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Student Innovator at Rensselaer Polytechnic Institute Seeks Brighter, Smarter, and More Efficient LEDs
Ming Ma Is One of Three Finalists for the
$30,000 2013 Lemelson-Rensselaer Student
Prize
Ming Ma has developed a new method to manufacture
light-emitting diodes (LEDs) that are brighter, more energy
efficient, and have superior technical properties than those on
the market today. His innovation holds the promise of hastening
the widespread adoption of LEDs and reducing the overall cost,
energy consumption, and environmental impact of illuminating
our homes and businesses.
Ma, a doctoral student in the Department of Materials Science
and Engineering at Rensselaer Polytechnic
Institute, is one of three finalists for the 2013 $30,000
Lemelson-Rensselaer Student Prize. A public ceremony announcing
this year’s winner will be held at 3:30 p.m. on Tuesday, March
5, in the auditorium of the Rensselaer Center for Biotechnology and
Interdisciplinary Studies. For more information on the
ceremony visit: http://www.eng.rpi.edu/lemelson
Ma’s project is titled “Graded-refractive-index (GRIN)
Structures for Brighter and Smarter Light-Emitting Diodes.” His
faculty advisers are E. Fred Schubert,
the Wellfleet Senior Professor in the Future Chips
Constellation at Rensselaer and a faculty member of the
university’s Department of Electrical,
Computer, and Systems Engineering and Department of Physics,
Applied Physics, and Astronomy, and Linda Schadler,
professor of materials science and engineering and associate
dean for academic affairs in the School of
Engineering.
Over the past decade, there has been a profound shift in the
way we light our homes, offices, and businesses. Conventional
incandescent and fluorescent light sources are increasingly
being replaced by more energy-efficient, longer-lived, and
environmentally friendlier LEDs. Beyond illumination,
researchers and companies are finding new uses for LEDs in
areas as diverse as communication, health care, and
imaging.
Improving the efficiency of LEDs and introducing new
functionalities such as controllable light emission patterns
are critical steps to continuing and accelerating their
widespread adoption. One major challenge still needing to be
solved is improving the low light-extraction efficiency of
LEDs—or the percentage of produced light that actually escapes
from the LED chip. Currently, most unprocessed LEDs have a
light-extraction efficiency of only 25 percent, which means 75
percent of light produced gets trapped within the device
itself.
One solution that has emerged is to roughen the surface of
LEDs, in order to create nanoscale gaps and valleys that enable
more light to escape. While surface roughening leads to
brighter and more efficient light emission, the roughening
process creates random features on the LED’s surface that do
not allow for a complete control over other critical device
properties such as surface structure and refractive index.
Ma’s solution to this problem was to create an LED with
well-structured features on the surface to minimize the amount
of light that gets reflected back into the device, and thus
boost the amount of light emitted. He invented a process for
creating LEDs with many tiny star-shaped pillars on the
surface. Each pillar is made up of five nanolayers specifically
engineered to help “carry” the light out of the LED material
and into the surrounding air.
Ma’s patent-pending technology, called GRIN
(graded-refractive-index) LEDs, has demonstrated a
light-extraction efficiency of 70 percent, meaning 70 percent
of light escaped and only 30 percent was left trapped inside
the device—a huge improvement over the 25 percent
light-extraction efficiency of most of today’s unprocessed
LEDs. In addition, GRIN LEDs also have controllable emission
patterns, and enable a more uniform illumination than today’s
LEDs.
Overall, Ma’s innovation could lead to entirely new methods
for manufacturing LEDs with increased light output, greater
efficiency, and more controllable properties than both
surface-roughened LEDs and the LEDs currently available in the
marketplace.
In his time at Rensselaer, Ma has been the first author on
five research papers, published in Applied Physics Letters,
Journal of Applied Physics, and Optics Express,
and co-author of several studies in other journals. He is also
a reviewer for Optics Letters and Optics
Express.
As an undergraduate student, Ma became interested in the
impact of materials and advanced materials on everyday life.
This interest sharpened to the area of LEDs. New innovations
and inventions in LEDs, he said, hold the promise of improving
light quality, efficiency, and introducing new uses for light
that can benefit individuals and businesses around the
world.
When not in the lab or classroom, Ma enjoys playing
basketball, soccer, and table tennis. Another favorite pastime
is traveling and visiting interesting destinations across the
United States, from Los Angeles and Las Vegas to Miami, Boston,
and New York.
Ma’s family and friends are rooting for him to win the
$30,000 Lemelson-Rensselaer Student Prize. His father, a
newspaper editor, and his mother, a mechanical engineer at a
pharmaceutical manufacturer, along with many cousins, are
cheering for him in his hometown in the Jiangxi Province in
southeast China.
Ma received his bachelor’s degree in materials science and
engineering from Fudan University in Shanghai, China, and his
master’s degrees in materials science and engineering from
Rensselaer in 2010. Upon completing his doctoral degree from
Rensselaer, Ma plans to continue researching materials and LEDs
in academia or industry.
About the $30,000 Lemelson-Rensselaer Student
Prize
The $30,000 Lemelson-Rensselaer Student Prize is
funded through a partnership with the Lemelson-MIT Program,
which has awarded the $30,000 Lemelson-MIT Student Prize to
outstanding student inventors at MIT since 1995.
About The Lemelson-MIT Program
Celebrating innovation, inspiring
youth
The Lemelson-MIT Program celebrates outstanding
innovators and inspires young people to pursue creative lives
and careers through invention.
Jerome H. Lemelson, one of U.S. history’s most prolific
inventors, and his wife, Dorothy, founded the Lemelson-MIT
Program at the Massachusetts Institute of Technology in 1994.
It is funded by The Lemelson Foundation and administered by the
School of Engineering. The Lemelson Foundation uses the power
of invention to improve lives by inspiring and enabling the
next generation of inventors and invention-based enterprises to
promote economic growth in the United States and social and
economic progress for the poor in developing countries. http://web.mit.edu/invent/
Read about past winners of the $30,000 Lemelson-Rensselaer
Student Prize:
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Published
February 28,
2013 |
Contact: Michael Mullaney
Phone: (518) 276-6161
E-mail: mullam@rpi.edu |
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