AVS 51st International Symposium
    Science of Semiconductor White Light Topical Conference Wednesday Sessions
       Session WL-WeM

Invited Paper WL-WeM9
Efficiency Limitations of Solid-State Sources used in General-Lighting Applications

Wednesday, November 17, 2004, 11:00 am, Room 304B

Session: Science of Semiconductor White Light I
Presenter: E.F. Schubert, Rensselaer Polytechnic Institute
Authors: E.F. Schubert, Rensselaer Polytechnic Institute
Y.-L. Li, Rensselaer Polytechnic Institute
J. Kim, Rensselaer Polytechnic Institute
T. Gessmann, Rensselaer Polytechnic Institute
Correspondent: Click to Email
The use of highly efficient solid-state light sources for illumination applications can enable huge energy savings, a reduced generation of green-house gases, and a reduction in environmental pollution. Luminous source efficiencies exceeding 300 lm/W and color-rendering indices (CRIs) greater 90 are feasible with solid-state sources. This talk discusses critical issues in solid-state lighting including practical limits to efficacy and efficiency, scalability of chip size, and scalability of current density. Possible solutions to these issues based on new materials and structures are presented including low-refractive index materials, omni-directional reflectors, and polarization-enhanced contacts. Furthermore it is shown that solid-state sources based on light-emitting diodes (LEDs) have advantages not offered by conventional light sources, namely tunability and adaptability. Future smart light sources based on LEDs could offer full tunability of their spectral composition, color temperature, and other parameters, thereby allowing for the optimization of light sources for specific applications. Several application areas and the potential benefits of smart light sources are discussed.