A5007513610- Transition Metal Oxide Nanomaterials
- ZnO doping and properties
- Phase-change materials and chalcogenides
- Photonic and Optical Devices
- Ga2O3 and related materials
- Chalcogenide Semiconductor Thin Films
- Plasmonic and Surface Plasmon Research
- Quantum Dots Synthesis And Properties
- Advanced Memory and Neural Computing
- Liquid Crystal Research Advancements
- Nonlinear Optical Materials Studies
- Metamaterials and Metasurfaces Applications
- Optical Coatings and Gratings
- Advanced Fiber Laser Technologies
- Copper-based nanomaterials and applications
- Optical Wireless Communication Technologies
- Advanced Electron Microscopy Techniques and Applications
- Nanowire Synthesis and Applications
- Thin-Film Transistor Technologies
- Neural Networks and Reservoir Computing
- Magneto-Optical Properties and Applications
- Electronic and Structural Properties of Oxides
- Hydrogen embrittlement and corrosion behaviors in metals
- Silicon Nanostructures and Photoluminescence
- Corrosion Behavior and Inhibition
Friedrich Schiller University Jena
2016-2024
University of Wisconsin–Madison
2022
Purdue University West Lafayette
2022
Helmholtz Institute Jena
2016
Erbium-doped fiber amplifiers revolutionized long-haul optical communications and laser technology. Erbium ions could provide a basis for efficient amplification in photonic integrated circuits but their use remains impractical as result of insufficient output power. We demonstrate circuit-based erbium amplifier reaching 145 milliwatts power more than 30 decibels small-signal gain-on par with commercial surpassing state-of-the-art III-V heterogeneously semiconductor amplifiers. apply ion...
Abstract We demonstrate spatial modification of the optical properties thin-film metal oxides, zinc oxide (ZnO) and vanadium dioxide (VO 2 ) as representatives, using a commercial focused ion beam (FIB) system. Using Ga + FIB thermal annealing, we demonstrated variable doping wide-bandgap semiconductor, ZnO, achieving carrier concentrations from 10 18 cm −3 to 20 . same without subsequent defect-engineered correlated VO , locally modifying its insulator-to-metal transition (IMT) temperature...
Abstract The dynamics of color centers, being a promising quantum technology, is strongly dependent on the local environment. A synergistic approach X‐ray fluorescence analysis and excited optical luminescence (XEOL) using hard nanoprobe applied. simultaneous acquisition provides insights into compositional functional variations at nanoscale demonstrating extraordinary capabilities these combined techniques. findings cobalt doped zinc oxide nanowires show an anticorrelation between band edge...
We present the integration of four individual erbium-doped waveguide optical amplifiers on a Si 3 N 4 photonic integrated circuit hybrid with four-lane semi-conductor pump laser diode chip. Each amplifier achieves 15 dB on-chip gain.
Active optical metasurfaces with dynamic switchable, tunable, and reconfigurable functionalities are an emerging field in photonics optoelectronics. Especially, chalcogenide-based phase-change materials, such as Ge2Sb2Te5 (GST), can be fast repeatedly switched by external stimuli between crystalline amorphous states, typically accompanied a tremendous difference of the electronic photonic properties. Here, we demonstrate that focused ion beam-induced disorder highly confined regions...
We study the molecular structure of one monolayer picene on a Ag(100) surface. Low energy electron diffraction and scanning tunneling microscopy experiments show that molecules arrange in highly ordered manner exhibiting point-on-line epitaxy with two differently arranged per unit cell. Comparing measured simulated photoelectron momentum maps allows further conclusions about composition The structural basis consists parallel molecules; molecule lies face-on other is tilted by ≈45° around its...
Understanding the mechanism of oxide layer growth on 316 L requires knowledge, e.g., about reaction front position, phase formation and diffusion paths elements involved. We gain essential information for early stages oxidation up to 600°C, utilizing Mn as tracer in a novel experimental approach. Reasoning is based monitoring implanted Mn-free before after oxidation. The located inside each grain at ~400°C but shifts towards surface ~600°C. Detection Cr6+ 600°C suggests so far undocumented...
Abstract Highly doped semiconductors are an emerging platform for plasmonic devices. Unlike in noble metals, the carrier concentration of can vary by many orders magnitude, resulting a widely tunable range plasma wavelengths spanning mid‐infrared and terahertz ranges. In this work, potential highly doped, ion‐beam‐patterned silicon is demonstrated as fabrication‐friendly flat optical Detailed characterization properties performed at various doping levels, diffractive elements...
The integration of phase-change materials into the design optical metasurfaces already enables dynamically switchable, tunable, and reconfigurable devices. Their functionality is based on fast repeatable switching between two stable states—amorphous crystalline—which typically accompanied by drastic changes electrical properties can be accomplished external stimuli. In this study, we demonstrate that focused ion beam irradiation used to locally tailor amount disorder in highly confined...
Abstract Nanowire chip-based electrical and optical devices such as biochemical sensors, physical detectors, or light emitters combine outstanding functionality with a small footprint, reducing expensive material energy consumption. The core of many nanowire-based is embedded in their p-n junctions. To fully unleash potential, require – besides high performance stability reliability. Here, we report on an axial junction GaAs nanowire X-ray detector that enables ultra-high spatial resolution...
Chalcogenide Cu(In,Ga)Se2 solar cells yield one of the highest efficiencies among all thin-film photovoltaics. However, variability absorber compositions and incorporated alkali elements strongly affect conversion efficiency. Thus, effective strategies for spatially resolved tracking concentration composition during operation are needed to alleviate this limitation. Here, using a hard X-ray nanoprobe, we apply synergistic approach fluorescence analysis beam-induced current techniques under...
The invention of erbium-doped fiber amplifiers (EDFAs) [1] evolutionized long-haul fiber-based optical communications. Erbium have a number unique properties highly suitable for communications, such as the broadband gain covering communication bands around 1550 nm, long ms-lifetime parity forbidden intra-4-f shell transition that leads to slow dynamics and negligible inter-channel crosstalk, high temperature stability, low noise figure. Rare-earth ion doping can equally provide basis compact...
Heavy and hyper doping of ZnO by a combination gallium (Ga) ion implantation using focused beam (FIB) system post‐implantation laser annealing is demonstrated. Ion allows for the incorporation impurities with nearly arbitrary concentrations, laser‐annealing process enables dopant activation close to or beyond solid‐solubility limit Ga in ZnO. Heavily doped ZnO:Ga free‐carrier concentrations ≈10 21 cm −3 , resulting plasma wavelength 1.02 μm, which substantially shorter than telecommunication...
Phase-change materials serve a broad field of applications ranging from non-volatile electronic memory to optical data storage by providing reversible, repeatable, and rapid switching between amorphous crystalline states accompanied large changes in the electrical properties. Here, we demonstrate how ion irradiation can be used tailor disorder initially Ge 2 Sb Te 5 (GST) thin films via intentional creation lattice defects. We found that continuous Ar + -ion at room temperature GST causes...
A novel approach of characterizing nano-scaled luminescent materials using time-resolved X-ray excited optical luminescence (TR-XEOL) is presented. With the unique possibility to combine nanoscale spatial and pico-second temporal resolution, we investigate perovskite nanowires with exceptional precision. Integrated fluorescence spectroscopy in combination TR-XEOL enables correlating carrier dynamics material composition at nanoscale. In this study, focus on CsPbBr3 nanowires, potential...
We investigate hyper-doping, a promising approach to introduce high concentration of impurities into silicon beyond its solid solubility limit, for potential applications in near-infrared plasmonics. systematically explore the incorporation dopants using ion implantation and pulsed laser melting annealing processes. Reflectance spectra analysis shows an achievable plasma wavelength around 1.5 $\mu$m dopant concentrations exceeding 4 at.%. Complex refractive index data doped samples are...
We modify the transition temperature of vanadium dioxide films using two different methods: Ar + irradiation and transition-metal-doping observe a unified relationship between lattice strain, regardless modification method or combination thereof.
We demonstrate that metal doping and defect engineering can work in tandem to modify phase-transition temperature hysteresis of vanadium dioxide films, enabling new opportunities for reconfigurable infrared optics.
The generation of laser-induced periodic surface structures (LIPSS) using femtosecond lasers facilitates the engineering material surfaces with tailored functional properties. Numerous aspects their complex formation process are still under debate, despite intensive theoretical and experimental research in recent decades. This particularly concerns challenge verifying approaches based on electromagnetic effects or hydrodynamic processes by experiment. In present study, a marker experiment is...
A tiling of mid-infrared images an ion-beam-doped Fresnel zone plate embedded within a silicon wafer is shown on the cover, see also article number 1701027 by Mikhail A. Kats and co-workers. In one set images, human hand in background acts as infrared light source, highlighting transparent opaque regions defined via ion-beam doping. other, emitted from camera itself reflected metal-like regions. (Photo credit: Jad Salman Zhaoning Yu.)
The ability to control light in the infrared is central improving sensing, spectroscopy, communication, and directed-energy technologies. In this presentation, we demonstrate a platform for flat optical devices based on selectively doped semiconductors monolithic diffractive, plasmonic, gradient-index infrared.
The free charge carrier concentration of semiconductors, such as in silicon, is tunable over several orders magnitude. Thus, the plasma wavelength these materials can be adjusted a wide spectral range by controlling doping concentration. Here we demonstrate that high fluence ion beam and subsequent pulsed laser annealing extend accessible silicon far into near-infrared region reaching telecommunication wavelength. Further, how area selective activation dopants focused used to create flat...
We demonstrate a method to modify the optical properties of zinc oxide by doping with gallium using focused-ion beam system, which may be promising way create ultrathin plasmonic devices.