The Influence of Electrochemical Anodization for Porous Silicon Microcavity Fabrication

2013 ◽  
Vol 275-277 ◽  
pp. 1960-1963
Author(s):  
Hong Yan Zhang ◽  
Xiao Yi Lv ◽  
Zhen Hong Jia
Keyword(s):  
Porous Silicon ◽  
Stop Band ◽  
Interface Layer ◽  
Electrochemical Process ◽  
Electrochemical Anodization ◽  
Resonant Peak ◽  
Chemical Dissolution ◽  
Full Width ◽  
Number Of Layers

The present work reports the electrochemical anodization for porous silicon microcavity (PSM) fabrication, including the number of layers and electrochemical process effect in the optical response quality of PSM. These PSMs have been obtained by using PS technology. It is found that the electrochemical process limits the maximum number of layers because there is a chemical dissolution effect during electrochemical anodization. The reflectance spectra of the PSMs indicates that stop-band and the resonant peak of the PSM shift down with the increases of the number of layers due to the decrease of layer's thickness. The value of the full width at half maximum (FWHM) dependents on the number of layers, and the number of layer increases when the FWHM decreases, which is due to the light scattering at roughness interface layer.

Correlation between Structural and Morphological Properties of multilayer perovskite ZnTiO3 coated porous silicon

2021 ◽  
Author(s):  
Hammedi khadija ◽  
Marouan Khalifa ◽  
M. Consuelo Alvarez –Galvan ◽  
Ezzaouia Hatem
Keyword(s):  
Porous Silicon ◽  
Hexagonal Phase ◽  
Sol Gel ◽  
Electrochemical Anodization ◽  
Spherical Particles ◽  
Morphological Properties ◽  
Sem Image ◽  
Number Of Layers ◽  
Average Grain Size ◽  
P Type

This work reports on correlation between structural and morphological properties of ZnTiO3/ porous silicon (PS). The PS were elaborated by electrochemical anodization from the single-crystal p-type silicon wafer. Nanocrystalline ZnTiO3 thin films have been prepared on PS using sol-gel spin coating technique. The deposited films were annealed in air at 800 °C for two hours. The structural, and morphological properties of the films were studied for different number of layers. X-ray diffraction spectra confirms that ZnTiO3 films were hexagonal phase and the crystallite size of ZnTiO3 films increased from 120.56 nm to 125.45nm when the number of layers increase from 4 to 8 layers. SEM image shows approximate semi-spherical particles with a little agglomeration for all samples. The morphologies changed and the average grain size changed and increase from 81nm to 131nm.

scholarly journals Electrochemical removal of pyrite scale using green formulations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Musa Ahmed ◽  
Ibnelwaleed A. Hussein ◽  
Abdulmujeeb T. Onawole ◽  
Mohammed A. Saad ◽  
Mazen Khaled
Keyword(s):  
Hydrogen Sulfide ◽  
Current Density ◽  
Iron Sulfide ◽  
Chelating Agent ◽  
Electrical Current ◽  
Electrochemical Process ◽  
Chemical Dissolution ◽  
Hydrocarbon Production ◽  
Rotational Rate ◽  
Diethylenetriamine Pentaacetic Acid

AbstractPyrite scale formation is a critical problem in the hydrocarbon production industry; it affects the flow of hydrocarbon within the reservoir and the surface facilities. Treatments with inorganic acids, such as HCl, results in generation toxic hydrogen sulfide, high corrosion rates, and low dissolving power. In this work, the dissolution of pyrite scale is enhanced by the introduction of electrical current to aid the chemical dissolution. The electrolytes used in this study are chemical formulations mainly composed of diethylenetriamine-pentaacetic acid–potassium (DTPAK5) with potassium carbonate; diethylenetriamine pentaacetic acid sodium-based (DTPANa5), and l-glutamic acid-N, N-diacetic acid (GLDA). DTPA and GLDA have shown some ability to dissolve iron sulfide without generating hydrogen sulfide. The effect of these chemical formulations, disc rotational rate and current density on the electro-assisted dissolution of pyrite are investigated using Galvanostatic experiments at room temperature. The total iron dissolved of pyrite using the electrochemical process is more than 400 times higher than the chemical dissolution using the same chelating agent-based formulation and under the same conditions. The dissolution rate increased by 12-folds with the increase of current density from 5 to 50 mA/cm2. Acid and neutral formulations had better dissolution capacities than basic ones. In addition, doubling the rotational rate did not yield a significant increase in electro-assisted pyrite scale dissolution. XPS analysis confirmed the electrochemical dissolution is mainly due to oxidation of Fe2+ on pyrite surface lattice to Fe3+. The results obtained in this study suggest that electro-assisted dissolution is a promising technique for scale removal.

INFLUENCE OF THE LATTICE MISMATCH ON THE PHOTOLUMINESCENCE BAND-TAIL PARAMETER IN InGaAsP/InP HETEROSTRUCTURES

2001 ◽  
Vol 15 (17n19) ◽  
pp. 708-711
Author(s):  
A. IRIBARREN
Keyword(s):  
Linear Dependence ◽  
Lattice Mismatch ◽  
Semiconductor Heterostructures ◽  
Full Width ◽  
Half Maximum ◽  
Photoluminescence Spectra ◽  
Band Tail ◽  
Photoluminescence Band ◽  
Grown Layer

The compositional inhomogeneities in semiconductor heterostructures leads to diminishing the quality of the grown layer which reflects in the shape of the rocking curves, where the full width at half maximum (FWHM) of the peaks is larger. Consequently, the quality of the layers characterized by an increase of the disorder also reflects in the band-tail parameter ( E 0) of the photoluminescence spectra. A linear dependence of the FWHM with the lattice mismatch (Δa) was found. The dependence of E 0 as a function of FWHM are presented. It was found that E 0 keep constant up to Δ a / a ≅ 0.15% and FWHM ≅ 50" from where it begins to increase.

Depositing Metals into Porous Silicon - the Impact on Luminescence

1994 ◽  
Vol 358 ◽  
Author(s):  
P. Steiner ◽  
F. Kozlowski ◽  
W. Lang
Keyword(s):  
Porous Silicon ◽  
Porous Layer ◽  
Electron Microprobe ◽  
Uv Light ◽  
Electrochemical Process ◽  
Photoluminescence Intensity ◽  
Spectral Position ◽  
Metal Atoms ◽  
Metal Treatment ◽  
The Impact

ABSTRACTIndium, tin, antimony and aluminum are deposited by an electrochemical process into the pores of n-type porous silicon which is anodized with ultraviolet light applied during formation. The presence of these metal atoms in the porous layer is checked by electron microprobe measurement. As reported previously, UV-light etched material shows red photoluminescence (630 nm) and blue electroluminescence (470 nm) without the metal treatment. After metal deposition the photoluminescence intensity decreases slightly (factor 0.5 - 0.8), whereas the spectral position remains constant. The electroluminescence efficiency is significantly enhanced by indium, aluminum and tin in the pores (factor 5 - 90). The tin and antimony treatment causes a red shift to 580 nm and 740 nm, respectively. The conductivity is slightly increased by all kinds of metals by a factor 2-5.

The Effect of Modified Crucible Design and Seed Attachment on SiC Crystal Grown by PVT

2013 ◽  
Vol 740-742 ◽  
pp. 77-80
Author(s):  
Jung Young Jung ◽  
Sang Il Lee ◽  
Mi Seon Park ◽  
Doe Hyung Lee ◽  
Hee Tae Lee ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Temperature Gradient ◽  
Single Crystals ◽  
Crystal Quality ◽  
Full Width ◽  
Half Maximum ◽  
Radial Temperature Gradient ◽  
Radial Temperature ◽  
Better Than

The present research was focused to investigate the effect of internal crucible design that influenced the 4H-SiC crystal growth onto a 6H-SiC seed by PVT method. The crucible design was modified to produce a uniform radial temperature gradient in the growth cell. The seed attachment was also modified with a use of polycrystalline SiC plate. The crystal quality of 4H-SiC single crystals grown in modified crucible and grown with modified seed attachment was revealed to be better than that of crystal grown in conventional crucible. The full width at half maximum (FWHM) values of grown SiC crystals in the conventional crucible, the modified seed attachment and the modified crucible were 285 arcsec, 134 arcsec and 128 arcsec, respectively. The micropipe density (MPD) of grown SiC crystals in the conventional crucible, the modified seed attachment and the modified crucible were 101ea/cm^2, 81ea/cm^2 and 42ea/cm^2, respectively.

Sensing mechanism analysis on one-dimensional photonic crystal with air slot-porous silicon-air slot F–P cavity

2019 ◽  
Vol 33 (13) ◽  
pp. 1950159 ◽  
Author(s):  
Ying Chen ◽  
Xinbei Gao ◽  
Pei Luo ◽  
Yangmei Xu ◽  
Jinggang Cao ◽  
...  
Keyword(s):  
Refractive Index ◽  
Photonic Crystal ◽  
Porous Silicon ◽  
Structural Parameters ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Resonant Peak ◽  
Mechanism Analysis ◽  
Q Value ◽  
Quality Factor Q

Based on the evanescent wave resonance, a photonic crystal sensing structure with air slot-porous silicon-air slot Fabry–Perot cavity (F–P cavity) is proposed. Taking the F–P cavity as the sensing unit, when the gas to be detected is filled into the sensing unit, the refractive index of the air slot will be changed and the refractive index of the porous silicon layer will also be varied, both of which will shift the resonant peak and greatly increase the sensitivity of the sensor. By adjusting the structural parameters, the quality factor (Q value) can be optimized. A model for the relationship between the resonant wavelength and the refractive index of the detected organic gas was established, and the refractive index sensing performance was analyzed. The results show that the Q value of the structure can attain to 12312.2 and the sensitivity is about 8661.708 nm/RIU, which can provide effective theoretical reference and technical guidance for organic gas detection with low concentration.

Influence of Etching Time on Surface Structural Properties of p- and n- Type Porous Silicon Nanostructures by Photo-Electrochemical Anodic Etching

2012 ◽  
Vol 576 ◽  
pp. 511-515
Author(s):  
N.A. Asli ◽  
Maslihan Ain Zubaidah ◽  
S.F.M. Yusop ◽  
Khairunnadim Ahmad Sekak ◽  
Mohammad Rusop ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Crystalline Silicon ◽  
Surface Characteristic ◽  
Electrochemical Anodization ◽  
Silicon Nanostructures ◽  
Etching Time ◽  
Force Microscopy ◽  
Etching Parameters ◽  
P Type ◽  
Substrate Doping

Porous silicon nanostructures (PSiN) are nanoporous materials which consist of uniform network of interconnected pore. The structure of PSiN is depending on etching parameters, including current density, HF electrolyte concentration, substrate doping type and level. In this work, the results of a structural p-type and n-type of porous silicon nanostructures were investigated by Field Emission Scanning Electron Microscopy (FESEM) and Atomic Force Microscopy (AFM) is reported. Samples were prepared by photo-electrochemical anodization of p- and n-type crystalline silicon in HF electrolyte at different etching time. The surface morphology of PSiN was studied by FESEM with same magnification shown n-type surface form crack faster than p-type of PSiN. While the topography and roughness of PSiN was characterize by AFM. From topography shown the different etching time for both type PSiN produce different porosity and roughness respectively. There is good agreement between p- and n-type have different in terms of surface characteristic.

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