Peculiarity of Porous Silicon Formed in the Transition Regime

1994 ◽  
Vol 358 ◽  
Author(s):  
S. Lazarouk ◽  
V. Chumash ◽  
E. Fazio ◽  
S. La Monica ◽  
G. Maiello ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Large Range ◽  
Anodic Oxide ◽  
Electrochemical Anodization ◽  
Transition Regime ◽  
X Ray Diffraction ◽  
X Ray ◽  
Silicon Suboxide ◽  
Fourier Transform Ir ◽  
P Type

ABSTRACTElectrochemical anodization in the transition regime, between porous silicon formation region and electropolishing region, of monocrystalline silicon was investigated. Using this process bright and stable photoluminescence could be obtained on a very large range of substrate resistivities: p=12-0.005 Ωcm for p-type silicon and p = 20-0.001 Ωcm for n-type substrates.Photoluminescence spectra, Fourier Transform IR (FTIR) absorbance and X-Ray Diffraction (XRD) measurements are reported. Investigations showed that anodic silicon suboxide was formed on the surface. The porous structure obtained in the transition regime is suggested to consist of silicon crystallites built inside an anodic oxide.

Gold nanoclusters reductively deposited on porous silicon: morphology and electronic structures

1998 ◽  
Vol 76 (11) ◽  
pp. 1707-1716 ◽  
Author(s):  
I Coulthard ◽  
S Degen ◽  
Y -J Zhu ◽  
T K Sham
Keyword(s):  
Gold Nanoparticles ◽  
Porous Silicon ◽  
Photoelectron Spectroscopy ◽  
Gold Nanoclusters ◽  
Gold Complex ◽  
X Ray Diffraction ◽  
Complex Ions ◽  
X Ray ◽  
Preparation Conditions ◽  
P Type

Utilizing porous silicon as a reducing agent and a substrate, gold complex ions [AuCl4]- were reduced from aqueous solution to produce nanoparticles of gold upon the surface of porous silicon. Scanning electron microscopy (SEM) was utilized to study the morphology of the porous silicon layers and the deposits of gold nanoparticles. It is found that preparation conditions have a profound effect on the morphology of the deposits, especially on porous silicon prepared from a p-type wafer. The gold nanoparticles, varying from micrometric aggregates of clusters of the order of 10 nm, to a distribution of nearly spherical clusters of the order of 10 nm, to strings of ~10 nm were observed and compared to bulk gold metal using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS). These techniques confirm and complement the SEM findings. The potential for this reductive deposition technique is noted.Key words: gold nanostructures, reductive deposition, porous silicon, morphology, X-ray spectroscopy.

EFFECT OF ETCHING TIME ON THE CHARACTERISTICS OF LOW RESISTIVITY POROUS Si DEVICES

2013 ◽  
Vol 27 (30) ◽  
pp. 1350217 ◽  
Author(s):  
RAID A. ISMAIL
Keyword(s):  
Porous Silicon ◽  
Photoelectron Spectroscopy ◽  
Crystalline Silicon ◽  
Electrochemical Anodization ◽  
Etching Time ◽  
X Ray ◽  
Force Microscopy ◽  
Low Resistivity ◽  
Time Scanning ◽  
P Type

In this paper, we report the effect of etching time on the morphological, structural and electrical properties of porous silicon ( PSi ) synthesized by electrochemical anodization of low resistivity p-type crystalline silicon at current density of 15 mA/cm2. Atomic force microscopy (AFM) measurements showed that the square root of roughness is increased with etching time. Scanning electron microscopy (SEM) investigations revealed that the microstructure of porous silicon is varying with etching time and pores from nano-size to micro-size were formed. Energy dispersive X-ray (EDX) analysis confirmed that the amount of oxygen increases with etching time. Porosity and thickness estimated gravimetrically showed a dependence on the anodization time. The room temperature dark electrical resistivity of porous silicon has observed to be increased with etching time. X-ray photoelectron spectroscopy (XPS) analysis of synthesized porous silicon has shown peaks of C 1s, Si 2p, O 1s, F 1s and N 1s. Current–voltage (I–V) characteristics of synthesized Al / PSi /c -Si junctions prepared at different etching times are investigated and analyzed. The ideality factor, barrier height and built-in potential of porous silicon junctions were strongly found to be dependent on the etching time.

scholarly journals Synthesis of gold nanoparticles by laser ablation on porous silicon for sensing CO2 gas

2018 ◽  
Vol 16 (36) ◽  
pp. 1-10
Author(s):  
Uday Muhsin Nayef
Keyword(s):  
Laser Ablation ◽  
Porous Silicon ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
X Ray Diffraction ◽  
Laser Ablation In Liquid ◽  
Co2 Gas ◽  
X Ray ◽  
P Type ◽  
Si Wafer

In this research, porous silicon (PS) prepared by anodization etching on surface of single crystalline p-type Si wafer, then Gold nanoparticle (AuNPs) prepared by pulsed laser ablation in liquid. NPs deposited on PS layer by drop casting. The morphology of PS, AuNPs and AuNPs/PS samples were examined by AFM. The crystallization of this sample was characterized by X-ray diffraction (XRD). The electrical properties and sensitivity to CO2 gas were investigated to Al/AuNPs/PS/c-Si/Al, we found that AuNPs plays crucial role to enhance this properties.

Structure and non-uniform strain analysis on p-type porous silicon by X-ray reflectometry and X-ray diffraction

1996 ◽  
Vol 276 (1-2) ◽  
pp. 238-240 ◽  
Author(s):  
J.M López-Villegas ◽  
M Navarro ◽  
D Papadimitriou ◽  
J Bassas ◽  
J Samitier
Keyword(s):  
Porous Silicon ◽  
Strain Analysis ◽  
Uniform Strain ◽  
X Ray Diffraction ◽  
X Ray ◽  
P Type

Rapid Thermal Oxidation for Passivation of Porous Silicon

1994 ◽  
Vol 342 ◽  
Author(s):  
I. BÁrsony ◽  
J.G.E. Klappe ◽  
É. Vázsonyi ◽  
T. Lohner ◽  
M. Fried
Keyword(s):  
Porous Silicon ◽  
Mechanical Stability ◽  
Porous Substrate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Tetragonal Lattice ◽  
Optical Heating ◽  
Vertical Inhomogeneity ◽  
Highly Porous

ABSTRACTChemical and mechanical stability of porous silicon layers (PSL) is the prerequisite of any active (luminescent) or passive (e.g. porous substrate) integrated applications. In this work X-ray diffraction (XRD) was used to analyze quantitatively the strain distribution obtained in different morphology PSL that were prepared on (100) p and p+Si substrates. Tetragonal lattice constant distortion can be as high as 1.4% in highly porous “as-prepared” samples. Incoherent optical heating RTO is governed by the absorption in the oxidized specimen. PSL show vertical inhomogeneity according to interpretation of spectroscopic ellipsometry (SE) data. Oxygen incorporation during RTO is controlled by specific surface (in p+ proportional, in p inversely proportional with porosity), while the developing compressive stress depends on pore size, and decreases with porosity in both morphologies.

Properties of Sputter Deposited ZnO Films Co-doped with Lithium and Phosphorus

2013 ◽  
Vol 1494 ◽  
pp. 77-82
Author(s):  
T. N. Oder ◽  
A. Smith ◽  
M. Freeman ◽  
M. McMaster ◽  
B. Cai ◽  
...  
Keyword(s):  
Rf Magnetron Sputtering ◽  
Zno Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sapphire Substrates ◽  
Hall Effect Measurements ◽  
Sputter Deposited ◽  
P Type ◽  
Post Deposition ◽  
Co Doped

ABSTRACTThin films of ZnO co-doped with lithium and phosphorus were deposited on sapphire substrates by RF magnetron sputtering. The films were sequentially deposited from ultra pure ZnO and Li3PO4 solid targets. Post deposition annealing was carried using a rapid thermal processor in O2 and N2 at temperatures ranging from 500 °C to 1000 °C for 3 min. Analyses performed using low temperature photoluminescence spectroscopy measurements reveal luminescence peaks at 3.359, 3.306, 3.245 eV for the co-doped samples. The x-ray diffraction 2θ-scans for all the films showed a single peak at about 34.4° with full width at half maximum of about 0.17°. Hall Effect measurements revealed conductivities that change from p-type to n-type over time.

Study on Phases and Thermoelectric Properties of Bulk Fe4Sb12 and Fe3CoSb12 Prepared by Milling and Sintering

2011 ◽  
Vol 121-126 ◽  
pp. 1526-1529
Author(s):  
Ke Gao Liu ◽  
Jing Li
Keyword(s):  
Thermoelectric Properties ◽  
Impurity Phase ◽  
Semiconductor Materials ◽  
Thermal Constant ◽  
X Ray Diffraction ◽  
X Ray ◽  
Seebeck Coefficients ◽  
Maximum Value ◽  
Type Semiconductor ◽  
P Type

Bulk Fe4Sb12 and Fe3CoSb12 were prepared by sintering at 600 °C. The phases of samples were analyzed by X-ray diffraction and their thermoelectric properties were tested by electric constant instrument and laser thermal constant instrument. Experimental results show that, the major phases of bulk samples are skutterudite with impurity phase FeSb2. The electric resistivities of the samples increase with temperature rising at 100~500 °C. The bulk samples are P-type semiconductor materials. The Seebeck coefficients of the bulk Fe4Sb12 are higher than those of bulk Fe3CoSb12 samples at 100~200 °C but lower at 300~500 °C. The power factor of the bulk Fe4Sb12 samples decreases with temperature rising while that of bulk Fe3CoSb12 samples increases with temperature rising at 100~500 °C. The thermal conductivities of the bulk Fe4Sb12 samples are relatively higher than those of and Fe3CoSb12, which maximum value is up to 0.0974 Wm-1K-1. The ZT value of bulk Fe3CoSb12 increases with temperature rising at 100~500 °C, the maximum value is up to 0.031.The ZT values of the bulk Fe4Sb12 samples are higher than those of bulk Fe3CoSb12 at 100~300 °C while lower at 400~500 °C.

X-ray diffraction studies of porous silicon

1996 ◽  
Vol 276 (1-2) ◽  
pp. 1-6 ◽  
Author(s):  
Daniel Bellet ◽  
Gérard Dolino
Keyword(s):  
Porous Silicon ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Structural Studies of Zno Nanostructures on Porous Silicon: Effect of Post-Annealing Temperature

2018 ◽  
Vol 7 (3.11) ◽  
pp. 48
Author(s):  
Kevin Alvin Eswar ◽  
Mohd Husairi Fadzillah Suhaimi ◽  
Muliyadi Guliling ◽  
Zuraida Khusaimi ◽  
Mohamad Rusop ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Annealing Temperature ◽  
Electrochemical Etching ◽  
Texture Coefficient ◽  
Zno Nanostructures ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Post Annealing ◽  
Post Annealing Temperature

ZnO Nanostructures have been successfully deposited on of Porous silicon (PSi) via wet colloid chemical approach. PSi was prepared by electrochemical etching method. ZnO/PSi thin films were annealed in different temperature in the range of 300 °C to 700 °C. Surface morphology studies were conducted using field emission scanning microscopy (FESEM). Flower-like structures of ZnO were clearly seen at annealing temperature of 500 °C. The X-ray diffraction spectra (XRD) have been used to investigate the structural properties. There are three dominant peaks referred to plane (100), (002) and (101) indicates that ZnO has a polycrystalline hexagonal wurtzite structures. Plane (002) shows the highest intensities at annealing temperature of 500 °C. Based on plane (002) analysis, the sizes were in range of 30.78 nm to 55.18. In addition, it was found that the texture coefficient of plane (002) is stable compared to plane (100) and (101). 

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