TITLE

Nitride deep-ultraviolet light-emitting diodes with microlens array

AUTHOR(S)
Khizar, M.; Z. Y. Fan; K. H. Kim; J. Y. Lin; H. X. Jiang
PUB. DATE
April 2005
SOURCE
Applied Physics Letters;4/25/2005, Vol. 86 Issue 17, p173504
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
We report on the fabrication of 280-nm AlGaN-based deep-ultraviolet light-emitting diodes (UV LEDs) on sapphire substrates with an integrated microlens array. Microlenses with a diameter of 12 μm were fabricated on the sapphire substrate by resist thermal reflow and plasma dry etching. LED devices were flip-chip bonded on high thermal conductive AlN ceramic submounts to improve the thermal dissipation, and the emitted UV light was extracted through the sapphire substrates. With the integrated microlens array, a 55% enhancement in the output power at 20-mA dc driving was achieved compared with the same LED without microlens. The light extraction enhancement is the result of the reduced internal reflections of the light caused by the microlens surface profile.
ACCESSION #
17227609

 

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