LEDs for Lighting Applications

In a recent Scientific American article entitled "In Pursuit of the Ultimate Lamp", authors George Craford, Nick Holonyak and Frederick Kish discuss the progress in light emitting diodes. LEDs have exceeded the efficiency of incandescent sources in the past few years, but remain cost prohibitive in manufacture compared to incandescent lighting for ordinary lighting applications. They place the cost of commercial white LEDs at 50¢ per lumen compared to a fraction of a cent per lumen for incandescent light bulbs.