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December 1, 2009
Jeff Tsao gave the opening talk at a “Research Frontiers in Solid State Lighting” one-day (Dec. 1, 2009) workshop at Nanyang Technological University. The workshop was organized by Professor Xiaowei Sun of Nanyang Technological University and was sponsored by the Photonics Research Center at Nanyang Technological University, the Singapore and Malaysia Chapter of the Society for Information Display, and the IEEE Photonics Society.
Both inorganic and organic approaches to SSL were covered, and a common theme throughout was the use of nanostructures (e.g., quantum dots) to facilitate the energy and wavelength conversion processes necessary to create high-quality white light for illumination. Many approaches are being explored, including the direction injection of carriers into the QDs, Forster transfer of electron-hole-pair excitations from quantum wells into QDs, and photon-mediated transfer of electron-hole-pair excitations from quantum wells into QDs.
September 9, 2009
Marlan Scully (joint professor at Texas A&M and Princeton) visited Sandia on Sept. 9, 2009 for an informal brainstorming session with a group of staff members. Those present included Willie Luk, Jeff Nelson, Jeff Tsao, Jerry Simmons, Weng Chow, Ganesh Subramania, Dave Sandison, Ihab El-kady, Murat Okandan, Mike Wanke, Paul Davids, and Julia Hsu. Among the ideas discussed were the chemical and electrochemical driving forces underlying solar cell operation and novel schemes for dispersing, compressing and harvesting the solar spectrum so as to exceed the Schockley-Queisser single-band-gap limit to solar-cell efficiency. The two-way exchange was extremely profitable, and many ideas were generated and discussed.
August 20, 2009
Our Solid-State Lighting Sciences Energy Frontier Research Center (EFRC) is up and running. We had an EFRC kick-off meeting on Aug. 20, attended by most of the Sandia Labs participants. This was the first gathering of the large group of research participants since the center began. It was an opportunity to discuss expectations of our DOE Basic Energy Sciences sponsors for the EFRC program in general and the opportunity we have to impact the nation through fundamental research on the scientic foundations of solid-state lighting. The principal investigators of our six initial EFRC research challenges gave overviews of the goals and scientic issues in their projects.
Front row: Bob Biefeld, Emil Kadlec, Andy Armstrong, Eric Shaner, George Wang, Qiming Li, Dan Barton. Back row: Troy Ribaudo, Brandon Passmore, Weng Chow, Willie Luk, Rohit Prasankumar, Ganesh Subramania, Igal Brener, Kate Bogart, Jerry Simmons, Mary Crawford, Jim Martin, Lauren Rohwer, Julie Phillips, Mike Coltrin, Jeff Tsao, Dan Koleske.
August 3, 2009
A group of research staff from our Solid-State Lighting EFRC participated in the Aug. 3-7, 2009 Texas A&M / Princeton Workshop on Quantum Science and Engineering held in Jackson Hole, WY. This workshop is an annual, invitation-only event organized by Marlan Scully, an internationally acclaimed scientist in the field of quantum optics, and a joint professor at the above universities. It has developed into an intimate (~50 people), Gordon-conference-like forum for exchanging ideas at the cutting edge of quantum optics and light-matter interactions.
This year, Professor Scully invited a group of 9 Sandia scientists to participate and to introduce workshop participants to research topics of long-term importance to energy applications such as solid-state lighting and solar photovoltaics. Weng Chow, a former Ph.D. student of Professor Scully, was instrumental in creating this opportunity. Sandia participants (and the talks they gave) were: Jeff Tsao / 1120 (Solid-state lighting: progress and challenges); Eric Shaner / 1123 (Plasmonic approaches to light manipulation, absorption and emission); Willie Luk / 1725 (Enhancing solar energy harvesting with a quantum-dot monolayer on a photonic crystal); Ines Waldmueller / 1123 (Thinking outside the box: quantum cascade lasers seen differently); Weng Chow / 1123 (Will quantum dot lasers ever replace quantum well lasers?); Jeff Nelson / 6330 (Solar photovoltaics: progress and challenges); Jerry Simmons / 1120; Ganesh Subramania (1725); and Art Fischer / 1123.
At the same time, Sandia participants were exposed to topics at the cutting edge of quantum optics, including talks by: Dudley Herschbach / Harvard and Texas A&M and 1986 Chemistry Nobel Laureate (Coherent Control of Chemical Reactions); Sunney Xie / Harvard (The quest for ultimate sensitivity in biomedical imaging); Aleksey Zheltikov / Moscow State (Photonic crystal fibers: shining a new light on ultrafast optical science); Bob Nevels / Texas A&M (Plasmonic nano-antennas); Shaul Mukamel / UC Irvine (Coherent multidimensional spectroscopy of excitons using classical fields and entangled photons); and Marlan Scully / Texas A&M and Princeton (Superradiance and infinity-free quantum electrodynamics).
The two-way exchange was extremely profitable, and many ideas were generated, discussed and refined, all with an eye towards advancing basic science of long-term importance to energy applications.
August 1, 2009
Portal to the Public is a collaborative project, funded by the National Science Foundation, between the Explora Museum in Albuquerque, NM; the Pacific Science Center in Seattle, WA; the North Museum of Natural History and Science in Lancaster, PA; and the Institute for Learning Innovation in Annapolis, MD. Its purpose is to explore how face-to-face interactions between scientists and public audiences can promote appreciation and understanding of current scientific research and its application.
This year, our EFRC Chief Scientist Jeff Tsao was one of a number of researchers from Sandia and the University of New Mexico who participated. Jeff and Josh Larson (Explora Museum Exhibit Developer), developed a hands-on exhibit on solid-state lighting, illustrating different ways of creating solid-state white light from monochromatic light-emitting diodes and the resulting differences in how the colors of typical objects in our environment are rendered. Jeff participated in two public program sessions (May 31 and Aug. 1), in which he interacted with visitors of all ages as they “played” with the exhibit.