High performance thin-film flip-chip InGaN-GaN light-emitting diodes

Data are presented on the operation of thin-film flip-chip InGaN/GaN multiple-quantum-well light-emitting diodes (LEDs). The combination of thin-film LED concept with flip-chip technology is shown to provide surface brightness and flux output advantages over conventional flip-chip and vertical-injection thin-film LEDs. Performance characteristics of blue, white, and green thin-film flip-chip 1x1 mm(2) LEDs are described. Blue (similar to 441 nm) thin-film flip-chip LEDs are demonstrated with radiance of 191 mW/mm(2) sr at 1 A drive, more than two times brighter than conventional flip-chip LEDs. An encapsulated thin-film flip-chip blue LED lamp is shown to have external quantum efficiency of 38% at forward current of 350 mA. A white lamp based on a YAG:Ce phosphor coated device exhibits luminous efficacy of 60 lm/W at 350 mA with peak efficiency of 96 lm/W at 20 mA and luminance of 38 Mcd/m(2) at 1 A drive current. Green (similar to 517 nm) devices exhibit luminance of 37 Mcd/m(2) at 1 A. (c) 2006 American Institute of Physics.