Researchers create miniscule graphene-MoS2 transistors

Researchers from China's Tsinghua University and East China Normal University have created a transistor with the smallest gate length ever reported. This milestone was made possible by using graphene and molybdenum disulfide and stacking them into a staircase-like structure with two steps.

Vertical MoS2 transistors with sub-1-nm gate lengths imageThe structure of the side-wall transistor: Silicon dioxide base (dark blue), aluminum covered in aluminum oxide (brown ), the thin, light blue strip is graphene, the yellow and black strip is molybdenum disulfide, and underneath it, the hafnium dioxide.

On the higher step, there is the source, and on top of the lower step, there is the drain. Both are made of a titanium palladium alloy separated by the surface of the stairs, which is made of a single sheet of a molybdenum disulfide (MoS2), itself resting on a layer of hafnium dioxide that acts as an electrical insulator.

Researchers experiment with LIG to create improved wearable health devices

A Penn State-led international research team (led by Professor Huanyu “Larry” Cheng at Penn State) recently published two studies that could boost research and development of future motion detection, tactile sensing and health monitoring devices.

Graphene made with lasers for wearable health devices image

There are various substances that can be converted into carbon to create graphene through laser radiation, in a process called laser-induced graphene (LIG). The resulting product can have specific properties determined by the original material. The team set out to test this process and has reached interesting conclusions.

Graphene ‘nano-origami’ could enable tiny microchips

Scientists at the University of Sussex have developed a technique for making tiny microchips from graphene and other 2D materials, using a form of ‘nano-origami’.

By creating distortions in the structure of the graphene, the researchers were able to make the nanomaterial behave like a transistor. “We’re mechanically creating kinks in a layer of graphene,” says Professor Alan Dalton of the School of Mathematical and Physics Sciences at the University of Sussex. “It’s a bit like nano-origami. Using these nanomaterials will make our computer chips smaller and faster. It is absolutely critical that this happens as computer manufacturers are now at the limit of what they can do with traditional semiconducting technology. Ultimately, this will make our computers and phones thousands of times faster in the future.”

New technique may enable large-area integration of 2D materials

Researchers affiliated with the Graphene Flagship from RWTH Aachen University, Universität der Bundeswehr München and AMO in Germany, KTH Royal Institute of Technology in Sweden and with Protemics have reported a new method to integrate graphene and 2D materials into semiconductor manufacturing lines, a milestone for the recently launched 2D-EPL project.

Schematic illustration of the methodology for wafer-level transfer of two-dimensional materials imageImage from Nature Communications

Two-dimensional (2D) materials have a huge potential for providing devices with much smaller size and extended functionalities with respect to what can be achieved with today's silicon technologies. But to exploit this potential, it is vital to be able to integrate 2D materials into semiconductor manufacturing lines - a notoriously difficult step. This new technique could be a step in the right direction as far as solving this problem is concerned.

Stretchable and ultrasensitive NO2 sensors based on rGO and MOS2 nanocomposites

Researchers at Penn State, Northeastern University and five universities in China have developed and tested a stretchable, wearable gas sensor for environmental sensing.

Stretchable, ultrasensitive, and low-temperature NO2 sensors based on MoS2@rGO nanocomposites image

The sensor combines a newly developed laser-induced graphene foam material with a unique form of molybdenum disulfide and reduced-graphene oxide nanocomposites. The researchers were interested in seeing how different morphologies of the gas-sensitive nanocomposites affect the sensitivity of the material to detecting nitrogen dioxide molecules at very low concentration. To change the morphology, they packed a container with very finely ground salt crystals.