|Light Emitting Diodes (LEDs)
LEDs appeared in traffic light applications in the 1990s but the true breakthrough of the decade was the development of the high brightness blue LED by Shuji Nakamura when he was at Nichia Corporation. This in turn enabled white LED lighting, which now represents the majority of the LED market. LEDs have inherent advantages over incandescent lighting due to low energy use per unit light output and long lifetime, but they must overcome challenging cost barriers to develop broad based lighting applications in the future. Nevertheless, rapid progress in technology has led to higher efficiency (lumens per watt) and lower manufacturing costs that enable a number of key applications today. General illumination is being targeted by so-called warm-white LEDs while high brightness LEDs emerged as essential components in mobile phone LCD display backlighting. In this Newsletter we examine recent performance improvements; new fundamental technologies that often relate to substrate materials technology; and applications in LCD backlighting, automotive lights, and general illumination.