A5028906740- Superconducting and THz Device Technology
- GaN-based semiconductor devices and materials
- Semiconductor materials and devices
- Physics of Superconductivity and Magnetism
- Electron and X-Ray Spectroscopy Techniques
- Radio Frequency Integrated Circuit Design
- Semiconductor Quantum Structures and Devices
- Metal and Thin Film Mechanics
- Radiation Detection and Scintillator Technologies
- Advanced Sensor and Energy Harvesting Materials
- Supercapacitor Materials and Fabrication
- Astrophysics and Star Formation Studies
- Particle Detector Development and Performance
- Microwave Engineering and Waveguides
- Particle physics theoretical and experimental studies
- CCD and CMOS Imaging Sensors
- Silicon Carbide Semiconductor Technologies
- Ion-surface interactions and analysis
- Radio Astronomy Observations and Technology
- Graphene research and applications
- Ga2O3 and related materials
- Astronomy and Astrophysical Research
- Plasma Diagnostics and Applications
- Microwave and Dielectric Measurement Techniques
- Advanced Optical Sensing Technologies
Ferdinand-Braun-Institut
2021-2024
Johannes Gutenberg University Mainz
2014-2023
Brandenburg University of Technology Cottbus-Senftenberg
2023
Leipzig University
2022
Chalmers University of Technology
2014-2019
Institute for Mobile and Satellite Communication Technology
2014
Abstract The CALICE collaboration is developing highly granular electromagnetic and hadronic calorimeters for detectors at future energy frontier electron-positron colliders. After successful tests of a physics prototype, technological prototype the Analog Hadron Calorimeter has been built, based on design construction techniques scalable to collider detector. consists steel absorber structure active layers small scintillator tiles that are individually read out by directly coupled SiPMs....
The suitability of AlxGa1−xN epilayers to deposit onto ultra-thin NbN films has been demonstrated for the first time. High quality single-crystal with 5 nm thickness confirmed by high resolution transmission electron microscopy (HRTEM) have deposited in a reproducible manner means reactive DC magnetron sputtering at elevated temperatures and exhibit critical (Tc) as 13.2 K residual resistivity ratio (RRR) ∼1 on hexagonal GaN epilayers. On increasing Al content x epilayer above 20%, gradual...
This article proposes a novel modeling approach for the analysis of microwave power performance GaN HEMTs. By combining Technology Computer-Aided Design (TCAD) physical and circuit design standard compact trap models, surface buffer traps can be directly correlated, first time, with power-added efficiency (PAE) output ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\textit{P}_\text{out}$</tex-math>...
Context: We describe the new SEPIA (Swedish-ESO PI Instrument for APEX) receiver, which was designed and built by Group Advanced Receiver Development (GARD), at Onsala Space Observatory (OSO) in collaboration with ESO. It installed commissioned APEX telescope during 2015 an ALMA Band 5 receiver channel updated a frequency (ALMA 9) February 2016. Aims: This manuscript aims to provide, observers who use reference terms of hardware description, optics performance as well commissioning results....
We describe the design, performance, and commissioning results for new ALMA Band 5 receiver channel, 163–211 GHz, which is in final stage of full deployment expected to be available observations 2018. This manuscript provides description cartridge serves as a reference observers using observations. At time writing this paper, Production Consortium consisting NOVA Instrumentation group, based Groningen, NL, GARD Sweden have produced delivered Observatory over 60 cartridges. All cartridges...
In this paper, we present the comprehensive characterization of a waveguide balanced phonon-cooled NbN hot electron bolometer (HEB) mixer on GaN buffer-layer operating at approximately 1.3 terahertz (THz). The measured uncorrected double sideband noise temperature was as low 750 K 1 GHz intermediate frequency (IF) and 900 4 IF, respectively, suggests bandwidth 7 GHz. Moreover, IF gain HEB itself deduced from mixing experiment with second monochromatic THz signal source has shown 3 dB...
Precision calorimetry using highly granular sampling calorimeters is being developed based on the particle flow concept within CALICE collaboration. One design option of a hadron calorimeter silicon photomultipliers (SiPMs) to detect photons generated in plastic scintillator tiles. Driven by need automated mass assembly around ten million channels stringently required high granularity, we tiles directly coupled with surface-mounted SiPMs. A cavity created center bottom surface each tile...
Abstract Intermediate layers formed by thin NbN films are studied. A surface phase of different from the bulk one under oxide layer and a consisting x -SiO y between film substrate found.
We have investigated the properties of cleaved SmB$_6$ single crystals by x-ray photoelectron spectroscopy. At low temperatures and freshly samples a surface core level shift is observed which vanishes when temperature increased. A Sm valence between 2.5 - 2.6 derived from relative intensities Sm$^{2+}$ Sm$^{3+}$ multiplets. The B/Sm intensity ratio obtained levels always larger than stoichiometric value. Possible reasons for this deviation are discussed. B $1s$ signal shows an unexpected...
In this paper, we investigated the influence of GaN buffer layer on phonon escape time phonon-cooled hot electron bolometers (HEBs) based NbN material and compared our findings to conventionally employed Si substrate. The presented experimental setup operation HEB close critical temperature film allowed for extraction in a simplified manner. Two independent experiments were performed at GARD/Chalmers MSPU similar frequencies approximately 180 140 GHz, respectively, have shown reproducible...
The parasitic gate tunnelling of electrons into surface traps is shown to be responsible for the current collapse in GaN high electron mobility transistors. Simulations with and without are compared pulsed output leakage measurements showed that detrimental effect evident at positive voltages. Moreover, an apparent relationship between 2-dimensional density Schottky reverse revealed presence traps.
This paper presents the studies of high-quality 5-nm-thin NbN films deposited by means reactive dc magnetron sputtering at room temperature. The deposition without substrate heating offers major advantages from a processing point view and motivates extensive composition surface characterization comparison present with grown elevated temperatures. Monocrystalline have been epitaxially onto hexagonal GaN buffer layers (0002) show distinct low defect interface as confirmed high-resolution TEM....
In this paper, we present the analysis, design, and characterization of first frequency multiplier using distributed superconductor-insulator-superconductor (SIS) junctions. We derived analytical expressions describing properties SIS junction as a multiplier. The modeling junctions shows that high conversion efficiency can be achieved when used measured output power generated by such employing at second harmonic input is in good agreement with model. Furthermore, based on for time was able...
This paper reports an investigation of the dynamic behavior a GaN-HEMT, which is subjected to high reverse gate voltage pulses. These stress conditions are typical for robust LNAs under RF input overdrive and their quick recovery initial operating state crucial but scarcely investigated. It was found that trapping effects similar those in power amplifiers may play major role impairment process GaN HEMT-based with Fe-doping buffer. The interaction traps resulting adverse on device operation...
Abstract Large-signal modeling of Gallium Nitride (GaN) based high electron mobility transistors (HEMTs) demands a proper description trapping effects. In this paper, new, simplified yet accurate drain-lag is proposed, enhancing the simulation accuracy and extraction flow physics-based compact model ASM-HEMT. The present study investigates impact drain lag on specific physical phenomena, focusing relation between trap states, surface-potential calculations, transport properties. It...
Precision calorimetry using highly granular sampling calorimeters is being developed based on the particle flow concept within CALICE collaboration. One design option of a hadron calorimeter silicon photomultipliers (SiPMs) to detect photons generated in plastic scintillator tiles. Driven by need automated mass assembly around ten million channels stringently required high granularity, we tiles directly coupled with surface-mounted SiPMs. A cavity created center bottom surface each tile...
This paper presents the overall architecture, implementation, test setup, and first measurements results of a fully integrated multi-constellation two-frequency single-chip GNSS receiver. The ASIC supports simultaneous reception processing GPS L1/L5, Galileo E1/E5a GLONASS G1 signals with 40 versatile tracking channels. dual-band analog RF front-end is on same mixed-signal chip as baseband hardware including an embedded LEON2 processor to close loops. was realized in low-power 1.2V 65nm TSMC...
We demonstrate the suitability of employing suspended GaN beams on a Π-shaped Si frame for waveguide-based cryogenic THz components and systems. This concept addresses major challenges provides eased device handling, operation, micron-alignment possibilities, high integratability allows electrical contacting by using bonding wires. In particular, balanced hot electron bolometer (HEB) mixer was implemented frequencies at 1.3 with state-of-the-art IF performance, which combines micro-machined...
Silicon Photomultipliers (SiPM) are photo-sensors consisting of an array hundreds to thousands pixels with a typical pitch 10-100 μm. They exhibit excellent photon counting and time resolution. Therefore applications SiPMs emerging in many fields. In order characterize SiPMs, the PRISMA Detector Lab at Mainz has established three automated test setups. Setup-A is dedicated measure gain, dark count rate optical crosstalk probability. The temperature dependencies characterized by operating...
Layer chemical and phase profiling of niobium nitride thin films on a silicon substrate oxidized air was performed with the help method designed by us. The includes: new background subtraction multiple inelastically scattered photoelectrons considering depth inhomogeneity electron inelastic scattering; photoelectron line decomposition into component peaks physical nature different parameters; joint solution problems; control accuracy suggested performance criterion; calculation layer...
In this paper, we present carbon nanofiber (CNF)-based capacitors in a MIM configuration, CNF-MIM, with small footprint, low profile height, and high capacitance density that can be used both as integrated discrete component. Being produced fully CMOS compatible process it is likely to play major role further miniaturization of future electronics moves on. The devices were characterized from 25 °C 150 0 V 5 V. It was demonstrated CNF-MIM total CNF height 6 μm achieved about 400 nF/mm <sup...
XPS depth chemical and phase profiling of an air-oxidized niobium nitride thin film on a buffer-layer GaN is performed.It found that intermediate layer Nb5N6 NbONx under the oxide generated.
The omission of slow gate-induced electron trapping from compact models significantly weakens their accuracy when utilized in the design GaN-based robust low-noise and pulsed power amplifiers (PAs). Given highly negative gate voltage diverse off-periods inherent these systems, providing an accurate description trap time constants becomes paramount. This study deals with this problem by introducing a novel implementation suitable for large-signal models, particularly well-suited those based...