Search results for "Silicon"
showing 10 items of 1391 documents
The Influence of Nanoparticle Shape on Protein Corona Formation
2020
Nanoparticles have become an important utility in many areas of medical treatment such as targeted drug and treatment delivery as well as imaging and diagnostics. These advances require a complete understanding of nanoparticles' fate once placed in the body. Upon exposure to blood, proteins adsorb onto the nanoparticles surface and form a protein corona, which determines the particles' biological fate. This study reports on the protein corona formation from blood serum and plasma on spherical and rod‐shaped nanoparticles. These two types of mesoporous silica nanoparticles have identical chemistry, porosity, surface potential, and size in the y ‐dimension, one being a sphere and the other a …
Wpływ rozkładu widma promieniowania słonecznego na parametry multikrystalicznego ogniwa krzemowego
2014
W artykule opisano wyniki uzyskane z opracowanej aplikacji integrującej model rozkładu widma promieniowania słonecznego oraz model krzemowego monokrystalicznego ogniwa fotowoltaicznego. W ramach badań opracowano program - symulator widma promieniowania słonecznego wykorzystujący algorytmy i procedury numeryczne oparte na modelu SMARTS2. Ponadto, przygotowano aplikację pozwalającą na przeprowadzenie modelowania komputerowego zachowania się ogniw i analizę zmienności ich parametrów przy zastosowaniu różnych rozkładów spektralnych oświetlenia oraz różnych parametrów materiałowo-konstrukcyjnych ogniw PV. Z wykorzystaniem niniejszej aplikacji przeprowadzono szereg symulacji. Dokonano analizy zal…
Effects of Excimer Laser Irradiation on the Morphological, Structural, and Electrical Properties of Aluminum-Implanted Silicon Carbide (4H-SiC)
2022
This paper reports on the effects of excimer laser irradiation on an aluminum (Al)-doped silicon carbide (4H-SiC) layer. Specifically, high-concentration (1 × 1020at/cm3) Al-implanted 4H-SiC samples were exposed to a few pulses of 308 nm laser radiation (pulse duration of 160 ns), with fluence varying from 1.0 to 2.8 J/cm2. As a starting point, the laser-induced modifications of the morphological, microstructural, and nanoelectrical properties of the exposed 4H-SiC surface were monitored by combining different techniques. From these investigations, an evolution of the surface morphology was observed that can be ascribed to a conversion during irradiation of the uppermost part of the 4H-SiC …
Charge Transport Mechanisms in Heavy-Ion Driven Leakage Current in Silicon Carbide Schottky Power Diodes
2016
Under heavy-ion exposure at sufficiently high reverse bias voltages silicon carbide (SiC) Schottky diodes are observed to exhibit gradual increases in leakage current with increasing ion fluence. Heavy-ion exposure alters the overall reverse current-voltage characteristics of these diodes, leaving the forward characteristics practically unchanged. This paper discusses the charge transport mechanisms in the heavy-ion damaged SiC Schottky diodes. A macro model, describing the reverse current-voltage characteristics in the degraded SiC Schottky diodes is proposed. peerReviewed
Effect of the Si doping on the properties of AZO/SiC/Si heterojunctions grown by low temperature pulsed laser deposition
2020
Abstract The structural and photoelectrical properties of Al-doped ZnO (AZO)/SiC/p-Si and AZO/SiC/n-Si heterojunctions, fabricated at low temperature by pulsed laser deposition, were investigated by means of a number of techniques. Raman analysis indicates that SiC layers have the cubic 3C-SiC phase, whilst X-ray diffraction measurements show that AZO films exhibit a hexagonal wurtzite structure, highly textured along the c-axis, with average crystallites size of 35.1 nm and lattice parameter c of 0.518 nm. The homogeneous and dense surface morphology observed by scanning electron microscopy was confirmed by atomic force microscopy images. Moreover, UV–Vis-NIR spectra indicated a high trans…
Single Event Burnout of SiC Junction Barrier Schottky Diode High-Voltage Power Devices
2018
Ion-induced degradation and catastrophic failures in high-voltage SiC Junction Barrier Schottky (JBS) power diodes are investigated. Experimental results agree with earlier data showing discrete jumps in leakage current for individual ions, and show that the boundary between leakage current degradation and a single-event-burnout-like effect is a strong function of LET and reverse bias. TCAD simulations show high localized electric fields under the Schottky junction, and high temperatures generated directly under the Schottky contact, consistent with the hypothesis that the ion energy causes eutectic-like intermixture at the metal- semiconductor interface or localized melting of the silicon …
Particle radiation in microelectronics
2012
The unavoidable presence of particle radiation in space and on the ground combined with constantly evolving technology necessitates a deep understanding of the basic mechanisms underlying radiation effects in materials and electronic devices. This thesis provides an overview of the different radiation environments, with a review of the interaction mechanisms between energetic particles and matter. In this work a new semi-empirical model for estimating the electronic stopping force of solids for heavy ions is introduced. Radiation effects occurring in microelectronics due to particle radiation are also discussed with a brief introduction to radiation hardness assurance (RHA) testing of elect…
Amorphous silicon nanotubes
2017
In the following, the attention will be focused on the silicon nanotube (SiNTs) that is a highly desired form of silicon for its fundamental role in the miniaturization trend of the electronic devices. After a description of the properties and applications of SiNTs and their fabrication methods, the attention will be focused on chemical vapour deposition (CVD) template synthesis that is the most usual synthetic method for this material. Then, galvanic template synthesis will be described as a general method for the fabrication of different metals and oxides nanostructures, therefore the use of this technique for synthesizing SiNTs will be detailed. Characterization methods will be also desc…
Physiological parameters measurements in a cardiac cycle via a combo PPG-ECG system
2015
In this paper, we present an innovative way to measure some physiological parameters (such as the pre-ejection period, the pulse transit time, the blood pressure) in a cardiac cycle. A combo PPG-ECG system has been developed and employed to extract both the ECG signal from standard limb leads and simultaneously the photoplethysmography signal from the wrist and the forearm, to calculate the pre-ejection period. This system represents an easy and non-invasive technique to determine these biomedical parameters without using expensive impedance cardiography equipment.
P-on-N and N-on-P silicon photomultipliers: responsivity comparison in the continuous wave regime
2013
We report the electrical and optical comparison, in continuous wave regime, of two novel classes of silicon photomultipliers (SiPMs) fabricated on silicon P-type and N-type substrate respectively. Responsivity measurements have been performed with an incident optical power from tenths of picowatts to hundreds of nanowatts and on a broad spectrum, ranging from ultraviolet to near infrared (340-820 nm). For both classes of investigated SiPMs, responsivity shows flat response versus the optical incident power, when a preset overvoltage and wavelength is applied . More in detail, this linear behavior extends up to about 10 nW for lower overvoltages, while a shrink is observed when the reverse b…