White LED for general illumination applications

Abstract

In the 21st century, mankind faces problem of energy crisis through depletion of fossil fuels as well as global warning through the production of excessive greenhouse gases. Hence, there is an urgent need to look for new sources of renewable energy or ways to utilize energy more effectively. Solid state lighting (SSL) is a major area of research interest to use energy in a more efficient manner. Early light emitting devices (LEDs) were originally limited their use for low power indication lights. Later research produces high brightness LEDs (HB-LEDs) as well as blue color LEDs. This brings to reality of the entire visible light spectrum. White light is also made possible. As with other technologies, numerous obstacles will have to be surmounted in bringing LEDs from the laboratory to the marketplace. LEDs will also have to compete with established technologies such as incandescent and fluorescent lighting. This thesis will describe the current state of high powered LEDs, examine challenges faced by LEDs and look at future markets. Evaluation in the potential of LEDs for general illumination will be carried out through cost modeling and performance analysis.