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Proceedings Paper

4-mW microcavity LED at 650 nm on germanium substrates
Author(s): Mark D'Hondt; Prasanta Modak; Danae Delbeke; Ingrid Moerman; Peter Van Daele; Roel G. Baets; Piet M. A. Demeester; Paul Mijlemans
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Paper Abstract

We report on the realization of red micro cavity LED's on germanium substrates, offering a significant cost advantage compared to GaAs wafers. The MCLED structure, grown by LP- MOVPE, consists of 3 GaInP quantum wells within a (detuned) 1- (lambda) AlGaInP cavity, enclosed by Al95GaAs/Al55GaAs DBR's, with a current spreading layer on top. MCLED's with a 200 micrometer aperture, exhibit a quantum efficiency up to 4.35% (at 10 mA) and an optical power higher than 4 mW (at 80 mA), without any packaging. The optical spectrum was centered at 650 nm, with a FWHM of plus or minus 13 nm. Because of the detuning the opening angle of these structures was as much as 120 degrees. Rudimentary packaging resulted in a luminous intensity of 2.5 cd at 30 mA, with an opening angle of plus or minus 13 degrees. Initially the electrical performance was not optimal, but additional tests and a new processing have indicated that forward biases as low as 2.0 V (at 20 mA) can be obtained for LED's on Ge-substrates. The new processing further resulted in an improved optical output with 5 mW at 80 mA. We feel there is room for further improvement, but already we have demonstrated the feasibility of germanium substrates for commercial red (to orange/yellow) LED applications.

Paper Details

Date Published: 17 April 2000
PDF: 9 pages
Proc. SPIE 3938, Light-Emitting Diodes: Research, Manufacturing, and Applications IV, (17 April 2000); doi: 10.1117/12.382838
Show Author Affiliations
Mark D'Hondt, Union Miniere and IMEC (Belgium)
Prasanta Modak, IMEC (Belgium)
Danae Delbeke, IMEC (Belgium)
Ingrid Moerman, IMEC (Belgium)
Peter Van Daele, IMEC (Belgium)
Roel G. Baets, IMEC (Belgium)
Piet M. A. Demeester, IMEC (Belgium)
Paul Mijlemans, Union Miniere (Belgium)

Published in SPIE Proceedings Vol. 3938:
Light-Emitting Diodes: Research, Manufacturing, and Applications IV
H. Walter Yao; Ian T. Ferguson; E. Fred Schubert, Editor(s)

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