A5038262004- Diamond and Carbon-based Materials Research
- Semiconductor materials and devices
- Metal and Thin Film Mechanics
- Ion-surface interactions and analysis
- High-pressure geophysics and materials
- Electronic and Structural Properties of Oxides
- Graphene research and applications
- Force Microscopy Techniques and Applications
- Surface and Thin Film Phenomena
- Advanced Surface Polishing Techniques
- Physics of Superconductivity and Magnetism
- Advanced Fiber Laser Technologies
- Electron and X-Ray Spectroscopy Techniques
- Magnetic properties of thin films
- Theoretical and Computational Physics
- 2D Materials and Applications
- Rare-earth and actinide compounds
- ZnO doping and properties
- Quantum and electron transport phenomena
- Nuclear Physics and Applications
- Integrated Circuits and Semiconductor Failure Analysis
- Carbon Nanotubes in Composites
- Advanced Materials Characterization Techniques
- Nonlinear Optical Materials Studies
- Surface Chemistry and Catalysis
University of Augsburg
2016-2025
Universität Ulm
2021
Augsburg University
2002-2012
University of Tübingen
1990-1992
TH Bingen University of Applied Sciences
1989
University of Stuttgart
1989
We introduce a process for the fabrication of high quality, spatially isolated nano-diamonds on iridium via microwave plasma assisted CVD-growth. perform spectroscopy single silicon-vacancy (SiV)-centres produced during growth nano-diamonds. The colour centres exhibit extraordinary narrow zero-phonon-lines down to 0.7 nm at room temperature. Single photon count rates up 4.8 Mcps saturation make these SiV-centres brightest diamond based sources date. measure first time fine structure...
Abstract A detailed mechanism for heteroepitaxial diamond nucleation under ion bombardment in a microwave plasma enhanced chemical vapour deposition setup on the single crystal surface of iridium is presented. The novel Io n B ombardment I nduced uried L ateral G rowth (IBI-BLG) based induced formation and lateral spread epitaxial within ~1 nm thick carbon layer. Starting from one primary event buried island can expand laterally over distances several microns. During this growth typically...
A nanotemplate surface that functions as a regular array of traps for molecules such naphthalocyanine (see picture) is provided by nanomesh hexagonal BN on Rh(111), which has now been identified single, complete monolayer. The 2-nm-sized pores form at regions where the layer binds strongly to underlying metal, while network mesh wires corresponds not bonded substrate.
We study single silicon vacancy (SiV) centres in chemical vapour deposition (CVD) nanodiamonds on iridium as well an ensemble of SiV a high quality, low stress CVD diamond film by using temperature dependent luminescence spectroscopy the range 5-295 K. investigate detail fine structure zero-phonon-line (ZPL) centres. The ZPL transition is affected inhomogeneous homogeneous broadening and blue shifts about 20 cm-1 upon cooling from room to 5 employ excitation power g(2) measurements explore...
Deterministic coupling of single solid-state emitters to nanocavities is the key for integrated quantum information devices. We here fabricate a photonic crystal cavity around preselected silicon-vacancy color center in diamond and demonstrate modification internal population dynamics radiative efficiency. The controlled, room-temperature gives rise resonant Purcell enhancement zero-phonon transition by factor 19, coming along with 2.5-fold reduction emitter's lifetime.
Wafer bow is of considerable technological relevance for virtually all semiconductor materials grown by heteroepitaxy. In the case diamond, reported curvature values are exceptionally large synthesis plasma chemical vapor deposition on oxide substrates. contrast to usual explanation differences in coefficients thermal expansion (CTEs), present analysis reveals that CTE α substrate combined with its conductivity λ controls radius surface which diamond layer will grow. The ratio λ/α represents...
The development of ZnO-based semiconductor devices requires band gap engineering. Ternary Zn1−xCdxO allows reduction the relative to ZnO, which would be necessary for emitting visible light. We have analyzed structural and optical properties layers grown by metalorganic vapor-phase epitaxy. A narrowing fundamental up 300 meV has been observed, while introducing a lattice mismatch only 0.5% with respect binary ZnO. Photoluminescence, high-resolution x-ray diffraction, spatially resolved...
We report on the first observation of a pronounced reentrant superconductivity phenomenon in superconductor/ferromagnet layered system. The results were obtained using superconductor/ferromagnetic-alloy bilayer $\mathrm{Nb}/{\mathrm{Cu}}_{1\ensuremath{-}x}{\mathrm{Ni}}_{x}$. superconducting transition temperature ${T}_{c}$ drops sharply with increasing thickness ${d}_{\mathrm{CuNi}}$ ferromagnetic layer, until complete suppression is observed at...
Quite comparable: A graphene monolayer is used as a substrate for the growth of two-dimensional hydrogen-bonded supramolecular structures (see STM image). The formation these extended arises from commensurability between their dimensions and moiré pattern formed by graphene. Detailed facts importance to specialist readers are published "Supporting Information". Such documents peer-reviewed, but not copy-edited or typeset. They made available submitted authors. Please note: publisher...
We introduce an advanced material system for the production and spectroscopy of single silicon vacancy (SiV) color centers in diamond. use microwave plasma chemical vapor deposition to synthesize heteroepitaxial nanodiamonds approximately 160 nm lateral size with a thickness 75 nm. These oriented ``nanoislands'' combine enhanced fluorescence extraction from subwavelength-sized defined crystal orientation. The investigated SiV display narrow zero-phonon lines down 0.7 wavelength range...
A multilayer structure is presented which allows the deposition of high-quality heteroepitaxial diamond films on silicon. After pulsed-laser a thin yttria-stabilized zirconia (YSZ) layer silicon, iridium was deposited by e-beam evaporation. Subsequently, nucleation and growth performed in chemical vapor setup. The epitaxial orientation relationship measured x-ray diffraction diamond(001)[110]∥Ir(001)[110]∥YSZ(001) [110]∥Si(001)[110]. mosaicity about an order magnitude lower than for directly...
Heteroepitaxial diamond films with highly improved alignment have been realized by using the layer sequence diamond/Ir/SrTiO3(001). In a first step, epitaxial iridium misorientation <0.2° deposited on polished SrTiO3(001) surfaces electron-beam evaporation. Using bias-enhanced nucleation procedure in microwave plasma chemical vapor deposition, grains density of 109 cm−2 could be nucleated these substrates. The orientation relationship for this system is...
It is shown that diamond nucleation on iridium buffer layers followed by an appropriate textured-growth step offers a viable way to realize single-crystal films. Bias-enhanced results in heteroepitaxial films with highly improved alignment. By subsequent step, the mosaicity can be further reduced for tilt as well twist sharp contrast former experiments using silicon substrates. Minimum values of 0.17° and 0.38° have been measured twist, respectively. Plan view transmission electron...
The development of dislocation density and micro-strain in heteroepitaxial diamond films on iridium was measured over more than two decades thickness up to d ≈ 1 mm. Simple mathematical scaling laws were derived for the decrease with increasing film its correlation micro-strain. Raman line width as a measure showed huge 1.86 cm−1, close value perfect single crystals. charge collection properties particle detectors built from this material yield efficiencies higher 90% hole-drift mode,...
The setup of an apparatus for chemical vapor deposition (CVD) hexagonal boron nitride (h-BN) and its characterization on four-inch wafers in ultra high vacuum (UHV) environment is reported. It provides well-controlled preparation conditions, such as oxygen argon plasma assisted cleaning temperature annealing. In situ a wafer accomplished with target current spectroscopy. A piezo motor driven x-y stage allows measurements step size 1 nm the complete wafer. To benchmark system performance, we...
Large-area hexagonal boron nitride (h-BN) promises many new applications of two-dimensional materials, such as the protective packing reactive surfaces or membranes in liquids. However, scalable production beyond exfoliation from bulk single crystals remained a major challenge. Single-orientation monolayer h-BN nanomesh is grown on 4 in. wafer crystalline rhodium films and transferred arbitrary substrates SiO2, germanium, transmission electron microscopy grids. The transfer process involves...
In this work, three distinct heteroepitaxial single-crystal boron-doped diamond (SC-BDD) electrodes were fabricated and subjected to detailed surface analysis electrochemical characterization. Specifically, the heteroepitaxy approach allowed synthesize large-area (1 cm2) heavily-doped (100)-oriented SC-BDD electrodes. Their nature crystal orientation confirmed by X-ray diffraction, while scanning electron atomic force microscopies revealed marked variations in morphology resulting from their...
We investigate native nitrogen vacancy (NV) and silicon (SiV) color centers in a commercially available, heteroepitaxial, wafer-sized, mm thick, single-crystal diamond. observe single, NV with density of roughly 1 per μm3 moderate coherence time (T2 = 5 μs) embedded an ensemble SiV centers. Using low temperature luminescence as probe, we prove the high crystalline quality diamond especially close to growth surface, consistent reduced dislocation density. ion implantation plasma etching,...
We consider a supersymmetric extension of quantum gauge theory based on vector multiplet containing partners spin 3/2 for the fields. The constructions model follows closely usual construction models in Epstein-Glaser framework perturbative field theory. Accordingly, all arguments are completely nature without reference to classical As an application we electroweak resulting self-couplings bosons agree with standard up divergence.