Abstract :
The LED lightbulb has loads to recommend it. Compared to the compact fluorescent, it can be twice as efficient, lasts far longer, and is free of mercury. But high prices are holding back sales: A??40-watt-equivalent LED bulb with a good hue starts at around US $20, and 60-W versions retail for far more. The good news is that this barrier to mass adoption should fall in the next two to three years, thanks to recent developments by the LED maker Bridgelux that should spur the launch of a $5 bulb. This California-based firm plans to slash the price of white emitting chips-which account for up to 70 percent of the cost of this type of bulb-by churning out millions of gallium nitride LEDs on 200-millimeter-diameter silicon wafers.