The Structure of Porous Silicon Revealed by Electron Microscopy

1991 ◽  
Vol 256 ◽  
Author(s):  
A. G. Cullis ◽  
L. T. Canham ◽  
O. D. Dosser
Keyword(s):  
Electron Microscopy ◽  
Porous Silicon ◽  
Quantum Wires ◽  
Crystalline Silicon ◽  
High Porosity ◽  
Microporous Material ◽  
Mesoporous Silicon ◽  
Quantum Size ◽  
Transmission Electron ◽  
Silicon Structures

ABSTRACTThis detailed electron microscope study of porous silicon compares the different structures of macro-, meso- and microporous material. Mesoporous silicon of high porosity (∼-80%) exhibits efficient red photoluminescence at room temperature. Transmission electron microscopy provides strong direct evidence that this visible luminescence arises from dramatic carrier confinement in quantum-size, crystalline silicon structures. Images of undulating, interconnected ‘quantum wires’ of widths <3nm are shown.

Structural Properties of Amorphous Silicon Produced by Electron Irradiation

1999 ◽  
Vol 557 ◽  
Author(s):  
J. Yamasaki ◽  
S. Takeda
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Distribution Function ◽  
Structural Properties ◽  
Electron Irradiation ◽  
Low Temperatures ◽  
Crystalline Silicon ◽  
Transmission Electron ◽  
Amorphous Si ◽  
Means Of Transmission

AbstractThe structural properties of the amorphous Si (a-Si), which was created from crystalline silicon by 2 MeV electron irradiation at low temperatures about 25 K, are examined in detail by means of transmission electron microscopy and transmission electron diffraction. The peak positions in the radial distribution function (RDF) of the a-Si correspond well to those of a-Si fabricated by other techniques. The electron-irradiation-induced a-Si returns to crystalline Si after annealing at 550°C.

Nano-Thermometry: Transmission Electron Microscopy of Femtosecond Laser Irradiated Co/Si Multilayer Thin Foils

2005 ◽  
Vol 899 ◽  
Author(s):  
Yoosuf Picard ◽  
Steven M. Yalisove
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Amorphous Silicon ◽  
Heat Dissipation ◽  
Crystalline Silicon ◽  
Pulse Length ◽  
Multilayer Systems ◽  
Hole Edge ◽  
Thin Foils ◽  
Transmission Electron

AbstractPre-thinned foils composed of amorphous silicon and polycrystalline cobalt were irradiated using femtosecond pulse-length lasers at fluences sufficient for ablation (material removal). The resultant ablated hole and surrounding vicinity was studied using transmission electron microscopy to determine modifications to the structure. Evidence of cobalt silicide formation was observed within a 3 micron radius of the laser hole edge by use of selected area electron diffraction (SAED). In addition, elongated grains of crystalline silicon was observed within 500 nm of the laser hole edge, indicating melting of the amorphous silicon and heat dissipation slow enough to allow recyrstallization. This initial work demonstrates the use of pre-designed nanostructured multilayer systems as a method for nanoscale profiling of heat dissipation following pulsed laser irradiation.

scholarly journals Biomass-Derived Activated Carbon as a Catalyst for the Effective Degradation of Rhodamine B dye

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 926
Author(s):  
Shamim Ahmed Hira ◽  
Mohammad Yusuf ◽  
Dicky Annas ◽  
Hu Shi Hui ◽  
Kang Hyun Park
Keyword(s):  
Electron Microscopy ◽  
Activated Carbon ◽  
Rhodamine B ◽  
Photoelectron Spectroscopy ◽  
High Specific Surface Area ◽  
High Porosity ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
X Ray ◽  
Transmission Electron

Activated carbon (AC) was fabricated from carrot waste using ZnCl2 as the activating agent and calcined at 700 °C for 2 h in a tube furnace. The as-synthesized AC was characterized using Fourier-transform infrared spectroscopy, X-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller analysis; the results revealed that it exhibited a high specific surface area and high porosity. Moreover, this material displayed superior catalytic activity for the degradation of toxic Rhodamine B (RhB) dye. Rate constant for the degradation of RhB was ascertained at different experimental conditions. Lastly, we used the Arrhenius equation and determined that the activation energy for the decomposition of RhB using AC was approximately 35.9 kJ mol−1, which was very low. Hopefully it will create a great platform for the degradation of other toxic dye in near future.

THE DEPOSITION AND CONTROL OF SELF ASSEMBLED SILICON NANO ISLANDS ON CRYSTALLINE SILICON

2008 ◽  
Vol 18 (04) ◽  
pp. 901-910
Author(s):  
RAGNAR KIEBACH ◽  
ZHENRUI YU ◽  
MARIANO ACEVES-MIJARES ◽  
DONGCAI BIAN ◽  
JINHUI DU
Keyword(s):  
Electron Microscopy ◽  
Integrated Circuit ◽  
Crystalline Silicon ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
High Density ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
And Control ◽  
Circuit Technology

The formation of nano sized Si structures during the annealing of silicon rich oxide (SRO) films was investigated. These films were synthesized by low pressure chemical vapor deposition (LPCVD) and used as precursors, a post-deposition thermal annealing leads to the formation of Si nano crystals in the SiO 2 matrix and Si nano islands ( Si nI ) at c-Si /SRO interface. The influences of the excess Si concentration, the incorporation of N in the SRO precursors, and the presence of a Si concentration gradient on the Si nI formation were studied. Additionally the influence of pre-deposition substrate surface treatments on the island formation was investigated. Therefore, the substrate surface was mechanical scratched, producing high density of net-like scratches on the surface. Scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) were used to characterize the synthesized nano islands. Results show that above mentioned parameters have significant influences on the Si nIs . High density nanosized Si islands can epitaxially grow from the c-Si substrate. The reported method is very simple and completely compatible with Si integrated circuit technology.

Effect of Au on the Performance of Porous Silicon/V2O5 Nanorods Heterojunctions to NO2 Gas

NANO ◽  
2016 ◽  
Vol 11 (07) ◽  
pp. 1650079 ◽  
Author(s):  
Wenjun Yan ◽  
Ming Hu ◽  
Jiran Liang ◽  
Dengfeng Wang ◽  
Yulong Wei ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Porous Silicon ◽  
Room Temperature ◽  
Au Nanoparticles ◽  
Analytical Techniques ◽  
Heating Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

A novel composite of Au-functionalized porous silicon (PS)/V2O5 nanorods (PS/V2O5:Au) was prepared to detect NO2 gas. PS/V2O5 nanorods were synthesized by a heating process of pure vanadium film on PS, and then the obtained PS/V2O5 nanorods were functionalized with dispersed Au nanoparticles. Various analytical techniques, such as field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), have been employed to investigate the properties of PS/V2O5:Au. Herein, the PS/V2O5:Au sample exhibited improved NO2-sensing performances in response, stability and selectivity at room temperature (25[Formula: see text]C), compared with the pure PS/V2O5 nanorods. These phenomena were closely related to not only the dispersed Au nanoparticles acting as a catalyst but also the p-n heterojunctions between PS and V2O5 nanorods. Whereas, more Au nanoparticles suppressed the improvement of response to NO2 gas.

Transmission Electron Microscopy Investigations of Metal-Impurity-Related Defects in Crystalline Silicon

2011 ◽  
Vol 178-179 ◽  
pp. 275-284 ◽  
Author(s):  
Michael Seibt ◽  
Philipp Saring ◽  
Philipp Hahne ◽  
Linda Stolze ◽  
M.A. Falkenberg ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Focused Ion Beam ◽  
Crystalline Silicon ◽  
Ion Beam ◽  
Extended Defects ◽  
Metal Impurity ◽  
Transmission Electron ◽  
Electron Beam Induced Current

This contribution summarizes recent efforts to apply transmission electron microscopy (TEM) techniques to recombination-active extended defects present in a low density. In order to locate individual defects, electron beam induced current (EBIC) is applied in situ in a focused ion beam (FIB) machine combined with a scanning electron microscope. Using this approach defect densities down to about 10cm-2 are accessible while a target accuracy of better than 50nm is achieved. First applications described here include metal impurity related defects in multicrystalline silicon, recombination and charge collection at NiSi2 platelets, internal gettering of copper by NiSi2 precipitates and site-determination of copper atoms in NiSi2.

Properties of Freestanding Buckypapers with Monodispersion of Multi-Walled Carbon Nanotube Aqueous Solution

2013 ◽  
Vol 765-767 ◽  
pp. 3162-3165 ◽  
Author(s):  
Shao Wei Lu ◽  
Chun Xu Zhang ◽  
Xian Jun Zeng ◽  
Ji Jie Wang ◽  
Peng Nie ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotube ◽  
Volume Density ◽  
High Porosity ◽  
Filtration Method ◽  
Vacuum Filtration ◽  
Carbon Nanotube Dispersion ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotube ◽  
Nanotube Dispersion

The monodispersion situation of Multi-walled carbon nanotube dispersion is vital for fabricating high quality MWCNT buckypapers with vacuum filtration method. In this paper, the MWCNT buckypapers were fabricated by surfactants Triton-X100, sonication, centrifugation, vacuum filtration, rinsing and annealing processes. Transmission electron microscopy (TEM) and Zeta potential results show the maximum achievable separation has been reached. The properties of MWCNTs buckypaper can be characterized by Scanning electron microscopy (SEM), a four-point probe, N2 adsorption isotherm, TGA-DSC methods. The results showed that the buckypaper exhibits a low surface and volume density, a high porosity and electric conductivity. The pore diameter is up to 22.02nm, no substantial mass loss below 600°C in air.

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