Search results for "Silicon"

Enhancing silicon solar cell efficiency with metal nanoparticles

2009

Cheap sensor made of multicrystalline silicon for insolation and temperature measurements

2016

In the paper some results on measurement of insolation and „real” cell’s temperature carried out with use of standard silicon solar cells are presented. Two identical cells are applied in such a sensor. Short circuit current of one cell is a direct indication of insolation value and open circuit voltage of the other cell is indirect indication of actual sensor’s temperature but in this case more complex formula must be used for temperature calculation.

Optical quality of hyperopic and myopic phakic intraocular lenses

2013

Aims: To assess and compare the optical quality of the myopic and hyperopic implantable collamer lens (ICL) from its wavefront aberrations for different powers and pupil diameters. Settings and Design: Prospective study. Material and Methods: The wavefront aberrations of two myopic (−3 and −6 diopters (D)) and two hyperopic V4b ICLs (+3 and +6D) were measured in vitro . To assess and compare the optical quality of different powers of ICLs, we analyzed the root mean square (RMS) of total higher order aberrations (HOAs), trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration at 3- and 4.5-mm pupil. In addition, the point spread functions (PSFs) of each ICL evaluated were ca…

Photoluminescence and Electron Spin Resonance of Silicon Dioxide Crystal with Rutile Structure (Stishovite)

2018

This work was supported by ERANET MYND. Also, financial support provided by Scientific Research Project for Students and Young Researchers Nr. SJZ/2017/2 realized at the Institute of Solid State Physics, University of Latvia is greatly acknowledged. The authors express our gratitude to R.I. Mashkovtsev for help in ESR signal interpretation. The authors are appreciative to T.I. Dyuzheva, L.M. Lityagina, N.A. Bendeliani for stishovite single crystals and to K. Hubner and H.-J. Fitting for stishovite powder of Barringer Meteor Crater.

Facile synthesis of a monolith of silicon nanocrystal embedded in silica

2013

Unifying Concepts for Ion-Induced Leakage Current Degradation in Silicon Carbide Schottky Power Diodes

2020

The onset of ion-induced reverse leakage current in SiC Schottky diodes is shown to depend on material properties, ion LET, and bias during irradiation, but not the voltage rating of the parts. This is demonstrated experimentally for devices from multiple manufacturers with voltage ratings from 600 V to 1700 V. Using a device with a higher breakdown voltage than required in the application does not provide increased robustness related to leakage current degradation, compared to using a device with a lower voltage rating. peerReviewed

Formation of Si/SiO2 Luminescent Quantum Dots From Mesoporous Silicon by Sodium Tetraborate/Citric Acid Oxidation Treatment

2019

We propose a rapid, one-pot method to generate photoluminescent (PL) mesoporous silicon nanoparticles (PSiNPs). Typically, mesoporous silicon (meso-PSi) films, obtained by electrochemical etching of monocrystalline silicon substrates, do not display strong PL because the silicon nanocrystals (nc-Si) in the skeleton are generally too large to display quantum confinement effects. Here we describe an improved approach to form photoluminescent PSiNPs from meso-PSi by partial oxidation in aqueous sodium borate (borax) solutions. The borax solution acts to simultaneously oxidize the nc-Si surface and to partially dissolve the oxide product. This results in reduction of the size of the nc-Si core …

Simulation studies of electronic transport in a-Si:H thin film solar cells

2009

The thin film solar cells in Hydrogenated Amorphous Silicon (a-Si:H) are attractive for cheaper production and used in ultra low cost, high volume applications but have a relatively lower electronic performance. These limitations are mainly due to properties of the a-Si:H and relies on the production technique. In this study we investigate the physical mechanisms which are on the basis of the electronic transport and their relation with the technological processes. The transport-simulation computer program ATLAS (Silvaco) has been used to examine the role of the mid gap defect density in determining the performance of a-Si:H p-i-n homojunction solar cell.

Properties of SnO2:F/p-type aSi:H interface in thin film a-Si:H solar cells

2011

Luminescent Silicon nanocrystals produced by ns pulsed laser ablation

2013

The reduction of Si down to nanoscale introduces a peculiar visible luminescence, surprisingly for a not highly emissive material. This feature is relevant in connection with several application fields (optoelectronics, medicine) and has lead the research towards the development of production methods successful to control the physical and chemical properties of the nanosized Si so as to enhance and tune the luminescence. To this purpose, the laser ablation in liquids is particularly promising since it provides effective controlling parameters (laser photon energy, fluence, repetition rate, liquid reactivity) for the morphology and the structure of Si-related products. Here we report a study…