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silicon-nanoparticles
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Formation of Silicon Nanoparticles From Porous Silicon for LED Application
, M.Sc. Thesis Sharif University of Technology ; Taghavinia, Nima (Supervisor)
Abstract
Semiconductor nanocrystals act as a good luminescent layer in new coming electroluminescence devices. Research on luminescent devices based on nanocrystals such as silicon nanoparticles, has been progressed over the last decades. In this research, silicon nanoparticles have been synthesized from porous silicon layer that was created through an electrochemical process. The effective luminescent parameters like electrolyte contents, current density and reaction time have been investigated. The maximum luminescence has been captured when the current density and reaction time were adjusted at 30 and 20 min, respectively. In addition, volume ratio Ethanol:HF 14:8 was another modified...
Nanofluid flooding in a randomized heterogeneous porous media and investigating the effect of capillary pressure and diffusion on oil recovery factor
, Article Journal of Molecular Liquids ; Volume 320 , December , 2020 ; Esfandeh, S ; Hosseinizadeh, E ; Sharif University of Technology
Elsevier B.V
2020
Abstract
In the initial recovery stage, only 5 to 15% of hydrocarbons can be extracted from oil reservoirs, so it is necessary to supply energy from an external reservoir or to use advanced solutions to increase oil recovery. By using secondary recovery method and flooding, greater amount of oil can be extracted. In this study, a new procedure of flooding using nanofluid was simulated. The nanofluid and source rock were modeled as a single phase and heterogeneous porous media, respectively. The geometry was considered as a two-dimensional rectangular area. Two phase Darcy equations and mass transfer equations were utilized to simulate this process. Moreover, the effects of different volume fractions...
Efficiency improvement of solar stills through wettability alteration of the condensation surface: An experimental study
, Article Applied Energy ; Volume 268 , 2020 ; Soltani Goharrizi, A ; Ayatollahi, S ; Feilizadeh, M ; Dashti, H ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
The condensation process is of great importance in many heat transfer devices in which a large amount of energy must be transferred. Furthermore, condensation is a crucial part of energy conversion and affects the energy efficiency of thermal desalination plants and solar stills. During the condensation process in solar stills, an essential part of the energy is transferred through the condensation surface to produce fresh water. Therefore, the condensation surface plays a significant role in the working efficiency of solar stills. The wettability of the condensation surface influences the condensation mechanism, which, in turn, affects the efficiency of solar stills. This study aims to...
Oxidation effects on transport characteristics of nanoscale MOS capacitors with an embedded layer of silicon nanocrystals obtained by low energy ion implantation
, Article Materials Science and Engineering B: Solid-State Materials for Advanced Technology ; Volume 124-125, Issue SUPPL , 2005 , Pages 494-498 ; 09215107 (ISSN) ; Shalchian, M ; Benassayag, G ; Coffin, H ; Bonafos, C ; Schamm, S ; Atarodi, S. M ; Claverie, A ; Sharif University of Technology
2005
Abstract
In this paper, we have studied the effect of annealing under slightly oxidizing ambient (N2 + O2) on the structural and electrical characteristics of a limited number of silicon nanoparticles embedded in an ultra-thin SiO2 layer. These nanoparticles were synthesized by ultra-low energy (1 keV) ion implantation and annealing. Material characterization techniques including transmission electron microscopy (TEM), Fresnel imaging and spatially resolved electron energy loss spectroscopy (EELS) have been used to evaluate the effects of oxidation on structural characteristics of nanocrystal layer. Electrical transport characteristics have been measured on less than one hundred nanoparticles by...
Electrical properties of nanocontacts on silicon nanoparticles embedded in thin SiO2 synthesized by ultralow energy ion implantation
, Article Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures ; Volume 23, Issue 6 , 2005 , Pages 2821-2824 ; 10711023 (ISSN) ; Shalchian, M ; Coffin, H ; Claverie, A ; Grisolia, J ; Dumas, C ; Atarodi, S. M ; Sharif University of Technology
2005
Abstract
In this paper, we present the room temperature current-voltage characteristics of large (100×100 μ m2) and a nanoscale (100×100 nm2) metal-oxide-semiconductor (MOS) capacitor containing few silicon nanocrystals. The layer of silicon crystals is synthesized within the oxide of this capacitor by ultralow energy ion implantation and annealing. Current fluctuations in the form of discrete current steps and sharp peaks are apparent in the static and dynamic I (V) characteristics of the capacitor. These features have been associated to quantized charging and discharging of the nanoparticles and the resulting Coulomb interaction to the tunneling current. © 2005 American Vacuum Society
Room-temperature quantum effect in silicon nanoparticles obtained by low-energy ion implantation and embedded in a nanometer scale capacitor
, Article Applied Physics Letters ; Volume 86, Issue 16 , 2005 , Pages 1-3 ; 00036951 (ISSN) ; Grisolia, J ; Assayag, G. B ; Coffin, H ; Atarodi, S. M ; Claverie, A ; Sharif University of Technology
2005
Abstract
In this article, we present the room-temperature current-voltage characteristics of a nanometer scale (100×100 nm2) metal-oxide-semiconductor capacitor containing few (less than 100) silicon nanoparticles. The layer of silicon nanoparticles is synthesized within the oxide of this capacitor by ultra low-energy ion implantation and annealing. Current fluctuations in the form of discrete current steps and sharp peaks appeared in the static and dynamic I (V) characteristics of the capacitor. These features have been associated to quantized charging and discharging of the nanoparticles and the resulting Coulomb interaction to the tunneling current. © 2005 American Institute of Physics
Evolution of quantum electronic features with the size of silicon nanoparticles embedded in a sio2 layer obtained by low energy ion implantation
, Article 11th International Autumn Meeting on Gettering and Defect Engineering in Semiconductor Technology, GADEST 2005, 25 September 2005 through 30 September 2005 ; Volume 108-109 , 2005 , Pages 71-76 ; 10120394 (ISSN); 9783908451136 (ISBN) ; Shalchian, M ; Benassayag, G ; Coffin, H ; Bonafos, C ; Dumas, C ; Atarodi, S. M ; Claverie, A ; Pichaud B ; Claverie A ; Alquier D ; Richter H ; Kittler M ; Richter H ; Kittler M ; Sharif University of Technology
Trans Tech Publications Ltd
2005
Abstract
In this paper, we have studied the evolution of quantum electronic features with the size of silicon nanoparticles embedded in an ultra-thin SiO2 layer. These nanoparticles were synthesized by ultralow energy (1 KeV) ion implantation and annealing. Their size was modified using the effect of annealing under slightly oxidizing ambient (N2+O2). Material characterization techniques including transmission electron microscopy (TEM) Fresnel imaging and spatially resolved electron energy loss spectroscopy (EELS) have been used to evaluate the effects of oxidation on structural characteristics of nanocrystal layer. Electrical transport characteristics have been measured on few (less than two...