Visible Luminescence of Nanoporous Silicon Using Alternating Current Photo-Assisted Electrochemical Etching for Potential MSM Photodetector

2016 ◽  
Vol 846 ◽  
pp. 274-282
Author(s):  
Ainorkhilah Mahmood ◽  
Zainuriah Hassan ◽  
Naser Mahmoud Ahmed ◽  
Ellis Shahiri ◽  
Alhan Farhanah Abd Rahim ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Electrochemical Etching ◽  
Quantum Confinement Effect ◽  
Blue Shift ◽  
Alternating Current ◽  
Sine Wave ◽  
Force Microscopy ◽  
Atomic Force ◽  
Circular Structure ◽  
Msm Photodetector

The formation of nanocrystalline porous silicon (PS) was successfully prepared under a novel alternating current (sine-wave a.c. (50 Hz)) photo-assisted electrochemical (ACPEC) etching condition of an n-type (100) silicon (Si) substrate under the illumination of an incandescent white light. As grown Si and PS through conventional direct current(DC) anodization were also included for comparison. The ACPEC formed porous Silicon (PS) with excellent structural and surface morphological characteristic. According to the field emission scanning electron microscope (FESEM) micrographs, the nanoporous structures exhibited pores with uniform circular structure with estimated sizes, ranging between 20.5 nm and 30.5 nm. The atomic force microscopy (AFM) revealed an increase in the surface roughness induced by porosification. As compared to the as-grown Si, PS by AC method exhibited a substantial visible photoluminescence (PL) intensity enhancement with blue-shift associated with the quantum confinement effect of the nanostructure Si. Thermally treated nickel (Ni) finger contact was deposited on the PS to form MSM photodetector. Ni/PS MSM photodetector showed lower dark and higher photocurrent compared to the as grown Si device.

Quantum Confinement of Integrated Pulse Electrochemical Etching of Porous Silicon for Metal Semiconductor Metal Photodetector

2016 ◽  
Vol 846 ◽  
pp. 245-255 ◽  
Author(s):  
Alhan Farhanah Abd Rahim ◽  
Mohamad Syarizal Abdullah ◽  
Ainorkhilah Mahmood ◽  
Nihad K. Ali ◽  
Musa Mohamed Zahidi
Keyword(s):  
Porous Silicon ◽  
Delay Time ◽  
Quantum Confinement ◽  
Electrochemical Etching ◽  
Quantum Confinement Effect ◽  
Blue Shift ◽  
Pulse Method ◽  
Etching Process ◽  
Metal Semiconductor Metal ◽  
Msm Photodetector

Porous silicon (PS) was successfully synthesized via novel integrated pulsed electrochemical etching of an n-type (100) silicon (Si) substrate under various condition. The PS was etched using hydrofluoric acid (HF) based solution and the porosity was optimized by introducing electroless chemical etching process prior to photo electrochemical (PEC) anodization. In the electroless etching, a delay time (TD) of 2 min was applied. After that a cycle time (T) and pause time () of pulsed current were supplied throughout the 30 min PEC etching process. As grown Si and PS through conventional direct current (DC) anodization were also included for comparison. The result obtained showed that applying delay time helps to improve the uniformity and density of the porous structures. AFM indicated that the roughness of the Si increases as the dissolution of the Si occurred. Raman spectroscopy showed that an improvement in the crystalline quality of PS under pulse etching method compared to DC method indicated by the reduction of full width at half maximum (FWHM). A broad visible photoluminescence (PL) was observed from green to red with blue shift as nanocrystallite size decreases which constituted quantum confinement effect from the PS structures. Nickel (Ni) finger contact was deposited onto the PS to form metal semiconductor metal (MSM) photodetector. Ni/PS MSM photodetector by pulse method exhibited higher gain (2 times) compared to conventional Si device at 5 V bias.

I-V and Surface Topography Study of Nanostructure Porous Silicon Layer Prepared by Electrochemical Etching

2012 ◽  
Vol 576 ◽  
pp. 519-522 ◽  
Author(s):  
Fadzilah Suhaimi Husairi ◽  
Maslihan Ain Zubaidah ◽  
Shamsul Faez M. Yusop ◽  
Rusop Mahmood Mohamad ◽  
Saifolah Abdullah
Keyword(s):  
Electrical Properties ◽  
Porous Silicon ◽  
Surface Topography ◽  
Electrochemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Force Microscopy ◽  
Atomic Force ◽  
Current Voltage ◽  
P Type

This article reports on the electrical properties of porous silicon nanostructures (PSiNs) in term of its surface topography. In this study, the PsiNs samples were prepared by using different current density during the electrochemical etching of p-type silicon wafer. PSiNs has been investigated its electrical properties and resistances for different surface topography of PSiNs via current-voltage (I-V) measurement system (Keithley 2400) while its physical structural properties was investigated by using atomic force microscopy (AFM-XE100).

scholarly journals Study of the Electrical Properties of Porous Silicon Prepared by Electrochemical Etching Technique

2019 ◽  
Vol 54 (5) ◽  
Author(s):  
Warood Kream Alaarage ◽  
Luma Hafedh Abed Oneiza ◽  
Mohanad Ghulam Murad Alzubaidi
Keyword(s):  
Electrical Properties ◽  
Porous Silicon ◽  
Ideality Factor ◽  
Thermal Emission ◽  
Electrochemical Etching ◽  
Point Of View ◽  
Etching Technique ◽  
Force Microscopy ◽  
Atomic Force ◽  
P Type

In our work, a P-type porous silicon (PSi) with orientation (100) have been prepared using the chemical etching method; the goal is to study the electrical properties of PSi samples prepared with completely different etching current (7, 9, 11 and 13) mA and glued for (15 min) anodization time. Depending on the atomic force microscopy (AFM) investigation, we notice the roughness of Si surface increases with increasing etching current because of increases within the dimension (diameter) of surface pits. The electrical and optoelectronic properties of prepared PSi, specifically capacitance-voltage (C-V), current-voltage (I-V), responsivity and detectivity, are analyzed. It had been found that electrical characteristics of porous Si samples measured in dark (Id) and below illumination (IPh) will be fitted well by the equations of thermal emission. From this point of view, Schottky barrier height (ɸB) and ideality factor (n) of made-up photodetectors were calculated. We tended to determine from I-V characteristics of a dark, and illuminations that the pass current through the PSi layer reduced by increasing the etching current, as a result of increasing the electrical resistance of PSi layer and therefore the optimum value of ideality factor is (2.7), whereas from C-V characteristic we determined that in-built potential accumulated with increasing etching current. The results show that there are clear results for better performance of photodetectors.

scholarly journals The Effect of Etching Time On Structural Properties of Porous Quaternary AlInGaN Thin Films

2021 ◽  
Vol 19 (50) ◽  
pp. 77-83
Author(s):  
Ghasaq Ali Tomaa ◽  
Alaa Jabbar Ghazai
Keyword(s):  
Porous Silicon ◽  
Crystal Size ◽  
Electrochemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Etching Time ◽  
Etching Technique ◽  
Force Microscopy ◽  
Atomic Force ◽  
Homogeneous Pattern

Using photo electrochemical etching technique (PEC), porous silicon (PS) layers were produced on n-type silicon (Si) wafers to generate porous silicon for n-type with an orientation of (111) The results of etching time were investigated at: (5,10,15 min). X-ray diffraction experiments revealed differences between the surface of the sample sheet and the synthesized porous silicon. The largest crystal size is (30 nm) and the lowest crystal size is (28.6 nm) The analysis of Atomic Force Microscopy (AFM) and Field Emission Scanning Electron Microscope (FESEM) were used to research the morphology of porous silicon layer. As etching time increased, AFM findings showed that root mean square (RMS) of roughness and porous silicon grain size decreased and FESEM showed a homogeneous pattern and verified the formation of uniform porous silicon.

IMPROVING THE PHOTORESPONSE OF POROUS SILICON FOR SOLAR CELL APPLICATIONS BY EMBEDDING OF CdTe NANOPARTICLES

2017 ◽  
Vol 24 (Supp01) ◽  
pp. 1850012 ◽  
Author(s):  
IBRAHIM R. AGOOL ◽  
AHMED N. ABD ◽  
MOHAMMED O. DAWOOD ◽  
HARITH M. ABD AL-AMEER ◽  
NADIR F. HABUBI ◽  
...  
Keyword(s):  
Solar Cell ◽  
Porous Silicon ◽  
Electrochemical Etching ◽  
Etching Time ◽  
Reverse Bias Voltage ◽  
Tunneling Microscopy ◽  
Laser Ablation In Liquid ◽  
Force Microscopy ◽  
Cdte Nanoparticles ◽  
Atomic Force

The present work is concerned with the preparation of thin films of nanocrystalline porous silicon (PSi) by the method of electrochemical etching. CdTe nanoparticles (NPs) have been prepared by utilizing the pulsed laser ablation in liquid. The measurements of tunneling microscopy, X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FTIR) and atomic force microscopy (AFE) were carried out and revealed that the PSi was nanostructured and the produced CdTe NPs were ball shaped, having good disposability. The diffusion of CdTe NPs on the properties of PSi solar cell assures that there was an improvement upon their properties. The relationship between [Formula: see text] and the reverse bias voltage was observed to be linear. Values of the built-in potential were observed to be dependent on the laser fluence, current density and the etching time.

Study on Photoluminescence of Porous Silicon with Cu Deposition

2011 ◽  
Vol 675-677 ◽  
pp. 1303-1306
Author(s):  
Xiu Hua Chen ◽  
Wen Hui Ma ◽  
Ting Ting Ma ◽  
Xing Hui Wu
Keyword(s):  
Porous Silicon ◽  
Blue Shift ◽  
Peak Position ◽  
Stress Effect ◽  
Force Microscopy ◽  
Chemical Plating ◽  
Surface Stress Effect ◽  
Atomic Force ◽  
Pl Spectrum ◽  
Surface Morphologies

Detailed studies on Photoluminescence (PL) of porous silicon (PS) with copper deposition were presented. PS was prepared via double electrobath, and then copper was deposited on PS surface by chemical plating. Atomic force microscopy (AFM) measurement indicates that there are different surface morphologies of PS samples with hemispherical, mountain, and tubes-like shape in different etching conditions. PL results show that the PL spectrum intensity of PS with Cu post-deposition increases 50% and do not decay after being laid 4 months than that of PS with pre-deposition. And the peak position from the PL spectrum with Cu deposition has a 14nm blue shift due to the surface stress effect of Cu to PS.

scholarly journals Morphology, chemical and electrical properties of CdO Nanoparticles on porous silicon

2019 ◽  
Vol 11 (21) ◽  
pp. 102-107
Author(s):  
Uday Muhsin Nayef
Keyword(s):  
Electrical Properties ◽  
Porous Silicon ◽  
Current Density ◽  
Electrochemical Etching ◽  
Laser Deposition ◽  
Force Microscopy ◽  
Atomic Force ◽  
Depletion Width ◽  
Cdo Nanoparticles ◽  
P Type

In this paper, CdO nanoparticles prepared by pulsed laser deposition techniqueonto a porous silicon (PS) surface prepared by electrochemical etching of p-type silicon wafer with resistivity (1.5-4Ω.cm) in hydrofluoric (HF) acid of 20% concentration. Current density (15 mA/cm2) and etching times (20min). The films were characterized by the measurement of AFM, FTIR spectroscopy and electrical properties.   Atomic Force microscopy confirms the nanometric size.Chemical components during the electrochemical etching show on surface of PSchanges take place in the spectrum of CdO deposited PS when compared to as-anodized PS. The electrical properties of prepared PS; namely current density-voltage characteristics under dark, show that the pass current through the PS layer is more than that obtained from the CdO/PS/Si which is related to increasing junction resistivity that come from increasing in depletion width.

scholarly journals Toxicity of Porous Silicon Nanoparticles on Liver of Mice

2018 ◽  
Vol 28 (3) ◽  
pp. 209
Author(s):  
Kareem H. Jwaid ◽  
Majid S. Jabir ◽  
Uday M. Nayef
Keyword(s):  
Porous Silicon ◽  
Silicon Nanoparticles ◽  
Electrochemical Etching ◽  
Histological Study ◽  
Laboratory Animals ◽  
Force Microscopy ◽  
Atomic Force ◽  
Porous Silicon Nanoparticles ◽  
Liver Parameters ◽  
Microscopy Techniques

Nanoparticles are a special group of materials with unique features and extensive application in diverse fields. The present work demonstrates the toxicity impact of porous silicon nanoparticles (PSNPs) on kidney parameter which is prepared by electrochemical etching method. the synthesis of porous silicon nanoparticles are conformed by using structural and optical properties from through scanning electron microscope and atomic force microscopy techniques. The effect of toxicity of these nanoparticles on the liver parameters in laboratory animals use four groups each groups involve three duplicities was studied. Injected of porous silicon nanoparticles in the intraperitoneal at concentration of 1mg/kg. The results of biochemical assay Aspartate Amino-Transferase (GOT), Alanine Amino-Transferase (GPT), Alkaline Phosphatase (ALP) were compared with the control groups, for four weeks and then confirm a result was made with Histological study for section of liver. Results show no significant differences in levels (GOT, GPT, ALT) among the test groups via comparison with controls groups. This Result indicates no toxic effect of porous silicon nanoparticles' on kidney parameters.

EFFECT OF ETCHING TIME ON OPTICAL AND MORPHOLOGICAL FEATURES OF N-TYPE POROUS SILICON PREPARED BY PHOTO-ELECTROCHEMICAL METHOD

2016 ◽  
Vol 78 (3) ◽  
Author(s):  
Asad A. Thahe ◽  
Noriah Bidin ◽  
Mohammed A. Al-Azawi ◽  
Naser M. Ahmed
Keyword(s):  
Porous Silicon ◽  
Gravimetric Method ◽  
Constant Current ◽  
Etching Time ◽  
Absorption Data ◽  
Time Duration ◽  
Constant Current Density ◽  
Force Microscopy ◽  
Atomic Force ◽  
Structure Properties

Achieving efficient visible photoluminescence from porous-silicon (PSi) is demanding for optoelectronic and solar cells applications. Improving the absorption and emission features of PSi is challenging. Photo-electro-chemical etching assisted formation of PSi layers on n-type (111) silicon (Si) wafers is reported. Samples are prepared at constant current density (~30 mA/cm2) under varying etching times of 10, 15, 20, 25, and 30 min. The influence of etching time duration on the growth morphology and spectral properties are inspected. Room temperature photoluminescence (PL) measurement is performed to determine the optical properties of as-synthesized samples. Sample morphologies are imaged via Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The thickness and porosity of the prepared samples are estimated using the gravimetric method. The emission and absorption data is further used to determine the samples band gap and electronic structure properties. Results and analyzed, interpreted with different mechanisms and compared.  

Growth and Investigation of GaN/AlN Quantum Dots

2000 ◽  
Vol 639 ◽  
Author(s):  
Hadis Morkoç ◽  
Michael A. Reshchikov ◽  
Keith M. Jones ◽  
Feng Yun ◽  
Paolo Visconti ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Blue Shift ◽  
Microscopy Study ◽  
High Quantum Efficiency ◽  
Force Microscopy ◽  
Quantum Size ◽  
Atomic Force ◽  
Layer Structures ◽  
Bulk Gan ◽  
Very High

ABSTRACTWe have fabricated GaN quantum dots (QDs) in AlN confined layer structures by molecular beam epitaxy. The size distribution and density of the QDs have been estimated from an atomic force microscopy study. Very high quantum efficiency of photoluminescence (PL) has been obtained in some samples with QDs. Compared to the GaN bulk samples, it increased by orders of magnitude. In some samples the quantum size effect dominated, resulting in the blue-shift of the QD related PL peak, whereas in the samples with larger dots a red-shift up to 0.8 eV has been observed, which is related to strong polarization effects. We have observed a blue-shift of the PL peak with excitation intensity in the samples with large dots due to screening effect. The temperature-induced quenching of PL occurs at higher temperatures compared to bulk GaN due to the confinement of nonequilibrium carriers in the QDs. An excited state has been observed in some samples.

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