Lee, Wen Zhao ; Ong, Duu Sheng ; Choo, Kan Yeep ; Yilmazoglu, Oktay ; Hartnagel, Hans L. (2021)
Monte Carlo evaluation of GaN THz Gunn diodes.
In: Semiconductor Science and Technology, 36 (12)
doi: 10.1088/1361-6641/ac2b4d
Article

Sirkeli, Vadim P. ; Yilmazoglu, Oktay ; Hajo, Ahid S. ; Nedeoglo, Natalia D. ; Nedeoglo, Dmitrii D. ; Preu, Sascha ; Küppers, Franko ; Hartnagel, Hans L. (2018)
Enhanced Responsivity of ZnSe‐Based Metal–Semiconductor–Metal Near‐Ultraviolet Photodetector via Impact Ionization.
In: physica status solidi (RRL) – Rapid Research Letters, 12 (2)
doi: 10.1002/pssr.201700418
Article

Küppers, Franko ; Sirkeli, Vadim P. ; Yilmazoglu, Oktay ; Al-Daffaie, Shihab ; Oprea, Ion ; Ong, Duu Sheng ; Hartnagel, Hans L. (2018)
Internal Quantum Efficiency Enhancement of InGaN/GaN LEDs WITH Mg-Si pin-Doped GaN Quantum Barrier.
9th International Conference on Materials Science and Condensed Matter Physics, Chisinau, Moldova.
Conference or Workshop Item

Sirkeli, Vadim P. ; Yilmazoglu, Oktay ; Preu, Sascha ; Küppers, Franko ; Hartnagel, Hans L. (2018)
Proposal for a Monolithic Broadband Terahertz Quantum Cascade Laser Array Tailored to Detection of Explosive Materials.
In: Sensor Letters, 16 (1)
doi: 10.1166/sl.2018.3919
Article

Sirkeli, V. P. ; Yilmazoglu, Oktay ; Ong, D. S. ; Preu, Sascha ; Küppers, F. ; Hartnagel, Hans L. (2017)
Resonant Tunneling and Quantum Cascading for Optimum Room-Temperature Generation of THz Signals.
In: IEEE Transactions on Electron Devices, 64 (8)
doi: 10.1109/TED.2017.2718541
Article

Sirkeli, Vadim P. ; Yilmazoglu, Oktay ; Al-Daffaie, Shihab ; Preu, Sascha ; Küppers, Franko ; Hartnagel, Hans L. (2017)
1.33 THz room-temperature quantum cascade lasers based on ZnMgSe/ZnSe.
Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), 2017 42nd International Conference on.
Conference or Workshop Item

Sirkeli, Vadim P. ; Yilmazoglu, Oktay ; Al-Daffaie, Shihab ; Oprea, Ion ; Ong, Duu Sheng ; Küppers, Franko ; Hartnagel, Hans L. (2017)
Resonant tunneling transport in Zn x Be 1-x Se/ZnSe/Zn y Be 1-y Se asymmetric quantum structures.
Nanotechnology VIII.
Conference or Workshop Item

Sirkeli, Vadim P. ; Yilmazoglu, Oktay ; Al-Daffaie, Shihab ; Oprea, Ion ; Ong, Duu Sheng ; Küppers, Franko ; Hartnagel, Hans L. (2016)
Efficiency enhancement of InGaN/GaN light-emitting diodes with pin-doped GaN quantum barrier.
In: Journal of Physics D: Applied Physics, 50 (3)
Article

Sirkeli, Vadim P. ; Yilmazoglu, Oktay ; Küppers, Franko ; Hartnagel, Hans L. (2015)
Effect of p-NiO and n-ZnSe interlayers on the efficiency of p-GaN/n-ZnO light-emitting diode structures.
In: Semiconductor Science and Technology, 30 (065005)
Article

Sirkeli, Vadim P. ; Yilmazoglu, Oktay ; Küppers, Franko ; Hartnagel, Hans L. (2015)
Effect of p-NiO Interlayer on Internal Quantum Efficiency of p-GaN/n-ZnO Light-Emitting Devices.
In: Journal of Nanoelectronics and Optoelectronics, 9 (6)
Article

Hartnagel, Hans L. ; Al-Daffaie, Shihab (2015)
Graphene Plasmonics for the Enhancement of THz-Signal Transfer.
The 39th European Workshop on Compound Semiconductor Devices and Integrated Circuits.
Conference or Workshop Item

Yilmazoglu, Oktay ; Evtukh, Anatoli ; Al-Daffaie, Shihab ; Biethan, Jens-Peter ; Pavlidis, Dimitris ; Litovchenko, Vladimir ; Hartnagel, Hans L. (2014)
Electron field emission from nanostructured semiconductors under photo illumination.
In: Turkish Journal of Physics, 38 (3)
Article

Hartnagel, Hans L. ; Preu, Sascha (2014)
Graphene THz Circuitry by Nano-Constriction Designs.
WOCSDICE 2014.
Conference or Workshop Item

Yilmazoglu, Oktay ; Al-Daffaie, Shihab ; Hartnagel, Hans L. ; Joshi, R. ; Yadav, S. ; Schneider, J. J. ; Nick, C. ; Thielemann, C. (2012)
CNT photocathodes based on GaAs high-frequency photoswitches.
Vacuum Nanoelectronics Conference (IVNC), 2012 25th International.
Conference or Workshop Item

Koops, Hans W. P. ; Al-Daffaie, Shihab ; Hartnagel, Hans L. ; Rudzinski, A. (2012)
Development of a miniaturized Dynatron THz-Oscillator with a FEBIP system.
Vacuum Nanoelectronics Conference (IVNC), 2012 25th International.
Conference or Workshop Item

Koops, Hans W. P. ; Rudzinski, Axel ; Nouvertné, Frank ; Al-Daffaie, Shihab ; Hartnagel, Hans L. (2012)
Portable 0.1 To 10 THz Radiation Source With Free Electron Beams.
3rd ITG Int. Vacuum Electronics Workshop Physikzentrum Bad Honnef , Germany.
Conference or Workshop Item

Koops, Hans W. P. ; Al-Daffaie, Shihab ; Hartnagel, Hans L. (2012)
Portable source with free electron beams for 0.1 to 10 THZ.
In: Proceedings of WOCSDICE-EXMATEC
Article

Al-Daffaie, Shihab ; Acedo, Pablo ; Hartnagel, Hans L. (2012)
Simulation of a CW THz camera scheme.
In: Proceedings of WOCSDICE-EXMATEC
Article

Vicente, C. ; Wolk, D. ; Hartnagel, Hans L. ; Gimeno, B. ; Boria, V. E. ; Raboso, D. (2007)
Experimental analysis of passive intermodulation at waveguide flange bolted connections.
In: IEEE transactions on microwave theory and techniques, 55 (5)
doi: 10.1109/TMTT.2007.895400
Article

Dragoman, M. ; Müller, A. ; Neculoiu, D. ; Konstantinidis, G. ; Grenier, K. ; Dubuc, D. ; Bary, L. ; Plana, R. ; Fourn, E. ; Flahaut, E. ; Hartnagel, Hans L. (2007)
Carbon nanotubes-based microwave and millimeter wave sensors.
Conference or Workshop Item

Schoenherr, Daniel ; Sydlo, Cezary ; Goebel, Thorsten ; Feiginov, Michael N. ; Hartnagel, Hans L. ; Meissner, Peter ; Bach, H.-G. ; Kunkel, R. ; Mekonnen, G. G. ; Zhang, R. (2007)
Characterization of THz emitter based on a high-speed p-i-n photodiode.
Conference or Workshop Item

Cojocari, Oleg ; Oprea, I. ; Sydlo, Cezary ; Zimmermann, R. ; Walber, A. ; Henneberger, R. ; Hartnagel, Hans L. (2007)
Design and characterization of Schottky structures for THz-applications.
In: Frequenz, 61
Article

Litovchenko, V. ; Evtukh, A. ; Semenenko, M. ; Grigoriev, A. ; Yilmazoglu, Oktay ; Hartnagel, Hans L. ; Sirbu, L. ; Tiginyanu, I. M. ; Ursaki, V. V. (2007)
Electron field emission from narrow band gap semiconductors (InAs).
In: Semiconductor science and technology, 22
Article

Nicolae, B. ; Chowdhury, D. Roy ; Hartnagel, Hans L. (2007)
Experimental and modelled configuration of double-barrier HBV based on Al0.7Ga0.3As/GaAs.
Conference or Workshop Item

Ong, D. S. ; Hartnagel, Hans L. (2007)
Generation of THz signals based on quasi-ballistic electron reflections in double-heterojunction structures.
In: Semiconductor science and technology, 22
Article

Halbritter, Hubert ; Sydlo, Cezary ; Koegel, Benjamin ; Riemenschneider, Frank ; Hartnagel, Hans L. ; Meissner, Peter (2007)
Impact of micromechanics on the linewidth and chirp performance of MEMS-VCSELs.
In: IEEE/LEOS journal of selected topics on quantum electronics, 13
Article

Sigmund, Jochen ; Zogal, Karolina ; Lampin, J. F. ; Ivannikov, V. ; Sydlo, Cezary ; Feiginov, Michael N. ; Pavlidis, Dimitris ; Meissner, Peter ; Hartnagel, Hans L. (2007)
Low-temperature grown GaAsSb with sub-picosecond photocarrier lifetime for continuous-wave terahertz applications.
Conference or Workshop Item

Neculoiu, D. ; Konstantinidis, G. ; Müller, A. ; Kostopoulos, A. ; Vasilache, D. ; Mutamba, Kabula ; Sydlo, Cezary ; Hartnagel, Hans L. ; Bary, L. ; Plana, R. (2007)
Microwave FBAR structures fabricated using micromachined GaN membranes.
Conference or Workshop Item

Kunkel, R. ; Beling, A. ; Bach, H.-G. ; Mekonnen, G. G. ; Schmidt, D. ; Sydlo, Cezary ; Schoenherr, Daniel ; Feiginov, Michael N. ; Hartnagel, Hans L. ; Meissner, Peter (2007)
Monolithic integration of a waveguide-integrated p-i-n-photodiode and a planar antenna for THz applications.
Conference or Workshop Item

Dragoman, M. ; Takacs, A. ; Muller, A. A. ; Hartnagel, Hans L. ; Plana, R. ; Grenier, K. ; Dubic, D. (2007)
Nanoelectromechanical switches based on carbon nanotubes for microwave and millimetre waves.
In: Applied physics letters, 90
Article

Ong, D. S. ; Hartnagel, Hans L. (2007)
Novel concept for THz signals generations in heterostructures.
In: Physica status solidi / Rapid research letters, 1
Article

Vicente, C. ; Hartnagel, Hans L. (2007)
Passive intermodulation at junctions.
Conference or Workshop Item

Yilmazoglu, Oktay ; Hartnagel, Hans L. ; Pavlidis, Dimitris ; Evtukh, A. ; Litovchenko, V. ; Semenenko, M. ; Gorbanyuk, T. ; Grigoriev, A. (2007)
Pecularities of electron field emission from nanostructured GaN and AlGaN.
Conference or Workshop Item

Nicolae, B. ; Chowdhury, D. Roy ; Pop, G. ; Hartnagel, Hans L. ; Pasquet, D. (2007)
The Planar Approach to a Al0.12Ga0.88N/GaN Based Double Barrier HBV.
In: Frequenz, 61
Article

Dragoman, M. ; Cismaru, A. ; Müller, A. A. ; Dragoman, D. ; Hartnagel, Hans L. ; Plana, R. (2007)
RF NEMS-carbon-nanotube based nanoelectromechanical systems for microwave and millimeter wave applications.
Conference or Workshop Item

Goebel, Thorsten ; Schoenherr, Daniel ; Sydlo, Cezary ; Feiginov, Michael N. ; Meissner, Peter ; Hartnagel, Hans L. (2007)
Resonant metal gratings for THz material characterization.
Conference or Workshop Item

Nicolae, B. ; Chowdhury, D. Roy ; Hartnagel, Hans L. (2007)
S Parameter Measurements of Superlattice Heterostructure Barrier Junctions towards THz Varactors.
In: Frequenz, 61
Article

Cojocari, Oleg ; Oprea, I. ; Sydlo, Cezary ; Zimmermann, R. ; Walber, A. ; Henneberger, R. ; Hartnagel, Hans L. (2007)
THz Schottky diodes on epitaxial AIGaAs-membrane.
Conference or Workshop Item

Goebel, Thorsten ; Schoenherr, Daniel ; Feiginov, Michael N. ; Meissner, Peter ; Hartnagel, Hans L. (2007)
THz grating sensors for investigation of thin dielectric layers.
Conference or Workshop Item

Ong, D. S. ; Hartnagel, Hans L. (2007)
A new concept for THz frequency multipliers.
Conference or Workshop Item

Cojocari, Oleg ; Hartnagel, Hans L. (2006)
Generalized model of the metal/n-GaN Schottky interface and improved performance by electrochemical Pt deposition.
In: Journal of Vacuum Science and Technology B, 24
Article

Halbritter, Hubert ; Sydlo, Cezary ; Kögel, Benjamin ; Riemenschneider, F. ; Jatta, Sandro ; Hartnagel, Hans L. ; Meissner, Peter (2006)
Micromechanic effects and their impact on the characteristics of MEMS-tunable lasers.
Conference or Workshop Item

Mutamba, K. ; Yilmazoglu, Oktay ; Cojocari, Oleg ; Sydlo, Cezary ; Pavlidis, Dimitris ; Hartnagel, Hans L. (2006)
Technology of Wide-Bandgap Diode Struvtures for High Frequency Operation.
Conference or Workshop Item

Mutamba, K. ; Sydlo, C. ; Yilmazoglu, O. ; Neculoiu, D. ; Konstantinidis, G. ; Georgakilas, A. ; Chatzopoulos, Z. ; Müller, A. ; Hartnagel, Hans L. (2006)
A new compound semiconductor technology for advanced RF MEMS applications.
Conference or Workshop Item

Sydlo, Cezary ; Kögel, Benjamin ; Cojocari, Oleg ; Feiginov, Michael N. ; Hartnagel, Hans L. ; Meissner, Peter (2005)
Broadband power detector using a circularly-toothed planar logarithmic-periodic antenna.
Conference or Workshop Item

Cojocari, Oleg ; Biber, S. ; Mottet, Bastian ; Rodriguez-Girones Arboli, Manuel ; Hartnagel, Hans L. ; Schmidt, L.-P. (2005)
DC and IF-noise performance optimisation of GaAs Schottky diodes for THz applications.
In: Semiconductor science and technology, 20
Article

Cojocari, Oleg ; Sydlo, Cezary ; Hartnagel, Hans L. ; Tiginyanu, I. M. (2005)
Quasi-vertical Schottky-structures for THZ-Applications.
Conference or Workshop Item

Mottet, B. ; Sydlo, Cezary ; Mutamba, ; Cojocari, Oleg ; Hartnagel, Hans L. (2005)
RF and thermal design of compound semiconductor devices using MEMS approach.
In: Frequenz, 59
Article

Sigmund, Jochen ; Sydlo, Cezary ; Hartnagel, Hans L. ; Benker, Nathalie ; Fuess, Hartmut ; Rutz, F. ; Kleine-Ostmann, T. ; Koch, M. (2005)
Structure investigation of low-temperature-grown GaAsSb : a material for photoconductive terahertz antennas.
In: Applied physics letters, 87
Article

Biber, S. ; Cojocari, Oleg ; Rehm, G. ; Mottet, Bastian ; Schmidt, L.-P. ; Hartnagel, Hans L. (2004)
A novel system for systematic microwave noise and DC characterization of terahertz Schottky diodes.
In: IEEE Transactions on Instrumentation and Measurement, 53 (2)
doi: 10.1109/TIM.2003.820487
Article

Vincze, A. ; Kovac, J. ; Srnanek, R. ; Sigmund, Jochen ; Hartnagel, Hans L. ; Irmer, G. (2004)
Annealing behaviour of low temperature grown GaAs investigated by raman spectroscopy.
Conference or Workshop Item

Vincze, A. ; Michalka, M. ; Podskocova, J. ; Sigmund, Jochen ; Kovac, J. ; Hartnagel, Hans L. (2004)
Annealing investigation of LT GaAs with AFM.
Conference or Workshop Item

Sydlo, Cezary ; Kögel, Benjamin ; Cojocari, Oleg ; Hartnagel, Hans L. ; Meissner, Peter (2004)
Characterisation of a circularly-toothed planar logarithmic-periodic antenna for broadband power detection.
In: Frequenz, 58 (9/10)
doi: 10.1515/FREQ.2004.58.9-10.207
Article

Mendis, Rajind ; Sydlo, Cezary ; Sigmund, Jochen ; Feiginov, Michael N. ; Meissner, Peter ; Hartnagel, Hans L. (2004)
Coherent generation and detection of continuous THz waves using two photomixers driven by laser diodes.
Conference or Workshop Item

Mendis, R. ; Sydlo, Cezary ; Sigmund, Jochen ; Feiginov, Michael N. ; Meissner, Peter ; Hartnagel, Hans L. (2004)
Continuous-wave terahertz system for spectroscopy and imaging.
Conference or Workshop Item

Evtukh, A. A. ; Hartnagel, Hans L. ; Litovchenko, V. G. ; Semenenko, M. O. ; Yilmazoglu, Oktay (2004)
Enhancement of electron field emission stability by nitrogen-doped diamond-like carbon film coating.
In: Semiconductor science & technology, 19
Article

Cojocari, Oleg ; Biber, S. ; Mottet, Bastian ; Hartnagel, Hans L. ; Schmidt, L.-P. (2004)
GaAs Schottky diode fabrication for THz-frequency mixer applications.
Conference or Workshop Item

Handel, P. H. ; Hartnagel, Hans L. ; Sia, K. E. ; Mishra, U. K. ; York, R. (2004)
GaN HEMT geometry and piezoelectric quantum 1/f noise.
Conference or Workshop Item

Cojocari, Oleg ; Popa, V. ; Ursaki, V. V. ; Tiginyanu, I. M. ; Hartnagel, Hans L. ; Daumiller, I. (2004)
GaN Schottky multiplier diodes prepared by electroplating : a study of passivation technology.
In: Semiconductor science and technology, 19
Article

Saglam, Mustafa ; Irvine, A. C. ; Hartnagel, Hans L. (2004)
Heterostructure barrier varactors on gold substrate.
Conference or Workshop Item

Cojocari, Oleg ; Biber, S. ; Mottet, Bastian ; Sydlo, Cezary ; Hartnagel, Hans L. ; Schmidt, L.-P. (2004)
IF-noise improvement of the GaAs Schottky diodes for THz-frequency mixer applications.
Conference or Workshop Item

Zverev, V. N. ; Muhammad, M. ; Rahman, S. ; Debray, P. ; Saglam, Mustafa ; Sigmund, Jochen ; Hartnagel, Hans L. (2004)
Magnetotransport properties of two-dimensional electron gas in AlSb/InAs quantum well structures designed for device applications.
In: Journal of applied physics, 96
Article

Schür, J. ; Biber, S. ; Gumbmann, F. ; Mottet, Bastian ; Cojocari, Oleg ; Schmidt, L.-P. ; Hartnagel, Hans L. (2004)
Micromachined split-block Schottky-diode mixer for 600GHz.
Conference or Workshop Item

Cojocari, Oleg ; Popa, V. ; Ursaki, V. V. ; Tiginyanu, I. M. ; Mutamba, Kabula ; Saglam, Mustafa ; Hartnagel, Hans L. (2004)
Micrometer-size GaN Schottky-diodes for MM-wave frequency multipliers.
Conference or Workshop Item

Dehe, Alfons ; Beilenhoff, Klaus ; Fricke, Klaus ; Klingbeil, Harald ; Krozer, Viktor ; Hartnagel, Hans L. (2004)
Microwave measurement.
In: Electrical measurements, signal processing and displays / ed. by John G. Webster. -
Book Section

Vicente, C. ; Mattes, M. ; Cervello, A. ; Wolk, D. ; Mottet, Bastian ; Hartnagel, Hans L. ; Mosig, J. ; Raboso, D. (2004)
Multipactor and corona discharge, prediction in rectangular waveguide based microwave components.
Conference or Workshop Item

Vicente, C. ; Mattes, M. ; Cervello, A. ; Wolk, D. ; Mottet, Bastian ; Hartnagel, Hans L. ; Mosig, J. R. ; Raboso, D. (2004)
Prediction of corona discharge : towards a simulation tool for arbitrary geometries.
Conference or Workshop Item

Litovchenko, V. G. ; Evtukh, A. A. ; Kryuchenko, Yu. ; Goncharuk, N. M. ; Yilmazoglu, Oktay ; Mutamba, Kabula ; Hartnagel, Hans L. ; Pavlidis, Dimitris (2004)
Quantum size resonance tunneling in the field emission phenomenon.
In: Journal of applied physics, 96
Article

Altes, A. ; Mutamba, Kabula ; Heiderhoff, R. ; Hartnagel, Hans L. ; Balk, L. J. (2004)
Scanning near field thermal microscopy on a micromachined thin membrane.
In: Superlattices and Microstructures, 35 (3-6)
doi: 10.1016/j.spmi.2003.09.008
Article

Mendis, R. ; Sydlo, Cezary ; Sigmund, Jochen ; Feiginov, Michael N. ; Meissner, Peter ; Hartnagel, Hans L. (2004)
Tunable CW-THz system with LTG-GaAs based log-periodic emitter.
Conference or Workshop Item

Mendis, R. ; Sydlo, Cezary ; Sigmund, Jochen ; Feiginov, Michael N. ; Meissner, Peter ; Hartnagel, Hans L. (2004)
Tunable CW-THz system with a log-periodic photoconductive emitter.
Conference or Workshop Item

Mendis, R. ; Sydlo, Cezary ; Sigmund, Jochen ; Feiginov, Michael N. ; Meissner, Peter ; Hartnagel, Hans L. (2004)
Tunable CW-THz system with a log-periodic photoconductive emitter.
In: Solid-state electronics, 48
Article

Mottet, Bastian ; Sydlo, Cezary ; Kögel, Benjamin ; Robillard, Q. de ; Cojocari, Oleg ; Hartnagel, Hans L. (2004)
The impact of process optimisation on planar THz-Schottky device reliability.
Conference or Workshop Item

Cojocari, Oleg ; Biber, S. ; Rodriguez-Girones Arboli, Manuel ; Mottet, Bastian ; Marchand, L. ; Schmidt, L.-P. ; Hartnagel, Hans L. (2004)
A new structural approach for uniform sub-micrometer anode metallization of planar THz Schottky components.
In: Semiconductor science & technology, 19
Article

Biber, S. ; Cojocari, Oleg ; Rehm, G. ; Mottet, Bastian ; Schmidt, L.-P. ; Hartnagel, Hans L. (2004)
A novel system for systematic IF noise and DC characterization of THz Schottky diodes.
In: IEEE Transactions on Instrumentation and Measurement, 53 (2)
doi: 10.1109/TIM.2003.820487
Article

Yilmazoglu, Oktay ; Pavlidis, Dimitris ; Litvin, Yu. M. ; Hubbard, S. M. ; Tiginyanu, I. M. ; Mutamba, Kabula ; Hartnagel, Hans L. ; Litovchenko, V. G. ; Evtukh, A. A. (2003)
Field emission from quantum size GaN structures.
In: Applied Surface Science, 220 (1-4)
doi: 10.1016/S0169-4332(03)00750-5
Article

Litovchenko, V. G. ; Evtukh, A. A. ; Litvin, Yu. M. ; Goncharuk, N. M. ; Hartnagel, Hans L. ; Yilmazoglu, Oktay ; Pavlidis, Dimitris (2003)
Peculiarities of the electron field emission from quantum-size structures.
In: Applied Surface Science, 215 (1-4)
doi: 10.1016/S0169-4332(03)00283-6
Article

Hartnagel, Hans L. (2003)
Electron emission modulation effects in microsize structures.
In: Semiconductor physics, quantum electronics and optoelectronics, 6 (1)
doi: 10.15407/spqeo6.01.062
Article

Hartnagel, Hans L. ; Rodriguez-Gironés Arboli, Manuel (2003)
Current status and future prospects of semiconductor terahertz electronics.
In: IEICE transactions on electronics, E86-C (10)
Article

Saglam, Mustafa ; Sigmund, Jochen ; Hartnagel, Hans L. (2003)
Einflüsse der Deckschichten auf die Ladungsträgerkonzentration und Elektronenbeweglichkeit in MBE-gewachsenen AlSb/InAs-Quantentöpfe.
Conference or Workshop Item

Evtukh, A. A. ; Litovchenko, V. G. ; Litvin, Yu. M. ; Hartnagel, Hans L. ; Yilmazoglu, Oktay (2003)
Field emission from SiOx films deposited on Si and GaAs tip arrays.
Conference or Workshop Item

Saglam, Mustafa ; Schumann, B. ; Dure, K. ; Domoto, C. ; Megej, Alexander ; Rodriguez-Gironés Arboli, Manuel ; Müller, J. ; Judaschke, R. ; Hartnagel, Hans L. (2003)
High performance 450 GHz GaAs-based heterostructure barrier varactor tripler.
In: IEEE electron device letters, 24
Article

Miao, Jianmin ; Hartnagel, Hans L. (2003)
High-energy ion implantation : an alternative technology for micromachining 3-dimensional GaAs structures.
Book

Saglam, Mustafa ; Mutamba, Kabula ; Megej, Alexander ; Sydlo, Cezary ; Hartnagel, Hans L. ; Daumiller, I. (2003)
Influence of polarization chages in Al 0.4 Ga 0.6 N/GaN barrier varactors.
In: Applied physics letters, 82
doi: 10.1063/1.1537516
Article

Sigmund, Jochen ; Karova, K. ; Miehe, Gerhard ; Saglam, Mustafa ; Hartnagel, Hans L. ; Fuess, Hartmut (2003)
Investigation of a growth interruption under an As flux at AlSb/InAs interfaces with InSb bonds.
In: Journal of crystal growth
Article

Valakh, M. Ya. ; Litovchenko, V. G. ; Strelchuk, V. V. ; Hartnagel, Hans L. ; Sigmund, Jochen (2003)
Manifestation of the intersubband plasmon-phonon excitations and the pecularities of interfaces in the Raman spectra of InAs/AlSb quantum well structures.
Conference or Workshop Item

Ensling, David ; Hunger, Ralf ; Kraft, Daniel ; Mayer, Thomas ; Jaegermann, Wolfram ; Rodriguez-Girones Arboli, Manuel ; Ichizli, Victoria M. ; Hartnagel, Hans L. (2003)
Pulse Plating of Pt on n-GaAs(100) Wafer Surfaces: Synchrotron Induced Photoelectron Spectroscopy and XPS of Wet Fabrication Processes.
In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 200
Article

Biber, S. ; Schmidt, L.-P. ; Cojocari, Oleg ; Mottet, Bastian ; Rodriguez-Girones Arboli, Manuel ; Hartnagel, Hans L. (2003)
Systematic quality assessment of Schottky diodes for THz-applications.
Conference or Workshop Item

Mendis, R. ; Sydlo, Cezary ; Sigmund, Jochen ; Feiginov, Michael N. ; Meissner, Peter ; Hartnagel, Hans L. (2003)
Tunable CW-THz system with a log-periodic photoconductive emitter.
Conference or Workshop Item

Cojocari, Oleg ; Mottet, Bastian ; Rodriguez-Girones Arboli, Manuel ; Biber, S. ; Schmidt, L.-P. ; Hartnagel, Hans L. (2003)
Whisker-device-based optimisation of fabrication process for planar THz Schottky diode.
Conference or Workshop Item

Saglam, Mustafa ; Schumann, B. ; Müllerwiebus, V. ; Megej, Alexander ; Auer, U. ; Rodriguez-Girones Arboli, Manuel ; Judaschke, R. ; Tegude, F. J. ; Hartnagel, Hans L. (2002)
450 GHZ mm-wave signal from frequency tripler with heterostructure barrier varactors on gold substrate.
In: Electronics letters, 38 (13)
Article

Litovchenko, V. G. ; Evtukh, A. A. ; Goncharuk, N. M. ; Litvin, Yu. M. ; Hartnagel, Hans L. ; Yilmazoglu, Oktay (2002)
Anomalous field emission from quantum size structure.
Conference or Workshop Item

Sydlo, Cezary ; Sigmund, Jochen ; Hartnagel, Hans L. ; Loata, G. ; Siebert, K. J. ; Roskos, H. G. (2002)
Efficient THz-emitters for low-temperature-grown GaAs photomixers.
Conference or Workshop Item

Saglam, Mustafa ; Leo, E. ; Bozzi, M. ; Perregrini, L. ; Rodriguez-Girones Arboli, Manuel ; Arcioni, P. ; Hartnagel, Hans L. (2002)
Fabrication, testing and lumped element modeling of planar heterostructure barrier varactors.
Conference or Workshop Item

Yilmazoglu, Oktay ; Pavlidis, Dimitris ; Litvin, Yu. M. ; Hubbard, S. M. ; Tiginyanu, I. ; Mutamba, Kabula ; Hartnagel, Hans L. ; Litovchenko, V. G. ; Evtukh, A. A. (2002)
Field emission from quantum size GaN whiskers.
Conference or Workshop Item

Hartnagel, Hans L. ; Mutamba, Kabula ; Pfeiffer, J. (2002)
III-V compound MEMS and optical communication tunable filters.
In: Micromachined microwave devices and circuits.- [Bucuresti]: Ed. Acad. Romane, 2002.- ISBN 973-27-0908-1.- S. 10-23
Article

Sigmund, Jochen ; Saglam, Mustafa ; Hartnagel, Hans L. ; Miehe, Gerhard ; Fuess, Hartmut (2002)
Influence of growth interruptions at AlSb/InAs interfaces on the atomic morphology and electron transport properties.
Conference or Workshop Item

Megej, Alexander ; Beilenhoff, Klaus ; Schuessler, M. ; Ziroff, A. ; Mottet, Bastian ; Yilmazoglu, Oktay ; Mutamba, Kabula ; Hamann, C. D. ; Baican, R. ; Hartnagel, Hans L. (2002)
Integrated microwave sensor for cavity-length measurement in machine engineering.
In: IEEE transactions on microwave theory and techniques, 5 (12)
Article

Megej, Alexander ; Beilenhoff, Klaus ; Schuessler, M. ; Ziroff, A. ; Mottet, Bastian ; Yilmazoglu, Oktay ; Mutamba, Kabula ; Hamann, C. D. ; Baican, R. ; Hartnagel, Hans L. (2002)
Integrated microwave sensor for cavity-length measurement with sub-millimeter accuracy.
Conference or Workshop Item

eds.: Isermann, Rolf ; Breuer, Bert ; Hartnagel, Hans L. (2002)
Mechatronische Systeme für den Maschinenbau : Ergebnisse aus dem Sonderforschungsbereich 241 ...
Book

Hartnagel, Hans L. ; Mutamba, Kabula (2002)
Power sensors for microwave and millimeter-wave frequencies.
Conference or Workshop Item

Ichizli, Victoria M. ; Rodriguez-Girones Arboli, Manuel ; Marchand, L. ; Garden, C. ; Cojocari, Oleg ; Mottet, Bastian ; Hartnagel, Hans L. (2002)
Process control and failure analysis implementation for THz Schottky-based components.
Conference or Workshop Item

Ichizli, Victoria M. ; Rodriguez-Girones Arboli, Manuel ; Marchand, L. ; Garden, C. ; Cojocari, Oleg ; Mottet, Bastian ; Hartnagel, Hans L. (2002)
Process control methods for THz Schottky-based components.
Conference or Workshop Item

Sydlo, Cezary ; Saglam, Mustafa ; Mottet, Bastian ; Rodriguez-Girones Arboli, Manuel ; Hartnagel, Hans L. (2002)
Reliability investigations on HBV using pulsed electrical stress.
In: Microelectronics reliability, 42
Article

Sigmund, Jochen ; Saglam, Mustafa ; Hartnagel, Hans L. ; Zverev, V. N. ; Raichev, O. E. ; Debray, P. ; Miehe, Gerhard ; Fuess, Hartmut (2002)
Structural and transport characterization of AISb/InAs QW structures grown by MBE with two growth interruptions.
In: Journal of vacuum science & technology / B, 20
Article

Hartnagel, Hans L. ; Ichizli, V. ; Rodriguez-Girones Arboli, Manuel (2002)
Surface, interface issues in THz electronics.
In: Applied surface science, 190
Article

Mutamba, Kabula ; Megej, Alexander ; Beilenhoff, Klaus ; Weinzierl, J. ; Hartnagel, Hans L. (2002)
Technology of compound semiconductor MEMS for millimeter-wave power measurement.
Conference or Workshop Item

Hartnagel, Hans L. ; Mutamba, Kabula ; Brandt, Michael ; Yilmazoglu, Oktay (2002)
Verbindungshalbleitersensorik für mechatronische Systeme.
In: Mechatronische Systeme für den Maschinenbau : Ergebnisse aus dem Sonderforschungsbereich ... / Hrsg.: Rolf Isermann.- Weinheim: Wiley-VCH-Verl., 2002.- ISBN 3-527-27730-7.- S. 287-316
Book Section

Litvin, Yu. M. ; Evtukh, A. A. ; Yilmazoglu, Oktay ; Hartnagel, Hans L. (2002)
The influence of the self-organization nano-size structures on the electron field emission.
Conference or Workshop Item

Debray, P. ; Zverev, V. N. ; Raichev, O. E. ; Hartnagel, Hans L. ; Sigmund, Jochen ; Saglam, Mustafa ; Kohn, E. ; Densienko, A. ; Ahmed, H. ; Irvine, A. C. ; Lee, S.-B. (2002)
A nanoscale electron waveguide for very high-speed analog-to-digital converters.
Conference or Workshop Item

Lohrberg, H. ; Stoffel, B. ; Voß, B.
eds.: Isermann, Rolf ; Breuer, Bert ; Hartnagel, Hans L. ; Deutsche Forschungsgemeinschaft (2002)
Im Laufrad integrierte Messung der Kavitationsaggressivität in Turbomaschinen.
In: Mechatronische Systeme für den Maschinenbau : Ergebnisse aus dem Sonderforschungsbereich 241 "Integrierte Mechanisch-elektronische Systeme für den Maschinenbau (IMES)"
Book Section

Mimura, H. ; Yilmazoglu, Oktay ; Shimawaki, H. ; Yokoo, K. ; Mutamba, K. ; Hartnagel, Hans L. (2001)
Emission characteristics of a gallium arsenide wedge emitter monolithically fabricated with an air-bridge and a cantilever anode.
Conference or Workshop Item

Yokoo, K. ; Okamura, K. ; Hasegawa, H. ; Mimura, H. ; Yilmazoglu, Oktay ; Mutamba, Kabula ; Hartnagel, Hans L. ; Ishizuka, H. ; Kawamura, Y. (2001)
Experiments of microwave and optical wave radiation using field emission micro cathode.
Conference or Workshop Item

Hartnagel, Hans L. ; Megej, A. ; Mutamba, K. (2001)
Microwave and millimeter-wave monolithic signal sources with MEMS-based power monitoring for sensing applications.
Conference or Workshop Item

Hartnagel, Hans L. ; Ichizli, Victoria M. ; Rodriguez-Girones Arboli, Manuel (2001)
Semiconductor technology for THz integration.
Conference or Workshop Item

Hartnagel, Hans L. ; Ichizli, Victoria M. ; Rodriguez-Girones Arboli, Manuel (2001)
Surface/interface issues in THz electronics.
Conference or Workshop Item

Hartnagel, Hans L. ; Yilmazoglu, Oktay ; Mutamba, Kabula (2000)
Concepts of microwave power electronics based on electron field emission from structures fabricated in semiconducting materials.
Conference or Workshop Item

Hartnagel, Hans L. ; Pfeiffer, J. ; Peerlings, J. ; Samal, N. ; Meissner, P. (2000)
Fabry-Pérot filter for WDM.
Conference or Workshop Item

Yokoo, K. ; Okamura, K. ; Mimura, H. ; Yilmazoglu, Oktay ; Arslan, D. ; Hartnagel, Hans L. ; Ishizuka, H. (2000)
Field emission studies for microwave and optical wave generation.
Conference or Workshop Item

Lin, Chih-I. ; Ichizli, Victoria M. ; Rodriguez-Girones Arboli, Manuel ; Saglam, Mustafa ; Szeliga, P. ; Hartnagel, Hans L. (2000)
From honey-comb to SMMIC: Schottky diodes at TU Darmstadt.
Conference or Workshop Item

Mimura, H. ; Okamura, K. ; Shimawaki, H. ; Yokoo, K. ; Yilmazoglu, Oktay ; Hartnagel, Hans L. (2000)
GaAs lateral field emitters for generation of modulation beam using gunn effect.
Conference or Workshop Item

Saglam, Mustafa ; Megej, A. ; Sigmund, Jochen ; Rodriguez-Girones Arboli, Manuel ; Mutamba, Kabula ; Ichizli, Victoria M. ; Lin, C.-I. ; Hartnagel, Hans L. (2000)
III-V Material systems for heterostructure barrier varactors.
Conference or Workshop Item

Hartnagel, Hans L. ; Mutamba, K. ; Pfeiffer, J. (2000)
III-V compound materials for MEMS including filters.
Conference or Workshop Item

Hartnagel, Hans L. ; Mutamba, Kabula ; Yilmazoglu, Oktay (2000)
New aspects of quantum electronics based MEMS.
Conference or Workshop Item

Mottet, Bastian ; Sydlo, Cezary ; Hartnagel, Hans L. (2000)
Pulsed electrical stress techniques for the detection of non-thermal lifetime-problems with semiconductor devices and their IC's.
Conference or Workshop Item

Hartnagel, Hans L. ; Lin, C. I. ; Rodriguez-Girones, M. ; Ichizli, V. ; Saglam, M. ; Szeliga, P. (2000)
Recent development in device technology for integrated THz circuits.
Conference or Workshop Item

Lin, Chih-I. ; Saglam, Mustafa ; Rodriguez-Girones Arboli, Manuel ; Ichizli, Victoria M. ; Szeliga, P. ; Hartnagel, Hans L. (2000)
Recent development of Pt/n-GaAs Schottky diodes for THz applications.
Conference or Workshop Item

Lin, Chih-I. ; Rodriguez-Girones Arboli, Manuel ; Ichizli, Victoria M. ; Saglam, Mustafa ; Szeliga, P. ; Hartnagel, Hans L. (2000)
Technological developments for THz electronics.
Conference or Workshop Item

Hartnagel, Hans L. ; Mutamba, Kabula ; Brandt, M. ; Yilmazoglu, Oktay (2000)
Verbindungshalbleitersensoren für mechatronische Systeme.
In: Thema Forschung, 6
Article

Hartnagel, Hans L. ; Brandt, M. ; Mayer, K. ; Mutamba, Kabula ; Yilmazoglu, Oktay ; Megej, Alexander ; Lin, C. I. ; Rodriguez, M. (1999)
Contact free sensor signal transfer by microwave and RF links.
Conference or Workshop Item

Hartnagel, Hans L. ; Pfeiffer, J. ; Mutamba, K. ; Peerlings, J. ; Riemenschneider, R. ; Meißner, P. (1999)
III-V Membrane structures for tunable Fabry-Pérot filters and sensor applications.
Conference or Workshop Item

Hartnagel, Hans L. ; Mutamba, K. ; Brandt, M. ; Pfeiffer, J. ; Riemenschneider, R. ; Meißner, P. ; Breuer, B. ; Hennecke, Dietmar K. ; Stoffel, B. (1999)
III-V-Micromechanics for sensing applications in mechanical engineering and for optical communications.
Conference or Workshop Item

Pfeiffer, Joachim ; Peerlings, J. ; Riemenschneider, Rolf ; Genovese, R. ; Aziz, M. ; Böhm, G. ; Amann, Markus-Christian ; Meissner, Peter ; Hartnagel, Hans L. (1999)
InP-based bulk-micromachined tunable filter applications for WDM systems.
Conference or Workshop Item

Hartnagel, Hans L. ; Mutamba, K. ; Pfeiffer, J. ; Riemenschneider, R. ; Peerlings, J. (1999)
MEMS for sensing and optical communication systems.
In: Compound semiconductor, 5
Article

Hartnagel, Hans L. ; Lin, C. I. (1999)
Passivation of compound-semiconductor surfaces for low-noise terahertz devices.
Conference or Workshop Item

Hartnagel, Hans L. (1999)
Proposal of a new type of non-linear component for harmonic extraction.
In: Frequenz, 53
Article

Hartnagel, Hans L. (1999)
THz-device technology for monolithic integration using III-V semiconductors.
Conference or Workshop Item

Hartnagel, Hans L. ; Arslan, D. ; Brandt, M. ; Dehé, A. ; Mutamba, K. ; Vogt, (1998)
Compound semiconductor microsensors for applications in mechanical engineering.
Conference or Workshop Item

Riemenschneider, Rolf ; Peerlings, Joachim ; Pfeiffer, Joachim ; Dehé, A. ; Vogt, Andreas ; Meißner, Peter M. ; Hartnagel, Hans L. ; Chitica, N. ; Daleiden, Jürgen ; Streubel, Klaus P. ; Künzel, Harald ; Goertz, W. (1998)
Mechanical-optical analysis of InP-based Bragg Membranes for selective tunable WDM receivers.
doi: 10.1117/12.302395
Conference or Workshop Item

Hartnagel, Hans L. ; Brandt, ; Dehé, ; Simon, (1998)
Mikro-Sensorik für den Einsatz in Maschinen bis hin zum Satelliten.
In: Thema Forschung. 1998, H. 1, S. 14-21
Article

Hartnagel, Hans L. ; Mutamba, ; Sigurdardottir, A. (1998)
A basic quantum dot element: proposal of a HBT-dot cell for high-packing density memory circuits.
Conference or Workshop Item

Grajal, J. ; Krozer, V. ; Schuessler, M. ; Brandt, M. ; Hartnagel, Hans L. (1997)
Application of semiconductor interface modelling to reliability characterisation.
Conference or Workshop Item

Hartnagel, Hans L. (1997)
III-V-compounds for high temperature operation.
In: Materials science and engineering. B 46 (1997), S. 47-51
Article

Hartnagel, Hans L. (1997)
New devices for millimeter-wave applications.
In: Annales des télécommunications. 52 (1997), No. 3-4
Article

Tiginyanu, I. ; Pavlidis, D. ; Cao, J. ; Eisenbach, A. ; Ichizli, Victoria M. ; Hartnagel, Hans L. ; Anedda, A. ; Corpino, R. (1997)
Time-resolved photoluminescence characterisation of GaN layers grown by metalorganic chemical vapor deposition.
Conference or Workshop Item

Hartnagel, Hans L. (1997)
Ultra-small quantum devices for memory and logic.
Conference or Workshop Item

Schuessler, M. ; Statzner, ; Granero, ; Hartnagel, Hans L. (1997)
A new self aligned technique for HBTs using electrolytical deposition of base metal.
Conference or Workshop Item

Krozer, Viktor ; Ruppert, Markus ; Schüßler, Martin ; Fricke, Klaus ; Lee, Woo-Yong ; Hartnagel, Hans L. (1996)
Calculation of the power capabilities of HBT amplifiers based on a new physical HBT model.
In: International Journal of Microwave and Millimeter-Wave Computer-Aided Engineering, 6 (4)
doi: 10.1002/(SICI)1522-6301(199607)6:4<270::AID-MMCE6>3.0.CO;2-R
Article

Hartnagel, Hans L. (1996)
Are new device and material concepts needed in the future?
Conference or Workshop Item

Schuessler, M. ; Statzner, ; Lin, ; Krozer, ; Horn, ; Hartnagel, Hans L. (1996)
Electrochemical deposition of Pd, Ti, and Ge for applications in GaAs technology.
In: Journal of the Electrochemical Society. 143 (1996), No. 4, S. 73-75
Article

Hartnagel, Hans L. (1996)
III-V compounds for high-temperature operations.
Conference or Workshop Item

Hartnagel, Hans L. (1996)
Microwave opportunities for city communications and for motor-car traffic handling.
Conference or Workshop Item

Hartnagel, Hans L. (1996)
Nanometric structures in future quantum electronics.
In: Review of radio science 1993-1996. Hrsg.: W.R. Stone. S. 295-303
Article

Schuessler, M. ; Krozer, ; Bock, ; Brandt, ; Vecchi, ; Losi, ; Hartnagel, Hans L. (1996)
Pulsed stress reliability investigations of Schottky diodes and HBTs.
In: Microelectronics and reliability. 36 (1996), S. 1907-1910
Article

Tiginyanu, I. ; Miao, ; Hartnagel, Hans L. ; Rück, ; Tinschert, ; Ursaki, ; Ichizli, Victoria M. (1996)
Raman and electrical characterisation of n-InP implanted by 630-keV nitrogen.
Conference or Workshop Item

Hartnagel, Hans L. (1996)
(Rez.) Ploog, K.H.: III-V quantum system research.
In: Electronics & communication: engineering journal. 8 (1996), S. 277
Article

Tiginyanu, I. ; Ichizli, Victoria M. ; Hartnagel, Hans L. (1996)
Surface vibrational modes in nanoporous III-V compounds.
Conference or Workshop Item

Schuessler, M. ; Krozer, ; Pfeiffer, ; Statzner, ; Lee, ; Hartnagel, Hans L. (1995)
AlGaAs/GaAs and GaInP/GaAs HBT for high temperature microwave operation.
Conference or Workshop Item

Hartnagel, Hans L. (1995)
Engineering at German universities.
In: Engineering science and education journal. 4 (1995), Nr. 1, S. 43-47
Article

Hartnagel, Hans L. (1995)
Heterostructure transistors for MMIC applications: HEMTs and HBTs.
Conference or Workshop Item

Hartnagel, Hans L. (1995)
III-V semiconductor properties for high temperature electronics.
In: Materials Science and Engineering: B, 29 (1-3)
doi: 10.1016/0921-5107(94)04028-3
Article

Hartnagel, Hans L. (1995)
Temperature independent HBT oscillator design.
Conference or Workshop Item