Michael Free
(left) holds a light emitting diode and Prashant Sarswat (right) holds
carbon dots in
suspension. Photo credit: Prashant
Sarswat
DEVELOPMENT CAN OFFER AN ENVIRONMENTALLY SUSTAINABLE
ALTERNATIVE TO CURRENT METHODS
(October 13, 2015) Most
Christmas lights, televisions and flashlights have one thing in common: they’re
made with light emitting diodes (LEDs). LEDs are widely used for a variety of
applications and have been a popular, more efficient alternative to fluorescent
and incandescent bulbs for the past few decades. Two University of Utah
researchers have now found a way to create LEDs from food and beverage waste.
In addition to utilizing food and beverage waste that would otherwise decompose
and be of no use, this development can also reduce potentially harmful waste
from LEDs generally made from toxic elements.
LEDs are a type of device that can efficiently convert
electricity to light. Unlike fluorescent and incandescent bulbs, which direct
80% of the energy consumed to producing heat, LEDs direct 80% of the energy
consumed to producing light. This is made possible by the fact that LEDs do not
require a filament to be heated as incandescent and fluorescent bulbs do.
The luminescence
of carbon dots can be seen when
irradiated with UV light. Photo credit:
Prashant Sarswat
LEDs can be produced by using quantum dots, or tiny crystals
that have luminescent properties, to produce light. Quantum dots (QDs) can be
made with numerous materials, some of which are rare and expensive to
synthesize, and even potentially harmful to dispose of. Some research over the
past 10 years has focused on using carbon dots (CDs), or simply QDs made of
carbon, to create LEDs instead.
Compared to other types of quantum dots, CDs have lower
toxicity and better biocompatibility, meaning they can be used in a broader
variety of applications.
Photo credit: Prashant Sarswat
U Metallurgical Engineering Research Assistant Professor
Prashant Sarswat and Professor Michael Free, over the past year and a half,
have successfully turned food waste such as discarded pieces of tortilla into
CDs, and subsequently, LEDs.
The results were recently published in Physical Chemistry
Chemical Physics, a journal of the Royal Society of Chemistry.