Transistors - Page 6

Researchers from the University of Strasbourg & CNRS (France), in collaboration with Humboldt University of Berlin and DWI Leibniz Institute for Interactive Materials/RWTH Aachen University in Germany, have shown that graphene devices can be used to monitor in real time the dynamics of molecular self-assembly at the solid/liquid interface.

Molecular self-assembly on surfaces is an attractive strategy to provide substrates with specific properties. Understanding the dynamics of the self-assembly process is vital in order to master surface functionalization. However, real-time monitoring of molecular self-assembly on a given substrate has proven complicated by the challenge to disentangle interfacial and bulk phenomena.

Following a $7.8 Million Series A-1 financing announced in March 2019, Cardea, (formerly called Nanomedical Diagnostics), a U.S-based manufacturer of a biology-enabled transistor technology made from graphene-based biosensors, now announced another $7.5 Million raised in the Series A2 Financing.

The capital will help accelerate the growth and development of the Company’s proprietary Tech+Bio Infrastructure and chipsets that enable Cardea’s Innovation Partners to bring Powered by Cardea" products to market with features and competitive advantages Cardea defines as "never seen before".

Graphenea recently announced that its graphene foundry service (GFAB), launched in 2019, will be getting an upgrade. Graphenea Foundry said that it will start a Multi-Project Wafer run service from January 2021, and it is currently speaking with customers interested in this first run.

Graphenea Foundry follows a pure-play foundry model, in which it manufactures graphene-based devices for its customers and third parties under request. Nevertheless, the factory also makes usable plug&play graphene devices from scratch, thus covering all aspects of device manufacturing. The staple product and the starting point for satisfying most customer needs is the GFET, the graphene field effect transistor. These readily-available devices are said to be ideal for early experiments and proof-of-concept measurements.

An international team of researchers, led by Tohoku University's professor Taiichi Otsuji, successfully demonstrated a room-temperature coherent amplification of terahertz (THz) radiation in graphene, electrically driven by a dry cell battery.

About 40 years ago, the arrival of plasma wave electronics fascinated scientists with the possibility that plasma waves could propagate faster than electrons, suggesting that so-called "plasmonic" devices could work at THz frequencies. However, experimental attempts to realize such amplifiers or emitters remained elusive.

Graphenea has announced the successful completion of project G4SEMI, funded by the European Commission SME Instrument.

The project, which lasted two years, aimed at integrating graphene into CMOS semiconductor workflows. The business goal was to create added value through fast-tracking market acceptance of graphene-on-wafer by lowering the technological barriers to adoption of graphene by the €545 billion semiconductor devices industry.

A team led by Boston College researchers has used a sheet of graphene to track the electronic signals inherent in biological structures, in order to develop a platform to selectively identify deadly strains of bacteria. This effort could lead to more accurate targeting of infections with appropriate antibiotics, according to the team.

The prototype demonstrates the first selective, rapid, and inexpensive electrical detection of the pathogenic bacterial species Staphylococcus aureus and antibiotic resistant Acinetobacter baumannii on a single platform, said Boston College Professor of Physics Kenneth Burch, a lead co-author of the paper.

Researchers from Loughborough University have created a unique graphene-based device which may unlock the elusive terahertz wavelengths and make revolutionary new technologies possible.

Light in the THz frequencies hits the ‘sandwich’ and is reflected with additional energy. Credit: Loughborough University

Terahertz waves (THz) are located between microwaves and infrared in the light frequency spectrum, but due to their low energy, scientists have been unable to harness their potential. This issue is known as the "terahertz gap".

Researchers from the Chinese Academy of Sciences have fabricated a graphene-based transistor with a Schottky emitter - a silicon-graphene-germanium transistor. Using a semiconductor membrane and graphene transfer, the team stacked three materials including an n-type top single-crystal Si membrane, a middle single-layer graphene (Gr) and an n-type bottom Ge substrate.

Device design and fabrication. Image credit: Nature Communications

The team explained that compared with previous tunnel emitters, the on-current of the Si-Gr Schottky emitter shows the maximum on-current and the smallest capacitance, leading to a delay time more than 1,000 times shorter. Thus, the alpha cut-off frequency of the transistor is expected to increase from about 1 MHz by using the previous tunnel emitters to above 1 GHz by using the current Schottky emitter. THz operation is expected using a compact model of an ideal device.

Physicists from the University of Groningen constructed a two-dimensional spin transistor, in which spin currents were generated by an electric current through graphene. A monolayer of a transition metal dichalcogenide (TMD) was placed on top of the graphene to induce charge-to-spin conversion in the graphene.

Spintronics is an attractive alternative way of creating low-power electronic devices. It is not based on a charge current but rather on a current of electron spins. Spin is a quantum mechanical property of an electron, a magnetic moment that could be used to transfer or store information.

In November 2018, researchers from the University of California, Santa Barbara presented a paper on CMOS-compatible graphene interconnects. Following this work, a team of University of California Santa Barbara (UCSB) engineering researchers recently came out with a method to utilize nanometer-scale doped multilayer graphene (DMG) interconnects well suited to the mass-production of integrated circuits.

For more than 20 years interconnects have been manufactured using copper as the base material, yet, the limitations of this metal when shrinking it to the nanoscale resistivity increase, which poses a fundamental threat to the $500 billion semiconductor industry, say researchers at UCSB. Graphene holds the potential to resolve this issue as a global desire for smarter, faster, lighter and affordable technology and devices continues to expand.