Displays - Page 8

Researchers at Purdue University suggest wrapping silver nanowires with an ultrathin layer of graphene can protect the structures from damage and could represent a key to realizing their commercial potential. Silver nanowires are known to hold promise for applications such as flexible displays and solar cells, but their susceptibility to damage from UV radiation and harsh environmental conditions has limited their commercialization.

The scientists state that Devices made from silver nanowires and graphene could find uses in solar cells, flexible displays for computers and consumer electronics, future "optoelectronic" circuits and more, since that graphene "extracts and spreads" most of the thermal energy away from the nanowires. Raman spectroscopy was performed by the Purdue Department of Physics and Astronomy and findings showed the graphene sheathing protected the nanowires even while being subjected to 2.5 megawatts of energy intensity per square centimeter from a high-energy laser, which vaporizes the unwrapped wires. The unwrapped wires were damaged with an energy intensity as little as .8 megawatts per square centimeter. The graphene also helps to prevent moisture damage.

Thomas Swan has announced the availability of two new graphene grades: Elicarb Electrical Grade Graphene Powder for conductive inks and Elicarb Materials Grade Graphene Powder for composites & plastics. In combination with the company's existing products of Elicarb Premium Grade Graphene Powder and Elicarb Premium Grade Graphene Dispersion (AQ) which are meant for electronics & displays applications, the company now provides a full suite of graphene products.

Thomas Swan states that it continues to focus on reliably delivering high quality, consistent graphene products via the Direct Exfoliation process which extracts graphene directly from graphite raw materials. By tuning its extraction process, the company can produce graphene products that range from the Few Layer Graphene through to the Multi-Layer graphene nanoplatelet. 

Haydale recently announced that its proprietary HDPlas technology has been used to create functionalized Graphene Nanoplatelets (GNPs) that have been incorporated into a functional graphene ink, which has been developed for screen printing. The ink has been created with area printing applications in mind.

A recent report details how a screen-printable functional graphene based ink, supplied by Goodfellow, performs better than many normal carbon-based ink, opening the door to innovative applications that require enhanced electrical conductivity, excellent adhesion on a range of substrates and high print resolution. Such applications are found in sensors, displays, printed electronics and electrodes.

The Centre of Process Innovation (CPI) has announced that it will be part of a UK-based collaboration to develop the next generation of graphene-based ultra-barrier materials for flexible transparent plastic electronic based displays. The materials on which this work focuses on are required for the next generation of smartphones, tablets and wearable electronics and the twelve month project titled ‘Gravia’ will investigate the feasibility of producing graphene-based barrier films for next generation flexible OLED lighting and display products. 

The project combines the skills from each of the partners (University of Cambridge, FlexEnable Ltd, the National Physical Laboratory and the Centre for Process Innovation) and expects to deliver a feasible material and process system. It builds upon significant existing investments by InnovateUK and the EPSRC in this area. The resulting ultra-barrier material can be potentially used in a wide range of novel applications by the lead business partner, FlexEnable.

A few weeks ago we reported on a new IDTechEx market report, in which they predict that the graphene market will reach nearly $200 million by 2026, with the estimation that the largest sectors will be composites, energy applications and graphene coatings.

We were very interested in learning more, and Dr Khasha Ghaffarzadeh, IDTechEx's head of consulting was kind enough to answer a few questions and explain the company's view on the graphene market.

Q: IDTechEx has been following graphene for a long time with dedicated events and reports. Why is this new material interesting for IDTechEx?

We have a long track record of analyzing emerging advanced materials such as quantum dots, CNTs, Ag nanostructures, silicon nanostructures, OLED materials, etc. We were however pulled into the world of graphene by our clients’ questions. Once in, we soon realized that there is a big synergy between graphene and our events. in fact, our events on supercapacitors and printed electronics were the right near-term addressable market for graphene, and that is why we managed to rapidly build up the largest business-focused event on graphene. Our events on graphene are held in the USA and Europe each year see www.IDTechEx.com/usa.

Researchers from Korea Advanced Institute of Science and Technology (KAIST) have fabricated light-emitting diodes (LEDs) based on graphene quantum dots (GQDs). The researchers made pure GQDs using a cost-effective, scalable and environmentally friendly method that allows direct fabrication of GQDs using water, without surfactants or chemical solvents.

Those GQDs were then used as emitter material to create an OLED device.The scientists constructed GQD LEDs exhibiting luminance of 1000 cd/m2, which is well over the typical brightness levels of the portable displays used in smartphones.

A team of scientists from Columbia, Seoul National University (SNU), and Korea Research Institute of Standards and Science (KRISS) reported the creation of an on-chip visible light source using graphene as a filament. Creating light in small structures on the surface of a chip is crucial for developing fully integrated 'photonic' circuits that do with light what is now done with electric currents in semiconductor integrated circuits.

The scientists attached small strips of graphene to metal electrodes, suspended the strips above the substrate, and passed a current through the filaments to cause them to heat up. The team refers to this design as 'the world's thinnest light bulb', a type of 'broadband' light emitter that can be integrated into chips and may pave the way towards the realization of atomically thin, flexible, and transparent displays, and graphene-based on-chip optical communications.

Scientists at the Goethe University in Germany have developed a new class of organic luminescent materials through the targeted introduction of boron atoms into the molecular structures of graphene. The compound feature an intensive blue fluorescence and are therefore of interest for use in organic light-emitting diodes (OLEDs). 

A comparison of the new boron-containing nanographenes with an analogous boron-free material verifies the fact that the boron atoms have a great impact on two important properties of an OLED: the fluorescence shifts into the desirable blue spectral range and the capacity to transport electrons is substantially improved. currently, very limited use can be made of boron-containing nanographenes, since most of the exponents are sensitive to air and moisture. The scientists in this study claim that this problem does not occur with their materials, which is important with regard to practical applications. 

Graphenea recently introduced large area monolayer graphene suspended over microcavities as a standard catalog product, that can be used for NEMS (Nanoelectromechanical systems) due to its reliance on small vibrating membranes, which are sensitive to tiny forces.

Image courtesy of Stefan Wagner / Max Lemme, University of Siegen

NEMS are entering mainstream technology through sensors and actuators in platforms as common as inkjet printers, accelerometers, displays, and optical switches. The membranes used in NEMS need to be lightweight and stiff, with a high Young's modulus. As such, graphene is a very promising candidate for applications that require ultrathin membranes with excellent mechanical properties.

Researchers from the University of Maryland found that intercalating (embedding) sodium ions in a reduced graphene oxide (rGO) network, printed with graphene oxide (GO) ink, can significantly improve its performance as a transparent conductor in displays, solar cells and electronic devices.

The scientists used cost-effective materials and production techniques to receive a highly scalable printed electronics system that produces relatively inexpensive and stable conductors. The team theorizes the increased stability is due to the natural oxidation of sodium along the edges of the printed networks which forms a barrier that prevents ion loss. Networks printed with the ink exhibit up to 79 percent optical transmittance and 311 Ohms per square of sheet resistance.