Energy, Climate, & Infrastructure Security (ECIS)

Energy Efficiency

Four-color laser white illuminant demonstrating high color-rendering quality

On August 15, 2011, in News, Solid-State Lighting

July 4, 2011 Solid-state lighting is currently based on light-emitting diodes (LEDs) and phosphors.  Solid-state lighting based on lasers would offer significant advantages including high potential efficiencies at high current densities. Light emitted from lasers, however, has a much narrower spectral linewidth than light emitted from LEDs or phosphors.  Therefore it is a common belief [...]

Light Creation Materials

On July 14, 2011, in

Light Creation Materials Different families of inorganic semiconductor materials can contribute to solid-state white lighting. The primary chemical systems used for LEDs are Group-III nitrides and Group-III phosphides. It is, however, possible that breakthroughs in a different material system, for example ZnO, will be important. AlGaInN Materials LEDs based on gallium nitride (GaN) and ternary [...]

Wavelength Conversion Materials

On July 14, 2011, in

Wavelength Conversion Materials Rare-Earth Phosphors Inorganic phosphors doped with rare-earth metals are used for a variety of applications. A wide array of these phosphors has been developed for use with fluorescent lamps. The first SSL white LEDs have used an yttrium aluminum garnet doped with trivalent cerium (YAG:Ce+3) to convert output from a blue LED [...]

White Light Creation Architectures

On July 14, 2011, in

White Light Creation Architectures The entire spectral range of visible light can be produced by III-V semiconductor LEDs. AlGaInP LEDs can cover the spectral range from red to amber, and their commercial production is relatively mature. AlGaInN LEDs are the prime candidates for producing wavelengths from blue to yellow. Two main approaches for producing white [...]

InAs Quantum Dot Transitions

March 1, 2011 The fundamental interaction governing light emission from semiconductor materials is the coupling between electronic states in the semiconductor and a local electromagnetic field. The current generation of solid-state lighting devices operates in the so-called “weak-coupling” regime, in which the rate of energy transfer between the electronic states and the local electromagnetic field [...]

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