UNT Research, Volume 18, 2009

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and operate than incandescent lights, which
would lead to billions of dollars in savings
and enormous reduction in carbon emissions.
Obstacles do remain, however. UNT
scientists are attempting to determine which
materials best create the perfect white light
and how to improve the lifetime of devices.
With nearly $2.3 million from the
U.S. Department of Energy, Omary and
his fellow researchers are addressing - and
solving - those problems.
"This is a very different, very new way
of thinking about lighting," says Oussama
Elbjeirami, a post-doctoral student at UNT
who works with Omary. "The future of
lighting is changing."
Light bulbs, long the staple source for
light in most homes, are inexpensive and

relatively long-lasting. They work by forc-
ing electricity through a metal filament into
a vacuum.
But consider this, Omary says. An
incandescent bulb gives off 10 percent
light; the rest of its energy is useless heat.
"The efficiency is really bad," Omary
says. "Ninety percent of its energy is wasted."
Beginning in 2012, the United States
plans to phase out incandescent lamps.
Compact fluorescent lights, or CFLs,
have been touted as a way to reduce energy
and cut greenhouse gases. Fluorescent lamps
use only about a quarter of the power of
incandescent lamps and last 10 times longer,
according to the U.S. Department of Energy.
But CFLs contain a small amount of
mercury in the glass tubing, which makes
them potentially harmful to dispose of and
requires a careful cleanup if one breaks.

immad Omary directs a UNT team that is
ering research in the field of organic light-
ng diodes, an emerging technology that
tists say could revolutionize lighting.
Organic light-emitting diodes could be
the solution, UNT scientists say.
Developed by Kodak more than 30
years ago, the technology has gained traction
in recent years because of the relatively low
amount of energy required to produce and
power it. An OLED is essentially a wafer-
thin carbon-based film sandwiched between
two conductors. When electrical voltage is
.pplicd, the organic material glows.
Ihe U.S. Department of Energy has
11 c.,tcd about $100 million during the last
five to six years in solid-state lighting, light
that is emitted from a solid object rather
than from a vacuum or gas tube. The DOE
hopes to have OLEDs ready for residential
use by 2015.
"Organic light-emitting diodes are one
of the most promising lighting technologies
envisioned by the DOE to replace today's
less efficient light sources," says Joel
Chaddock, a project manager at the DOE.
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To meet the goal, Omary and fellow
researchers synthesize new metal-organic
materials by mixing organic materials (con-
taining carbon, hydrogen and nitrogen) with
precursors of metals like gold, platinum or
copper. The solid materials are capable of
producing bright phosphorescence, or long-
lived light emission.
Omary's group then sends those
materials to Nigel Shepherd, an assistant
professor of materials science and engineer-
ing at UNT, whose group is in charge of
the design and construction of the light-
emitting devices.
Shepherd's group uses equipment at
UNT's Center for Advanced Research and

SPRING 2009 UNT RESEARCH

University of North Texas. UNT Research, Volume 18, 2009. Denton, Texas. UNT Digital Library. http://digital.library.unt.edu/ark:/67531/metadc115032/. Accessed August 28, 2014.