A bright future for blue/green LEDs

Despite intensive research on blue light-emitting diodes (LEDs) and laser diodes (LDs), attaining the high brightness required for commercial full-color displays and indicators remains an elusive goal. Category II-VI materials such as ZnSe and SiC still cannot achieve luminous intensities greater than 1 candela (cd) or so, and reliable laser diodes are difficult to fabricate even with basic III-V materials. Category III-V devices, however, such as fabricated from InGaN and AlGaN, are making steady progress, and recent advances have brought them to the fringe of the marketplace.<>