High Output Power from 260nm Pseudomorphic Ultraviolet Light-Emitting Diodes with Improved Thermal Performance

This letter reports on the improved performance of a pseudomorphic ultraviolet light-emitting diode (LED). At 100mA input current, 9.2mW of quasi-CW output power was measured in a calibrated integrating sphere. The addition of a heat sink, required for CW and higher power operation, introduced a numerical aperture of 0.86, and 72mW was measured in pulsed mode at 1.7 A, indicating that the total output power exceeds 100mW when corrected by the coupling factor. The high characteristic temperature of 983 K was instrumental in achieving these record output powers for an LED with wavelength shorter than 265 nm. (C) 2011 The Japan Society of Applied Physics