Design, fabrication, and characterization of near-milliwatt-power RCLEDs emitting at 390 nm
We report on the realization and first demonstration of CW near-milliwatt-power emission at (lambda) = 390 nm from resonant-cavity light-emitting diode (RCLED) on GaN templates. The vertical cavity consists of a bottom AlGaN/GaN distributed Bragg reflector and a top dielectric SiO(2) = ZrO(2) mirror enclosing a GaInN/GaN multiple-quantum-well active layer. RCLEDs with total optical output of about 600 µW at an injection current of 20 mA were achieved before packaging, taking account of current growth and processing considerations. Dislocations generated during the growth of the RCLED structure seem to be affecting the mean light output. This can be further improved by the use of high-quality low-dislocation-density GaN templates or freestanding GaN substrates.