Increasing the extraction efficiency of AlGaInP LEDs via n-side surface roughening

• Published in: IEEE photonics technology letters Vol. 17; no. 11; pp. 2289 - 2291
• Main Authors: Lee, Y.J., Kuo, H.C., Wang, S.C., Hsu, T.C., Hsieh, M.H., Jou, M.J., Lee, B.J.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.11.2005; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adhesive bonding; Adhesive strength; AlGaInP; Bonding; Devices; Etching; Injection current; Light emitting diodes; Light scattering; light-emitting diode (LED); Mirrors; Optical reflection; Power generation; Reflection; Rough surfaces; Roughening; Surface morphology; surface roughening; Surface roughness; Wet etching
• ISSN: 1041-1135; 1941-0174
• DOI: 10.1109/LPT.2005.858153

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.