling transistors.

Graphene/hBN ceramic could act as a sensor for structures and aircraft

Rice University and Iran University of Science and Technology researchers have found a unique ceramic material that could act as a sensor for structures.

Graphene/hBN ceramic could act as a sensor for structures and aircraft image

The ceramic becomes more electrically conductive under elastic strain and less conductive under plastic strain, and could lead to a new generation of sensors embedded into structures like buildings, bridges and aircraft able to monitor their own health.