New process creates infrared LEDs using quantum dots
A new process developed by Dr. Liangfeng Sun and his coworkers holds promise for improving the production and capabilities of the infrared light emitting diode, or LED, for use in technologies ranging from communications to night vision devices used by the military.
Sun, a faculty member in physics and astronomy and member of BGSU's Center for Photochemical Sciences, was the leader of the National Science Foundation-funded project when he was at Cornell University. With his Cornell team members, he created infrared LEDs in the lab using nanocrystals in solution, which has produced record brightness and better performance at a dramatically lower cost.
Their work was featured in a recent issue of Nature Nanotechnology, the leading journal worldwide in the area of nanotechnology. Sun will also give a presentation on the team’s achievement at the conference of the Materials Research Society in Boston this November, while the follow-up research on the nanocrystal-based LEDs continues in his lab at BGSU.
The ingredients in Sun's formula are among the tiniest on earth: quantum dots (also known as nanocrystals) in solution. Quantum dots are a new material in nanoscience: tiny particles of a semiconductor — in Sun's case lead sulfide — that emit photons, which are visible to infrared cameras as light when excited.
"They possess a novel optical property that is governed by quantum mechanics. The 'color' of the light they emit is determined by its wavelength. These are broadly 'tunable' to different wavelengths. We are working with the infrared wavelength, which is invisible to the human eye but has many applications," Sun said.
The invisible infrared LED is what powers remote control devices, some notebook computer data ports, and night-vision devices. Infrared LEDs also have an important role in communications through fiber optic systems.
"Why should we use infrared light for fiber optic communication? It is the most efficient; the infrared light can travel thousands of kilometers with minimal loss," Sun said.
In contrast to the traditional LED manufacturing process used in the semiconductor industry that uses high temperatures and a high vacuum environment, the method devised by Sun is less costly, does not require the vacuum environment, and allows for greater adjustment of the wavelength to meet different purposes.
Sun began the research about five years ago as a postdoctoral researcher at Cornell University. "The success has come in the last two years. It's an exciting achievement that we think will have a huge impact on the nanoscience community," he said.
Sun received Bachelor of Engineering and Master of Science degrees from Tsinghua University (1997) and the Institute of High Energy Physics (2000) in Beijing, China. He completed his Ph.D. study at the University of Texas at Austin (2006).
Lactation room opens, conference looks at health, wellness
Today Jonah's Room, the campus's first lactation room, opens in the Women's Center, and the Intersections conference this Friday explores collaborations in health and wellness research. Get details In Brief.
Graduate student, faculty investigate the mating choices of penguins
– Science Newsline
Student Legacy Campaign kicks off
Theresa Popp Braun (left), chair of the BGSU Foundation, holds a $5,000 donation check for the Student Legacy Campaign from her and her husband, Ray Braun, dean of the College of Business Administration. Standing with Popp Braun are (left to right) Ryan Sowers, chair of the campaign; BGSU President Mary Ellen Mazey; Undergraduate Student Government President Alex Solis and Undergraduate Student Trustee Beau Slater, who are holding an additional $5,000 check to kick off the campaign. The Student Legacy Campaign is a student-led initiative designed to foster a culture of giving among undergraduates. All the money raised will go toward a new gateway entrance to the University off Thurstin Avenue. Solis says the goal is to raise $250,000.
Faculty Canvas training to begin Sept. 11
What we communicated by "Blackboard" before, we can now put on "Canvas." Canvas is the University's new, open source learning management system for faculty and students that replaces both Blackboard and Epsilen ePortfolio.
Canvas is accessible in MyBGSU with your username. Find it on the top navigation bar.
Faculty and graduate instructor training on the new learning management system will be offered beginning this week. Two, two-hour sessions will be offered Sept. 11, 13, 17, 19 and 21, from 9:30-11:30 a.m. and again from 1:30-3:30 p.m. Sessions are limited to 15 people per session. To sign up, visit https://webapp.bgsu.edu/pstrain/
Each session will offer training on Canvas features and capabilities and will be followed by time for the trainers to assist as attendees begin to use Canvas for course development.
Some faculty have already transitioned to Canvas, which was piloted last spring by 94 faculty and staff members and 3,400 students. Blackboard and Epsilen ePortfolio will be phased out by December 2013.
"Many hurdles are removed with Canvas," said Allison Goedde, who teaches in the online educational technology master's program and was among the pilot users of Canvas last spring and a member of the Core Group advising ITS on product choice and implementation. "Students can be much more engaged with the course content instead of spending time finding and placing materials, as happened with Blackboard. And so many mediums can be included in a confined content environment.
"The same is true for faculty, both for building courses and using Canvas in their teaching. It's very intuitive, clear and streamlined. It eliminates interpretation about instructions. It's sophisticated but easy to use, even by faculty who are not exceptionally tech-savvy.
"Evaluations are easy, measuring student engagement is easy, the analytics component is excellent; you can measure student progress using metrics."
In addition to the in-person faculty training sessions, the Canvas website contains project information, training guides, support information and faculty and student resources as well as background information about the Canvas project. It provides information for faculty who would like to begin to build course content in Canvas as well as those who would like to transfer content from Blackboard.
Training will continue to be developed and offered throughout the fall semester, and will also be offered for students in the future.
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