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Join the Graphene Flagship Core 3 Spearhead Project GRAPES

Posted By Graphene Council, Monday, January 13, 2020

The Graphene Flagship is looking for a new partner that brings in specific industrial and technology transfer competences or capabilities that complement the present consortium of the Spearhead Project GRAPES.

We are seeking an industrial partner with the following expertise and capabilities:

· A world-leader in renewable power generation.

· A proven track record in manufacturing and assembly of photovoltaic (PV) panels and operation of solar parks.

· A fully automated pilot silicon PV line in order to transfer the tandem process developed within SH5 Grapes to its line and demonstrates industrial S2S manufacturing.

· Operational solar parks in different European geographical locations.

· The Company must have:

1. Fully automated pilot line for the production of Si high efficiency solar cells (>20%) with a throughput>150 MW/year.

2. Manufacturing Execution System and Statistical Process Control for real-time out of control detection to costs and performances optimization.

3. Owner/Operator of solar parks for on-site outdoor testing of tandem PV panels in multiple sites across Europe.

The newly selected partner will be incorporated in the Core 3 Project under the Horizon 2020 phase of the Graphene Flagship, which will run during 1 April 2020 - 31 March 2023. The new partners will be requested to sign the relevant agreement with the European Commission.

Tags:  Graphene  Graphene Flagship  photovoltaics  solar cells 

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Mayor praises Manchester model of innovation as graphene applications gain real pace

Posted By Graphene Council, Monday, January 13, 2020
Andy Burnham, Mayor for Greater Manchester, made a fact-finding tour of facilities that are pioneering graphene innovation at The University of Manchester.

The Mayor toured the Graphene Engineering Innovation Centre (GEIC) which is an industry-facing facility specialising in the rapid development and scale up of graphene and other 2D materials applications.

As well as state-of-the art labs and equipment, the Mayor was also shown examples of commercialisation – including the world’s first-ever sports shoes to use graphene which has been produced by specialist sports footwear company inov-8 who are based in the North.

Andy Burnham – a running enthusiast who has previously participated in a number of marathons – has promised to put a pair of graphene trainers to the test and feedback his own experiences to researchers based at The University of Manchester.

Manchester is the home of graphene - and when you see the brilliant work and the products now being developed with the help of the Graphene@Manchester team it’s clear why this city-region maintains global leadership in research and innovation around this fantastic advanced material, Andy Burnham, Greater Manchester Mayor.

By collaborating with graphene experts in Manchester, inov-8 has been able to develop a graphene-enhanced rubber which they now use for outsoles in a new range of running and fitness shoes. In testing, the groundbreaking G-SERIES shoes have outlasted 1,000 miles and are scientifically proven to be 50% stronger, 50% more elastic and 50% harder wearing.

“Manchester is the home of graphene - and when you see the brilliant work and the products now being developed with the help of the Graphene@Manchester team it’s clear why this city-region maintains global leadership in research and innovation around this fantastic advanced material,” said Andy Burnham.

“I have been very impressed with the exciting model of innovation the University has pioneered in our city-region, with the Graphene Engineering Innovation Centre playing a vital role by working with its many business partners to take breakthrough science from the lab and apply it to real world challenges.

“And thanks to world firsts, like the graphene running shoe, the application of graphene is now gaining real pace. In fact, the experts say we are approaching a tipping point for graphene commercialisation – and this is being led right here in Greater Manchester.”

Tags:  2D materials  Andy Burnham  Graphene  Graphene Engineering Innovation Centre  inov-8  sporting goods  University of Manchester 

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Accelerating Graphene’s Commercial Deployment

Posted By Graphene Council, Monday, January 13, 2020
Updated: Friday, January 10, 2020
Guest Editorial from Dr. Francis Nedvidek, Faculty of Science at the Technical University of Dresden

After initial isolation in 2004 and a decade and one-half of follow-on discovery, material research and process development, only a trickle of graphene enhanced applications have reached the market. In spite of huge progress and critical advances the so called “killer applications” have yet to appear. Commercial deployment of nanoplatelet graphene, not to mention a cohort of emerging 2D materials, face three challenges.

The first and most obvious obstacle is a consequence of graphene’s newness. Harnessing novel functionality entails painstaking searches for new recipes, non-standard ingredients and adaptation of processes, manufacturing methods and industrial infrastructure. The second hurdle relates to graphene’s assimilation into industrial scale processes and supply and distribution networks. The third challenge demands rigorous focus on the applications where customers unambiguously recognize graphene’s unique value and for which graphene-enabled solutions eclipse all contenders.

Commercial graphene-enhanced products are penetrating niche markets with formulations demonstrating cost to performance ratios decisively better than the alternatives. And the production and supply issues impeding broader commercial development of graphene-based materials - including quantity, consistency, dependability, standardized characterization, certification, traceability and purity - are being remedied. Never-the-less, the number of deployments in high-volume graphene-enhanced application remains modest.

Let’s delve deeper into why this is so; and, then explore ways to accelerate graphene’s wider-adoption.

1) Building a Better Product Using Graphene – A View from the Material Engineering Lab
Nanomaterials – to the dismay of material engineers and production plant managers - store, transport, mix and behave markedly differently from their bulk material counterparts. Not only is the graphene nano-platelet characteristically distinct from the precursor graphite, but specific flake size, topology, and nuances of compound constitution and processing particulars influence nearly every aspect of how the material performs in the final application. At best, bulk material recipes serve only - but in not all cases - as rough starting points from which to begin iterative “expeditions” into uncharted design and engineering territory. Exploiting graphene’s exemplary properties requires iteratively investigating, testing and re-evaluating formulations, modifying existing processes, and adapting contemporary production equipment.

Figure 1 - A generalized development plan for graphene material applications

2) Harnessing Graphene as Enabler

Creating a graphene-enhanced compound typically begins with selection of a specific nanoplatelet profile of lateral size, thickness, defect density, purity and topology. Functionalization, in most instances, plays a pivotal role in dispersion and therefore the molecular bonds and structures assembled within the graphene-doped host matrix which impact the properties of the final and end product. Single digit % by weight graphene concentrations (and often less than 1% by weight) are common making process precision and consistency crucial. Commercially available matrix substances (typically polymers), various bulk ingredients and chemical additives are mixed per specified quantity and according to one, or a combination of, mechanical sheer milling, ultrasonic agitation or pressurization etc., techniques. Processing duration, extrusion method and temperature are just a few of the parameters adjusted during injection molding, thermal-set molding, spin drawing, aerosol spraying, dip coating, adsorption, relief printing etc. to yield the desired end component or product. All data including recipe, ingredient concentrations, process parameters are meticulously registered both quantitatively and qualitatively. The front end of the procedure appears in the graphic of Figure 2 below.

Figure 2 – Data collection in graphene formulation discovery

The network of Figure 3 below depicts material selection, ingredient integration, processing, preparation evaluation and the filtering of outcomes cascades through a maze of options. The exercise begins with selection of the graphene supply and proceeds though to completion of a selection of final compounds or a final product. Successive attempts are sorted according to ingredient constellation, concentration level, process parameter regime etc. The outcomes most closely approaching the desired product performance and estimated per unit production cost are used for subsequent trials.

Figure 3 – Recipe discovery - a labyrinth of options

Progressive iterations eventually coalesce into a small number of potentially most suitable “material recipes and process regimes”. Further refinements culminate in material assays, sub-component samples or final product prototypes demonstrating the characteristics, behavior, supply chain ecosystem fit and benchmark economic prerequisites before undertaking scale production of the winning viable intermediate component or the end product.

3) Solve Problems & Satisfy Needs with Graphene-Enhanced Materials
A formidable assortment of options and combinations of ingredients and procedures conspire to create a graphene-enhanced product destined for use as a vehicle component, battery electrode, integrated sensor module, anticorrosion chassis coating, rubber seal or auto dashboard – or even piece of sporting gear. Formulations, masterbatches and intermediate components may be marketed/sold separately to end up in any number of downstream products and applications. The Figure 4 below displays the major product development activities according to relevant development stages.

Figure 4 - The value creation chain for a graphene-enhanced product.

The arches traversing individual upstream and downstream value creation stages represent enquiries, specification requests, test protocols, parts, components, software code and exchange of standard business documentation. This bi-directional flow of human liaisons including problem solving sessions, teleconferences, schedule update meetings and business and industry forecast exchanges ricochet between partners and among collaborators. Each link of the chain represents an enterprise bound to reconcile its own technical, operational, and logistic capabilities and economic obligations. Close and dynamic collaboration is vital in charting routes through the network promising the best chance for success of individual contributors and the end user solution.

Figure 5 below illustrates the perspective of the graphene technologists peering downstream in search of problems in need of solving. They are eager to monetize exceptional effort, personal risk, patented intellectual property and acquired know how.

Figure 5 – View from the engineering lab

Improved functionality, reduced cost of ownership, appropriate certification, higher income garnering potential etc. must render value exceeding the price in light of alternative approaches including compensation for perceived risk, switching cost or similar disadvantages. However, if the inventive engineers lack information pertaining to the end customer’s problems, needs or wants, they may not be able to precisely identify the ultimate customer or enduser.

4) Problems, Needs and Unidentified Opportunities

Customers purchasing graphene enhanced products or materials expect to enjoy or otherwise benefit from the utility generated from these graphene-enhanced products. Owing to good luck, fortuitous contacts and helpful channels via suppliers, sales agents and distribution partners, a development team can gain at least some understanding of how graphene serves the application and lends value and satisfaction to end customers. Figure 6 portrays the customer’s viewpoint.

Figure 6 – View from the customer

The benefits of graphene are diverse and varied and determined by the appraisal of the product’s functional and economic attributes by the customer and buying influencers. Cost savings, space savings, flexibility of use, physical attractiveness, prestige, ease of maintenance, product safety, peace of mind and enhanced value and finally desirability in terms of the customer’s customers are a few examples of value. An enterprise selling / delivering the value is rewarded in terms of purchase price, future repurchases, volume orders, collaborative relationships, ecosystem intelligence etc.

In the case of graphene or other novel or disruptive technologically driven innovations, any departure from standard application methods, practices or fulfillment models requires increased attention to issues not encumbering traditional or entrenched competitors – initially. Particularly for graphene, prospects with potential to disburse large orders reciprocally demand delivery quantities and lead times unattainable for shops not yet operating at industrial sale. Conversely, suppliers of ingredients, plant and equipment tend to eschew new enterprises lacking financial gravitas. Instead, innovative companies must play to their strengths: flexibility, speed and readiness to work collaboratively in revealing, inventing, testing and fine-tuning formulations and products that address the customer’s needs, mitigating the user’s problems in ways competing offers cannot. Figure 7 below summarizes how the innovator views the endeavor and the customer considers purchasing the graphene-enhanced product.

Figure 7 – Successful Innovation and the Meeting of Minds

5) Problems, Needs and Unidentified Opportunities

How does one acquire a relevant and unambiguous overview of the utility, benefit and advantages graphene products should target? Market studies offer a perspective of industry fundamentals, market size and trends, existing benchmarks and statistics. Trade shows and industry events provide information regarding the ecosystem’s competitive landscape, technological progress and future developments. However, speaking directly with customers represented by Product Managers, CTOs, Marketing Managers and Distribution Partners confers more specific and highly relevant detail. And building relationships with customer groups as well as other stakeholders proves immeasurably helpful in uncovering latent needs, unappreciated deficiencies and previously unarticulated insights.

Interactions with customers as well as upstream and downstream value chain stakeholders including suppliers, service providers and manufacturing partners typically yields highly useful information concerning production methods, process short cuts, unexpected and unexpressed potential for cost savings or unrealized means for improving product quality, logistics or utility that are normally inaccessible to laboratory denizens. Even financiers may lend assistance through discussing strategy in terms of key industry metrics, opening doors to export prospects or building bridges to large buyer consortiums and industry clusters.

Most importantly, direct interfacing and repeated interaction with value chain stakeholders - from suppliers to endusers, installers and support services – offers valuable observations and breeds trust and collaboration. A much broader and deeper reserve of know-how, skills and information may be brought to bear in seizing the maximum portion of problem space with valuable, practicable and profitable solutions, as depicted in Figure 8.

Figure 8 – Successful Innovation - a Meeting of Minds, Technology and Resources

6) Lessons Learning

Three major issues have come to light during attempts to commercialize graphene-based solutions directed at real world problems and inadequacies. Successful market innovations combine and integrate the know-how and capabilities of graphene scientists together with value chain partners to solve the customer’s problem. Value is generated and equitably distributed sufficient to incentivize all stakeholders and customers to perpetuate collaboration, production and further innovation.

Figure 9 displays the three areas where proficiency becomes vital in successfully bringing graphene-enhanced products to markets and individual customers and clients.

Figure 9 The Sweet Spot Driving Collaborative Commercially Successful Innovation

a) Technical: Solving practical problems and grasping exciting opportunities demands technically feasible, stable and scalable solutions, whether materials, formulations, compounds, components or end products.

b) Business Case: The process of delivering solutions using graphene must be economically and commercially sound and sustainable for all value creation chain contributors from the graphene supplier to the final purchaser. This holds true across contributors; viable business case must hold for each stage.

c) Stakeholders: Developing, producing and then scaling novel materials and products requires the combined interest, commitment, investment and ideas only achievable via concerted collaborative engagement and mutual reward. A team approach is essential to overcome challenges at each stage progressing from raw material to actual application and final recycling.

Graphene nanoplatelets are a substance unlike the bulk material graphite from which it is made, or like other bulk materials used in traditional product design. At an advanced level, exploiting the functional possibilities of graphene, (electrical conductivity, tensile strength, chemical affinity and compatibility with multilaminar plastic extrusion techniques, etc.) is ONLY achieved through exemplary collaboration.

7) Conclusion

Three observations are noteworthy. They allude to different ways of managing teams, dealing with uncertainty and discovering what and how products earn their worth. The journey from the lab to installation in the latest model of automobiles is a longer and more tortious path for graphene products than it has been for traditional materials. The skills threshold has been raised for business development and product management professionals orchestrating commercialization. Re-training with new conceptual tools and software aids is on the agenda for the entire team stretching from development laboratory to the end user. A refurbished and invigorated organizational dynamic will be needed to meet the challenge.

a) Graphene is a multifaceted and complex material demanding engineering ingenuity to unleash its potential. Intermediaries further down the value creation chain applying conventional equipment to fashion contemporary materials must learn to experiment, adapt, improvise and collaborate;

b) Graphene pioneers must strive via all possible means and channels to understand the process prerequisites, performance expectations and appreciated worth of innovations in the eyes of the customer, enduser but also intermediate value chain partners. The ability to deliver value to customers depends as much on uncovering and serving latent opportunities as solving salient customer urgent problems lucrative opportunities.

c) No catalogue of graphene formulations combined with common and exotic matrix materials, additives, process methods and forming techniques presently exists. Working as an extended team between vendor and customer, service provider and users along the span of the manufacturing network is vital to navigating the path toward launching commercially successful next generation of functional materials.

Tags:  2D materials  Francis Nedvidek  Graphene  Graphite  Material Engineering Lab  Nanomaterials  University of Dresden 

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Generation and manipulation of spin currents for advanced electronic devices

Posted By Graphene Council, Friday, January 10, 2020
Graphene-based heterostructures of the van der Waals class could be used to design ultra-compact and low-energy electronic devices and magnetic memories. This is what a paper published in the latest issue of the Nature Materials journal suggests. The results have shown that it is possible to perform an efficient and tunable spin-charge conversion in these structures and, for the first time, even at room temperature.

The work has been led by ICREA Prof. Sergio O. Valenzuela, head of the ICN2 Physics and Engineering of Nanodevices Group. The first authors are L. Antonio Benítez and Williams Savero Torres, of the same group. Members of the ICN2 Theoretical and Computational Nanoscience Group, as its head, ICREA Prof. Stephan Roche, also signed the paper. This study has been developed within the framework of the Graphene Flagship, a broad European Project in which researchers of the Catalan Institute of Nanoscience and Nanotechnology (ICN2) play a leadership role. The results complement recent researches carried out within this same initiative, such as the one published in 2019 in NanoLetters by scientists from the University of Groningen (RUG).

The electronics that use spin - a property of electrons - to store, manipulate and transfer information, called spintronics, are driving important markets, such as those of motion sensors and information storage technologies. However, the development of efficient and versatile spin-based technologies requires high-quality materials that allow long-distance spin transfer, as well as methods to generate and manipulate spin currents, i.e. electron movements with their spin oriented in a given direction.

The spin currents are usually produced and detected using ferromagnetic materials. As an alternative, spin-orbit interactions allow the generation and control of spin currents exclusively through electric fields, providing a much more versatile tool for the implementation of large-scale spin devices.

Graphene is a unique material for long distance spin transport. The present work demonstrates that this transport can be manipulated in graphene by proximity effects. To induce these effects, transition metal dichalcogenides have been used, which are two-dimensional materials as graphene. Researchers have demonstrated a good efficiency of spin-charge interconversion at room temperature, which is comparable to the best performance of traditional materials.

These advances are the result of a joint effort by experimental and theoretical researchers, who worked side by side in the framework of the Graphene Flagship. The outcomes of this study are of great relevance for the communities of spintronics and two-dimensional materials, as they provide relevant information on the fundamental physics of the phenomena involved and open the door to new applications

Tags:  Catalan Institute of Nanoscience and Nanotechnolog  Graphene  Graphene Flagship  L. Antonio Benítez  Nature Materials  Physics and Engineering of Nanodevices Group  Sergio O. Valenzuela  Stephan Roche  Theoretical and Computational Nanoscience Group  University of Groningen  Williams Savero Torres 

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A breath of fresh air for longer-running batteries

Posted By Graphene Council, Friday, January 10, 2020
DGIST researchers are improving the performance of lithium-air batteries, bringing us closer to electric cars that can use oxygen to run longer before they need to recharge. In their latest study, published in the journal Applied Catalysis B: Environmental, they describe how they fabricated an electrode using nickel cobalt sulphide nanoflakes on a sulphur-doped graphene, leading to a long-life battery with high discharge capacity.

“The driving distance of electric cars running on lithium-ion batteries is about 300 kilometers,” says chemist Sangaraju Shanmugam of Korea’s Daegu Gyeongbuk Institute of Science & Technology (DGIST). “This means it’s difficult to make a round trip between Seoul and Busan on these batteries. This has led to research on lithium-air batteries, due to their ability so store more energy and thus provide longer mileage.”

But lithium-air batteries face many challenges before they can be commercialized. For example, they don’t discharge energy as fast as lithium-ion batteries, meaning an electric car with a lithium-air battery might travel further without needing to recharge, but you’d have to drive very slowly. These batteries are also less stable and would need to be replaced more often.

Shanmugam and his colleagues focused their research on improving the capacity of lithium-air batteries to catalyse the reactions between lithium ions and oxygen, which facilitate energy release and the recharging process.

Batteries have two electrodes, an anode and a cathode. The reactions between lithium ions and oxygen happen at the cathode in a lithium-air battery. Shanmugam and his team developed a cathode made from nickel cobalt sulphide nanoflakes placed on a porous graphene that was doped with sulphur.

Their battery demonstrated a high discharge capacity while at the same time maintaining its battery performance for over two months without the capacity waning.

The success of the battery is due to several factors. The different-sized pores in the graphene provided a large amount of space for the chemical reactions to occur. Similarly, the nickel cobalt sulphide catalyst flakes posses abundant active sites for these reactions. The flakes also form a protective layer that makes for a more robust electrode. Finally, doping the graphene with sulphur and the interconnectivity of its pores improves the transportation of electrical charges in the battery. DOI: 10.1016/j.apcatb.2019.118283

The team next plans to work on improving other aspects of the lithium-air battery by conducting research on understanding the discharge/charge behaviours of the electrodes and its surface characteristics. “Once we’ve secured the core technologies of all parts of the battery and combined them, it will be possible to start manufacturing prototypes,” says Shanmugam.

Tags:  Batteries  Cobalt  Daegu Gyeongbuk Institute of Science & Technology  Graphene  Lithium  Nickel  Sangaraju Shanmugam 

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Layered heterostructures put a spin on magnetic memory devices

Posted By Graphene Council, Thursday, January 9, 2020
Graphene is a unique material with great potential for the long-distance transportation of spin information. However, spin-to-charge interconversion (SCI) in graphene and graphene-based heterostructures to date could not be performed at room temperature. But now, researchers at Graphene Flagship partners ICN2 and Universitat Autònoma de Barcelona, Spain, and the University of Groningen, the Netherlands, have achieved efficient room temperature SCI in graphene-based structures, and devised a way to make this process tuneable using an external electric field. The findings, published in Nature Materials and Nano Letters, could allow scientists to use layered heterostructures for ultra-compact, low-power consumption magnetic memory devices.

Spintronics is a branch of electronics which uses electrons' spin to store, manipulate and transfer information. Spintronics could benefit many emerging markets, like motion sensing and next-generation memory devices. Developing efficient and versatile spin-based technologies requires both high-quality materials for long-distance spin transfer, and suitable engineering methods to generate and manipulate spin currents, to ensure electrons move in a controlled way with their spins oriented along a given direction.

Generally, spin currents are generated and detected using ferromagnetic contacts. But as an alternative, spin-orbit interactions could enable spin currents to be controlled entirely by an electric field, resulting in a far more versatile tool to be implemented in large-scale spin devices. Now, Graphene Flagship researchers ICREA Prof. Sergio O. Valenzuela, ICREA Prof. Stephan Roche, and colleagues have exploited the unique spin properties of graphene to transport spin information across long distances in large-scale SCI electronics. Additionally, by interfacing graphene with transition metal dichalcogenides (TMDs), another family of layered materials with strong spin-orbit coupling, they were able to precisely control spin transport in these devices. "Thanks to this research, the Graphene Flagship's Spintronics Work Package has made a major step towards the engineering of SCI in quantum devices, with genuine potential for spintronics applications," explains Roche.

By fabricating a high-quality device and using very sensitive detection techniques to evaluate the spin Hall and inverse spin Galvanic effects – focusing in particular on spin precession and non-local measurements – they demonstrated experimentally that the SCI in graphene–TMD heterostructures is in good agreement with theoretical models. Furthermore, using these techniques, Graphene Flagship researchers not only demonstrated the spin-related character of the signals, but also tailored the efficiency of their SCI and sign using electrostatic gating. This important feature directly showcases their ability to manipulate spin information in the heterostructures with an electric field, and this could soon lead to new applications in magnetic memory devices. Most notably, they found that the room temperature SCI efficiencies were just as high as the best results using other materials.

"We're very excited to report the first unambiguous evidence of large and tuneable SCI in van der Waals heterostructures at room temperature," comments Valenzuela, from Graphene Flagship partner ICN2. "This is a significant step forward towards the long sought-after goal of electrostatic control of spin information," he continues. Additionally, Prof. Bart van Wees, from Graphene Flagship partner the University of Groningen, elaborates: "It is difficult to imagine how complex it is to fabricate spin devices combining various types of magnetic and non-magnetic materials, graphene, boron nitride, and strong spin-orbit coupling materials such as TMDs. Thanks to this work, the Spintronics Work Package has developed a unique expertise in realizing operational spin devices which really show the full potential of layered materials."

Kevin Garello, Graphene Flagship Work Package Leader for Spintronics, comments: "Devices involving the spin–orbit torque phenomenon, such as the spin Hall effect and the spin Galvanic effect, are great candidates for future spintronics applications as they require low power input and are capable of ultra-fast performance. It is great to see that spin-orbit torques can be electrically manipulated and improved by the smart engineering of layered materials, which has now been unequivocally confirmed independently by two experimental teams in Work Package Spintronics. This opens the door for new and exciting perspectives and strategies to manipulate spin information and further advance applications in spintronics based on layered materials."

The success of these studies is the result of the joint effort between experimental and theoretical researchers working closely together in the EU-funded Graphene Flagship framework. The results provide valuable insights for the spintronics and layered materials communities, and the researchers hope that their findings will enable scientists to explore new theoretical models and further experiments in the future.

Andrea C. Ferrari, Science and Technology Officer of the Graphene Flagship and Chair of its Management Panel, adds: "The Graphene Flagship has invested in spintronics research since the very beginning. The great potential of graphene and related materials in this area has been showcased by world-leading work done in the Flagship. These results indicate that we are getting close to the point where the fundamental work can be translated into useful applications, as foreseen in our science and technology and innovation roadmaps."

Tags:  Andrea C. Ferrari  Electronics  Graphene  Graphene Flagship  ICN2  ICREA  Kevin Garello  Sergio O. Valenzuela  Stephan Roche  Universitat Autònoma de Barcelona  University of Groningen 

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New production method for carbon nanotubes gets green light

Posted By Graphene Council, Thursday, January 9, 2020
A new method of producing carbon nanotubes - tiny molecules with incredible physical properties used in touchscreen displays, 5G networks and flexible electronics - has been given the green light by researchers, meaning work in this crucial field can continue.

Single-walled carbon nanotubes are among the most attractive nanomaterials for a wide range of applications ranging from nanoelectronics to medical sensors. They can be imagined as the result of rolling a single graphene sheet into a tube.

Their properties vary widely with their diameter, what chemists call chirality - how symmetrical they are - and by how the graphene sheet is rolled.

The problem faced by researchers is that it is no longer possible to make high quality research samples of single-walled carbon nanotubes using the standard method. This was associated with the Carbon Center at Rice University, which used the high-pressure carbon monoxide (HiPco) gas-phase process developed by Nobel Laureate, the late Rick Smalley.

The demise of the Carbon Center in the mid-2010s, the divesting of the remaining HiPco samples to a third-party entity with no definite plans of further production, and the expiration of the core patents for the HiPco process, meant that this existing source of nanotubes was no longer an option.

Now however, a collaboration between scientists at Swansea University (Wales, UK), Rice University (USA), Lamar University (USA), and NoPo Nanotechnologies (India) has demonstrated that the latter's process and material design is a suitable replacement for the the Rice method.

Analysis of the Rice "standard" and new commercial-scale samples show that back-to-back comparisons are possible between prior research and future applications, with the newer HiPco nanotubes from NoPo Nanotechnologies comparing very favourably to the older ones from Rice.

These findings will go some way to reassure researchers who might have been concerned that their work could not continue as high-quality nanotubes would no longer be readily available.

Professor Andrew Barron of Swansea University's Energy Safety Research Institute, the project lead, said:
"Variability in carbon nanotube sources is known to be a significant issue when trying to compare research results from various groups. What is worse is that being able to correlate high quality literature results with scaled processes is still difficult".

Erstwhile members of the Smalley group at Rice University, which developed the original HiPco process, helped start NoPo Nanotechnologies with the aim of updating the HiPco process, and produce what they call NoPo HiPCO® SWCNTs.

Lead author Dr. Varun Shenoy Gangoli stated:
"It is in the interest of all researchers to understand how the presently available product compares to historically available Rice materials that have been the subject of a great range of academic studies, and also to those searching for a commercial replacement to continue research and development in this field."

Tags:  Andrew Barron  carbon nanotubes  Graphene  Medical  nanoelectronics  Rice University  Sensors  Swansea University  Varun Shenoy Gangoli 

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Energy levels in electrons of 2D materials are mapped for the first time

Posted By Graphene Council, Thursday, January 9, 2020
Researchers based at the National Graphene Institute at The University of Manchester have developed an innovative measurement method that allows, for the first time, the mapping of the energy levels of electrons in the conduction band of semiconducting 2D materials.

Writing in Nature Communications, a team led by Dr Roman Gorbachev reports the first precise mapping of the conduction band of 2D indium selenide (InSe) using resonant tunnelling spectroscopy, to access the previously unexplored part of the electronic structure. They observed multiple subbands for both electrons and holes and tracked their evolution with the number of atomic layers in InSe.

Many emerging technologies rely on novel semiconductor structures, where the motion of electrons is restricted in one or more directions. Such confinement is in the nature of 2D materials and it is responsible for many of their new and exciting properties.

For instance, the colour of the emitted light shifts towards shorter wavelengths as they get thinner, analogous to quantum dots changing colour when their size is varied. As another consequence, the allowed energy available for the electrons in such materials, called conduction and valence bands, split into multiple subbands.

We hope this study will pave the way for exploration of intersubband transitions and lead to development of prototype optoelectronic devices with tuneable emission in the challenging terahertz range, Dr Roman Gorbachev.

Optical transitions between such subbands present a large potential for real-life applications as they provide optically active in terahertz and far-infrared ranges, which can be employed for security and communication technologies as light emitters or detectors.

Dr Roman Gorbachev said: “We hope this study will pave the way for exploration of intersubband transitions and lead to development of prototype optoelectronic devices with tuneable emission in the challenging terahertz range.”

Tags:  2D materials  Graphene  optoelectronics  Roman Gorbachev  Semiconductor  University of Manchester 

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Carbon Nanotubes & Quantum Dots: Army Thinks VERY Small

Posted By Graphene Council, Thursday, January 9, 2020
While the rest of the Army works on new hypersonic missiles, robotic mini-tanks, and ultra-high-speed helicopters, the Army Research Office is diving deep into the submicroscopic world of nanotechnology and quantum mechanics.

The military is intensely interested in the potential to improve the costs and capabilities of its electronics, which in modern warfare are as vital to survival as guns and armor. But as with the Internet, radar, and other originally military technologies, there are civilian applications as well.

Carbon Nanotubes

One Army Research Office project is looking to replace traditional silicon-based semiconductors with more efficient carbon nanotubes, program manager Joe Qiu told me. The new technology is particularly useful at the very high frequencies (30-plus gigahertz) and very short wavelengths (millimeter wave) that the telecommunications industry wants to use for 5G networks – including on military bases – and for whatever replaces 5G.

“The initial deployment of 5G, they will be lower than six gigahertz, but there are plans…to improve frequencies to 28 GHz and higher,” Qiu said. “It’s not just 5G — it’s beyond 5G.”

How soon could the private sector reap the benefits of ARO-funded research?

“Commercial use of carbon nanotube-based integrated circuits? Maybe five years,” he said, then added with a laugh: “That’s an estimate. Don’t hold me to that!”

This kind of research can take a long time to bear fruit, Qiu cautioned. Army funding actually helped get the ball rolling on carbon nanotubes for electronics 10 years ago, he said, and it’s taken that long to work out the kinks.

It was mathematically proven a decade ago that nanotubes could channel electricity much more efficiently, Qiu told me. While silicon semiconductors form a lattice that lets electrons scatter in all directions – imagine downtown traffic moving through a grid of streets – carbon nanotubes essentially act like a highway that funnels all the electrons in the desired direction. (The technical term is quantum ballistic transport). But actually producing enough nanotubes of consistent size and quality and getting them to line up right took years of further work, much of it Army funded.

Last year, under a Small Business Technology Transfer (STTR) grant from ARO, the University of South California and venture-backed startup Carbonics Inc. developed working carbon nanotube transistors. The next big step is to integrate many transistors together into an actual circuit. Then, Qiu said, you can talk about integrating many circuits together to build actual equipment.

That would be a job for other parts of the Army. “The Army Research Office, our core mission actually is investing in basic science,” Qiu emphasized. ARO is just one piece of the Army Research Laboratory, which is in turn part of Combat Capabilities Development Command (formerly RDECOM), which is in turn one of the three major components of Army Futures Command, created in 2018 to coordinate all aspects of modernization from brainstorming futuristic concepts to fielding new equipment.

At ARO, said one of Qiu’s colleagues, Joseph Myers, “we’re a bunch of program managers here who support basic research likely to lead to advances in a variety of different technologies.”

Quantum Dots

While the Chinese-born, US-trained Qiu is a physicist-turned-engineer-turned-program manager, Myers is a mathematician and head of the mathematical sciences division at ARO – a field, he jokes, notoriously disconnected from mundane reality. Qiu’s carbon nanotubes are a fraction of the size of a single human hair. Their lengths vary widely, but their thickness is typically six nanometers or less. Myers is funding research on quantum dots, miniscule crystals of semiconductor whose longest dimension is no more than six nanometers, meaning they could conceivably fit inside a nanotube.

Extremely small size allows extremely fine precision. When energized, a quantum dot will always emit a very specific wavelength (which wavelength depends on the dot’s exact size). They also emit these precise frequencies more powerfully, for a longer time, than traditional semiconductors. Some companies already sell high-end “quantum LED” TV sets that use this property to produce more vivid colors: You can even get one at Best Buy.

The downside, Myers went on, is that it’s much harder to design electronics using quantum dots. Classical models of physics start to fail as you start to enter the strange domain of quantum mechanics, where seemingly solid objects turn into fuzzy fields of energy that can pulse and jump in unpredictable ways. Unlike traditional electronics that use electrical charges to represent 1s and 0s, “the physics of what’s going on isn’t as clean as zero/one anymore,” he said. “It’s got some probability of being a zero, some probability of being a one.”

To predict those probabilities precisely, using current techniques, is arduous and slow. “We largely know the equations, but the equations are just too intractable to solve exactly,” Myers said. “If you’ve got the age of the universe… you can maybe complete one of the calculations.”

“You want to do it in less than one human lifetime,” he said. “You want to do it in a day or two, or a week or so, or maybe even a few hours.”

So how much precision can you safely give up to get your results fast enough to actually use them?

Myers funded work by Southern Methodist University professor Wei Cai, who’s figured out a streamlined modeling technique, using an old Air Force supercomputer that Myers managed to get transferred to SMU before it was scrapped. (The Pentagon has a standing High Performance Computer Modernization Reutilization Program to pass on its older machines.)

Put simply (very, very simply), Cai has figured out which parts of the traditional models tend to have such a miniscule impact on the final result – about 0.000000001 percent – that you can safely ignore them. Then you can just do the calculations that actually matter.

Cai’s technique is 750 times faster than rival approaches, Myers said proudly. In its current form, he cautioned, it is still wrong about 20 percent of the time, but Cai is working on that – he’s likely to apply for further Army funding this year – and in the meantime there are ways to double-check the results.

What kind of improved technologies could you use Cai’s model to design? Besides the QLED televisions already on sale, Myers said there’s interest from multiple parts of the Army Research Laboratory that work on everything from solar panels – a useful complement to fuel-hungry diesel generators and heavy lithium-iron batteries – to military sensors and other electronics. There’s a potential medical application in improving CT scans, as well, which is potentially life-changing not just for civilians but for survivors of skull-rattling roadside bombs.

Congress and good-government watchdogs often wonder, with good reason, about oddball research projects that slip into the Pentagon budget with no clear connection to any military purpose. Then-undersecretary of the Army, Ryan McCarthy – now the secretary – was widely praised in 2017-2018 when he overhauled the service’s science & technology portfolio to cull low-payoff projects and focus 80 percent of investment on the service’s Big Six modernization priorities. But McCarthy was also very careful to leave 20 percent to continue basic research, unconstrained by near-term needs, to sow the seeds of real long-term breakthroughs.

Tags:  Carbon Nanotubes  Carbonics Inc  Graphene  Joe Qiu  quantum dots  Southern Methodist University  The Army Research Office  transistor  University of South California  Wei Cai 

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Jeffrey Grossman named head of the MIT Department of Materials Science and Engineering

Posted By Graphene Council, Tuesday, January 7, 2020
Jeffrey Grossman, the Morton and Claire Goulder and Family Professor in Environmental Systems and a MacVicar Faculty fellow, has been appointed the new head of the MIT Department of Materials Science and Engineering effective Jan. 1, 2020.

Grossman received his PhD in theoretical physics from the University of Illinois and performed postdoctoral work at the University of California at Berkeley. He was a Lawrence Fellow at the Lawrence Livermore National Laboratory and returned to Berkeley as director of a Nanoscience Center and head of the Computational Nanoscience research group, with a focus on energy applications. In fall 2009, he joined MIT, where he has developed a research program known for its contributions to energy conversion, energy storage, membranes, and clean-water technologies.

Grossman’s passion for teaching and outstanding contributions to education are evident through courses such as 3.091 (Introduction to Solid-State Chemistry) — within which Grossman applies MIT’s “mens-et-manus” (mind-and-hand) learning philosophy. He uses “goodie bags” containing tools and materials that he covers in his lectures, encouraging hands-on learning and challenging students to ask big questions, take chances, and collaborate with one another.

In recognition of his contributions to engineering education, Grossman was named an MIT MacVicar Faculty Fellow and received the Bose Award for Excellence in Teaching, in addition to being named a fellow of the American Physical Society. He has published more than 200 scientific papers, holds 17 current or pending U.S. patents, and recently co-founded a company, Via Separations, to commercialize graphene-oxide membranes.

“Professor Grossman has done remarkable work in materials science and engineering, in particular energy conversion, energy storage, and clean-water technologies,” says Anantha Chandrakasan, dean of the MIT School of Engineering and the Vannevar Bush Professor of Electrical Engineering and Computer Science. “He has demonstrated exceptional commitment and vision as an educator. I am thrilled that he will be serving as the new head of our materials science and engineering department, and know he will be a tremendous leader.”

Tags:  Graphene  Jeffrey Grossman 

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