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Electrical investigations of AlGaN/AlN structures for LEDs on Si(111)
Author(s) -
Witte H.,
Rohrbeck A.,
Günther K.M.,
Saengkaew P.,
Bläsing J.,
Dadgar A.,
Krost A.
Publication year - 2011
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.201001146
Subject(s) - heterojunction , materials science , optoelectronics , light emitting diode , equivalent series resistance , diode , quantum well , substrate (aquarium) , optics , electrical engineering , voltage , laser , oceanography , physics , geology , engineering
The carrier transport in AlGaN light emission diode (LED) structures on Si‐substrates including an AlN multilayer (ML) buffer for reduction of defects was investigated using I – V ‐characteristics and admittance spectroscopy. Additionally, AlN on Si ML and AlN/AlGaN:Si on Si structures were grown and analyzed separately. The AlN‐ML/AlGaN:Si heterojunction, and the pn‐junction including the AlGaN/GaN multi quantum well (MQW)‐structure were identified. As the main space charge regions (SCRs) controlling the carrier transport through the ultraviolet‐light emission diode (UV‐LED) structure the Si‐substrate/AlN‐ML heterojunctions pointed out. The I – V ‐characteristic of the LED structure is described by the series resistance of the AlN‐ML and a parallel resistance with respect to the pn‐junction. Interface defect states and/or deep defects impact the series resistance. The carrier transport through the LED structure is controlled by a tunnel process described by a Fowler–Nordheim (FN)‐emission mainly through the AlN‐ML buffer forming the series resistance.