Berkeley Lab Researchers Discover Universal Law For Light Absorption In 2D Semiconductors

Nano Particles for Steel 324x182From solar cells to optoelectronic sensors to lasers and imaging devices, many of today’s semiconductor technologies hinge upon the absorption of light. Absorption is especially critical for nano-sized structures at the interface between two energy barriers called quantum wells, in which the movement of charge carriers is confined to two-dimensions. Now, for the first time, a simple law of light absorption for 2D semiconductors has been demonstrated.

Working with ultrathin membranes of the semiconductor indium arsenide, a team of researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) has discovered a quantum unit of photon absorption, which they have dubbed “AQ,” that should be general to all 2D semiconductors, including compound semiconductors of the III-V family that are favored for solar films and optoelectronic devices. This discovery not only provides new insight into the optical properties of 2D semiconductors and quantum wells, it should also open doors to exotic new optoelectronic and photonic technologies.

“We used free-standing indium arsenide membranes down to three nanometers in thickness as a model material system to accurately probe the absorption properties of 2D semiconductors as a function of membrane thickness and electron band structure,” says Ali Javey, a faculty scientist in Berkeley Lab’s Materials Sciences Division and a professor of electrical engineering and computer science at the University of California (UC) Berkeley. “We discovered that the magnitude of step-wise absorptance in these materials is independent of thickness and band structure details.”

Javey is one of two corresponding authors of a paper describing this research in the Proceedings of the National Academy of Sciences (PNAS). The paper is titled “Quantum of optical absorption in two-dimensional semiconductors.” Eli Yablonovitch, an electrical engineer who also holds joint appointments with Berkeley Lab and UC Berkeley, is the other corresponding author. Co-authors are Hui Fang, Hans Bechtel, Elena Plis, Michael Martin and Sanjay Krishna.

Previous work has shown that graphene, a two-dimensional sheet of carbon, has a universal value of light absorption. Javey, Yablonovitch and their colleagues have now found that a similar generalized law applies to all 2D semiconductors. This discovery was made possible by a unique process that Javey and his research group developed in which thin films of indium arsenide are transferred onto an optically transparent substrate, in this case calcium fluoride.

“This provided us with ultrathin membranes of indium arsenide, only a few unit cells in thickness, that absorb light on a substrate that absorbed no light,” Javey says. “We were then able to investigate the optical absorption properties of membranes that ranged in thickness from three to 19 nanometers as a function of band structure and thickness.”

Using the Fourier transform infrared spectroscopy (FTIR) capabilities of Beamline 1.4.3 at Berkeley Lab’s Advanced Light Source, a DOE national user facility, Javey, Yablonovitch and their co-authors measured the magnitude of light absorptance in the transition from one electronic band to the next at room temperature. They observed a discrete stepwise increase at each transition from indium arsenide membranes with an AQ value of approximately 1.7-percent per step.

“This absorption law appears to be universal for all 2D semiconductor systems,” says Yablonovitch. “Our results add to the basic understanding of electron–photon interactions under strong quantum confinement and provide a unique insight toward the use of 2D semiconductors for novel photonic and optoelectronic applications.”

This research was supported by DOE’s Office of Science and the National Science Foundation.

Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more information, visit

The DOE Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit

The Advanced Light Source is a third-generation synchrotron light source producing light in the x-ray region of the spectrum that is a billion times brighter than the sun. A DOE national user facility, the ALS attracts scientists from around the world and supports its users in doing outstanding science in a safe environment. The Advanced Light Source is a third-generation synchrotron light source producing light in the x-ray region of the spectrum that is a billion times brighter than the sun. A DOE national user facility, the ALS attracts scientists from around the world and supports its users in doing outstanding science in a safe environment. For more information, visit

SOURCE: The U.S. Department of Energy


Reducing Energy Costs with Better Batteries

3adb215 D BurrisA better battery—one that is cheap and safe, but packs a lot of power—could lead to an electric vehicle that performs better than today’s gasoline-powered cars, and costs about the same or less to consumers.  Such a vehicle would reduce the United States’ reliance on foreign oil and lower energy costs for the average American, so one of the Department of Energy’s (DOE’s) goals is to fund research that will revolutionize the performance of next-generation batteries.

In honor of DOE’s supercomputing month, we are highlighting some of the ways researchers are using supercomputers at the National Energy Research Scientific Computing Center (NERSC) are working to achieve this goal.

New Anode Boots Capacity of Lithium-Ion Batteries

Lithium-ion batteries are everywhere— in smart phones, laptops, an array of other consumer electronics, and electric vehicles. Good as they are, they could be much better, especially when it comes to lowering the cost and extending the range of electric cars. To do that, batteries need to store a lot more energy.

Using supercomputers at NERSC, Berkeley Lab researchers developed a new kind of anode—energy storing component—that is capable of absorbing eight times the lithium of current designs. The secret is a tailored polymer that conducts electricity and binds closely to lithium storing particles. The researchers achieved this result by running supercomputer calculations of different promising polymers until they found the perfect one. This research is an important step toward developing lithium-ion batteries with eight times their current capacity.

After more than a year of testing and many hundreds of charge-discharge cycles, Berkeley researchers found that their anode maintained its increased energy capacity.  This is a significant improvement from many lithium-ion batteries on the market today, which degrade as they recharge. Best of all, the anodes are made from low-cost materials that are also compatible with standard lithium battery manufacturing technologies.

Read More:

Engineering Better Energy Storage

One of the biggest weaknesses of today’s electric vehicles is battery life—most cars can only go about 100-200 miles between charges. But researchers hope that a new type of battery, called the lithium-air battery, will one day lead to a cost-effective, long-range electric vehicles that could travel 300 miles or more between charges.

Using supercomputers at NERSC and powerful microscopes, a team of researchers from the Pacific Northwest National Laboratory (PNNL) and Princeton University built a novel graphene membrane that could produce a lithium-air battery with the highest-energy capacity to date. Because the material does not rely on platinum or other precious metals, its potential cost and environmental impact are significantly less than current technology.

Read More:

Promise for Onion-Like Carbons as Supercapacitors

The two most important electrical storage technologies on the market today are batteries and capacitors—both have their pluses and minuses. Batteries can store a lot of energy, but have slow charge and discharge rates. While capacitors generally store less energy but have very fast (nearly instant) charge and discharge rates, and last longer than rechargeable batteries. Developing technologies that combine the optimal characteristics of both will require a detailed understanding of how these devices work at the molecular level. That’s where supercomputers come in handy.

One promising electrical storage device is the supercapacitator, which combines the fast charging and discharging rates of conventional capacitators, as well as the high-power density, high-capacitance (ability to store electrical charge), and durability of a battery. Today supercapacitators power electric vehicles, portable electronic equipment and various other devices. Despite their use in the marketplace, researchers believe these energy storage devices could perform much better. One area that they are hoping to improve is the device’s electrode, or a conductor through which electricity enters or leaves.

Most supercapacitor electrodes are made of carbon-based materials, but one promising material yet to be explored is graphene. The strongest material known, graphene also has unique electrical, thermal, mechanical and chemical properties. Using supercomputers at NERSC, scientists ran simulations to understand how the shape of a graphene electrode affects its electrical properties. They hope that one-day this work will inspire the design of supercapacitators that can hold a much more stable electric charge.

Read More:

A Systematic Approach to Battery Design

New materials are crucial for building advanced batteries, but today the development cycle is too slow. It takes about 15 to 18 years to go from conception to commercialization. To speed up this process, a team of researchers from Lawrence Berkeley National Laboratory (Berkeley Lab) and the Massachusetts Institute of Technology (MIT) created a new computational tool called the Materials Project, which is hosted at NERSC.

The Materials Project uses supercomputers at NERSC, Berkeley Lab and the University of Kentucky to characterize the properties of inorganic compounds—such as stability, voltage, capacity and oxidation state—via computer simulations. The results are then organized into a database with a user-friendly web interface that allows users to easily access and search for the compound that they would like to use in their new material design. Knowing the properties of a compound beforehand allows researchers to quickly assess whether their idea will be successful, without spending money and time developing prototypes and experiments that will eventually lead to a dead-end.

In early 2013, DOE pledged $120 million over five years to establish the Joint Center for Energy Storage Research (JCESR). As part of this initiative, the Berkeley Lab and MIT researchers will run simulations at NERSC to predict the properties of electrolytes—a liquid. The results will be incorporated into a database similar to the Materials Project. Eventually researchers will be able to combine the JCESR database with the Materials Project to get a complete scope of battery components. Together, these resources allow scientists to employ a systematic and predictive approach to battery design.

Read More:

For more information about how Berkeley Lab is celebrating DOE supercomputing month, please visit:

About Berkeley Lab Computing Sciences

The Lawrence Berkeley National Laboratory (Berkeley Lab) Computing  Sciences organization provides the computing and networking resources  and expertise critical to advancing the Department of Energy’s research  missions: developing new energy  sources, improving energy efficiency, developing new materials and  increasing our understanding of ourselves, our world and our universe. ESnet, the Energy Sciences Network, provides the high-bandwidth, reliable connections that link scientists at 40 DOE research sites to each other and to experimental facilities and supercomputing centers around the country. The National Energy Research  Scientific Computing Center (NERSC) powers the discoveries of 5,500 scientists at national laboratories and universities, including those at Berkeley Lab’s Computational Research Division (CRD). CRD  conducts research and development in mathematical modeling and  simulation, algorithm design, data storage, management and analysis,  computer system architecture and high-performance software  implementation.

The Four Disruptive Technology Forces that Will Change the World

4 Disruptive

The “gales of creative destruction” forecast by Austrian economist Joseph Schumpeter in the 1940s are blowing as hard as ever.
The twin disruptive forces of tough economic times and technology-driven innovation are giving birth to new innovations, new markets and new opportunities.
Just this month the family-owned US media institution that is the Washington Post sprung a huge surprise, announcing it was selling up to Amazon founder and dot com billionaire Jeff Bezos. While the media industry is undergoing huge disruption right now, few saw that move coming and there’s plenty of speculation about how that might play out.
But disruption and ‘creative destruction’ have been a feature of the corporate landscape for decades. Kodak and Polaroid are two of the most well-known victims of this process. Back in the 1970s Polaroid was one of the so-called ‘nifty 50’ largest stocks on the NYSE, with a huge army of skilled engineers, while Kodak sold 90% of the film used in the US.
Neither was quick enough to foresee and react to the rapid disruption of digital technology and the move to digital photography. When disruption happens it is often swift. Polaroid filed for bankruptcy protection in 2001 and Kodak in 2012.
From shop assistants and financial traders to engineers and celebrities, all our jobs, skills and industries are under constant threat from technology-driven disruption.
A glaring modern example is the decline of the high street video and DVD rental store. These have been overtaken and replaced by online streaming companies who offer the latest movies and TV series delivered instantly to your TV, PC, tablet or smartphone, anytime and anywhere.
The high street companies involved didn’t innovate and the superfast pace of technology overtook them.

But a central line of the creative destruction theory is the idea of a process of constant renewal through innovation. While disruption clearly poses threats to established ways of doing things, it also presents huge opportunities both for existing legacy businesses and nimble new start-ups. When those gales start howling it’s a case of adapt or die.


Here are 4 powerful technological forces the I believe will drive disruption, innovation and opportunity in all areas of business and society in coming years and decades.

1. The internet of things A world where everyone and everything is connected. Sensors in everyday objects and devices will be capable of automatically transmitting data over high-speed networks. Those previously ‘dumb’ objects will then become ‘smart’ objects capable of automated machine-to-machine (M2M) communications.
2. 3D printing This technology opens up amazing possibilities for individuals and businesses, with fully working parts able to be created at the touch of a button and for a fraction of the cost of doing it previously. Already 3D printers have been used to create everything from toys and parts for NASA’s Mars explorer to medical implants.
3. Graphene The development of the super strong and highly conductive graphene has huge implications for the traditionally silicon-dependant technology industry. Potential applications include flexible display screens, electric circuits, solar cells and use in medical, chemical and industrial processes.
4. Connectivity Ubiquitous connectivity through a combination of superfast mobile broadband, fibre optic fixed line broadband and wi-fi will drive massive changes in consumer activity and also the way we live and work, especially with faster, lighter and smarter mobile devices. Advances such as Google Glass are also just scratching the surface of connected augmented and virtual reality devices.
I’d be interested in hearing your thoughts on how your business is adapting to new technologies and what other technological forces you think will impact our world in the coming years.

Water 2.0 2013 Water Management And Nano Energy Summit

Water 2.0 open_img

2013 Water Management And Nano Energy Summit : November 13 & 14, 2013

Rice University – Shell Auditorium Jones Graduate School of Business Rice University 6100 Main Street Houston, Texas 77005

THE SUMMIT is a gathering of the world’s leading experts who are generating cutting-edge technological solutions for challenges in the water and energy sectors.

Produced in partnership with the Water Innovations Alliance, WATER 2.0, the NanoBusiness Commercialization Association, the Rice Alliance, and the Smalley Institute at Rice University, THE SUMMIT will feature prominent speakers from industry, government, finance and academia. THE SUMMIT will address state-of-the-art innovative solutions to decades-old problems in the water and oil and gas sectors. These pioneering technologies are emerging rapidly into the market thanks to revolutionary breakthroughs in material science, nanoscience and computational power.

For Full Details, Sponsors, Presenters and Exhibitors, go here:




Since 2009, Vincent Caprio’s Blog EVOLVING INNOVATIONS has addressed issues on Science & Technology.

About The Water Innovations Alliance Foundation The Water Innovations Alliance Foundation is focused on educating the public and key stakeholders as to new developments in fresh and waste water technologies. The Foundation works to gather data, develop reports, standards, economic analysis, and model training programs for advancing the development and deployment of new water technologies.

The Water Innovations Alliance Foundation is located in Cambridge, MA and Shelton, CT. It is a 501(c)(3) organization that works in conjunction with the Water Innovations Alliance. The Foundation was launched in Spring 2009. It is undertaking a series of initiatives to advance the understanding of new opportunities, technologies, and best practices for the water field.

To learn more about the Foundation and its membership, contact Vincent Caprio,

NANOTECHNOLOGY – Photons to Electricity Nano Based Solar Cells

longpredicte“Dr. Sargent provides us with a very detailed presentation on integrating ‘nanotechnology’ and photovoltaics. It is well recognized the ‘solar energy model’ will require advancements to lower manufacturing (production) costs and …

… “harvest” with greater efficiencies the available (and abundant) renewable source of energy from our sun.”  –  GenesisNanoTechnology



Published on Jul  9, 2013 

What is Nanotechnology? A basic definition: Nanotechnology is the engineering of functional systems at the molecular scale. This covers both current work and concepts that are more advanced. In its original sense, ‘nanotechnology’ refers to the projected ability to construct items from the bottom up, using techniques and tools being developed today to make complete, high performance products.

Nanotechnology (sometimes shortened to “nanotech”) is the manipulation of matter on an atomic and molecular scale. The earliest, widespread description of nanotechnology referred to the particular technological goal of precisely manipulating atoms and molecules for fabrication of macroscale products, also now referred to as molecular nanotechnology.


A more generalized description of nanotechnology was subsequently established by the National Nanotechnology Initiative, which defines nanotechnology as the manipulation of matter with at least one dimension sized from 1 to 100 nanometers.

This definition reflects the fact that quantum mechanical effects are important at this quantum-realm scale, and so the definition shifted from a particular technological goal to a research category inclusive of all types of research and technologies that deal with the special properties of matter that occur below the given size threshold.


It is therefore common to see the plural form “nanotechnologies” as well as “nanoscale technologies” to refer to the broad range of research and applications whose common trait is size. Because of the variety of potential applications (including industrial and military), governments have invested billions of dollars in nanotechnology research. Through its National Nanotechnology Initiative, the USA has invested 3.7 billion dollars. The European Union has invested 1.2 billion and Japan 750 million dollars


Nanotubes images



Nanofuture – David Bradburn

There is not much you can do today without witnessing the involvement of nanotechnology to some degree; nanotechnology is present in almost every part of our lives. Transport, entertainment, communications, most electronic technology, including TVs, computers and cameras, and even in our food; for creating new textures, packaging, taste, and performance enhancement. There is very little we can do in the 21st Century without paying some credit to nanotechnology.
Nanotechnology is pivotal to global markets and worth billions of dollars annually, when you look at the United States and the interest in performance of Apple Inc. you can begin to understand the role nanotechnology will have in our lives over the next few decades.


To try and create a more cohesive structure to how nanotechnology works across all of these areas and begin to explore the opportunities it holds, NANOfutures was set up. NANOfutures was actually set up in 2010 to address these challenges and opportunities, it was set up to run for two years with funding from the European Union. NANOfutures is known as a European Technology and Innovation Platform or ETIP, bringing together industry, academia, research establishments, NGOs, SMEs, policy, legal and all other sectors with interest or involvement in nanotechnology.


The most important findings from the ETIP is their Research and Industrial Roadmap report, which charts a strategy for accelerated growth to 2020 for a safe and commercially viable nanofuture. NANOfutures had some very challenging targets and given the diversity of issues facing this area of science, this is a useful result for us to continue growing.

Click below to access more MT blog listings:

The Biomaterials blog

The Characterization blog

The Energy blog

The Nanotechnology blog

The Polymers and Soft Materials blog

Smart Windows: Behind the Scenes @ Berkeley Lab

Published on Dec 10, 2012

3adb215 D BurrisPart of the Behind the Scenes series at the Lawrence Berkeley National Lab, this video highlights the team research on Smart Windows underway at the Lab.  It features Delia Milliron of the Molecular Foundry, Andre Anders of the Accelerator and Fusion Research Division, and Howdy Goudey from the Buildings Energy Efficiency Program.





Dynamic, energy efficient windows can play a huge role in reducing energy consumption, reducing energy costs, and improving lighting and heating conditions in buildings – and the research being done at Berkeley Lab is leading the way.
Produced, directed, and edited by Ivan Berry Camera and production assistance by Cutler Andrus Writing and content development by Paul Preuss




The College of Nanoscale Science and Engineering (CNSE) Hosts U.S. Secretary of Commerce Penny Pritzker

QDOTS imagesCAKXSY1K 8Published on Jul 30, 2013




The College of Nanoscale Science and Engineering (CNSE) hosted U.S. Secretary of Commerce Penny Pritzker on Tuesday, July 30 as part of her “Listening Tour” across America. The event included a roundtable discussion with Lt. Governor Robert Duffy and executives from CNSE’s corporate partners; a briefing on the New York State-CNSE-SEMATECH nanotechnology ecosystem; and a tour of CNSE’s world-class Albany NanoTech Complex.




Biz Tips: Renewable Energy Tax Credits

how-nanotechnology-could-change-solar-panels-photovoltaic_66790_600x450Businesses should consider these federal renewable energy tax incentives.

Michael Silvio is a Managing Director with CBIZ MHM, LLC.  He  is the National Federal Credits and Incentives Practice Leader  for the firm where he  focuses on Research & Development (R&D)  Credits, Energy Incentives  and other  federal tax credits.  His office is in Orange County, California.



Charge Your Cell Phone In 5 Seconds

Mega UploadsPublished on Feb 27, 2013

Supercapacitors: They’ll enable you to charge your cell phone in 5 seconds, or an electric car in about a minute. They’re cheap, biodegradable, never wear out and as Trace’ll tell you, could be powering your life sooner than you’d think.


Read More: “See The Scientific Accident That May Change The World (Or At Least Your Battery Life)”…