UPDATE: Check out the interview with Fox 13 News here.

Sept. 29, 2013 – One problem in developing more efficient organic LED light bulbs and displays for TVs and phones is that much of the light is polarized in one direction and thus trapped within the light-emitting diode, or LED. University of Utah physicists believe they have solved the problem by creating a new organic molecule that is shaped like rotelle – wagon-wheel pasta – rather than spaghetti.

The rotelle-shaped molecule – known as a “pi-conjugated spoked-wheel macrocycle” – acts the opposite of polarizing sunglasses, which screen out glare reflected off water and other surfaces and allow only direct sunlight to enter the eyes.

The new study showed wagon-wheel molecules emit light randomly in all directions – a necessary feature for a more efficient OLED, or organic LED. Existing OLEDs now in some smart phones and TVs use spaghetti-shaped polymers – chains of repeating molecular units – that emit only polarized light.

“This work shows it is possible to scramble the polarization of light from OLEDs and thereby build displays where light doesn’t get trapped inside the OLED,” says University of Utah physicist John Lupton, lead author of a study of the spoked-wheel-shaped molecules published online Sunday, Sept. 29 in the journal Nature Chemistry.

“We made a molecule that is perfectly symmetrical, and that makes the light it generates perfectly random,” he adds. “It can generate light more efficiently because it is scrambling the polarization. That holds promise for future OLEDs that would use less electricity and thus increase battery life for phones, and for OLED light bulbs that are more efficient and cheaper to operate.”

Lupton emphasizes the study is basic science, and new OLEDs based on the rotelle-shaped molecules are “quite a way down the road.”

He says OLEDs now are used in smart phones, particularly the Samsung Galaxy series; in pricey new super-thin TVs being introduced by Sony, Samsung, LG and others; and in lighting.

“OLEDs in smart phones have caught on because they are somewhat more efficient than conventional liquid-crystal displays like those used in the iPhone,” he says. “That means longer battery life. Samsung has already demonstrated flexible, full-color OLED displays for future roll-up smart phones.” Lupton says smart phones could produce light more efficiently using molecules that don’t trap as much light.

The large rotelle-shaped molecules also can “catch” other molecules and thus would make effective biological sensors; they also have potential use in solar cells and switches, he adds.

The study was funded by the Volkswagen Foundation, the German Chemical Industry Fund, the David and Lucille Packard Foundation and the European Research Council.

Lupton is a research professor of physics and astronomy at the University of Utah and also on the faculty of the University of Regensburg, Germany. He conducted the study with Utah physics graduate student Alexander Thiessen; Sigurd Höger, Vikas Aggarwal, Alissa Idelson, Daniel Kalle and Stefan-S. Jester of the University of Bonn; and Dominik Würsch, Thomas Stangl, Florian Steiner and Jan Vogelsang of the University of Regensburg.

Read the whole press release here.

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Sept. 13, 2013 – By inserting platinum atoms into an organic semiconductor, University of Utah physicists were able to “tune” the plastic-like polymer to emit light of different colors – a step toward more efficient, less expensive and truly white organic LEDs for light bulbs of the future.

“These new, platinum-rich polymers hold promise for white organic light-emitting diodes and new kinds of more efficient solar cells,” says University of Utah physicist Z. Valy Vardeny, who led a study of the polymers published online Friday, Sept. 13 in the journal Scientific Reports.

Certain existing white light bulbs use LEDs, or light-emitting diodes, and some phone displays use organic LEDs, or OLEDs. Neither are truly white LEDs, but instead use LEDs made of different materials that each emit a different color, then combine or convert those colors to create white light, Vardeny says.

In the new study, Vardeny and colleagues report how they inserted platinum metal atoms at different intervals along a chain-like organic polymer, and thus were able to adjust or tune the colors emitted. That is a step toward a truly white OLED generated by multiple colors from a single polymer.

Existing white OLED displays – like those in recent cell phones – use different organic polymers that emit different colors, which are arranged in pixels of red, green and blue and then combined to make white light, says Vardeny, a distinguished professor of physics. “This new polymer has all those colors simultaneously, so no need for small pixels and complicated engineering to create them.”

“This polymer emits light in the blue and red spectral range, and can be tuned to cover the whole visible spectrum,” he adds. “As such, it can serve as the active [or working] layer in white OLEDs that are predicted to replace regular light bulbs.”

Vardeny says the new polymer also could be used in a new type of solar power cell in which the platinum would help the polymer convert sunlight to electricity more efficiently. And because the platinum-rich polymer would allow physicists to “read” the information stored in electrons’ “spins” or intrinsic angular momentum, the new polymers also have potential uses for computer memory.

Read the whole press release here.

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John Viner, 1987

The Department of Physics & Astronomy is saddened to announce that John Viner, a member of the staff for many years, passed away on August 15, 2013. Details are still incoming and will be added soon.

His obituary is available here.

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University of Utah astronomers will participate in a six-year project to study the formation of our Milky Way galaxy; map stars, gas and supermassive black holes in 10,000 neighbor galaxies; and chart 1 million galaxies and quasars to learn about mysterious “dark energy” that makes the universe expand.

Five years after joining the third phase of the Sloan Digital Sky Survey, or SDSS-III, Utah’s largest research university is signing up for the fourth phase of the international effort to map the heavens – thanks to a $350,000 “challenge grant” from the Willard L. Eccles Charitable Foundation and a matching $350,000 from the university.

The sky survey’s first phase began in 2000. The University of Utah joined the six-year third phase in 2008 with a $450,000 donation from the Eccles foundation and university match. SDSS-IV begins in July 2014 and will operate until mid-2020.

Membership in the Sloan survey’s fourth phase is “a critical extension and expansion of the success achieved by the U’s astronomy program as a participant in SDSS-III,” says Michael Hardman, interim senior vice president for academic affairs.

“We are eager to continue our support for astronomy at the University of Utah,” says Stephen Eccles Denkers, executive director of the Willard L. Eccles Charitable Foundation.

Denkers noted that his family foundation’s support for University of Utah participation in the Sloan survey’s third phase “has been a key pillar of the establishment of the astronomy program at the university, and has led to multiple, high-profile results in research, education, outreach and external funding.”

Indeed, the university’s $900,000 participation since 2008 in the third Sloan survey attracted another $1.7 million in grants for faculty members doing research for the survey, says Dave Kieda, chair of physics and astronomy.

Adam Bolton and Kyle Dawson – both assistant professors of physics and astronomy – will serve as the U’s lead scientists in the fourth Sloan survey.

More than 30 research institutions will participate in SDSS-IV. The Sloan surveys use the 2.5-meter-diameter telescope at Apache Point Observatory at Sunspot, N.M.

That telescope “is the world’s most powerful facility for observing large volumes of space with the technique of spectroscopy,” Bolton says. “This technique breaks the light from stars and galaxies into its component wavelengths, allowing scientists to measure unique signatures of their orbital motions and chemical ingredients.”
The University of Utah signed and finalized a memorandum of understanding June 18 with the Seattle-based Astrophysical Research Consortium, which operates the Sloan surveys and hopes to raise $59 million for the survey’s fourth phase.

The consortium normally would charge the university $1.05 million to buy into SDSS-IV, but the price was reduced to $700,000 if the university fronted the full amount by June 30, which it did. The Eccles foundation will pay its $350,000 share to the university in installments of $120,000 this year and 2014, and $110,000 in 2015.

The university’s Center for High Performance Computing will host a massive archive of data collected by the fourth Sloan survey.

Read the full press release here.

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