InGaN/GaN single-quantum-well light-emitting diodes optical output efficiency dependence on the properties of the barrier layer separating the active and p-layer regions

We have examined the output optical efficiency dependence of InGaN/GaN single-quantum-well (SQW) structures on the properties of the barrier layer separating the active and p-layer regions in typical metalorganic chemical vapor deposition grown light-emitting-diode (LED) devices. Based on room-temperature electroluminescence and 10-300 K photoluminescence findings, the optical output of SQW LEDs was found to be extremely sensitive to narrow range variations in thickness, growth temperature, and surface roughness of the uppermost barrier layer in such devices. Applying these principles and observations, a thermally robust 465 nm SQW LED with an unpackaged chip-level output power in the 5.0-6.0 mW range and forward voltage <3.2 V at 20 mA has been achieved. (C) 2004 American Institute of Physics.