Results 131 to 140 of about 3,102 (186)

AlGaN/GaN/AlGaN ultraviolet photodetectors on Si

2001 6th International Conference on Solid-State and Integrated Circuit Technology. Proceedings (Cat. No.01EX443), 2005
AlGaN/GaN/AlGaN ultraviolet photodetectors were grown on Si [111] substrates using an AlN buffer by metalorganic chemical vapor deposition. These detectors showed a high response in a narrow range of wavelength with a peak position at 365 nm. A peak responsivity of 24 A/W was obtained at 5.5 V bias.
R.L. Jiang, Z.M. Zhao, P. Chen, D.J. Xi, B. Shen, R. Zhang, Y.D. Zheng   +6 more
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High-reflectivity ultraviolet AlGaN∕AlGaN distributed Bragg reflectors

Applied Physics Letters, 2006
We demonstrate high-reflectivity crack-free Al0.18Ga0.82N∕Al0.8Ga0.2N distributed Bragg reflectors (DBR) for the spectral region around 350nm grown by molecular-beam epitaxy on thick GaN templates. The structural quality of the DBR layers is maintained by compensating the compressive and tensile stress in each λ∕4 pair.
Mitrofanov, Oleg, Schmult, Stefan, Manfra, Michael J., Siegrist, Theo M., Weimann, Nils, Sergent, Arthur Michael, Molnar, Richard J.   +6 more
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AlGaN Nanocolumns and AlGaN/GaN/AlGaN Nanostructures Grown by Molecular Beam Epitaxy

physica status solidi (b), 2002
This work reports on the characterization of hexagonal, single crystal AlGaN nanocolumns with diameters in the range of 30 to 100 nm grown by molecular beam epitaxy on Si(111) substrates. The change of the flux ratio between the Al and the total III-element controls the alloy composition.
J. Risti?, M.A. S�nchez-Garc�a, J.M. Ulloa, E. Calleja, J. Sanchez-P�ramo, J.M. Calleja, U. Jahn, A. Trampert, K.H. Ploog   +8 more
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Fabrication and characterization of N-face AlGaN/GaN/AlGaN HEMTs

63rd Device Research Conference Digest, 2005. DRC '05., 2005
The paper reports on the characteristics of N-face AlGaN/GaN/AlGaN HEMTs. Ohmic contact optmization experiments based on the Ti/Al/Ni/Au metallization scheme commonly used for Ga-face AlGaN/GaN HEMTs were carried out and a low contact resistance of 1.3 Ohm/mm was achieved. The devices were then characterized before and after SiN passivation.
CHINI, Alessandro, Rajan, S., Wong, M., Fu, Y., Speck, J. S., Mishra, U. K.   +5 more
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AlGaN/GaN heterostructures on insulating AlGaN nucleation layers

Applied Physics Letters, 1999
A single temperature process using AlGaN nucleation layers has been developed that produces device-quality, GaN-based materials with bilayer step surfaces. The AlGaN nucleation layer is deposited by flow modulation organometallic vapor phase epitaxy at temperatures in excess of 1000 °C, where GaN and AlGaN films can be subsequently grown.
Smart, Joseph A., Schremer, Alfred T., Weimann, Nils, Ambacher, Oliver, Eastman, Lester F., Shealy, James Richard   +5 more
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Growth and characterization of AlGaN/AlN/GaN/AlGaN double heterojunction structures with AlGaN as buffer layers

Journal of Crystal Growth, 2013
Abstract High electron mobility transistors (HEMTs) structures with GaN, Al0.025Ga0.975N and Al0.04Ga0.96N high resistivity (HR) buffers were grown on sapphire by metal organic chemical vapor deposition (MOCVD). The structural and electrical properties of these three samples were investigated and compared. By increasing Al composition of AlGaN buffer,
Enchao Peng, Xiaoliang Wang, Hongling Xiao, Cuimei Wang, Haibo Yin, Hong Chen, Chun Feng, Lijuan Jiang, Xun Hou, Zhanguo Wang   +9 more
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Optical characterization of AlGaN-GaN-AlGaN quantum wells

Journal of Electronic Materials, 1992
High quality AL x Ga1−x N-GaN-Al x Ga1−x N quantum wells of different thicknesses andx values were grown by low pressure metalorganic chemical vapor deposition (LPMOCVD).
S. Krishnankutty, R. M. Kolbas, M. A. Khan, J. N. Kuznia, J. M. Van Hove, D. T. Olson   +5 more
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Photoluminescence characteristics of AlGaN-GaN-AlGaN quantum wells

Applied Physics Letters, 1990
AlxGa1−xN-GaN quantum wells were grown on basal plane sapphire by low-pressure metalorganic vapor deposition. The photoluminescence spectra of samples of different well thicknesses and x values were measured. The experimental data were compared with the calculated solutions of the finite square quantum well and the bound states involved in the optical ...
M. A. Khan, R. A. Skogman, J. M. Van Hove, S. Krishnankutty, R. M. Kolbas   +4 more
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Bipolar characteristics of AlGaN/AlN/GaN/AlGaN double heterojunction structure with AlGaN as buffer layer

Journal of Alloys and Compounds, 2013
Abstract This is a theoretical study of AlGaN/AlN/GaN/AlGaN double heterojunction (DH) structure with AlGaN as buffer layer. Our calculation shows that as the buffer Al content increases, though two-dimensional electron gas (2DEG) sheet density decreases, the channel back-barrier caused by polarization-induced electric field in GaN provides better ...
Enchao Peng, Xiaoliang Wang, Hongling Xiao, Cuimei Wang, Haibo Yin, Hong Chen, Chun Feng, Lijuan Jiang, Xun Hou, Zhanguo Wang   +9 more
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Investigation of the low-temperature AlGaN interlayer in AlGaN/GaN/AlGaN double heterostructure on Si substrate

Applied Physics Express, 2014
A low-temperature (LT) AlGaN interlayer is inserted in the Al0.1Ga0.9N back barrier layer of an Al0.2Ga0.8N/GaN/Al0.1Ga0.9N double heterostructure grown on a 150 mm Si substrate. It is found that the 21-nm-thick LT-AlGaN interlayer plays an important role in stress relaxation and dislocation reduction of the Al0.1Ga0.9N back barrier layer, especially ...
Yu-Lin Hsiao, Yi-Jie Wang, Chia-Ao Chang, You-Chen Weng, Yen-Yu Chen, Kai-Wei Chen, Jer-Shen Maa, Edward Yi Chang   +7 more
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