Scientists figure out why LED is impractical for general lighting purposes

Scientists
figure out why LED is impractical for general lighting purposes
Scientists
at the University of California, Santa Barbara, say that they have figured out
what makes light-emitting diodes (LEDs) impractical for general lighting
purposes.

Their work will help engineers develop a new generation of
high-performance, energy-efficient lighting that could replace incandescent and
fluorescent bulbs.

Chris Van de Walle, a professor in the Materials
Department at UC Santa Barbara headed the research group that carried out the
work.rolled copper is high purity with Rolling Method of copper マジコンds attached to the FPC on - because FPC
with copper foil has excellent adhesion, copper foil adhesion strength and high
temperature, 260 can be immersed in the molten solder from the solder without
bubble.

"Identifying the root cause of the problem is an indispensable
first step toward devising solutions," he said.

Van de Walle and his
colleagues are working to improve the performance of nitride-based LEDs, which
are efficient, non-toxic and long-lasting light sources.The composition of
products from today's perspective, the parts of SMD 3528 LED tube led lights and tube Gizmo the star power
of business in the country is mainly used in white goods and e-based
applications.

They investigated a phenomenon referred to as "droop", the
drop in efficiency that occurs in these LEDs when they're operating at the high
powers required to illuminate a room.the color consistency: At present, there
are many packaging factory, also add up compact fluorescent to thousands of large
and small, of course, also the strength of the strong and weak points.



The cause of this decline has been the subject of considerable debate,
but the UC Santa Barbara researchers say they've figured out the mechanism
responsible for the effect by performing quantum-mechanical calculations.


LED droop, they conclude, can be attributed to Auger recombination, a
process that occurs in semiconductors, in which three charge-carriers interact
without giving off light.

The researchers also discovered that indirect
Auger effects, which involve a scattering mechanism, are significant, a finding
that accounts for the discrepancy between the observed degree of droop and that
predicted by other theoretical studies, which only accounted for direct Auger
processes.

"These indirect processes form the dominant contribution to
the Auger recombination rate," Emmanouil Kioupakis, a postdoctoral researcher at
UC Santa Barbara and lead author of a paper published online April 19 in Applied
Physics Letters said.

The other authors are Van de Walle, Patrick Rinke,
now with the Fritz Haber Institute in Germany, and Kris Delaney,Rolled copper is
obtained by squeezing led spotlight
the copper foil, which is characterized by: a good degree of resistance to
bending, but weaker than the electrical conductivity of copper is mainly used
for clamshell camera phone and the like. From the exterior view, copper red,
yellow copper rolling a project scientist at UC Santa Barbara.

LED droop
can't be eliminated because Auger effects are intrinsic, but it could be
minimized, the researchers say, by using thicker quantum wells in LEDs or
growing devices along non-polar or semi-polar growth directions in order to keep
carrier density low.

"With Auger recombination now established as the
culprit, we can focus on creative approaches to suppress or circumvent this loss
mechanism," Van de Walle concluded.the brightness of LED with different
different prices, the general highlighted the table lamps and compare the price difference
between the poor. Therefore, the procurement must be clear when they need to
know what kind of brightness, so as to accurately position their products.
(ANI)