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Ultraviolet GaN‐based nanocolumn light‐emitting diodes grown on n‐(111) Si substrates by rf‐plasma‐assisted molecular beam epitaxy
Author(s) -
Sekiguchi Hiroto,
Kato Kei,
Tanaka Jo,
Kikuchi Akihiko,
Kishino Katsumi
Publication year - 2008
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.200778733
Subject(s) - electroluminescence , materials science , molecular beam epitaxy , optoelectronics , light emitting diode , ultraviolet , diode , full width at half maximum , plasma , wavelength , fabrication , epitaxy , nanotechnology , medicine , physics , alternative medicine , layer (electronics) , quantum mechanics , pathology
We report the fabrication of GaN/AlGaN nanocolumn LEDs on n‐(111) Si substrates by RF‐MBE for the first time. Clear diode characteristics with a turn‐on voltage of 4 V and an ultraviolet emission spectrum with a peak wavelength of 354 nm were observed at room temperature. When the Al composition of p‐Al x Ga 1– x N was changed from 8.8% to 25.1%, the high Al content led a narrowing of the FWHM compared withthat for low Al contents due to the suppression of carrier overflow. We measured the electroluminescence (EL) under dc and pulsed operations. The integrated EL intensity under the pulsed operation was 3 times as strong as that under the dc operation at 100 mA due to the reduced generation of heat. The thermal resistance was estimated to be 40 °C/W from the EL peak wavelength difference between the dc and pulsed operations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)