Optical and Structural Properties of InGaN-AlGaN Ultraviolet Light-Emitting Diodes

Abstract

We fabricated and investigated the performances of InGaN-AlGaN ultraviolet (UV) light-emitting diodes (LEDs) emitting at 380 rim. The output power of a conventional LED, a patterned sapphire substrate LED (PSS LE D), and a PSS flip-chip LED (PSS FCLED) were about 0.94,1.86, and 5.18 mW, respectively, at a forward injection current of 20 mA. These results indicate that the light output-powers of the PSS LED and PSS FCLED were enhanced as much as 97% and 451 % compared to the conventional LED. Subsequent optical simulations confirm the remarkable enhancements, in optical power of the PSS FCLED at UV wavelengths.