Graphene CVD sheets - updates and market status - Page 9

Grolltex, a U.S-based advanced materials and equipment company, recently announced a large-capacity commercial lab for production of high quality CVD graphene. Grolltex states that it is now manufacturing the material in its new class 1000 clean room, producing both raw graphene as well as products made from the material, like sensors, perovskite solar cells, display materials and X-ray windows for use in spacecraft.

The new Grolltex graphene facility is said to be capable of producing large high-quality sheets of graphene for commercial sale. The Company is said to have a patented methodology to manufacture the material in a novel way that yields lower-cost materials of high quality. Grolltex leverages graphene research and patents developed at nearby University of California, San Diego.

Researchers from Korea and China have developed a method to synthesize large sheets of monolayer single-crystal graphene.

Polycrystalline graphene is formed by randomly oriented graphene islands, which decreases its quality. Currently, scientists can grow meter-sized polycrystalline graphene and smaller sizes of the usually higher-quality single-crystal graphene, ranging from 0.01 mm² to a few square centimeters. The synthesis of large single-crystal graphene at a low cost is considered a desirable goal. In this study, the team reported the synthesis of a large sheet of monolayer single-crystal graphene.

Scientists at Rice University and the University of Houston have developed a catalyst that can simplify the splitting of water into hydrogen and oxygen to produce clean energy. The electrolytic film is a three-layer structure of nickel, graphene and a compound of iron, manganese and phosphorus. The foamy nickel gives the film a large surface, the conductive graphene protects the nickel from degrading and the metal phosphide carries out the reaction.

The film was developed to overcome barriers that usually make a catalyst good for producing either oxygen or hydrogen, but not both simultaneously - as is often the case with regular metals. The team explained that normally, a hydrogen evolution reaction is done in acid and an oxygen evolution reaction is done in base. This work produced one material that is stable whether it's in an acidic or basic solution. In addition, the team used rather common materials in lieu of the usually-required platinum and other costly materials.

Researchers from MIT have fabricated a functional dialysis membrane from a sheet of graphene. The team’s membrane is able to filter out nanometer-sized molecules from aqueous solutions up to 10 times faster than state-of-the-art membranes, with the graphene itself being up to 100 times faster. The graphene membrane is also very thin; It's less than 1 nanometer thick, while the thinnest existing membranes are about 20 nanometers thick.

Dialysis can be generally described as the process by which molecules filter out of one solution by diffusing through a membrane, into a more dilute solution. The most recognizable form is hemodialysis, which removes waste from blood, but scientists also use dialysis for many other applications, like purifying drugs, removing residue from chemical solutions, and more, typically by allowing the materials to pass through a porous membrane.

Researchers from the ICFO have developed the first graphene-QDs-CMOS integrated camera, capable of imaging visible and infrared light at the same time. The camera may be useful for many applications like night vision, food inspection, fire control, vision under extreme weather conditions, and more.

The imaging system is said to be based on the first monolithic integration of graphene and quantum dot photodetectors, with a CMOS (complementary metal-oxide semiconductors) read-out integrated circuit. The implementation of such a platform in applications other than microcircuits and visible light cameras has been impeded by the difficulty to combine semiconductors other than silicon with CMOS, an obstacle that has been overcome in this work.

Researchers from the University of Hamburg and Graphenea have succeeded in upscaling high-quality graphene devices to the 100-micron scale and beyond. By perfecting CVD graphene production, transfer and patterning processes, the team managed to observe the quantum Hall effect in devices longer than 100 micrometers, with electronic properties on par with micromechanically exfoliated devices.

The work started from graphene grown by chemical vapor deposition (CVD) on a copper substrate. Since graphene on metal is not useful for applications in electronics, the material is usually transferred onto another substrate before use. The transfer process has proven to be a challenge, in many cases leading to cracks, defects, and chemical impurities that reduce the quality of the graphene.

Scientists from IEMN-CNRS, Graphenea, and Nokia have demonstrated flexible graphene transistors with a record high cut-off frequency of 39 GHz. The graphene devices, made on flexible polymer substrates, are stable against bending and fatigue of repeated flexing.

The graphene field effect transistor (GFET) is made from high quality CVD grown graphene with a carrier mobility of ~2500 cm2 V-1 s-1 on a flexible Kapton substrate with a thin alumina dielectric spacer in the channel region. The use of such sophisticated and optimized materials leads to the record high frequency performance as well as stability against bending. The GFET reportedly continues to operate even after 1,000 bending cycles and can be flexed to a radius of 12 mm with a cutoff frequency shift of up to 10%.

Researchers from King Abdullah University of Science and Technology (KAUST), in collaboration with the Georgia Institute of Technology, have recently demonstrated a simple, solution-based, method for surface doping of few-layer graphene (FLG) using novel dopants (metal-organic molecules) that show a minimal effect on the optical transmission as compared to other dopants like metal chlorides.

This work investigates the effect of dopant strength and dosage on the electronic and electrical transport properties of doped FLG. Moreover, It reveals fundamental differences between the doping results in single layer graphene and few-layer graphene. The study focused on few-layer CVD graphene, rather than single-layer CVD graphene, a somewhat less common area of research to date.

Researchers at Rice University have constructed a graphene foam, reinforced by carbon nanotubes, that can support more than 3,000 times its own weight and bounce back to its original height. In addition, its shape and size are easily controlled - which the team demonstrated by creating a screw-shaped piece of the material.

The 3D structures were created from a powdered nickel catalyst, surfactant-wrapped multiwall nanotubes and sugar as a carbon source. The materials were mixed and the water evaporated; the resulting pellets were pressed into a steel die and then heated in a chemical vapor deposition furnace, which turned the available carbon into graphene. After further processing to remove remnants of nickel, the result was an all-carbon foam in the shape of the die, in this case a screw. The team said the method will be easy to scale up.

Graphenea, a company focused on the production of high quality graphene for industrial applications, has announced a significant price reduction. The price of CVD films has dropped 15% on average this January, and the price of graphene oxide (GO) is being reduced by 30% on average.

CVD films are being offered on the copper substrates that they are grown on, in sizes ranging from 10x10 mm to 4 inch diameter. The same high quality graphene films are also available on SiO2/Si, quartz, PET, suspended on TEM grids and cavities, and on custom substrates as required. For customers wishing to do their own transfer, CVD graphene is also available on polymer films for easy transfer.