Solid-State Lighting: Toward Superior Illumination

Solid-state lighting technology is now emerging as a cost-competitive,energy-efficient alternative to conventional electrical lighting. We review the history of lighting, discuss the benefits and challenges of the solid-state lighting technologies, and compare two approaches for generating white light from solid-state sources based on phosphor LEDs (which could be considered as solid-state replacement of fluorescent tubes) and multichip LED lamps,which offer many advantages, such as chromaticity control, better light quality,and higher efficiency.