Giving smart materials an IQ test at SSRL

Anna Llordés, a chemist at Lawrence Berkeley National Laboratory’s Molecular Foundry, looks for simple, inexpensive ways to make “smart” materials that save or store energy. One way she and her colleagues do this is by combining metal oxides that have…

Anna Llordés, a chemist at Lawrence Berkeley National Laboratory’s Molecular Foundry, looks for simple, inexpensive ways to make “smart” materials that save or store energy. One way she and her colleagues do this is by combining metal oxides that have desirable properties.

What they don’t know is how these materials will act in combination: Will the resulting composite retain the desirable structures and properties of its individual ingredients? Will the ingredients influence each other – for good or ill? And how can she tell what’s really going on?
That’s where Beam Line 11-3 at SLAC’s Stanford Synchrotron Radiation Lightsource (SSRL) comes in.
“11-3 is a really important beamline for us when we’re developing a new material,” Llordés said. “It allows a quick but detailed evaluation of the crystalline structure of thin films.”
Take, for example, one of their latest discoveries: a new type of transparent smart film that can be applied to a pane of window glass to control the amount of sunlight or heat that enters a room, thereby cutting electricity costs. These films have “electrochromic” properties, meaning the amount of sunlight they let through can be changed by applying a voltage. The ability to selectively filter different wavelengths of light is a new – and hard-won – development in what’s called “smart window” technology.
Llordés and her co-workers created this particular film by combining nanocrystals of tin-doped indium oxide (ITO), which absorbs infrared energy, with niobium oxide glass, which screens visible light.
What was surprising, she said, was the synergy between the two materials. “When the ITO nanocrystals bond to the glassy niobium oxide, you get better properties that you’d expect,” she said. In particular, the niobium oxide is much improved as a window coating – it’s five times better at blocking light than niobium oxide without nanocrystals. In addition, the composite material stands up better to repeated on-off cycles.
But why the big improvement? And what nanocrystal-in-glass recipe resulted in the best film?
To find out, Llordés used a technique called grazing incidence X-ray diffraction at Beam Line 11-3 to study the structures of films that had been processed at temperatures ranging from 400°C to 650°C. She discovered that the film with the best qualities forms between 400°C and 500°C.
She also discovered the film is a glassy matrix that actually incorporates the ITO nanocrystals into its structure, instead of simply trapping them as impurities. The glass molecules bond with the nanocrystals, changing the structure of the glass and affecting its properties. It’s this bond that makes the whole of the film so dramatically better than the sum of its parts.
“The work on 11-3 helped us prove we had a very unique composite material,” Llordés said, and during her most recent trip to the beamline, she investigated materials that are even easier and more energy-efficient to produce.
Finding new, useful materials that are energy-efficient to produce is her driving interest, said Llordés, Beamline 11-3 helps her do that.
But SSRL has another meaning for the native Spaniard, as well.
“When I first came here three years ago, the people at SSRL were very helpful and welcoming,” she said. “They explained how to run the experiments, and they were always open, fun and ready to talk science.
“I’m always happy when I need to come to SSRL.”

Explore further:

Raising the IQ of smart windows

Provided by

SLAC National Accelerator Laboratory

view popular

5 /5 (1 vote)

Related Stories

Raising the IQ of smart windows

Aug 14, 2013

Researchers at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have designed a new material to make smart windows even smarter. The material is a thin coating of nanocrystals …

More transparency: Optically transparent water oxidation catalyst made from copper nanowires

Oct 25, 2013

(Phys.org) —Hydrogen is used as an energy source in fuel cells and can be produced from water by using sunlight and a suitable catalyst. In the journal Angewandte Chemie, American researchers have now introduced a new …

Understanding how hydration affects color-changing windows can boost their efficiency

Nov 20, 2013

Electrochromic materials dynamically alter how they transmit light in response to an applied electrical signal. Engineers are currently working to turn these compounds into ‘smart windows’ for buildings that …

Researchers develop thin film semiconductor that will drive production of next-generation displays

Oct 22, 2013

Researchers at the National Institute for Materials Science have developed a pixel switching semiconductor, which will be the key to driving next-generation displays, by using an oxide film with a new elemental …

Get the light, beat the heat: Researchers develop new infrared coating for windows

Sep 07, 2011

Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) have unveiled a semiconductor nanocrystal coating material capable of controlling heat from …

Electricity from waste heat with more efficient materials

Dec 05, 2013

Thermoelectric materials can convert waste heat directly into electricity. Tommi Tynell, M.Sc., who is a doctoral candidate at the Aalto University School of Chemical Technology, has developed hybrid thermoelectric materials …

Recommended for you

Probing the inner secrets of nanowires

13 hours ago

(Phys.org) —Semiconductor nanowires (NWs) are vanishingly small: NWs from a recent batch made by scientists in PML’s Quantum Electronics and Photonics Division measure about 200 nanometers in diameter (less …

Quantum waves at the heart of organic solar cells

Dec 12, 2013

By using an ultrafast camera, scientists say they have observed the very first instants following the absorption of light into artificial yet organic nanostructures and found that charges not only formed …

Two teams independently find that adding vibration helps couple light to graphene

Dec 12, 2013

(Phys.org) —Two teams of researchers, one working in Saudi Arabia, the other in Spain, have discovered independently that adding vibrations to a graphene surface allows for more efficient conversion of …

Graphene-based nano-antennas may enable networks of tiny machines

Dec 12, 2013

(Phys.org) —Networks of nanometer-scale machines offer exciting potential applications in medicine, industry, environmental protection and defense, but until now there’s been one very small problem: the …

Nontoxic quantum dot research improves solar cells

Dec 11, 2013

Solar cells made with low-cost, nontoxic copper-based quantum dots can achieve unprecedented longevity and efficiency, according to a study by Los Alamos National Laboratory and Sharp Corporation.

Tables turn as nature imitates art

Dec 11, 2013

There are examples of art imitating nature all around us—whether it’s Monet’s pastel Water Lilies or Chihuly’s glassblown Seaforms, the human conception of natural phenomena dazzles but does not often surprise.

User comments : 0

More news stories

Probing the inner secrets of nanowires

(Phys.org) —Semiconductor nanowires (NWs) are vanishingly small: NWs from a recent batch made by scientists in PML’s Quantum Electronics and Photonics Division measure about 200 nanometers in diameter (less …

Quantum waves at the heart of organic solar cells

By using an ultrafast camera, scientists say they have observed the very first instants following the absorption of light into artificial yet organic nanostructures and found that charges not only formed …

Capturing wasted electricity with triboelectric generators

(Phys.org) —With one stomp of his foot, Zhong Lin Wang illuminates a thousand LED bulbs – with no batteries or power cord. The current comes from essentially the same source as that tiny spark that jumps …

Graphene-based nano-antennas may enable networks of tiny machines

(Phys.org) —Networks of nanometer-scale machines offer exciting potential applications in medicine, industry, environmental protection and defense, but until now there’s been one very small problem: the …

Electrical control of single atom magnets

The energy needed to change the magnetic orientation of a single atom – which determines its magnetic stability and therefore its usefulness in a variety of future device applications – can be modified …

Swirls in remnants of big bang may hold clues to universe’s infancy

South Pole Telescope scientists have detected for the first time a subtle distortion in the oldest light in the universe, which may help reveal secrets about the earliest moments in the universe’s formation.

Researchers study evolution on the molecular level

The theory of evolution suggests that present-day organisms evolved from earlier life forms.

New work gives credence to theory of universe as a hologram

(Phys.org) —In publishing a story regarding work reported by Japanese physicists last month, Nature News has set off a bit of a tabloid firestorm by describing an obscure bit of physics theory as “the clearest evide …

SpaceX to bid for rights to historic NASA launch pad

In a battle of technology titans for the right to lease a historic NASA launch pad in Florida, SpaceX has beat out competitor Blue Origin, the US space agency said Friday.

Motorola CEO talks about global vision

Google’s $12.4 billion purchase of Motorola Mobility was widely seen as a way for Google to acquire patents to defend its Android operating system from intellectual property lawsuits.