HIGH-EFFICIENCY INGAP LIGHT-EMITTING-DIODES ON GAP SUBSTRATES

Very high brightness In(x)Ga(1-x)P light-emitting diodes (LEDs) have been fabricated on GaP substrates by hydride vapor phase epitaxy. LEDs operating at wavelengths from 650 nm (red) to 565 nm (green) have been demonstrated. The brightest encapsulated lamps emit at 592 nm and have external quantum efficiencies of 0.9%. These LEDs are the brightest yet reported for this material system and are several times brighter than commercially available GaAsP:N diodes. A device structure is described that minimizes self-absorption and is critical to obtaining these high-brightness emitters. Reliability studies show greatly improved light output stability over GaAsP:N LEDs through 1000 h of operation between -55 and +55-degrees-C.