A5041638398- Acoustic Wave Resonator Technologies
- Thin-Film Transistor Technologies
- Ultrasonics and Acoustic Wave Propagation
- Nanowire Synthesis and Applications
- Mechanical and Optical Resonators
- Quantum Dots Synthesis And Properties
- GaN-based semiconductor devices and materials
- Radio Frequency Integrated Circuit Design
- Chalcogenide Semiconductor Thin Films
- Optical Coatings and Gratings
- Ferroelectric and Piezoelectric Materials
- Silicon and Solar Cell Technologies
- Microwave Engineering and Waveguides
- Microfluidic and Capillary Electrophoresis Applications
- Biosensors and Analytical Detection
- Nonlinear Optical Materials Studies
- Thermography and Photoacoustic Techniques
- Non-Destructive Testing Techniques
- Semiconductor materials and interfaces
- Semiconductor materials and devices
- Photochemistry and Electron Transfer Studies
- Ga2O3 and related materials
- Analytical Chemistry and Sensors
- Photonic and Optical Devices
Qorvo (United States)
2018-2022
University of Stuttgart
2013-2016
Johannes Kepler University of Linz
2011-2012
University of Würzburg
2010-2011
GaN nanowires have been grown by molecular beam epitaxy either catalyst-free or catalyst-induced means of Ni seeds. Under identical growth conditions temperature and V/III ratio, both types are wurtzite structure elongated in the Ga-polar direction constricted M-plane facets. However, contain many more basal-plane stacking faults their photoluminescence is weaker. These differences can be explained as effects catalyst
The number of frequency bands requiring BAW filters is expected to grow significantly with the launch 5G mobile applications. in particular well suited address new radio below 6 GHz also referred as nr-1. RF integration only path forward achieve full connectivity LTE + wireless due complexity antenna systems and resulting coexistence challenges. article gives an overview describes recent trends regarding for high bands, wide bandwidth filters, miniaturization thermal management. Evolution...
On Si(1 1 1) and Si(0 0 1), GaN nanowires (NWs) form in a self-induced way without the need for any external material. sapphire, NW growth is induced by Ni collectors. Both types of NWs exhibit wurtzite crystal structure grow Ga-polar C-direction perpendicular to substrate. The sidewalls are M-plane facets, although on Ni-induced also A-plane segments form, if temperature low. collector-induced free strain epitaxially aligned substrate, but particular former show significant spread tilt...
Luminescent down-shifting (LDS) as a purely optical approach increases solar cell's ultra-violet to blue response by shifting short-wavelength light longer-wavelengths where the external quantum efficiency (EQE) of cells is higher. We propose simple, universally applicable, model analyze EQE spectra modules with LDS layers using only two parameters. The successfully tested on ethylene-vinyl acetate encapsulated Si CdSe/ZnS nanocrystals luminescent particles. For beneficial effect in...
New Generation of BAW Technology has been developed. It supports the full frequency range from 1 GHz to above 8 including 5G NR and WiFi6E bands. Furthermore, it provides significant improvements in resonator performance: up 100% higher Q, over 50 % TCF improvement improved modes behavior. also makes Sc doping or applicable more Moreover, size could be decreased significantly at same time. Thus, filters have better power handling, IL rejection pair with device shrinkage %.
ABSTRACT Back‐side diffractive gratings enhance a solar cell's efficiency by trapping light inside the cell and increasing probability of absorption. We introduce three‐dimensional, polarization‐sensitive optical model combining ray tracing rigorous coupled‐wave analysis to investigate silicon cells with pyramidal front‐side texturing back‐side gratings. Parameter optimization is performed increase short‐circuit current density for linear binary grating period p height h . For investigated...
A new spectrum of frequencies are allotted for next generation wireless communication systems based on 5G. Bulk acoustic wave (BAW) filters well poised to support the 5G & WiFi6E radio frequency bands and beyond. This paper presents an overview BAW technology development high applications, filter design process integration challenges. In addition, demonstrations 5G, WiFi6E, UWB applications presented.
With the new 5G wireless communication standard on horizon, and formerly unused bands will be introduced with frequencies up to 6 GHz. BAW filters play a crucial role supporting those due their tight guard-band steep rejection requirements. This paper elaborate process design challenges based 5.2GHz filter design.
We present an evaluation of attenuation elastic waves in the GHz range, based on decay thickness-stretch resonances plates. measured response micro-scale aluminum plates, using a laser-ultrasound technique. The thermo-elastic laser excitation provides significant coupling into modes frequency range above 1.5 GHz. To suppress interference from other resonant and transient modes, we used spot size well plate thickness applied signal processing time domain. adapted existing theory...
A new spectrum of frequencies are allotted for next generation wireless communication systems based on 5G. Bulk acoustic wave (BAW) filters well poised to support the 5G radio-bands and beyond. This report presents an overview BAW filter development high frequency bands, design challenges integration complexities. In addition, feasibility technology applications is demonstrated through a 5.9 GHz filter.
Fluorescence spectroscopy is a highly sensitive detection method widely used in analytical chemistry, bioanalytics, and medicine. The here presented amorphous silicon (a‐Si:H) based thin film photodetector arrays contribute to the miniaturization of this measurement thereby enable integration point‐of‐care testing (POCT) device. Revealed from photocurrent decay measurements, limit photodiodes with an active area A = 36.3 mm 2 100 fA‐range. Dark current analysis at zero bias voltage yields...
Back–side diffraction gratings enhance a solar cell’s near–band–gap response by diffracting light into higher orders and thereby reducing front–side escape losses. The resulting increased photon absorption carrier generation improves short–circuit current densities cell efficiencies. Combining rigorous coupled–wave analysis ray tracing yields three–dimensional, polarization sensitive optical model to calculate Si absorbance, back–side For industrially used, pyramidally textured, 180 μm cells...
We investigate the numerical predictions of Finite Element Method for bulk acoustic wave resonators. A conventional 2D model is used to calculate major performance indicators piezoelectric resonators, such as energy confinement (Q-value) and effective coupling K <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">eff</sub> . The results are compared experimentally evaluated values. show that these can be accurately predicted by using a in...
In this work we are using spatially localized acoustic resonances, so-called zero group velocity (ZGV) Lamb waves, to assess the attenuation parameters from temporally decaying waves in thin plates. As these not propagating, temporal decay of is directly linked intrinsic material damping. Guided and ZGV excited detected fully optically frequency domain laser excitation optical vibrometry. The measured responses fitted with results obtained finite element simulations. Samples tungsten...
The determination of precise material parameters is indispensable for an accurate modeling the electrical response a BAW resonator and further filter modules. prediction accuracy highly dependent on used in simulation, where small discrepancies between simulation actual as achieved during production can result errors percent range. A fitter approach presented using dispersion input data to determine parameters. An improved fitted main acoustic modes well wideband resonances shown be within...
We fabricated and characterized NIR-active Schottky-contact solar cells with PbS nanocrystals (NCs) as the active medium. The photovoltaic e ffect is due to carrier generation in NCs proven by comparison of spectrally-resolved external quantum effciency devices absorbance spectra NCs. operative regime extended well beyond Si bandgap into infrared spectral region up 1500 nm limited our measurement setup. One sun I-V time-resolved photocurrent measurements help identify critical cell...
Instead of selective emitter technology we investigate an alternative way to optimize contact formation and increased blue responsivity highly resistive solar cells using screen print for the deposition frontside metallization grid. We show with aid inline doping/diffusion set-up at Blue Chip Energy that tuning doping profile is reduce effect Auger recombination in spectral range from 300 nm 600 nm. By properly choosing process conditions were able minimize detrimental low surface...