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Grolltex Releases ‘Enhanced Performance Graphene’ for Electronic Devices

Posted By Terrance Barkan, Monday, October 15, 2018

San Diego based graphene and 2D materials producer Grolltex has completed characterization and is releasing for commercial sale a configuration of large area, single layer graphene that exhibits dramatically improved ‘electron mobility’, which translates to better graphene performance.  This ‘heterostructure’ contains a layer or layers of hexagonal Boron Nitride (or ‘hBN’) underneath graphene, enabling enhanced graphene capabilities.  

Grolltex has begun commercial pre-sales to customers of this ‘Enhanced Performance Graphene’ product, which can significantly improve device performance for sensing, transistors, connectivity and other key aspects of nano-devices.  This type of material performance improvement is often a stepping stone for new applications enabling large market growth toward faster, smaller, cheaper and more sensitive silicon-based devices.

“The data back from our large European device partner showed carrier mobility performance improvements starting at 30%, and our internal work shows us that with some configuration adjustments, we can even build on this toward electron mobility improvements in exponential regimes”, said Jeff Draa, Grolltex CEO and co-founder.  “We believe this is going to be incredibly important to many of our customers that build things on silicon”.

The first reason for the improvement of graphene electron mobility performance, when layered on top of hBN on a wafer, is that the underlying layer of hBN, between the wafer and the graphene, planarizes the surface of the silicon wafer and allows graphene to sit on a surface (hBN) far more conducive to graphene electron flow.  

Another reason has to do with the electron interference of the oxide coming out of the underlying Si/SiO2 wafer, if graphene sits directly on top of it.  With the hBN layer between the graphene and the wafer, the negative effect of the oxide from the wafer on graphene electron performance is greatly reduced, allowing a much freer flow of graphene electrons.  Additional advantages are lower processing temperatures and a much stronger adhesion of the graphene layer to the underlying substrate, with hBN present.

“So, when graphene sits on hBN, it performs much closer to the theoretical ‘electron superhighway’ that graphene users expect”, according to Draa. “We have characterized and are selling this heterostructure to our pre-qualified customers in up to 8” (200mm) diameter configurations and can layer hBN and graphene in any combination”. 

“Device designers, especially advanced sensor makers, are really keyed in to electron mobility. There are many variables that affect this and he who can square those away and show dramatic improvements in mobility can help add real, unique and substantial value to device performance”, said Draa. “Next on our characterization list is MoS2, which is an important ‘band-gap’ material that has been missing in 2D offerings.”

Grolltex, short for ‘graphene-rolling-technologies’, uses patented research and techniques initially developed at the University of California, San Diego, to produce high quality, single layer graphene, hexagonal Boron Nitride and other 2D materials and products.  The company is a practitioner of, and specializes in, exclusively sustainable graphene production methods and is committed to advancing the field of graphene to improve the future of leading edge materials science and product design through the optimization of single atom thick materials.

About Grolltex:

Grolltex, Inc., is a nanotechnology materials, products and equipment company focusing on the optimization and advancement of the key monolayer material ‘graphene’ and related 2D materials.  The company holds a number of strategic patents and technological advantages in areas relating to the manufacture of high quality, monolayer ‘CVD’ graphene and hexagonal Boron Nitride as well as on several advanced products made of graphene and 2D materials, such as hyper efficient solar cells, next generation sensors, advanced fuel cells and futuristic super-thin and flexible displays for use in wearables, smart phones and other electronics.  

For complete information, please visit: https://grolltex.com/

 

Media Contact:

Attn: Media Relations, Grolltex, Inc.

10085 Scripps Ranch Court, Suite D

San Diego, CA 92131

support@grolltex.com

Tags:  CVD  Electronics  Graphene  Grolltex  HbN  Jeff Draa 

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2D materials - Graphene and hBN (hexagonal boron nitride) enhances methanol fuel cell performance

Posted By Terrance Barkan, Tuesday, November 29, 2016

This is an authorized reprint of a recent publication in Advanced Energy Materials journal (Impact Factor: 16) (http://dx.doi.org/10.1002/aenm.201601216), by Stuart M. Holmes (Reader) and Prabhuraj - (PhD student - http://www.prabhuraj.co.uk/) from the School of Chemical Engineering and Analytical Science, University of Manchester in collaboration with the School of Physics, reporting the usage of 2D materials in operating direct methanol fuel cells, showing zero resistance to protons enhancing cell performance, thereby opening the bottle neck for commercialization of fuel cells. 

The content published is the sole responsibility of the authors. 

Fuel cells are an interesting energy technology for the near future, as they aid in production of sustainable energy using hydrocarbons as fuels, such as methanol, ethanol, acetone etc by a simple oxidation-reduction reaction mechanism.

Among different liquid fuels, methanol is attractive as it has a higher energy density (compared to lithium ion batteries and hydrogen) and other features such as ease in handling, availability etc. Hence methanol fuel cells find their potential use in laptop chargers, military applications or other scenarios where the access to electricity is difficult.

However the wider spectrum of commercial potential for methanol systems is greatly hindered by methanol cross over occurring in the membrane area of fuel cells. This is defined as the passage of methanol from anode to the cathode through the membrane, hence creating short circuit and greatly affecting the fuel cell performance.

This is mitigated by using barrier layer, in addition to the membrane used. 

Figure 1: Schematic illustration of methanol fuel cell and structure of graphene

So far many materials have been used as a barrier layer in methanol fuel cells, where the proton conductivity is balanced with the methanol cross over. Proton conductivity is one of the dominant factors, where slight reduction in proton conductivity can influence the fuel cell performance to a large extent. All the materials reported in the literature to date have seen a reduction in proton conductivity though methanol cross over is reduced. 

It is known that Andre Geim and his co-workers (Nature, A.K. Geim et.al 2014), discovered proton transfer through single layer graphene and other 2D materials. Also graphene is known for its dense lattice packing structure, inhibiting the passage of methanol and other hydrocarbon based molecules across the membrane. However the actual application of these 2D materials in fuel cell systems has not yet been realized.

In this Advanced Energy Materials paper, the researchers have used single layer graphene and hBN, formed by chemical vapour deposition method, as a barrier layer in the membrane of methanol fuel cells. They have reported that this thinnest barrier layer ever used before shows negligible resistance to protons, at the same time reducing cross over, enhancing the cell performance by 50%. This is of significant interest, as this would lead to usage of 2D materials in fuel cells.

Based on the results of the research obtained, researchers have been granted EPSRC (Engineering and Physical Sciences Research council grant “Adventurers in Energy grant”) to pursue further research in this field. They have shown that as the surface coverage of the 2D material on the system improved, the performance improved.  This would lead to the usage of fuel cells, operating with high concentrated methanol fuels, as the current fuel cells suffer from cross over phenomena, with increased concentration. 

Moreover, this would pave the way for a membrane-less fuel cell system operating with higher efficiency. This technology could further be extended to other fuel cells types namely hydrogen fuel cells. Hydrogen fuel cells suffer from the usage of high cost humidifier, where the membrane needs to be humidified for improved proton conductivity. Whereas graphene, as reported in earlier studies, showed improved proton conductivity with temperature, without the need for humidifier systems. The future prospect could be realized in such a way that the fuel cells will make significant contribution to the future energy demand. 


Tags:  Fuel Cells  Graphene  hBN  Hexagonal boron nitride  Methane 

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