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Nils Weimann
Researcher at University of Duisburg-Essen
Publications - 160
Citations - 7764
Nils Weimann is an academic researcher from University of Duisburg-Essen. The author has contributed to research in topics: Heterojunction bipolar transistor & Bipolar junction transistor. The author has an hindex of 27, co-authored 160 publications receiving 7215 citations. Previous affiliations of Nils Weimann include Alcatel-Lucent & Agere Systems.
Papers
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Journal ArticleDOI
Two-dimensional electron gases induced by spontaneous and piezoelectric polarization charges in N- and Ga-face AlGaN/GaN heterostructures
Oliver Ambacher,Joseph A. Smart,James R. Shealy,Nils Weimann,K. Chu,M. J. Murphy,William J. Schaff,L.F. Eastman,Roman Dimitrov,L. Wittmer,Martin Stutzmann,W. Rieger,J. Hilsenbeck +12 more
TL;DR: In this article, the authors investigated the role of spontaneous and piezoelectric polarization on the carrier confinement at GaN/AlGaN and AlGaN/GaN interfaces.
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Two dimensional electron gases induced by spontaneous and piezoelectric polarization in undoped and doped AlGaN/GaN heterostructures
Oliver Ambacher,B. E. Foutz,Joseph A. Smart,James R. Shealy,Nils Weimann,K. Chu,M. J. Murphy,A. J. Sierakowski,William J. Schaff,L.F. Eastman,Roman Dimitrov,A. Mitchell,Martin Stutzmann +12 more
TL;DR: In this paper, a combination of high resolution x-ray diffraction, atomic force microscopy, Hall effect, and capacitance-voltage profiling measurements is used to calculate the polarization induced sheet charge bound at the AlGaN/GaN interfaces.
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Scattering of electrons at threading dislocations in GaN
TL;DR: In this paper, a model to explain the observed low transverse mobility in GaN by scattering of electrons at charged dislocation lines is proposed and the statistics of trap occupancy at different doping levels are investigated.
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Undoped AlGaN/GaN HEMTs for microwave power amplification
L.F. Eastman,V. Tilak,Joseph A. Smart,B.M. Green,E.M. Chumbes,Roman Dimitrov,Hyungtak Kim,Oliver Ambacher,Nils Weimann,T. Prunty,M. J. Murphy,William J. Schaff,James R. Shealy +12 more
TL;DR: In this paper, a two-dimensional electron gas (2DEG) is induced using the strong spontaneous and piezoelectric polarization inherent in the AlGaN/GaN structures, and three-dimensional nonlinear thermal simulations are made to determine the temperature rise from heat dissipation in various geometries.
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The role of dislocation scattering in n-type GaN films
TL;DR: In this paper, the lateral transport in GaN films produced by electron cyclotron resonance plasma-assisted molecular beam epitaxy doped n type with Si to the levels of 1015-1020 cm−3 was investigated.