Tag Archives: Centre for Research on Adaptive Nanostructures and Nanodevices

SEMANTICS, a major graphene project based in Ireland

A Jan. 28, 2015 news item on Nanowerk profiles SEMANTICS, a major graphene project based in Ireland (Note: A link has been removed),

Graphene is the strongest, most impermeable and conductive material known to man. Graphene sheets are just one atom thick, but 200 times stronger than steel. The European Union is investing heavily in the exploitation of graphene’s unique properties through a number of research initiatives such as the SEMANTICS project running at Trinity College Dublin.

A Dec. 16, 2014 European Commission press release, which originated the news item, provides an overview of the graphene enterprise in Europe,

It is no surprise that graphene, a substance with better electrical and thermal conductivity, mechanical strength and optical purity than any other, is being heralded as the ‘wonder material’ of the 21stcentury, as plastics were in the 20thcentury.

Graphene could be used to create ultra-fast electronic transistors, foldable computer displays and light-emitting diodes. It could increase and improve the efficiency of batteries and solar cells, help strengthen aircraft wings and even revolutionise tissue engineering and drug delivery in the health sector.

It is this huge potential which has convinced the European Commission to commit €1 billion to the Future and Emerging Technologies (FET) Graphene Flagship project, the largest-ever research initiative funded in the history of the EU. It has a guaranteed €54 million in funding for the first two years with much more expected over the next decade.

Sustained funding for the full duration of the Graphene Flagship project comes from the EU’s Research Framework Programmes, principally from Horizon 2020 (2014-2020).

The aim of the Graphene Flagship project, likened in scale to NASA’s mission to put a man on the moon in the 1960s, or the Human Genome project in the 1990s, is to take graphene and related two-dimensional materials such as silicene (a single layer of silicon atoms) from a state of raw potential to a point where they can revolutionise multiple industries and create economic growth and new jobs in Europe.

The research effort will cover the entire value chain, from materials production to components and system integration. It will help to develop the strong position Europe already has in the field and provide an opportunity for European initiatives to lead in global efforts to fully exploit graphene’s miraculous properties.

Under the EU plan, 126 academics and industry groups from 17 countries will work on 15 individual but connected projects.

The press release then goes on to describe a new project, SEMANTICS,

… this is not the only support being provided by the EU for research into the phenomenal potential of graphene. The SEMANTICS research project, led by Professor Jonathan Coleman at Trinity College Dublin, is funded by the European Research Council (ERC) and has already achieved some promising results.

The ERC does not assign funding to particular challenges or objectives, but selects the best scientists with the best ideas on the sole criterion of excellence. By providing complementary types of funding, both to individual scientists to work on their own ideas, and to large-scale consortia to coordinate top-down programmes, the EU is helping to progress towards a better knowledge and exploitation of graphene.

“It is no overestimation to state that graphene is one of the most exciting materials of our lifetime,” Prof. Coleman says. “It has the potential to provide answers to the questions that have so far eluded us. Technology, energy and aviation companies worldwide are racing to discover the full potential of graphene. Our research will be an important element in helping to realise that potential.”

With the help of European Research Council (ERC) Starting and Proof of Concept Grants, Prof. Coleman and his team are researching methods for obtaining single-atom layers of graphene and other layered compounds through exfoliation (peeling off) from the multilayers, followed by deposition on a range of surfaces to prepare films displaying specific behaviour.

“We’re working towards making graphene and other single-atom layers available on an economically viable industrial scale, and making it cheaply,” Prof. Coleman continues.

“At CRANN [Centre for Research on Adaptive Nanostructures and Nanodevices at Trinity College Dublin], we are developing nanosheets of graphene and other single-atom materials which can be made in very large quantities,” he adds. “When you put these sheets in plastic, for example, you make the plastic stronger. Not only that – you can massively increase its electrical properties, you can improve its thermal properties and you can make it less permeable to gases. The applications for industry could be endless.”

Prof. Coleman admits that scientists are regularly taken aback by the potential of graphene. “We are continually amazed at what graphene and other single-atom layers can do,” he reveals. “Recently it has been discovered that, when added to glue, graphene can make it more adhesive. Who would have thought that? It’s becoming clear that graphene just makes things a whole lot better,” he concludes.

So far, the project has developed a practical method for producing two-dimensional nanosheets in large quantities. Crucially, these nanosheets are already being used for a range of applications, including the production of reinforced plastics and metals, building super-capacitors and batteries which store energy, making cheap light detectors, and enabling ultra-sensitive position and motion sensors. As the number of application grows, increased demand for these materials is anticipated. In response, the SEMANTICS team has scaled up the production process and is now producing 2D nanosheets at a rate more than 1000 times faster than was possible just a year ago.

I believe that new graphene production process is the ‘blender’ technique featured here in an April 23, 2014 post. There’s also a profile of the ‘blender’ project  in a Dec. 10, 2014 article by Ben Deighton for the European Commission’s Horizon magazine (Horizon 2020 is the European Union’s framework science funding programme). Deighton’s article hosts a video of Jonathan Coleman speaking about nanotechnology, blenders, and more on Dec. 1, 2014 at TEDxBrussels.

The Irish mix up some graphene

There was a lot of excitement (one might almost call it giddiness) earlier this week about a new technique from Irish researchers for producing graphene. From an April 20, 2014 article by Jacob Aron for New Scientist (Note: A link has been removed),

First, pour some graphite powder into a blender. Add water and dishwashing liquid, and mix at high speed. Congratulations, you just made the wonder material graphene.

This surprisingly simple recipe is now the easiest way to mass-produce pure graphene – sheets of carbon just one atom thick. The material has been predicted to revolutionise the electronics industry, based on its unusual electrical and thermal properties. But until now, manufacturing high-quality graphene in large quantities has proved difficult – the best lab techniques manage less than half a gram per hour.

“There are companies producing graphene at much higher rates, but the quality is not exceptional,” says Jonathan Coleman of Trinity College Dublin in Ireland.

Coleman’s team was contracted by Thomas Swan, a chemicals firm based in Consett, UK, to come up with something better. From previous work they knew that it is possible to shear graphene from graphite, the form of carbon found in pencil lead. Graphite is essentially made from sheets of graphene stacked together like a deck of cards, and sliding it in the right way can separate the layers.

Rachel Courtland chimes in with her April 21,2014 post for the Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers]) website (Note: A link has been removed),

The first graphene was made by pulling layers off of graphite using Scotch tape. Now, in keeping with the low-tech origins of the material, a team at Trinity College Dublin has found that it should be possible to make large quantities of the stuff by mixing up some graphite and stabilizing detergent with a blender.

The graphene produced in this manner isn’t anything like the wafer-scale sheets of single-layer graphene that are being grown by Samsung, IBM and others for high-performance electronics. Instead, the blender-made variety consists of small flakes that are exfoliated off of bits of graphite and then separated out by centrifuge. But small-scale graphene has its place, the researchers say. …

An April 22, 2014 CRANN (the Centre for Research on Adaptive Nanostructures and Nanodevices) at Trinity College Dublin news release (also on Nanowerk as an April 20, 2014 news item) provides more details about the new technique and about the private/public partnership behind it,

Research team led by Prof Jonathan Coleman discovers new research method to produce large volumes of high quality graphene.

Researchers in AMBER, the Science Foundation Ireland funded materials science centre headquartered at CRANN, Trinity College Dublin have, for the first time, developed a new method of producing industrial quantities of high quality graphene. …

The discovery will change the way many consumer and industrial products are manufactured. The materials will have a multitude of potential applications including advanced food packaging; high strength plastics; foldable touch screens for mobile phones and laptops; super-protective coatings for wind turbines and ships; faster broadband and batteries with dramatically higher capacity than anything available today.

Thomas Swan Ltd. has worked with the AMBER research team for two years and has signed a license agreement to scale up production and make the high quality graphene available to industry globally. The company has already announced two new products as a result of the research discovery (Elicarb®Graphene Powder and Elicarb® Graphene Dispersion).

Until now, researchers have been unable to produce graphene of high quality in large enough quantities. The subject of on-going international research, the research undertaken by AMBER is the first to perfect a large-scale production of pristine graphene materials and has been highlighted by the highly prestigious Nature Materials publication as a global breakthrough. Professor Coleman and his team used a simple method for transforming flakes of graphite into defect-free graphene using commercially available tools, such as high-shear mixers. They demonstrated that not only could graphene-containing liquids be produced in standard lab-scale quantities of a few 100 millilitres, but the process could be scaled up to produce 100s of litres and beyond.

Minister for Research and Innovation Sean Sherlock, TD commented; “Professor Coleman’s discovery shows that Ireland has won the worldwide race on the production of this ‘miracle material’. This is something that USA, China, Australia, UK, Germany and other leading nations have all been striving for and have not yet achieved. This announcement shows how the Irish Government’s strategy of focusing investment in science with impact, as well as encouraging industry and academic collaboration, is working.”

Here’s a link to and a citation for the researchers’ paper,

Scalable production of large quantities of defect-free few-layer graphene by shear exfoliation in liquids by Keith R. Paton, Eswaraiah Varrla, Claudia Backes, Ronan J. Smith, Umar Khan, Arlene O’Neill, Conor Boland, Mustafa Lotya, Oana M. Istrate, Paul King, Tom Higgins, Sebastian Barwich, Peter May, Pawel Puczkarski, Iftikhar Ahmed, Matthias Moebius, Henrik Pettersson, Edmund Long, João Coelho, Sean E. O’Brien, Eva K. McGuire, Beatriz Mendoza Sanchez, Georg S. Duesberg, Niall McEvoy, Timothy J. Pennycook, et al. Nature Materials (2014) doi:10.1038/nmat3944 Published online 20 April 2014

This article is mostly behind a paywall but there is a free preview available through ReadCube Access.

For anyone who’s curious about AMBER, here’s more from the About Us page on the CRANN website (Note: A link has been removed),

In October 2013, a new Science Foundation Ireland funded research centre, AMBER (Advanced Materials and BioEngineering Research) was launched. AMBER is jointly hosted in TCD [Trinity College Dublin] by CRANN and the Trinity Centre for Bioenineering, and works in collaboration with the Royal College of Surgeons in Ireland and UCC. The centre provides a partnership between leading researchers in materials science and industry and will deliver internationally leading research that will be industrially and clinically informed with outputs including new discoveries and devices in ICT, medical device and industrial technology sectors.

Finally, Thomas Swan Ltd. can be found here.

Irish teach nanoscience, nanotechnology and new materials to 5th & 6th classes (grades)

Ireland’s CRANN (Centre for Research on Adaptive Nanostructures and Nanodevices) located in Trinity College Dublin seems to be hosting both the AMBER (Advanced Materials and BioEngineering Research) Centre and the NanoWOW education initiative. A Nov. 12, 2013 news item on Nanowerk describes NanoWOW and AMBER in more detail,

Ireland’s new materials science research centre has announced the launch of their new NanoWOW lesson plans. Designed for 5th and 6th class pupils the plans will introduce Irish Primary students to the world of nanoscience, nanotechnology and materials science.

Linked to the existing Primary science and maths syllabus while also including environment, history and art, the new lessons will enable school children to understand how the properties of materials can change on the nanoscale and provide opportunities for them to work like scientists through discussion, investigations and activities.

The Nov. 12, 2013 AMBER/CRANN news release, which originated the news item, gives more details about how NanoWOW is being launched during Ireland’s Science Week,

To celebrate the launch of NanoWOW, St Patrick’s College, Drumcondra are using this year’s Science Week theme, “Exploring the XTRA-Ordinary” to find out more about nanoscience and materials science amongst their students and staff. They have organised a number of CPD workshops to introduce primary school teachers to the NanoWOW lessons and will have guest speakers from AMBER visiting during the week.

Dr Cliona Murphy, Lecturer in Science Education, St Patrick’s College said “I think this is a wonderful initiative and we are very pleased to collaborate with AMBER on further developing the educational resources and bringing them to primary schools throughout Ireland.  The NanoWow investigations provide children with ample opportunities to work like scientists and to develop their scientific skills and knowledge.  Through engaging with the NanoWow activities the children are also provided with numerous opportunities to develop their language and thinking skills and to use a range of mathematical skills.  The NanoWow educational programme  provides children with first hand experience of the  ground breaking scientific research that is currently being conducted in Ireland and gives them an insight into careers that are potentially achievable for them.”

Prof. Stefano Sanvito, AMBER said, “The new NanoWOW lesson plans are designed to engage school children in a creative way that fosters their curiosity in nanoscience. We also want to develop their interest and understanding so they are aware of nanoscience as part of their everyday lives and the potential future career options that would be open to them.”

Prof. Sanvito went on to comment, “Ireland is currently ranked 6th worldwide for nanoscience research and 1st in the EU for European Research Council starting grants. With Nanoscience linked to €15 billion or 10% of Irish exports and 250,000 jobs in sectors like technology, biomedicine, pharmaceuticals, energy and more, the importance of making nanoscience relevant amongst school pupils is obvious for future development”.

The launch of the new NanoWOW lesson plans builds on the success of the “Nano in My Life” lesson plans for secondary schools which were launched by CRANN during Science Week 2011. Targeted at Transition Year students, the resource provides teachers with nanaoscience lesson plans free of charge. With nanonscience due to feature as part of the new Leaving Certificate, the NanoWOW lesson plans aim to build on this success and bring the subject to a wider audience.

Ireland’s Science Week is being held from Nov. 10 – 17, 2013, according to the 2013 Science Week theme webpage (on Ireland’s Science Week website),

Science Week 2013 – Exploring the XTRA-Ordinary

Every day we encounter XTRA-Ordinary processes that are behind the ordinary! From the water that comes out of our taps, to the grass that grows in our fields, to our body’s ability to heal itself and play sports – there are XTRA-Ordinary processes happening all around us. Science Week 2013 is calling on you to come and explore the XTRA-Ordinary too!

The objective of Science Week each year is to promote the relevance of science, technology, engineering and maths (STEM) in our everyday lives and to demonstrate their importance to the future of Irish society and to the economy.

This year we want to show everyone in Ireland that there are scientific processes behind everything around us, most of which are taken for granted every day. Exploring the XTRA-Ordinary invites you to stop, take note and explore the processes that are happening around you every day.

Co-ordinated by Science Foundation Ireland, Science Week 2013 runs from 10 to 17 November 2013 and is a collaboration of events run by colleges, schools, libraries, teachers, community groups, researchers and students throughout Ireland.

For anyone wanting to know more about the NanoWow initiative and the lessons on offer, go here. As for AMBER, that was launched in October 2013 according to an Oct. 24, 2013 CRANN news release,

Minister Bruton launches new €58 Million SFI Research Centre- AMBER

Advanced Materials and BioEngineering Research (AMBER) Centre positions Ireland as a global leader in the areas of materials and medical device development for industry.

More than 45% of multinational jobs wins are connected to SFI research.
Directly supporting 99 highly skilled jobs.
Investment of €23 million from 18 industry partners across diverse sectors.
Industry partners include Intel, DePuy, Medtronic, Merck Millipore and SAB Miller.
Research programme will translate science into new discoveries and devices for a range of sectors such as the development of the next generation computer chips and new medical implants and pharmaceuticals that will improve patirnt care.

The Minister for Jobs, Enterprise and Innovation, Richard Bruton TD, together with the Minister for Research & Innovation, Sean Sherlock TD, today (Thursday) launched the Advanced Materials and Bio-Engineering Research Centre (AMBER).

The Centre is funded by the Department of Jobs, Enterprise and Innovation through Science Foundation Ireland (SFI) in the amount of €35million. This funding is leveraged with an additional €23million from 18 industry partners.

AMBER will work to translate science into new discoveries and devices for a range of sectors, particularly ICT, medical devices and industrial technologies.

It’s very exciting to see what they’re doing in Ireland. And, until now, I’d completely forgotten about Canada’s annual Science and Technology week. This year’s was held from Oct. 18, – 27, 2013. While this celebration seems to have been winding down for a number of years,, perhaps 2013 marks a revitalized event,

Thousands of Canadians across the country joined together on Friday, October 18th [2013] to establish a World Record for the largest science lesson. [emphasis mine] Thank you to all of the organizers and all of the participants who made this inspiring event possible.

Over the next few weeks we’ll be collecting all the required evidence and forwarding it to Guinness for the final number to be calculated and an announcement to be made. As soon as the process is finished we will announce the results on Science.gc.ca.

Of course, Guinness World Records traces its roots back to Ireland, From the History webpage of the Guinness World Records website,

10 November 1951

Sir Hugh Beaver, Chairman of the Guinness Brewery, is out hunting game birds by the River Slaney in County Wexford, Ireland, when he misses a shot at a golden plover. Sir Hugh wonders if the plover is the fastest game bird in Europe but can’t find a reference book that answers the question.

I’m sure the Irish could rival Canadians for the size of the science lessons they might wish to hold. Perhaps Canadians should offer a friendly challenge?

2.5M Euros for Ireland’s John Boland and his memristive nanowires

The announcement makes no mention of the memristor or neuromorphic engineering but those are the areas in which  John Boland works and the reason for his 2.5M Euro research award. From the Ap. 3, 2013 news item on Nanowerk,

Professor John Boland, Director of CRANN, the SFI-funded [Science Foundation of Ireland] nanoscience institute based at Trinity College Dublin, and a Professor in the School of Chemistry has been awarded a €2.5 million research grant by the European Research Council (ERC). This is the second only Advanced ERC grant ever awarded in Physical Sciences in Ireland.

The Award will see Professor Boland and his team continue world-leading research into how nanowire networks can lead to a range of smart materials, sensors and digital memory applications. The research could result in computer networks that mimic the functions of the human brain and vastly improve on current computer capabilities such as facial recognition.

The University of Dublin’s Trinity College CRANN (Centre for Research on Adaptive Nanostructures and Nanodevices) April 3, 2013 news release, which originated the news item,  provides details about Boland’s proposed nanowire network,

Nanowires are spaghetti like structures, made of materials such as copper or silicon. They are just a few atoms thick and can be readily engineered into tangled networks of nanowires. Researchers worldwide are investigating the possibility that nanowires hold the future of energy production (solar cells) and could deliver the next generation of computers.

Professor Boland has discovered that exposing a random network of nanowires to stimuli like electricity, light and chemicals, generates chemical reaction at the junctions where the nanowires cross. By controlling the stimuli, it is possible to harness these reactions to manipulate the connectivity within the network. This could eventually allow computations that mimic the functions of the nerves in the human brain – particularly the development of associative memory functions which could lead to significant advances in areas such as facial recognition.

Commenting Professor John Boland said, “This funding from the European Research Council allows me to continue my work to deliver the next generation of computing, which differs from the traditional digital approach.  The human brain is neurologically advanced and exploits connectivity that is controlled by electrical and chemical signals. My research will create nanowire networks that have the potential to mimic aspects of the neurological functions of the human brain, which may revolutionise the performance of current day computers.   It could be truly ground-breaking.”

It’s only in the news release’s accompanying video that the memristor and neuromorphic engineering are mentioned,

I have written many times about the memristor, most recently in a Feb. 26, 2013 posting titled, How to use a memristor to create an artificial brain, where I noted a proposed ‘blueprint’ for an artificial brain. A contested concept, the memristor has attracted critical commentary as noted in a Mar. 19, 2013 comment added to the ‘blueprint’  post,

A Sceptic says:


Before talking about blueprints, one has to consider that the dynamic state equations describing so-called non-volatile memristors are in conflict with fundamentals of physics. These problems are discussed in:

“Fundamental Issues and Problems in the Realization of Memristors” by P. Meuffels and R. Soni (http://arxiv.org/abs/1207.7319)

“On the physical properties of memristive, memcapacitive, and meminductive systems” by M. Di Ventra and Y. V. Pershin (http://arxiv.org/abs/1302.7063)

My carbon nanotube heart and patents

The stem cell scientists at the National University of Ireland (NUI) and Trinity College Dublin’s CRANN (Centre for Research on Adaptive Nanostructures and Nanodevices) aren’t making hearts out of carbon nanotubes but they are using the particles to stimulate stem cells into becoming heart-like.The Sept. 19, 2012 news item on Nanowerk provides context for this work,

Stem cell scientists have capitalised on the electrical properties of a widely used nanomaterial to develop cells which may allow the regeneration of cardiac cells. The breakthrough has been led by a team of scientists at the Regenerative Medicine Institute (REMEDI) at the National University of Ireland Galway in conjunction with Trinity College Dublin.

Heart disease is the leading cause of death in Ireland. Once damaged by heart attack, cardiac muscle has very little capacity for self-repair and at present there are no clinical treatments available to repair damaged cardiac muscle tissue.

Over the last 10 years, there has been tremendous interest in developing a cell-based therapy to address this problem. Since the use of a patient’s own heart cells is not a viable clinical option, many researchers are working to try to find an alternative source of cells that could be used for cardiac tissue repair.

The NUI Sept. 19, 2012 news release, which originated the news item, describes how carbon nanotubes have properties similar to certain heart cells and how the researchers decided to exploit that similarity,

The researchers recognised that carbon nanotubes, a widely used nanoparticle, is reactive to electrical stimulation. They then used these nanomaterials to create cells with the characteristics of cardiac progenitors, a special type of cell found in the heart, from adult stem cells.

“The electrical properties of the nanomaterial triggered a response in the mesenchymal (adult) stem cells, which we sourced from human bone marrow. In effect, they became electrified, which made them morph into more cardiac-like cells”, explains Valerie Barron of REMEDI at National University of Ireland Galway. “This is a totally new approach and provides a ready-source of tailored cells, which have the potential to be used as a new clinical therapy. Excitingly, this symbiotic strategy lays the foundation stone for other electroactive tissue repair applications, and can be readily exploited for other clinically challenging areas such as in the brain and the spinal cord.”

The team’s collaborator at CRANN, Professor Werner Blau made a comment I found a bit odd (from the NUI news release),

“It is great to see two decades of our pioneering nanocarbon research here at TCD come to fruition in a way that addresses a major global health problem. Hopefully many people around the world will ultimately benefit from it. Some of our carbon nanotube research has been patented by TCD and is being licensed to international companies in material science, electronics and health care,” said Professor Blau.

I’m not a big fan of the current patenting regimes which seem to  have been turned  into innovation-killing machines.  As for patenting medicines and medical devices, I recall that Frederick Banting and Charles Best who discovered insulin refused to patent the discovery as they believed it would constrain access.

I appreciate that businesses need to make money and scientists need money to do their work and so on but this blind rush to patent discoveries seems a little misguided to me and it might be a good time to consider new business and economic models.

Better beer in plastic bottles

This innovation in beer bottling was developed in Ireland and I’m pretty sure the Irish have themselves braced for the humourous comments sure to follow given the legends about the Irish and beer.

Here’s more about the nanotechnology-enabled plastic beer bottles from the Sept. 18, 2012 news item on Nanowerk,

Scientists at CRANN [Centre for Research on Adaptive Nanostructures and Nanodevices], the Science Foundation Ireland-funded nanoscience institute based at Trinity College Dublin, have partnered with world-leading brewing company SABMiller on a project to increase the shelf life of bottled beer in plastic bottles. The new deal will see SABMiller invest in the project over a two year period.

Professor Jonathan Coleman and his team in CRANN are using nanoscience research methods to develop a new material that will prolong the shelf-life of beer in plastic bottles. Current plastic bottles have a relatively short shelf life, as both oxygen and carbon dioxide can permeate the plastic and diminish the flavour.

The new material, when added to plastic bottles will make them extremely impervious, meaning that oxygen cannot enter and that the carbon dioxide cannot escape, thus preserving the taste and ‘fizz’.

The Sept. 18, 2012 CRANN news release does not include many more details about the technology,

The team will exfoliate nano-sheets of boron nitride, each with a thickness of approximately 50,000 times thinner than one human hair. These nano-sheets will be mixed with plastic, which will result in a material that is extremely impervious to gas molecules. The molecules will be unable to diffuse through the material and shelf life will be increased.

As well as increasing the shelf life of the beer itself, less material is required in production, reducing cost and environmental impact.

If you are lucky enough to have a subscription or have some other access to Science magazine, you can read more about Coleman’s and his team’s work on boron nitride and thin films. Here’s the citation and abstract for the article,

Two-Dimensional Nanosheets Produced by Liquid Exfoliation of Layered Materials by Jonathan N. Coleman, Mustafa Lotya, Arlene O’Neill, Shane D. Bergin, Paul J. King, Umar Khan,  Karen Young, Alexandre Gaucher, Sukanta De, Ronan J. Smith, Igor V. Shvets, Sunil K. Arora, George Stanton, Hye-Young Kim, Kangho Lee, Gyu Tae Kim, Georg S. Duesberg, Toby Hallam, John J. Boland, Jing Jing Wang, John F. Donegan, Jaime C. Grunlan, Gregory Moriarty, Aleksey Shmeliov, Rebecca J. Nicholls, James M. Perkins, Eleanor M. Grieveson, Koenraad Theuwissen, David W. McComb, Peter D. Nellist, and Valeria Nicolosi in Science 4 February 2011: Vol. 331 no. 6017 pp. 568-571 DOI: 10.1126/science.1194975

If they could be easily exfoliated, layered materials would become a diverse source of two-dimensional crystals whose properties would be useful in applications ranging from electronics to energy storage. We show that layered compounds such as MoS2, WS2, MoSe2, MoTe2, TaSe2, NbSe2, NiTe2, BN, and Bi2Te3 can be efficiently dispersed in common solvents and can be deposited as individual flakes or formed into films. Electron microscopy strongly suggests that the material is exfoliated into individual layers. By blending this material with suspensions of other nanomaterials or polymer solutions, we can prepare hybrid dispersions or composites, which can be cast into films. We show that WS2 and MoS2 effectively reinforce polymers, whereas WS2/carbon nanotube hybrid films have high conductivity, leading to promising thermoelectric properties.

This announcement comes during Ireland’s Nanoweek 2012 (Sept. 14 – 21, 2012) which I mentioned along with other nano-themed events currently taking place in Ireland in my Sept. 14, 2012 posting.

Transforming flat screens with P-type conductors at CRANN

I’m not sure about window-integrated flat screens as one of the applications for this technology breakthrough at Trinity College Dublin’s (TCD) CRANN (Centre for Research on Adaptive Nanostructures and Nanodevices). I think there’s enough signage and video being beamed at me everywhere I go but all indications are that more and more surfaces are going to become display and/or communication devices and these researchers seem to have found a way to speed that process.

From the March 21, 2012 news item on Nanowerk,

Researchers at CRANN, the Science Foundation Ireland funded nanoscience institute based in Trinity College Dublin (TCD), have discovered a new material that could transform the quality, lifespan and efficiency of flat screen computers, televisions and other devices (see paper in Applied Physics Letters: “Magnesium, nitrogen codoped Cr2O3: A p-type transparent conducting oxide”).

The research team was led by Prof Igor Shvets, a CRANN Principal Investigator who has successfully launched and sold two spin out companies from TCD and who is involved in the Spirit of Ireland energy project. A patent application protecting the new material was filed by TCD. Commenting on the research, Prof Igor Shvets said, “This is an exciting development with a range of applications and we are hopeful this initial research will attract commercial interest in order to explore its industrial use. The new material could lead to innovations such as window-integrated flat screens and to increase the efficiency of certain solar cells, thus significantly impacting on the take-up of solar cells, which can help us to reduce carbon emissions.” [emphasis mine]

The application for solar cells sounds a lot more appealing to me. CRANN issued a March 21, 2012 press release which included some technical details,

Devices that the new material could be used with such as solar cells, flat screen TVs, computer monitors, LEDs all utilise materials that can conduct electricity and at the same time are see-through.  These devices currently use transparent conducting oxides, which are a good compromise between electrical conductivity and optical transparency. They all have one fundamental limitation: they all conduct electricity through the movement of electrons. [emphasis mine] Such materials are referred to as n-type transparent conducting oxides. Electricity can also be conducted through as p-type materials.  Modern day electronics make use of n-type and p-type materials.  The lack of good quality p-type transparent conducting oxides, however, led the research team to develop a new material – a p-type transparent conducting oxide.

I wish I better understood the fundamental limitation of an n-type transparent conducting oxide and how the new p-type transparent conducting oxide addresses that limitation.

After reading the description of p-type materials, it seems to me that electrons also move in that material. From the Wikipedia essay on p-type materials,

The dopant atom accepts an electron, causing the loss of half of one bond from the neighboring atom and resulting in the formation of a “hole”. Each hole is associated with a nearby negatively charged dopant ion, and the semiconductor remains electrically neutral as a whole. However, once each hole has wandered away into the lattice, one proton in the atom at the hole’s location will be “exposed” and no longer cancelled by an electron. [emphasis mine] This atom will have 3 electrons and 1 hole surrounding a particular nucleus with 4 protons. For this reason a hole behaves as a positive charge. When a sufficiently large number of acceptor atoms are added, the holes greatly outnumber thermal excited electrons. Thus, holes are the majority carriers, while electrons become minority carriers in p-type materials.

Well, I am interpreting the “wandering away” bit as a type of movement so I find the descriptions just a bit confusing. As for the holes being the majority carrier in p-type materials, perhaps the electrons in the n-type materials are the majority carriers?

If there’s anyone out there who could help lift the veil of confusion, I would much appreciate it.

For those who don’t need as much handholding as I do, you can find out more about Shvets and his work here.