June 2, 1999: Huntsville, AL Efforts by people to get thin are nothing compared with the efforts made by the electronics industry. Thin-film technology is considered to be a key
element of advanced electronics, from semiconductors to superconductors.
The Space Vacuum Epitaxy Center, a NASA Commercial Space Center, is working with industry to help advance this important area of research and
development. The center concentrates on four areas -- Nitride Materials
and Devices, Advanced Oxide Materials and Devices, Photovoltaics and
Nanostructures, and Optoelectronic Materials and Devices -- using both space - and ground-based research programs to make significant advances in technology. This work is profiled in a five page article in the March/April edition of the advanced semiconductor journal III-Vs Review.
The article notes the successes the Center has had in: developing advanced
mid-range IR semiconductor lasers, which hold promise for both
environmental monitoring and defense countermeasures; developing a unique
multi-quantum well Indium Phosphide (InP) solar cells, that not only are
radiation hardened, but thinner than conventional cells and with a greater
end-of-life efficiency; advances in nitride coatings for high-temperature
electronics, optoelectronic devices, and corrosion resistant coatings; and
for using oxide thin films to fabricate high temperature superconducting
(HTS) wires.
Semiconductor
lasers are of intense commercial interest because of their small size, low power
requirements, and low weight. Applied Optoelectronics
Incorporated will help commercialize a mid infrared semiconductor laser that
operates at room temperature. The Space Vacuum Epitaxy Center optimized the design
and fabrication of the laser, which can be used for several applications including
environmental monitoring on Earth and in space exploration. Because of its small
size and weight, it is also ideal for use on aircraft as a part of defenses against
heat-seeking missiles.
Improved solar cells are of interest, driven in part by the rapid explosion
of communications systems that require satellites. The harsh environment
of space, which includes exposure to radiation, can cut short the useful
life of many types of solar cells. The new cells developed by the Space
Vacuum Epitaxy Center offer improved performance along with a longer useful
lifetime for satellite developers.
One
opto-electronic device developed by the Center may have a biological optical
application. A new and unique optical micro-detector has been developed that
can be implanted into the eye to help restore sight in people with retinal damage.
The detector "sees" in the visible light region, just like the eye, and has sufficient
power to fire neurons in the optic nerve. Prototype detectors are in animal trials
in collaboration with the University of Texas
Health Science Center, and are expected to go to human trials under a cooperative
industry venture, possibly helping as many as 2 million people a year.
High temperature superconductors offer a variety of fascinating
possibilities for the future. One of the more immediate benefits may be in
the form of energy savings, by reducing resistance in transmission lines
and devices. The HTS wire developed by the Space Vacuum Epitaxy Center and
the Texas Center for Superconductivity is being commercialized by Metal Oxide Technologies, Inc., and pilot plant production of HTS wire for power
line transformers is expected in 2001.
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