Chicago, IL--Researchers at the University of Illinois at Chicago (UIC) have developed a way to introduce precisely four copper "guest" ions into each and every quantum dot in a doping process that opens up possibilities for fine-tuning the optical properties of the quantum dots and producing spectacular colors. Quantum dots are tiny nanocrystals with extraordinary optical and electrical properties with possible uses in dye production, bioimaging, and solar energy production.
"When the crystallinity is perfect, the quantum dots do something that no one expected—they become very emissive and end up being the world's best dye," says Preston Snee, assistant professor of chemistry at UIC and principal investigator on the study. The results are reported in the journal ACS Nano, available online in advance of print publication.
Incorporating guest ions into the crystal lattice can be very challenging, says UIC graduate student Ali Jawaid, first author of the paper. Controlling the number of ions in each quantum dot is tricky. Because merely targeting an average number of guest ions will not produce quantum dots with optimal electrical and optical properties, Jawaid developed a procedure that reliably produces perfect quantum dots, each doped with exactly four copper ions. Snee believes the method will enable them to substitute other guest ions with the same consistent results. "This opens up the opportunity to study a wide array of doped quantum dot systems," he said.
Donald Wink and Leah Page of UIC and Soma Chattopadhyay of Argonne National Laboratory also contributed to the study.
Support for the research came from UIC and the UIC Chancellor's Discovery Fund and the American Chemical Society Petroleum Research Fund. The Materials Research Collaborative Access Team, a consortium for building and operating x-ray beamlines at Argonne's Advanced Photon Source, is supported by the U.S. Department of Energy and the MRCAT member institutions. The use of the Advanced Photon Source was supported by the DOE Office of Basic Energy Sciences under contract DE-QC02-06CH11357.
SOURCE: University of Illinois at Chicago; http://news.uic.edu/quantum-dot
Gail Overton | Senior Editor (2004-2020)
Gail has more than 30 years of engineering, marketing, product management, and editorial experience in the photonics and optical communications industry. Before joining the staff at Laser Focus World in 2004, she held many product management and product marketing roles in the fiber-optics industry, most notably at Hughes (El Segundo, CA), GTE Labs (Waltham, MA), Corning (Corning, NY), Photon Kinetics (Beaverton, OR), and Newport Corporation (Irvine, CA). During her marketing career, Gail published articles in WDM Solutions and Sensors magazine and traveled internationally to conduct product and sales training. Gail received her BS degree in physics, with an emphasis in optics, from San Diego State University in San Diego, CA in May 1986.