Invited Paper IPF-MoM8
Current Status of Solid State Lighting

Monday, October 15, 2007, 10:20 am, Room 602/603

The light emitting diode (LED) takes electrical energy and converts it to bright bluelight. The light generation is very energy efficient (60%), which is much better than normal incandescent bulb (5%). The light is generated inside of a crystal of gallium nitride (GaN), and it only requires a 3-volt battery. The efficiency of white LEDs that use blue LEDs will become higher, almost close to 100% (currently 150 lm/W). Then, all of the conventional lighting, such as incandescent bulbs (10 lm/W), fluorescent lamps (70 lm/W), and others, would be replaced with the white LEDs in order to save energy and resources. Also, these white LEDs would be operated by a battery powered by a solar cell in the daytime. So, it means that this lighting would be operated with clean energy thanks to its high efficiency and low voltage operation. In the developing countries, there is no electricity and no light at night. However, white LEDs operated with a small battery powered by a solar cell in the daytime could be used as a light source in those developing countries.