Into the 21st Century: Light Emitting Diode advances into Solid
State
Lighting
Abstract:
Light emitting diode converts electric
energy into light. The color of emission depends on the
bang-gap energy of active layer used in the device. Full
color spectra of LED are available now through the
proper selection of III-V compound semiconductors. White light LEDS are also practical commercial products now.
Most significant implication of new developments is that the
energy conversion efficiency of LEDs (new record of 50 Lumens
per Watt for white light) is far exceeding 16 Lumens per Watt of
the regular household incandescent lamps. The tremendous
electrical power saving could contribute not only financial
benefits but also could avoid construction of many tens of
nuclear power plants. An introduction to the evolution of LED
developments in terms of device structures, performance
improvements and applications will be presented. A glimpse of
the road map of government sponsored solid state lighting
projects will explain the challenges and opportunities ahead the
LED industry.
Speaker Bio:
Dr. Jiann G. Yu received his B. S. Degree from Department of
Physics, Cheng Kung University, M.S. Degree from Department of
Physics, University of Wyoming and PhD from Department of Material
Science, UCLA. He started career on Si and GaAs solar cells in Jet
Propulsion Laboratory. Then He joined Northrop as a member of stuff
participating in the investigation of III-V materials that could
extend InSb CID array
technology. He then joined Tektronix research lab working in GaAs
IC development for high speed application. Since 1981 he joined
Optoelectronics Division of Hewlett Packard, working on
development and production of various light emitting diodes,
including GaP, GaAsP, InGaP, AlGaInP and the recent AlInGaN
compound semiconductors. These materials can cover the full color of
visible spectrum ranging from blue, cyan, and green, yellow, orange
to red. His specialty is epitaxial growth of compound semiconductor
layers. He retired from Agilent in 2000 and from Lumileds in 2003.
