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Electron transport properties in Al 0.25 Ga 0.75 N/AlN/GaN heterostructures with different InGaN back barrier layers and GaN channel thicknesses grown by MOCVD
Author(s) -
Kelekçi Özgür,
Taşlı Pınar T.,
Yu HongBo,
Kasap Mehmet,
Özçelik Süleyman,
Özbay Ekmel
Publication year - 2012
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.201100313
Subject(s) - materials science , metalorganic vapour phase epitaxy , heterojunction , scattering , phonon scattering , condensed matter physics , sapphire , electron mobility , optoelectronics , wide bandgap semiconductor , indium gallium nitride , indium nitride , phonon , indium , gallium nitride , epitaxy , layer (electronics) , nanotechnology , optics , thermal conductivity , composite material , laser , physics
The electron transport properties in Al 0.25 Ga 0.75 N/AlN/GaN/In x Ga 1− x N/GaN double heterostructures with various indium compositions and GaN channel thicknesses were investigated. Samples were grown on c ‐plane sapphire substrates by MOCVD and evaluated using variable temperature Hall effect measurements. In order to understand the observed transport properties, various scattering mechanisms, such as acoustic phonon, optical phonon, interface roughness, background impurity, and alloy disorder, were included in the theoretical model that was applied to the temperature‐dependent mobility data. It was found that low temperature ( T < 160 K) mobility is limited only by the interface roughness scattering mechanism, while at high temperatures ( T > 160 K), optical phonon scattering is the dominant scattering mechanism for AlGaN/AlN/GaN/InGaN/GaN heterostructures. The higher mobility of the structures with InGaN back barriers was attributed to the large conduction band discontinuity obtained at the channel/buffer interface, which leads to better electron confinement.