Title :
Increasing the extraction efficiency of AlGaInP LEDs via n-side surface roughening
Author :
Lee, Y.J. ; Kuo, H.C. ; Wang, S.C. ; Hsu, T.C. ; Hsieh, M.H. ; Jou, M.J. ; Lee, B.J.
Author_Institution :
Dept. of Photonics, Nat. Chiao Tung Univ., Hsinchu, Taiwan
Abstract :
An n-side-up AlGaInP-based light-emitting diode (LED) with a triangle-like surface morphology was fabricated using the adhesive layer bonding technique, followed by wet etching to roughen the surface. The light output power of the roughened-surface LED was 1.6 times higher than that of a flat-surface LED at an injection current of 20 mA, i.e., a significant improvement attributed to the ability of the roughened surface to not only reduce the internal reflection between the rear mirror system and the semiconductor-air interface, but also to effectively scatter the light outside the LED device.
Keywords :
III-V semiconductors; aluminium compounds; etching; gallium compounds; indium compounds; light emitting diodes; light reflection; light scattering; mirrors; surface morphology; surface roughness; 20 mA; AlGaInP; AlGaInP LED; LED fabrication; adhesive layer bonding; extraction efficiency; internal reflection; light output power; light scattering; n-side surface roughening; rear mirror system; roughened-surface LED; semiconductor-air interface; triangle-like surface morphology; wet etching; Bonding; Light emitting diodes; Light scattering; Mirrors; Optical reflection; Power generation; Rough surfaces; Surface morphology; Surface roughness; Wet etching; AlGaInP; light-emitting diode (LED); surface roughening;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2005.858153
