Porosification Analysis on the Effect of Resistivity Dependence on N-Type Pulsed Porous Silicon

2020 ◽  
Vol 301 ◽  
pp. 12-17
Author(s):  
Nurul Hanida Abd Wahab ◽  
Alhan Farhanah Abd Rahim ◽  
Ainorkhilah Mahmood ◽  
Noorezal Atfyinna Mohammed Napiah ◽  
Rosfariza Radzali ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Surface Morphology ◽  
Direct Current ◽  
Current Density ◽  
Cycle Time ◽  
Pulse Generator ◽  
Pulse Current ◽  
Etching Process ◽  
Homogeneous Structure ◽  
Photoelectrochemical Etching

A set of n-type porous silicon (PS) layers were fabricated by photoelectrochemical etching using direct current (DC) and pulse current (PC) techniques. The study aims to compare the effect of different resistivity (5 Ω and 10 Ω) on the formation of the PS structure. The samples were etched in a solution of HF:C2H6O with a composition ratio of 1:4. The etching process were done for 30 minutes with the current density of J = 10 mA/cm2. In the time of PC etching process, the current was supplied through a pulse generator with 14 ms cycle time (T) which the on time (Ton) set to 10 ms and pause time (Toff) set to 4 ms respectively. The samples were then being characterized in terms of surface morphology by using FESEM, AFM and XRD. Through the FESEM results, it can be seen that sample with 10 Ω resistivity which using PC form a more homogeneous structure of pores as compared to other samples.

Electrodeposition process and composition of Zn-Cr alloy coatings

2018 ◽  
Vol 23 (2) ◽  
pp. 3-10
Author(s):  
Ewa Osuchowska ◽  
Zofia Buczko ◽  
Klaudia Olkowicz
Keyword(s):  
Surface Morphology ◽  
Current Efficiency ◽  
Direct Current ◽  
Current Density ◽  
Pulse Current ◽  
Electrodeposition Process ◽  
Cr Content ◽  
Zinc Coatings ◽  
Deposition Current Density

In the present work, the electrodeposition process of Zn-Cr alloy coatings under the conditions of direct and pulse current was discussed. Changes in the Cr content in the obtained alloy coatings, current efficiency of the process, surface morphology, structure and microhardness as a function of chromium(III) concentration in the bath to deposition, current density (direct and pulse) and solution mixing were determined. Surface morphology, structure and hardness of the obtained coatings were investigated. The Zn-Cr alloy coatings of good quality contained up to 0.25 %Cr (for direct current) and up to 9% Cr (for pulse current). The tested Zn-Cr alloy coatings obtained under pulse current conditions showed higher microhardness than the Zn-Cr coatings obtained under direct current conditions and than zinc coatings.

scholarly journals Zn-Cr Alloy Coatings: Electrodeposition and Properties

2021 ◽  
Vol 51 (1) ◽  
pp. 29-42
Author(s):  
Ewa Osuchowska ◽  
Zofia Buczko ◽  
Klaudia Olkowicz
Keyword(s):  
Surface Morphology ◽  
Direct Current ◽  
Current Density ◽  
Pulse Current ◽  
Pulsed Current ◽  
Electrodeposition Process ◽  
Cr Content ◽  
Deposition Parameters ◽  
Zinc Coatings ◽  
Deposition Conditions

Abstract The electrodeposition process of Zn-Cr alloy coatings under the conditions of direct and pulsed current is discussed. The Cr content in the obtained alloy coatings, the current efficiency of the process, surface morphology, structure and wettability as a function of deposition parameters, such as current density, were determined. The Zn-Cr alloy coatings of good quality contained up to 20 wt.% Cr (for direct current) and up to 9 wt.% Cr (for pulse current). All the obtained coatings had a structure typical of zinc coatings (h.c.p.) and had a hydrophobic character. The morphology of the coatings changed significantly under the influence of changes in deposition conditions.

scholarly journals The study of Zn–Co alloy coatings electrochemically deposited by pulse current

2012 ◽  
Vol 66 (5) ◽  
pp. 749-757 ◽  
Author(s):  
Jelena Bajat ◽  
Miodrag Maksimovic ◽  
Milorad Tomic ◽  
Miomir Pavlovic
Keyword(s):  
Surface Roughness ◽  
Current Efficiency ◽  
Direct Current ◽  
Current Density ◽  
Pulse Current ◽  
Pulse Plating ◽  
Cathodic Current ◽  
Average Current Density ◽  
Corrosion Stability ◽  
Average Current

The electrochemical deposition by pulse current of Zn-Co alloy coatings on steel was examined, with the aim to find out whether pulse plating could produce alloys that could offer a better corrosion protection. The influence of on-time and the average current density on the cathodic current efficiency, coating morphology, surface roughness and corrosion stability in 3% NaCl was examined. At the same Ton/Toff ratio the current efficiency was insignificantly smaller for deposition at higher average current density. It was shown that, depending on the on-time, pulse plating could produce more homogenous alloy coatings with finer morphology, as compared to deposits obtained by direct current. The surface roughness was the greatest for Zn-Co alloy coatings deposited with direct current, as compared with alloy coatings deposited with pulse current, for both examined average current densities. It was also shown that Zn-Co alloy coatings deposited by pulse current could increase the corrosion stability of Zn-Co alloy coatings on steel. Namely, alloy coatings deposited with pulse current showed higher corrosion stability, as compared with alloy coatings deposited with direct current, for almost all examined cathodic times, Ton. Alloy coatings deposited at higher average current density showed greater corrosion stability as compared with coatings deposited by pulse current at smaller average current density. It was shown that deposits obtained with pulse current and cathodic time of 10 ms had the poorest corrosion stability, for both investigated average deposition current density. Among all investigated alloy coatings the highest corrosion stability was obtained for Zn-Co alloy coatings deposited with pulsed current at higher average current density (jav = 4 A dm-2).

Electroplating of Gold-Tin Solder for Optoelectronic Applications

1998 ◽  
Vol 515 ◽  
Author(s):  
Wenzhen Sun ◽  
Douglas G. Ivey
Keyword(s):  
Direct Current ◽  
Current Density ◽  
Chloride Solution ◽  
Lower Cost ◽  
Pulse Current ◽  
Research Interest ◽  
Composition Control ◽  
Optoelectronic Packaging ◽  
Buffering Agent ◽  
Bath Stability

ABSTRACTAu-Sn eutectic solder is widely used in optoelectronic packaging. Electroplating of Au-Sn alloys is attracting increasing research interest because of its lower cost and potential to minimize voiding in bonding layers. The challenge in developing a non-cyanide Au-Sn electroplating bath lies in bath stability and deposit composition control. In this paper a relatively stable electroplating bath is developed based on a chloride solution using citrate as a buffering agent. Direct current plating and pulse current plating are performed and compared. The effects of Au and Sn concentrations in the bath, current density, and ON time on deposit composition and microstructures are also studied.

Technology on Ni-ZrO2-CeO2 Nanocomposites by Pulse Electroforming in an Ultrasonic Field

2013 ◽  
Vol 579-580 ◽  
pp. 138-143
Author(s):  
Yang Yang Xu ◽  
Yu Jun Xue ◽  
Ji Shun Li ◽  
Yi Liu ◽  
Fang Yang
Keyword(s):  
Surface Morphology ◽  
Current Density ◽  
Pulse Current ◽  
Ultrasonic Field ◽  
Double Pulse ◽  
Duty Ratio ◽  
Positive Duty ◽  
Average Current Density ◽  
Average Current ◽  
Positive Frequency

Ni-ZrO2-CeO2 nanocomposites were prepared by double-pulse current in an ultrasonic field. The effect of average current density, duty ratio and frequency of double-pulse current on nanoparticles content of Ni-ZrO2-CeO2 nanocomposites was studied. Meanwhile, surface morphology and microhardness of nanocomposites were analyzed. The results show that, with the positive average current density, positive duty ratio and positive frequency increased, the nanoparticles contents increased at first and then decreased. On the contrary, it reduced while reverse average current density, reverse duty ratio and reverse frequency were increasing. Compared with Ni-ZrO2-CeO2 prepared by direct current and monopulse current, grain of Ni-ZrO2-CeO2 nanocomposite prepared by double-pulse current is finer, the microhardness is also higher.

Preparation of Zn-ZrO2 Nanocomposite Coating by DC and Pulsed Current Electrodeposition Technique with Low Current Density

2015 ◽  
Vol 827 ◽  
pp. 332-337
Author(s):  
Asep Ridwan Setiawan ◽  
Marsetio Noorprajuda ◽  
Aditianto Ramelan ◽  
Rochim Suratman
Keyword(s):  
Surface Morphology ◽  
Current Density ◽  
Erosion Resistance ◽  
Pulse Current ◽  
Copper Substrate ◽  
Nanocomposite Coating ◽  
Nanocomposite Coatings ◽  
Phase Identification ◽  
Pulsed Current ◽  
Electrodeposition Technique

In the present work, Zn-ZrO2 nanocomposite coatings were deposited on the copper substrate through DC and pulse electrodeposition technique with low current density (10 mA/cm2). The effect addition of ZrO2 nanoparticles and pulse current were studied. The surface morphology, microhardness and erosion resistance of Zn-ZrO2 nanocomposite coating were evaluated. The result shows that, with the addition of ZrO2 particles, the surface morphology of Zn-ZrO2 nanocomposite coating was smoother. Phase identification by XRD confirm that Zn layer had been sucessfully deposited. The presence of ZrO2 nanoparticles was not detected. Compared to DC, pulsed current electrodeposition technique showed higher cathodic efficiency, better microhardness and good erosion resistance.

Basic properties of anodized porous silicon formed under uniform current density

1994 ◽  
Vol 77 (4) ◽  
pp. 97-105
Author(s):  
Hidekazu Aoyagi ◽  
Akira Motohashi ◽  
Akira Kinoshita ◽  
Tomoyoshi Aono ◽  
Akinobu Satoh
Keyword(s):  
Porous Silicon ◽  
Current Density ◽  
Basic Properties ◽  
Uniform Current

Effects of Two-Step DC Electrochemical Pretreatment of Fine Grinding WC-Co Tool Surface on Morphology and Quality of Diamond Coatings

2011 ◽  
Vol 337 ◽  
pp. 59-62
Author(s):  
Xiang Hui Zhang ◽  
Ling Wang ◽  
Jian Ping Long
Keyword(s):  
Surface Morphology ◽  
Direct Current ◽  
Arc Discharge ◽  
Etching Time ◽  
Diamond Coating ◽  
Diamond Coatings ◽  
Fine Grinding ◽  
Electrolytic Etching ◽  
Electrochemical Pretreatment

In the present investigation, diamond coating was deposited on fine grinding cemented carbide substrate by direct current arc discharge chemical vapor deposition. The effect of electrolytic etching time in the two-step electrochemical pretreatment process (firstly using electrolytic etching, and then using acid etching) on morphology and quality of the diamond coating were systemically studied. The surface morphology feature and quality of diamond coatings were characterized by means of Scanning Electron Microscope (SEM), laser Raman spectrometer respectively. The results showed that the electrolytic etching duration has distinctly effect on the quality and crystal features such as morphology, crystal type and grain size of diamond coating. It showed that as electrolytic current is direct current 3A, electrolytic etching time altering from 0.5 min to 7.5min, the surface morphology of diamond films gradually transition from microcrystalline cubic-octahedron to cauliflower type nanocluster, and further increase the electrolytic etching time, will lead to several negative effects on the quality and nucleation of the coatings which is not only retard the diamond nucleation, but also promote the formation of graphite.

Study on Electrodeposition of Ni-Graphite Composite Coatings in Sulfamate Bath

2010 ◽  
Vol 150-151 ◽  
pp. 1546-1550 ◽  
Author(s):  
Xiang Zhu He ◽  
Xiao Wei Zhang ◽  
Xin Li Zhou ◽  
Zhi Hong Fu
Keyword(s):  
Surface Morphology ◽  
Process Parameters ◽  
Current Density ◽  
Graphite Particle ◽  
Particle Concentration ◽  
Composite Coatings ◽  
Nickel Matrix ◽  
Graphite Composite ◽  
Surface Morphologies ◽  
Sulfamate Bath

This paper presented the composite coatings of nickel with graphite particle on the aluminum substrate using a nickel sulfamate bath. Effects of graphite particle concentration on the surface morphologies of the composite coatings were investigated. The inclusion of graphite particle into metal deposits was dependent on many process parameters, including particle concentration, current density, pH and temperature. Results of SEM and XRD demonstrated that graphite particle had successfully deposited on that nickel matrix; besides, the surface morphology of coatings obtained from sulfamate bath containing 2g/L graphite particle dispersed more uniformly than the ones with higher concentration.

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