A5065233782- Diamond and Carbon-based Materials Research
- Metal and Thin Film Mechanics
- Force Microscopy Techniques and Applications
- High-pressure geophysics and materials
- Semiconductor materials and devices
- Advanced Fiber Laser Technologies
- Analytical Chemistry and Sensors
- Electronic and Structural Properties of Oxides
- Physics of Superconductivity and Magnetism
- Mechanical and Optical Resonators
- Acoustic Wave Resonator Technologies
- Advanced Surface Polishing Techniques
- Carbon Nanotubes in Composites
- Quantum and electron transport phenomena
- Ion-surface interactions and analysis
- Advanced materials and composites
- GaN-based semiconductor devices and materials
- Ferroelectric and Piezoelectric Materials
- Boron and Carbon Nanomaterials Research
- Graphene research and applications
- Electrochemical Analysis and Applications
- Supercapacitor Materials and Fabrication
- Molecular Junctions and Nanostructures
- Nonlinear Optical Materials Studies
- Advanced MEMS and NEMS Technologies
Cardiff University
2016-2025
Lowestoft Hospital
2017
Fraunhofer Institute for Applied Solid State Physics
2009-2014
BP (United Kingdom)
2014
Hasselt University
2005-2012
Advanced Diamond Technologies (United States)
2012
Applied Diamond (United States)
2012
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2012
CEA LIST
2012
Centre National de la Recherche Scientifique
2010
Photonic active diamond nanoparticles attract increasing attention from a wide community for applications in drug delivery and monitoring experiments as they do not bleach or blink over extended periods of time. To be utilized, the size these needs to around 4 nm. Cluster formation is therefore major problem. In this paper we introduce new technique modify surface particles with hydrogen, which prevents cluster buffer solution perfect starting condition chemical modifications. By annealing...
We report on the electronic and optical properties of boron-doped nanocrystalline diamond (NCD) thin films grown quartz substrates by ${\text{CH}}_{4}/{\text{H}}_{2}$ plasma chemical vapor deposition. Diamond with a thickness below 350 nm boron concentration ranging from ${10}^{17}$ to ${10}^{21}\text{ }{\text{cm}}^{\ensuremath{-}3}$ have been investigated. UV Raman spectroscopy atomic force microscopy used assess quality morphology films. Hall-effect measurements confirmed expected $p$-type...
The demonstration that Nanocrystalline Diamond (NCD) can retain the superior Young's modulus (1,100 GPa) of single crystal diamond twinned with its ability to be grown at low temperatures (<450 {\deg}C) has driven a revival into growth and applications NCD thin films. However, owing competitive crystals resulting film roughness evolves thickness, preventing films from reaching their full potential in devices where smooth is required. To reduce this roughness, have been polished using...
In this paper, the origin of positive zeta potential exhibited by nanodiamond particles is explained. Positive potentials in nano-structured carbons can be explained presence graphitic planes at surface, which leave oxygen-free Lewis sites and so promotes suppression acidic functional groups. Electron Microscopy Raman Spectroscopy have been used to show that only sp2 carbon surface.
Abstract To fabricate battery‐like supercapacitors with high power and energy densities, big capacitances, as well long‐term capacitance retention, vertically aligned carbon nanofibers (CNFs) grown on boron doped diamond (BDD) films are employed the capacitor electrodes. They possess large surface areas, conductivity, stability, importantly free of binder. The areas result from their porous structures. containment graphene layers copper metal catalysts inside CNFs leads to conductivity. Both...
Battery-like supercapacitors fabricated with a 3D diamond network and water-soluble redox electrolytes exhibit large capacitances high energy power densities.
Hall effect measurements have been carried out to determine the carrier density and mobilities in ultrananocrystalline diamond films grown with added nitrogen. The results show clear n-type conductivity very low thermal activation energy. Mobility values of 1.5cm2V−1s−1 are found for a sheet concentration 2×1017cm−2. These indicate that high nitrogen levels growth gas mixture can bulk concentrations up 1021, which is films. nature this material was also confirmed by Seebeck measurements.
Abstract The aim of this paper is to summarise recent progress in the growth small grain‐sized Chemical Vapor Deposition (CVD) diamond often called nanocrystalline diamond, i.e., with grains typically smaller than 500 nm. Nanocrystalline (NCD) and Ultrananocrystalline (UNCD) films are new materials offering interesting applications nanobioelectronics electrochemistry. However NCD UNCD thin comprise entirely different structures which highlighted here paper. We discuss detail main differences...
This letter describes the procedure to manufacture high-performance surface acoustic wave (SAW) resonators on AlN/diamond heterostructures working at frequencies beyond 10 GHz. In design of SAW devices systems, thickness piezoelectric layer is a key parameter. The influence film device response has been studied. Optimized thin films combined with advanced e-beam lithographic techniques have allowed fabrication one-port finger width and pitch 200 nm operating in 10-14 GHz range up 36 dB...
Boron-doped diamond has been utilized as an electrode material to construct electric double layer capacitor (EDLC) well support form a pseudocapacitor. In 1.0 M NaSO4 solution, the capacitance of EDLC is in range 3.6–7.0 μF cm–2, comparable with those EDLCs based on other carbon materials. During charge/discharge process for 1000 cycles at scan rate 100 mV s–1, only decreases 5%, indicating high stability and long lifetime such EDLC. To improve EDLCs, was coated MnO2 film...
The silicon-vacancy (SiV) color center in diamond is a solid-state single photon emitter and spin quantum bit suited as component devices. Here, we show that the SiV nanodiamond exhibits strongly inhomogeneous distribution with regard to wavelengths linewidths of zero-phonon-line (ZPL) emission at room temperature. We find centers separate two clusters: one group ZPLs within narrow range approximatly 730 nm 742 broad between 5 17 nm, whereas second comprises very 715 835 but from below 1 up...
The growth of >100-μm-thick diamond layers adherent on aluminum nitride with low thermal boundary resistance between and AlN is presented in this work. barrier was found to be the range 16 m2·K/GW, which a large improvement current state-of-the-art. While thick films failed adhere untreated films, treated hydrogen/nitrogen plasma retained layers. Clear differences ζ-potential measurement confirm surface modification due treatment. An increase non-diamond carbon initial grown pretreated seen...
Integrating diamond with GaN high electron mobility transistors (HEMTs) improves thermal management, ultimately increasing the reliability and performance of high-power high-frequency radio frequency amplifiers. Conventionally, an amorphous interlayer is used before growing polycrystalline onto in these devices. This layer contributes significantly to effective boundary resistance (TBReff) between HEMT diamond, reducing benefit heat spreader. Replacing a higher conductivity crystalline...
Nanodiamonds containing negatively charged nitrogen vacancy centers (${\text{NV}}^{\ensuremath{-}}$) have applications as localized sensors in biological materials and been proposed a platform to probe the macroscopic limits of spatial superposition quantum nature gravity. A key requirement for these is obtain nanodiamonds ${\text{NV}}^{\ensuremath{-}}$ with long spin coherence times. Using milling fabricate processes full 3D volume bulk material at once, unlike etching pillars, but has, up...
We report on the operation of ungated surface conductive diamond devices in electrolytic solutions. The effect electrolyte pH channel conductivity is studied detail. It shown that fully hydrogen terminated surfaces are not sensitive. However, a pronounced sensitivity arises after mild oxidation by ozone. propose charged ions from adsorbed oxidized regions induce lateral electrostatic modulation hole accumulation layer surface. In contrast, expected to be surface, either due screening induced...
The electronic transport properties of ultrananocrystalline diamond thin films grown from an argon-rich $\mathrm{Ar}∕\mathrm{C}{\mathrm{H}}_{4}$ microwave plasma have been investigated in the temperature range 300 up to $700\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ and as a function nitrogen added gas phase (from 0 20%). influence incorporation on was examined by conductivity Hall effect experiments. Electron spin resonance electrically detected magnetic-resonance measurements complement study....
The optical properties of nanocrystalline diamond films grown from a hydrogen-rich CH4∕H2 gas phase by hot filament chemical vapor deposition, as well an argon-rich Ar∕CH4 microwave plasma enhanced are reported. influence nitrogen incorporation on the absorption is investigated. characterized photothermal deflection spectroscopy and temperature dependent spectrally resolved photoconductivity. An onset at about 0.8eV in undoped attributed to transitions π states introduced into band gap high...