Friday, March 29, 2024

An Emerging Class Of Graphene Based Electronics

By Dr S.S. Verma

- Advertisement -

Researchers have developed a method for producing graphene-treated silver nanowires, which could significantly reduce production costs for nanowire based displays. This could mean that graphene offers a real alternative to indium-tin-oxide in flexible low-cost touchscreen displays. The work has cut the amount of expensive nanowires required to build such touchscreens by more than 50 times besides simplifying the production process by using graphene.

The key to the new process is to exploit graphene’s unmatched conducting properties. To do this, researchers changed from using graphene-oxide that is typically used in a solution based process to create nanowires to pristine graphene. Since pristine graphene is free of oxygen functional groups found in graphene-oxide, it could conduct electricity without any further chemical treatment, which resulted in more than a 50-fold reduction in the number of nanowires needed to produce viable electronic electrodes. This is a real alternative to indium-tin-oxide displays and could replace existing touchscreen technologies in electronic devices.

Energy-efficient transistors.

When graphene is placed on top of boron-nitride, it creates a super-lattice, which is a structure made of aligned, alternating layers of various nanomaterials. The super-lattice can move electrons perpendicular to the electric field without the influence of a magnetic field. This could lead to a new kind of energy-efficient transistor. While the research team has not attempted to build a transistor based on the phenomenon, the super-lattice material has displayed high sensitivity to gate voltage that operates transistors.

- Advertisement -

Another implication of this discovery is that electrons in the super-lattice appear to behave just like neutrinos, which are mass-less particles that do not interact with most kinds of matter. Researchers believe that this discovery could contribute to our understanding of the Universe.

Random access memory (RAM).

Researchers have developed a way of using graphene in order to improve the ferroelectric-tunnel-junction that is a component of RAM. They have improved the ferroelectric-tunnel-junction by combining graphene with ammonia so that it is capable of switching on and off the flow of electrons more completely.

The result is a distinct improvement in the reliability of RAM devices and the ability to read data without having to rewrite it. This is one of the most important differences between previous technology that has already been commercialised and this emergent ferroelectric technology.

In a typical ferroelectric-tunnel-junction design, a ferroelectric layer is placed between two electrodes so that when an electric field is applied to these, direction of the junction’s polarisation is reversed. This reversal of polarisation changes the alignment of positive and negative charges, which correspond to zero and one in binary computing.

Energy storage.

Being able to create super-capacitors out of graphene will possibly be the biggest step in electronics engineering. While development of electronic components has been progressing at a very high rate over the last 20 years, power storage solutions such as batteries and capacitors have been the primary limiting factor due to size, power capacity and efficiency (most types of batteries are very inefficient, and capacitors are even less so).

For example, with the development of currently-available lithium-ion batteries, it is difficult to create a balance between energy density and power density. In this situation, it is essentially about compromising one for the other.

Graphene is also being used to boost not only the capacity and charge rate of batteries but also longevity. Currently, while such materials as silicone are able to store large amounts of energy, that potential amount diminishes drastically on every charge or recharge. With graphene tin-oxide being used as an anode in lithium-ion batteries. for example, batteries can be made to last much longer between charges (potential capacity has increased by a factor of ten). And with almost no reduction in storage capacity between charges, it would effectively make electronically-powered vehicles a much more viable transport solution in the future.

This means that batteries (or capacitors) can be developed to last much longer and at higher capacities than previously realised. Also, it means that electronic devices may be able to be charged within seconds, rather than minutes or hours, and have hugely-improved longevity.

This illustration depicts a copper nanowire coated with graphene—an ultrathin layer of carbon—which lowers resistance and heating, suggesting potential applications in computer chips and flexible displays (Image courtesy: www.purdue.edu)
This illustration depicts a copper nanowire coated with graphene—an ultrathin layer of carbon—which lowers resistance and heating, suggesting potential applications in computer chips and flexible displays (Image courtesy: www.purdue.edu)

Textile electrodes.

A team of researchers has used chemical vapour deposition to fabricate monolayer graphene. This research has developed a way to peel graphene off the copper sheet and transfer it to a yarn without compromising the electronic properties of graphene. The methodology that has been developed to prepare transparent and conductive textile fibres by coating these with graphene will now open the way to the integration of electronic devices on these textile fibres.

Researchers envision this process will enable a range of potential applications including textile GPS systems, biomedical monitoring, personal security or even communication tools for those who are sensory impaired.

Graphene-coated copper nanowires.

In research that sort of bridges flexible displays with interconnects, researchers have been successful in developing copper nanowires coated with graphene to lower resistance and susceptibility to heating of copper wires. This research could allow copper wires to be used in a range of electronics including the flexible variety.

SHARE YOUR THOUGHTS & COMMENTS

Electronics News

Truly Innovative Tech

MOst Popular Videos

Electronics Components

Calculators