Description:
The invention is regarding a new method to achieve high-efficiency
III-Nitride light emitting diodes (LEDs) emitting in the visible regime
(covering from 420 nm up to 650 nm), with applications for solid state
lightings, display, biochemical sensing, and water purification
applications.
Specifically, the invention is related to a novel method to increase the
light extraction efficiency of optoelectronic emitters by utilizing a SiO2 /
polystyrene (PS) microlens array deposited on the surface on the light emission
area. The implementation of SiO2 / PS microspheres leads to a low-cost and
straight-forward approach to form microlens arrays on the emission surface of
emitters for improving light extraction efficiency, without using costly
electron-beam lithography process. The diameter of the microspheres can be
controlled accurately, resulting in good control and repeatability in the
microlens structure and optical properties. The deposition of 2D close-packed
SiO2 / PS colloidal crystal is also practical and straight forward, as compared
to electron-beam lithography or complex wafer fabrication techniques. As the
SiO2 microspheres are deposited as the final step on the top emission area of
the optoelectronic emitters, this approach avoids any degradation on the
electrical characteristics of the optoelectronic emitters.
The utilization of this novel invention allows one to realize light emitting
diodes with significantly enhanced light extraction efficiency, using a straight
forward and low-cost method.
APPLICATIONS AND ADVANTAGES
- General illumination light sources such as fluorescent and incandescent
lamps
- Solid state display applications (i.e. traffic lights, signage, etc)
- Efficient liquid crystal display (LCD) backlight
- Emerging technology of high-definition and true-color television using
LEDs-based pixels (ie. Sony Qualia).
- Entertainment lighting effects and luminaries for theatres, studios,
nightclubs, entertainments, restaurants and other high-visibility venues.
- Durable low voltage landscape Lighting for city, park, or residential.
- Portable lighting (i.e. Flashlights).
High brightness, low power LEDs for interior and exterior automotive lighting
with small footprints that offer improvement in safety, durability, and
design.
STATUS OF INTELLECTUAL PROPERTY
A US utility patent application and patent cooperation treaty (PCT) have been
filed.
Nelson Tansu's Lehigh
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