scholarly journals Nanostructures on the ZnSe Surface: Synthesis, Morphological and Photoluminescent Properties

2021 ◽  
Vol 22 (4) ◽  
pp. 614-620
Author(s):  
Y. Suchikova ◽  
A. Lazarenko ◽  
S. Kovachov ◽  
I. Bohdanov
Keyword(s):  
Chemical Analysis ◽  
Oxide Film ◽  
Zinc Selenide ◽  
Pore Formation ◽  
Pore Diameter ◽  
Electrochemical Etching ◽  
Etching Time ◽  
Electrochemical Dissolution ◽  
Surface Porosity ◽  
Two Phases

Nanostructured zinc selenide has been obtained by electrochemical etching with an H2SO4:H2O:H2O5OH=4:1:1 solution used as the electrolyte. The experiment has indicated that the surface consists of two phases, namely the upper layer made up of a dense oxide film and a low-sized porous layer underneath, with a pore diameter of (30-80) nm and a thickness of interporous walls of (15-50) nm. The investigated dependence of surface porosity on the etching time allows us to explain the main stages of the crystal’s electrochemical dissolution during anodizing. The experiment has indicated the presence of three main stages, such as the formation of the Gouy and Helmholtz layers at the semiconductor/electrolyte segregation; pore formation at defect and oxide crystallite locations; spontaneous pore formation. The PL spectra of the samples under study have demonstrated three maxima. The emission band at 2.45 eV is attributable to the presence of oxides, the band at 2.78 EV can be accounted for the corresponding excitons while the band at 2.82 eV stems from quantum-dimensional effects. Chemical analysis of the samples has also indicated the presence of oxides on the surface of the nanostructure.

Structural and Morphological Properties of Nano Photonic Silicon Structure for Photonics Applications

2020 ◽  
Vol 398 ◽  
pp. 29-33 ◽  
Author(s):  
Mariam M. Hassan ◽  
Makram A. Fakhri ◽  
Salah Aldeen Adnan
Keyword(s):  
Porous Silicon ◽  
Surface Morphology ◽  
Pore Diameter ◽  
Electrochemical Etching ◽  
Morphological Properties ◽  
Etching Time ◽  
Silicon Structure ◽  
Si Substrate ◽  
Etching Technique ◽  
Structure Surface

Porous silicon (n-PS) with diverse morphologies was prepared on silicon (Si) substrate via photo-electrochemical etching technique. We studies the structure, surface morphology, pore diameter, roughness, based on (XRD), (AFM), (SEM) at different etching time (5, 10 min) and current (10mA/cm2).

scholarly journals Effect of photo chemical etching and electro chemical etching on the topography of porous silicon wafers surfaces

2019 ◽  
Vol 24 (4) ◽  
pp. 52
Author(s):  
Amjad Hussein Jassem
Keyword(s):  
Porous Silicon ◽  
Layer Thickness ◽  
Porous Layer ◽  
Chemical Etching ◽  
Chemical Method ◽  
Pore Diameter ◽  
Electrochemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Etching Time

In This research we study the effect of photo chemical etching and electrochemical etching on topography of porous silicon surfaces, the results showed that photo chemical etching produced roughness silicon layer which can have thickness be less of porous silicon layer which is produced by electro chemical etching When all the wafers have same etching time  and hydrofluoric solution (HF) concentration, the wafers have same resistance (10 Ω.cm). Also the results showed the roughness of porous silicon layers produced  by  electro chemical method which is bigger than the roughness of porous silicon layers produced by photo chemical method and the results of roughness of porous silicon layers, Pore diameter and porous layer thickness were produced by electro chemical method (1.55(µm) ((0.99(µm)) and ((1.21(µm) respectively), the results of roughness of porous silicon layers, Pore diameter and porous layer thickness were produced by photo chemical method 0.63)) nm -1.55)) (µm) ),so the (84.9 (nm)- and (3.94(nm) respectively . This is reinforces because of using the electro chemical to etching the wafer surf ace of bulk silicon and changing it to roughness silicon surface  be share in success of many practicalities.   http://dx.doi.org/10.25130/tjps.24.2019.072

Current Automatic Control Technology for n-Type Macroporous Silicon Photo-Electrochemical Etching

2013 ◽  
Vol 423-426 ◽  
pp. 113-116
Author(s):  
Xiao Na Li ◽  
Guo Zheng Wang ◽  
Feng Yuan Yu ◽  
Yao Zhang ◽  
Yong Zhao Liang ◽  
...  
Keyword(s):  
Control System ◽  
Automatic Control ◽  
Automatic Control System ◽  
Current Density ◽  
Pore Diameter ◽  
Electrochemical Etching ◽  
Etching Time ◽  
Control Technology ◽  
Macroporous Silicon ◽  
The Relationship

The relationship between the etching current density and the macropore diameter was studied in the macroporous silicon (MPS) photo-electrochemical (PEC) etching. By measuring the depth of the channel with different etching time, the variation of critical current density with time was calculated. The importance to real-time adjust the etching current was discussed in the etching process. Based on the PSoC chip, an automatic control system for etching current was designed. The MPS growth was realized with the pore diameter constant using the automatic control system for etching current with a pre-set curve of etching current versus time.

scholarly journals Synthesis and Fabrication of In2O3: CdO Nanoparticles for NO2 Gas Sensor

2018 ◽  
Vol 15 (3) ◽  
pp. 292-299
Author(s):  
Baghdad Science Journal
Keyword(s):  
Gas Sensor ◽  
Pore Diameter ◽  
Electrochemical Etching ◽  
Morphological Characteristics ◽  
Etching Time ◽  
Gas Sensitivity ◽  
Average Pore ◽  
No2 Gas Sensor ◽  
Cdo Nanoparticles ◽  
Si Wafer

The physical and morphological characteristics of porous silicon (PS) synthesized via gas sensor was assessed by electrochemical etching for a Si wafer in diluted HF acid in water (1:4) at different etching times and different currents. The morphology for PS wafers by AFM show that the average pore diameter varies from 48.63 to 72.54 nm with increasing etching time from 5 to 15min and from 72.54 to 51.37nm with increasing current from 10 to 30 mA. From the study, it was found that the gas sensitivity of In2O3: CdO semiconductor, against NO2 gas, directly correlated to the nanoparticles size, and its sensitivity increases with increasing operating temperature.

Surface Effects on Alloys Drilled by Electrochemical are Machining

1986 ◽  
Vol 200 (4) ◽  
pp. 237-246 ◽  
Author(s):  
A de Silva ◽  
J A McGeough
Keyword(s):  
Oxide Film ◽  
Smooth Surface ◽  
Surface Characteristics ◽  
Pulsed Power ◽  
Low Alloy Steels ◽  
Electrochemical Dissolution ◽  
Electro Discharge Machining ◽  
Water Based ◽  
Alloy Steels ◽  
Side Gap

Electrochemical arc machining (ECAM) utilizes pulsed power in an electrolyte, in order to remove metal by combined electro-discharge erosion (EDE) and electrochemical dissolution (ECD). In drilling by this technique, EDE occurs at the frontal gap between the cathode-tool and anode-workpiece; in the side gap, ECD is predominant. Machining rates are much greater than those of electrochemical (ECM) and electro-discharge machining (EDM). This paper is concerned with an investigation of the effects of EDE and ECD on the surface integrity of a range of alloys of industrial interest, drilled by ECAM. Chrome, cobalt and low-alloy steels and nickel-based (nimonic) alloys all exhibited a smooth surface finish typical of that found with ECM, for most of the length of the drilled hole, except at the exit. There, metallurgical damage due to EDE was apparent. The surface characteristics with titanium were typical of those found in EDM, with virtually no evidence of ECM action. This effect was attributed to the presence of a tenacious oxide film formed on titanium in water-based electrolytes which effectively blocks ECM.

scholarly journals Fabrication of (ZnO)x: (Cu)1-x/PSi Solar Cell Using Laser Induced Plasma Technique

2021 ◽  
Vol 2114 (1) ◽  
pp. 012028
Author(s):  
G. H. Jihad ◽  
K.A. Aadim
Keyword(s):  
Solar Cell ◽  
Electrical Properties ◽  
Current Density ◽  
Electrochemical Etching ◽  
Average Diameter ◽  
Etching Process ◽  
Morphological Properties ◽  
Etching Time ◽  
Solar Cell Performance ◽  
Cell Efficiency

Abstract Fabrication of PSi is generated successfully depending upon photo-electrochemical etching process. The purpose is to differentiate the characterization of the PSi monolayer based on c-silicon solar cell compared to the bulk silicon alone. The surface of ordinary p-n solar cell has been reconstructed on the n-type region of (100) orientation with resistivity (3.2.cm) in hydrofluoric (HF) acid at a concentration of 2 ml was used to in order to enhance the conversion efficiency with 10-minute etching time and current density of 50 mA/cm2, The morphological properties (AFM) as well as the electrical properties have been investigated (J-V). The atomic force microscopy investigation reveals a rugged silicon surface with porous structure nucleating during the etching process (etching time), resulting in an expansion in depth and an average diameter of (40.1 nm). As a result, the surface roughness increases. The electrical properties of prepared PS, namely current density-voltage characteristics in the dark, reveal that porous silicon has a sponge-like structure and that the pore diameter increases with increasing etching current density and the number of shots increasing this led that the solar cell efficiency was in the range of (1-2%), resulting in improved solar cell performance.

scholarly journals Experimental Study on the Evolution Law of Mesofissure in Full Tailing Cemented Backfill

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Yufan Feng ◽  
Guanghua Sun ◽  
Xuejian Liang ◽  
Chenyang Liu ◽  
Yue Wang
Keyword(s):  
Mechanical Properties ◽  
Pore Diameter ◽  
Failure Process ◽  
Hole Diameter ◽  
Fracture Density ◽  
Surface Porosity ◽  
Characteristic Parameters ◽  
Average Pore ◽  
Cemented Backfill ◽  
Lower Structure

To understand the mechanical properties of the backfill, to reveal the evolvement of micromechanical fissure of backfill, a uniaxial compression experiment was carried out for the full tailing cemented backfill. After loading, the microstructure of the specimens was observed by microscope and the pore characteristic parameters were analyzed. The results showed that the diameter of the initial damage hole of the backfill was mostly between 0 and 40 μm, the hole diameter increases gradually with the increase of pressure, and the hole diameter reached more than 5000 μm in the postpeak damage stage. The upper structure of the backfill specimen is compact while the lower structure is relatively loose. The cracks and interfaces between tailings particles and cement paste are mechanical weak surfaces, where the cracks are mainly generated and propagated. The tip of microfractures in the backfill is damaged by the influence of stress concentration. In the failure process, both surface porosity and fracture density decrease first and then increase, and the average pore diameter increases gradually. The results have guiding significance for the study of backfill mechanical properties and goaf filling design.

In Situ Observation of an Electrochemical Etching Reaction in Silicon

1995 ◽  
Vol 404 ◽  
Author(s):  
Frances M. Ross ◽  
Peter C. Searson
Keyword(s):  
Pore Formation ◽  
Electrochemical Etching ◽  
Ex Situ ◽  
In Situ Observation ◽  
Specimen Holder

AbstractWe describe a TEM specimen holder which has been designed and constructed in order to observe the process of electrochemical pore formation in silicon. The holder incorporates electrical feedthroughs and a sealed reservoir for the electrolyte and it accepts lithographically patterned silicon specimens. We present ex situ observations of progressive pore propagation and show dynamic, in situ observations of electrolyte movement within the pores.

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