Title :
Improvement in light-output efficiency of AlGaInP LEDs fabricated on stripe patterned epitaxy
Author :
Lee, Y.J. ; Tseng, H.C. ; Kuo, H.C. ; Wang, S.C. ; Chang, C.W. ; Hsu, T.C. ; Yang, Y.L. ; Hsieh, M.H. ; Jou, M.J. ; Lee, B.J.
Author_Institution :
Dept. of Photonics, Nat. Chiao Tung Univ., Hsinchu, Taiwan
Abstract :
Quaternary AlGaInP light-emitting diodes (LEDs) operating at a wavelength of 630 nm with a stripe-patterned omni-directional reflector (ODR) were fabricated. It is demonstrated that the geometrical shape of stripe-patterned structure improves the light extraction efficiency by increasing the extraction of guided light. The optical and electrical characteristics of stripe-patterned ODR LEDs are presented and compared to typical ODR and distributed Bragg reflector (DBR) LEDs with the same epitaxial structure and emitting wavelength. It is shown that the output power of the stripe-patterned ODR LED exceeds that of the typical ODR and DBR LEDs by a factor of 1.15 and 2 times, respectively, and with an acceptable forward voltage of about 2.2 V.
Keywords :
III-V semiconductors; aluminium compounds; gallium compounds; indium compounds; integrated optics; integrated optoelectronics; light emitting diodes; mirrors; semiconductor epitaxial layers; 2.2 V; 630 nm; AlGaInP; AlGaInP LED; LED fabrication; guided light extraction; light extraction efficiency; light-output efficiency; omnidirectional reflector; quaternary light-emitting diodes; stripe patterned epitaxy; Distributed Bragg reflectors; Electric variables; Epitaxial growth; Gallium arsenide; Geometrical optics; Light emitting diodes; Power generation; Shape control; Stimulated emission; Substrates; AlGaInP; light-emitting diode (LED); omni-directional reflector (ODR);
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2005.859147
