<Tr> <Td> </Td> <Td> Cyan </Td> <Td> 490 <λ <520 </Td> <Td> 0.26 </Td> <Td> 75 </Td> </Tr> <Tr> <Td> </Td> <Td> Blue </Td> <Td> 460 <λ <490 </Td> <Td> 0.35 </Td> <Td> 37 </Td> </Tr> <P> In September 2003, a new type of blue LED was demonstrated by Cree . This produced a commercially packaged white light giving 65 lm / W at 20 mA, becoming the brightest white LED commercially available at the time, and more than four times as efficient as standard incandescents . In 2006, they demonstrated a prototype with a record white LED luminous efficacy of 131 lm / W at 20 mA . Nichia Corporation has developed a white LED with luminous efficacy of 150 lm / W at a forward current of 20 mA . Cree's XLamp XM - L LEDs, commercially available in 2011, produce 100 lm / W at their full power of 10 W, and up to 160 lm / W at around 2 W input power . In 2012, Cree announced a white LED giving 254 lm / W, and 303 lm / W in March 2014 . Practical general lighting needs high - power LEDs, of one watt or more . Typical operating currents for such devices begin at 350 mA . </P> <P> These efficiencies are for the light - emitting diode only, held at low temperature in a lab . Since LEDs installed in real fixtures operate at higher temperature and with driver losses, real - world efficiencies are much lower . United States Department of Energy (DOE) testing of commercial LED lamps designed to replace incandescent lamps or CFLs showed that average efficacy was still about 46 lm / W in 2009 (tested performance ranged from 17 lm / W to 79 lm / W). </P>

Difference between led and ordinary pn emetion diode