Open AccessVertical InGaN light-emitting diodes with a sapphire-face-up structure
Author(s) -
Ya-Yu Yang,
Jinn-Kong Sheu,
Ming Lun Lee,
Shang Ju Tu,
Fenglan Huang,
Wei Chih Lai,
S. J. Hon,
T.K. Ko
Publication year - 2011
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.00a119
Subject(s) - light emitting diode , materials science , optoelectronics , sapphire , wafer , junction temperature , gallium nitride , diode , wafer bonding , optics , laser , power (physics) , layer (electronics) , nanotechnology , physics , quantum mechanics
Vertical GaN-based light-emitting diodes (LEDs) were fabricated with a Si substrate using the wafer-bonding technique. Lapping and dry-etching processes were performed for thinning the sapphire substrate instead of removing this substrate using the laser lift-off technique and the thinning process associated with the wafer-bonding technique to feature LEDs with a sapphire-face-up structure and vertical conduction property. Compared with conventional lateral GaN/sapphire-based LEDs, GaN/Si-based vertical LEDs exhibit higher light output power and less power degradation at a high driving current, which could be attributed to the fact that vertical LEDs behave in a manner similar to flip-chip GaN/sapphire LEDs with excellent heat conduction. In addition, with an injection current of 350 mA, the output power (or forward voltage) of fabricated vertical LEDs can be enhanced (or reduced) by a magnitude of 60% (or 5%) compared with conventional GaN/sapphire-based LEDs.