O
Oliver Ambacher
Researcher at Fraunhofer Society
Publications - 862
Citations - 29006
Oliver Ambacher is an academic researcher from Fraunhofer Society. The author has contributed to research in topics: Amplifier & Monolithic microwave integrated circuit. The author has an hindex of 64, co-authored 848 publications receiving 26256 citations. Previous affiliations of Oliver Ambacher include Osram & Siemens.
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.
Journal ArticleDOI
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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Growth and applications of Group III-nitrides
TL;DR: In this article, the chemical and thermal stability of epitaxial nitride films is discussed in relation to the problems of deposition processes and the advantages for applications in high-power and high-temperature devices.
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Wireless sub-THz communication system with high data rate
S. Koenig,D. Lopez-Diaz,J. Antes,J. Antes,F. Boes,F. Boes,R. Henneberger,Arnulf Leuther,Axel Tessmann,Rene Schmogrow,Rene Schmogrow,David Hillerkuss,David Hillerkuss,Robert Palmer,Thomas Zwick,Christian Koos,Wolfgang Freude,Oliver Ambacher,Juerg Leuthold,Juerg Leuthold,Ingmar Kallfass,Ingmar Kallfass +21 more
TL;DR: A wireless sub-THz communication system near 237.5 GHz with one to three carriers and up to 100 Gbit/s with state-of-the-art active I/Q-MMIC at the Rx is demonstrated.
Journal ArticleDOI
Pyroelectric properties of Al(In)GaN/GaN hetero- and quantum well structures
Oliver Ambacher,Jacek A. Majewski,C. R. Miskys,A. Link,M. Hermann,Martin Eickhoff,Martin Stutzmann,Fabio Bernardini,Vincenzo Fiorentini,V. Tilak,B Schaff,L.F. Eastman +11 more
TL;DR: In this paper, it was shown that the macroscopic nonlinear pyroelectric polarization of wurtzite AlInN/GaN, InxGa1-xN and AlxIn1xN ternary compounds (large spontaneous polarization and piezoelectric coupling) dramatically affects the optical and electrical properties of multilayered Al(In)GaN/GAN hetero-, nanostructures and devices, due to the huge built-in electrostatic fields and bound interface charges caused by gradients in polarization at surfaces and heter