A5042233369- Acoustic Wave Resonator Technologies
- GaN-based semiconductor devices and materials
- Graphene research and applications
- Semiconductor Quantum Structures and Devices
- Mechanical and Optical Resonators
- Advanced Sensor and Energy Harvesting Materials
- Supercapacitor Materials and Fabrication
- ZnO doping and properties
- Semiconductor materials and devices
- Plasmonic and Surface Plasmon Research
- Graphene and Nanomaterials Applications
- Neutrino Physics Research
- Nanowire Synthesis and Applications
- Astrophysics and Cosmic Phenomena
- Quantum and electron transport phenomena
- Conducting polymers and applications
- Metal and Thin Film Mechanics
- Advanced MEMS and NEMS Technologies
- Thermal Radiation and Cooling Technologies
- Metamaterials and Metasurfaces Applications
- Photonic and Optical Devices
- Semiconductor materials and interfaces
- Analytical Chemistry and Sensors
- Thermal properties of materials
- Particle accelerators and beam dynamics
Universidad Politécnica de Madrid
2013-2024
University of Cambridge
2010-2020
Consejo Superior de Investigaciones Científicas
2019
Universidad San Pablo CEU
2013
Universitat Politècnica de Catalunya
1995
In this perspective, the recent trends in graphene supercapacitor research are shown, from use of pseudocapacitor elements to enhance performance large-area electrodes, its miniaturization driven by versatile fabrication techniques.
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...
We propose a scheme for coupling laser light into graphene plasmons with the help of electrically generated surface acoustic waves. The wave forms diffraction grating which allows us to excite long lived phononlike branch hybridized plasmon-phonon dispersion infrared light. Our approach avoids patterning sheet, does not rely on complicated optical near-field techniques, and switch between far-field radiation propagating plasmons.
We propose to achieve the proof-of-principle of PTOLEMY project directly detect Cosmic Neutrino Background (CNB). Each technological challenges described in [1,2] will be targeted and hopefully solved by use latest experimental developments profiting from low background environment provided LNGS underground site. The first phase focus on graphene technology for a tritium target demonstration TES microcalorimetry with an energy resolution better than 0.05 eV electrons. These technologies...
The PTOLEMY project aims to develop a scalable design for Cosmic Neutrino Background (CNB) detector, the first of its kind and only one conceived that can look directly at image Universe encoded in neutrino background produced second after Big Bang. scope work next three years is complete conceptual this detector validate with direct measurements non-neutrino backgrounds are below expected cosmological signal. In paper we discuss details theoretical aspects experiment physics goals....
Abstract In most applications based on chemical vapor deposition (CVD) graphene, the transfer from growth to target substrate is a critical step for final device performance. Manual procedures are time consuming and depend handling skills, whereas existing automatic roll-to-roll methods work well flexible substrates but tend induce mechanical damage in rigid ones. A new system that automatically transfers CVD graphene an arbitrary has been developed. The process all-fluidic manipulation of...
Abstract The long-distance quantum transfer between electron-spin qubits in semiconductors is important for realising large-scale computing circuits. Electron-spin to photon-polarisation conversion a promising technology achieving free-space or fibre-coupled transfer. In this work, using only regular lithography techniques on conventional 15 nm GaAs well, we demonstrate acoustically-driven generation of single photons from electrons, without the need self-assembled dot. device, electron...
The characteristics of surface acoustic waves (SAWs) in GaN layers grown on $c$-plane sapphire are investigated. Besides Rayleigh mode, Sezawa and Love modes, which confined the nitride layers, arise because slow sound propagation compared with substrate. In addition, pseudo-SAWs leaking into bulk observed. trigonal crystal symmetry not only leads to an anisotropic SAWs heterostructures, despite isotropic elastic properties GaN, but also mixes their polarization even for along...
Highly c-axis oriented ZnO films have been deposited at room temperature with high rates (∼50 nm·min−1) using an innovative remote plasma sputtering configuration, which allows independent control of the density and ion energy. The possess excellent crystallographic orientation, resistivity (>109 Ω·m), exhibit very low surface roughness. ability to increase energy without causing unwanted Ar+ bombardment onto substrate has shown be crucial for growth orientation need heating. In...
The characteristics and dispersion of the distinct surface acoustic waves (SAWs) propagating in ZnO/GaAs heterostructures have been studied experimentally theoretically. Besides Rayleigh mode, strong Sezawa modes, which propagate confined overlayer, arise due to smaller sound velocity ZnO than substrate. design parameters structure providing strongest piezoelectric field at a given depth within layered system for different modes determined. mode is shown be more 10 times stronger interface...
We experimentally demonstrate that the Raman active optical phonon modes of single layer graphene can be modulated by dynamic local strain created surface acoustic waves (SAWs). In particular, field SAW is shown to induce a scattering intensity variation as large 15% and frequency shift up 10 cm$^{-1}$ for G band, instance, an effective hydrostatic 0.24% generated in atop LiNbO$_{3}$ piezoelectric substrate with resonator operating at $ \sim 400 MHz. Thus, we SAWs are powerful tools modulate...
We theoretically demonstrate the coupling between excitons in 2D semiconductors and surface plasmons a thin metal film by means of acoustic wave (SAW), proving that generated exciton-plasmon polaritons (or plexcitons) are strong regime. The strain field SAW creates dynamic diffraction grating providing momentum match for plasmons, whereas piezoelectric field, could dissociate excitons, is cancelled out metal. This exemplified monolayer MoS$\mathrm{_{2}}$ mono- few-layer black phosphorus on...
New architectures of transparent conductive electrodes (TCEs) incorporating graphene monolayers in different configurations have been explored with the aim to improve performance silicon-heterojunction (SHJ) cell front contacts. In SHJ technology, play an important additional role as anti-reflectance (AR) coatings. this work, transparent-conductive-oxide (TCO) thin films combined configurations, yielding advanced specifically designed minimize surface reflection over a wide range wavelengths...
A voltage tunable surface acoustic wave (SAW) phase shifter on a two-dimensional electron gas (2DEG) AlGaN/GaN heterostructure has been developed. The acoustoelectric interaction is field-effect modulated by means of an insulated gate placed in the path SAW delay line. velocity under tuned modifying conductance 2DEG with dc bias, while insulating layer prevents screening piezoelectric fields gate. device compatible nitride transistor technology for signal processing and frequency control...
Active surface acoustic wave filters with voltage-controlled insertion losses have been achieved using AlGaN/GaN 2DEG heterostuctures as piezoelectric substrates. Transfer control is performed by moderate DC voltages between the fingers in either or both input and output interdigital transducers. These can be integrated into future MMIC circuits based on high electron mobility transistors.
Commercial carbon paper was coated with polyaniline (PANI) using in situ polymerization of aniline. Prior to the PANI coating, acid treatment performed carboxylate surface for enhancing adhesion by sonication a mixture concentrated sulfuric and nitric acids. The loading mass density on acid-treated increased more than three times compared that without treatment. specific capacitance also from 112 174 F/g two-electrode system (calculated total PANI) due better coating paper. simple provides...
The quenching of the photoluminescence induced by fundamental and guided high-order Rayleigh-type modes propagating in $\mathrm{Ga}\mathrm{N}∕6\mathrm{H}\text{\ensuremath{-}}\mathrm{Si}\mathrm{C}(0001)$ heterostructure is compared. Two material types have been considered: conventional GaN underneath Ga droplets formed during molecular-beam-epitaxy growth. different piezoelectric field-depth profile each surface acoustic wave (SAW) used to analyze their characteristics. A...
Abstract The interaction of two types fragmented graphene particles (30–160 nm) with human macrophages is studied. Since have significant phagocytic activity, the incorporation into cells has an effect on response to functional polarization stimuli, favoring anti‐inflammatory profile. Incubation foam particles, prepared by chemical vapor deposition, and commercially available nanoplatelet does not affect cell viability when added at concentrations up 100 µg mL −1 ; exhibit differential...