A5066812277- Chalcogenide Semiconductor Thin Films
- Quantum Dots Synthesis And Properties
- Energy Harvesting in Wireless Networks
- Antenna Design and Analysis
- Copper-based nanomaterials and applications
- Wireless Body Area Networks
- Advanced Memory and Neural Computing
- Magnetic properties of thin films
- Wireless Power Transfer Systems
- Neural Networks and Reservoir Computing
- Electric Power Systems and Control
- Microwave Engineering and Waveguides
- Neuroscience and Neural Engineering
- Innovative Energy Harvesting Technologies
- Neural Networks and Applications
- Theoretical and Computational Physics
- Acoustic Wave Resonator Technologies
- ZnO doping and properties
- solar cell performance optimization
- Advanced MEMS and NEMS Technologies
- Advanced Research in Systems and Signal Processing
- EEG and Brain-Computer Interfaces
- Industrial Engineering and Technologies
- Millimeter-Wave Propagation and Modeling
- Ferroelectric and Negative Capacitance Devices
International Iberian Nanotechnology Laboratory
2017-2024
University of Minho
2010-2019
Abstract Pinning at local defects is a significant road block for the successful implementation of technological paradigms which rely on dynamic properties non-trivial magnetic textures. Here, comprehensive study influence pinning sites non-homogeneous layers integrated as free layer tunnel junction presented, both experimentally and with corresponding micromagnetic simulations. The are found to be extremely detrimental frequency controllability devices, key requirement their use synapses in...
As electrodes are required to interact with sub-millimeter neural structures, innovative microfabrication processes enable fabrication of microdevices involved in such stimulation and/or recording. This requires the development highly integrated and miniaturized systems, comprising die-integration-compatible technology flexible microelectrodes. To elicit selective recordings sub-neural process flow can beneficiate from integration titanium nitride (TiN) microelectrodes onto a polyimide...
A new approach to fabricate copper, indium, gallium diselenide (CIGSe) solar cells on conductive fluorine-doped tin oxide (FTO) reached an efficiency of over 6% for a champion photovoltaic device. Commercial nanoparticles are formulated into high-quality screen-printable ink based ethyl cellulose solution in terpineol. The high homogeneity and good adhesion properties the play important role obtaining dense highly crystalline photoabsorber layers. This finding reveals that solution-based...
One of the critical challenges in engineering is wireless transfer energy to power miniaturized electronic devices that have sizes smaller than wavelength electromagnetic radiation. Here, we describe a strategy self-fold three-dimensional (3D) low gigahertz responsive antennas with small form factors using capillary forces. The are sub-millimeter (500 × 500 (m 3 ) cubic and hollow free space their interior which could be used embed other devices. We characterize demonstrate efficacy these...
Second-generation thin-film Cu(In, Ga)Se2 (CIGS) solar cells are a well-established photovoltaic technology with record power conversion efficiency of 23.6%. However, their reliance on critical raw materials, such as In and Ga, requires new approaches to reduce the amount materials employed. The micro-concentrator concept involves combination concentrator technology. This approach reduces size cell micrometer range uses optical concentration collect sunlight from larger area, focusing it...
This paper reports a 3D small micro-antenna suitable for energy harvesting applications in the low gigahertz regime to supply 1μW power small, implantable medical device. The micro antenna is designed envelope 500 × μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> device and simulated as embedded 5 mm of muscle tissue. proposed was fabricated by combining planar photolithography surface tension driven self-folding techniques order...
Abstract Micro-concentrator solar cells enable higher power conversion efficiencies and material savings when compared to large-area non-concentrated cells. In this study, we use materials-efficient area-selective electrodeposition of the metallic elements, coupled with selenium reactive annealing, form Cu(In,Ga)Se 2 semiconductor absorber layers in patterned microelectrode arrays. This process achieves significant low-abundance elements. The resulting copper-poor micro-absorber layers’...
The fabrication of Sb2Se3 thin-film solar cells deposited by a pulsed hybrid reactive magnetron sputtering (PHRMS) was proposed and examined for different growth conditions. influence temperature Se pulse period were studied in terms morphology, crystal structure, composition. showed to be dependent on the temperature, with larger size at 270 °C. By controlling period, structure could modified as function supplied amount. cell performance absorbers various temperatures, periods thicknesses...
Wireless power transfer using coupling in the near-field, opposition to far-field, shows advantages concerning link efficiency, however performance is widely dependent on proper antenna positioning. The transmission of energy a far-field would be desirable many applications, namely for powering biomedical devices placed inside body. This paper presents results from system that was designed operate human body and relies 3D (500×500×500 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Pinning at local defects is a significant road block for the successful implementation of technological paradigms which rely on dynamic properties non-trivial magnetic textures. In this report comprehensive study influence pinning sites non-homogeneous layers integrated as free layer tunnel junction presented, both experimentally and with corresponding micromagnetic simulations. The are found to be extremely detrimental frequency controllability devices, key requirement their use synapses in...
High-efficiency Cu(In,Ga)Se <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> (CIGSe) thin-film solar cells are typically fabricated by a multistage coevaporation process. The Cu-rich composition achieved during the second stage is known to favor grain growth of polycrystalline CIGSe film and has beneficial effect on cell performance. In this article, we analyze copper stoichiometry size sputtered absorbers efficiency respective cells....
Large‐scale industrial fabrication of Cu(In,Ga)Se 2 (CIGS) photovoltaic panels would benefit significantly if the buffer layer chemical bath deposition could be replaced by a cadmium‐free dry vacuum process suitable for in‐line production. This Letter reports on development Zn(O,S) deposited vacuum‐based magnetron sputtering from single target onto commercial CIGS absorbers cut module‐size glass/Mo/CIGS stack. The buffer‐window stack consisting Zn(O 0.75 S 0.25 )/i‐ZnO/ZnO:Al is optimized...
Abstract The quest for material‐efficient Cu(In,Ga)Se 2 (CIGS) solar cells encourages the development of ultra‐thin absorbers. Their use reduces material consumption and energy usage during production by increasing throughput. Thereby, both bill materials as well capital costs are reduced. However, because thin absorbers prone to increase back contact recombination, surface passivation schemes necessary reach a similar or higher conversion efficiency than with conventional thickness. Here,...
For mass fabrication of highly-efficient photovoltaic modules based on Cu(In,Ga)Se2 (CIGSe) absorber layers the availability and cost critical raw materials In Ga present a potential bottleneck. The micro-concentrator solar cell concept provides solution by using micro lenses to concentrate incoming sun light an array micro-sized CIGSe cells. challenge is fabricate islands in exactly desired positions only required material. Here, we analyze area-selective electrodeposition CuInSe2 into...
Implantable devices are becoming smaller and smaller, making possible new solutions for the current challenges in medical diagnosis, treatment monitoring. These implantable may rely on miniaturized that can be controlled powered via wireless communications. Due to high degree of system miniaturization very small antennas required pushing communication range frequencies domain. Nevertheless, since human body tissue attenuation increases with frequency it is challenging obtain an efficient...
The use of heterogeneous integration technologies is the path for development further miniaturized, smarter, and energy autonomous microdevices, which are required to tackle challenge monitoring and/or control health condition everyone, everywhere. interaction with human body requires flexible materials, while electronic component based on rigid like silicon substrates. Also, once inside body, it desirable have a wireless link data communication, as well RF powering, using harvesting...
The authors gratefully acknowledge the Erasmus scholarship support provided by Mundus EU-MARE NOSTRUM Program.
Abstract This tutorial paper presents an empirical model of a capacitive radio frequency microelectromechanical system switch in the microwave domain. The simulation results mechanical and electrical aspects proposed were computed with Matlab. modeling is validated by COMSOL software through finite element method to determine spring constant necessary applied voltage. electromagnetic are 3 different software: High‐Frequency Structure Simulator based on method, Computer Simulation Technology...
Implantable device miniaturization is a cornerstone in modern medicine and the key to unlock new exciting applications for both monitoring treatment of diseases. Such can be facilitated resorting miniaturized antennas that will support wireless communications, power transfer (WPT), energy-harvesting applications. The development such devices being supported by innovative fabrication integration technologies lead challenges antenna design characterization. In this article, microantenna...
This study proposes an adaptive impedance-matching network with tremendously reduced dimensions and presents its fabrication process. The proposed radio-frequency micro-electromechanical system (RF MEMS) device is based on a coplanar waveguide design relies suspended bridges for impedance tuning. tuning controlled by variable applied DC voltage to the bridges. Preliminary tests validate device's operation mechanism, simulations were performed both mechanical aspects of (bridge gap...