Characterization and Modeling of Laser Photothermal Heating of Nanocrystalline Silicon Nanowires in Cells to Explain Experimental Phenomena

2021 ◽  
Vol 125 (40) ◽  
pp. 22111-22119
Author(s):  
William Troy ◽  
Bozhi Tian ◽  
Mitra Dutta ◽  
Michael Stroscio
Keyword(s):  
Silicon Nanowires ◽  
Nanocrystalline Silicon ◽  
Photothermal Heating ◽  
In Cells

Percolation transport and filament formation in nanocrystalline silicon nanowires

2013 ◽  
Vol 113 (16) ◽  
pp. 164902 ◽  
Author(s):  
S. Fischer ◽  
C. Osorio ◽  
N. E. Williams ◽  
S. Ayas ◽  
H. Silva ◽  
...  
Keyword(s):  
Silicon Nanowires ◽  
Nanocrystalline Silicon ◽  
Filament Formation

Microcrystalline and Nanocrystalline Silicon: Simulation of Material Properties

2005 ◽  
Vol 862 ◽  
Author(s):  
R. Biswas ◽  
B. C. Pan ◽  
V. Selvaraj
Keyword(s):  
Silicon Nanowires ◽  
Amorphous Matrix ◽  
Volume Fraction ◽  
Crystalline Silicon ◽  
Amorphous Region ◽  
Nanocrystalline Silicon ◽  
Nano Crystalline ◽  
Crystalline Core ◽  
Silicon Structures ◽  
Dynamics Simulations

AbstractWe have simulated nano-crystalline silicon and microcrystalline silicon structures with varying crystallite volume fractions, using molecular dynamics simulations. The crystallite regions reside in an amorphous matrix. We find the amorphous matrix is better ordered in nanocrystalline-Si than in the homogenous amorphous silicon networks, consistent with the observed higher stability of H-diluted films. There is a critical size above which the crystallites are stable and may grow. Sub-nm size crystallites in the protocrystalline phase are found to reduce the strain of the amorphous matrix. We simulated micro-crystalline silicon with a substantial crystallite volume fraction. Microcrystalline structures exhibit a crystalline core surrounded by an amorphous shell with similarities to silicon nanowires. We find a relatively uniform H distribution in the amorphous region and a crystal-amorphous phase boundary that is not welldefined.

Thermoelectric Properties of p and n-type Nanocrystalline Silicon Nanowires with High Doping Levels

2012 ◽  
Vol 1408 ◽  
Author(s):  
F. Suriano ◽  
M. Ferri ◽  
S. Solmi ◽  
L. Belsito ◽  
A. Roncaglia ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Cross Section ◽  
Thermoelectric Properties ◽  
Silicon Nanowires ◽  
Low Cost ◽  
Nanocrystalline Silicon ◽  
Nanowire Diameter ◽  
Vertical Arrays ◽  
Heavily Doped ◽  
Average Size

ABSTRACTAn experimental investigation about the thermoelectric properties of heavily doped p ad n-type nanocrystalline silicon nanowires (NWs) is described. The NWs are produced with low cost CMOS compatible processes, highly customizable in terms of cross-section and placement, which enables the fabrication of both stacked NWs in nearly vertical arrays within nanostructured templates built with SiO2/Si3N4 thin films and individual, freestanding NWs suited for thermal conductivity measurements. The cross-section dimensions of the investigated NWs range between 30 and 120 nm in size and up to about 2 cm in length. The structure of the NWs, as shown by SEM/TEM observations, is nanocrystalline with average size of the nanocrystals in one dimension that is comparable with the nanowire diameter. On the NWs, Seebeck coefficient, electrical resistivity and thermal conductivity have been measured, yielding thermoelectric figure of merit (ZT) values of 0.2 at 300 K for the best case.

Optical Characterization of Oxide Encapsulated Silicon Nanowires of Various Morphologies

2008 ◽  
Vol 8 (8) ◽  
pp. 4202-4206 ◽  
Author(s):  
Sharon M. King ◽  
Shweta Chaure ◽  
Satheesh Krishnamurthy ◽  
Werner J. Blau ◽  
Alan Colli ◽  
...  
Keyword(s):  
Silicon Nanowires ◽  
Silicon Oxide ◽  
Crystalline Silicon ◽  
Silicon Nanowire ◽  
Visible Spectrum ◽  
Optical Characterization ◽  
Nanocrystalline Silicon ◽  
Oxide Nanowires ◽  
Emitting Species

The optical properties of four different silicon nanowire structures were investigated. Two of the samples consisted of spheres of nanocrystalline silicon en-capsulated by silicon oxide nanowires, with other two consisting of crystalline silicon nanowires coated by silicon oxide shells. The nanostructures produced by oxide assisted growth consisted of spheres of crystalline silicon encapsulated by silicon oxide shells. The absorption and photoluminescence of the different structures of the sample are investigated. The emitting species responsible for photoluminescence across the visible spectrum are discussed.

Numerical Modeling of Electrothermal Effects in Silicon Nanowires

2008 ◽  
Vol 1083 ◽  
Author(s):  
Cicek Boztug ◽  
Gokhan Bakan ◽  
Mustafa Akbulut ◽  
Ali Gokirmak ◽  
Helena Silva
Keyword(s):  
Temperature Profile ◽  
Silicon Nanowires ◽  
Electrical Current ◽  
Nanocrystalline Silicon ◽  
Heat Diffusion ◽  
Small Scale ◽  
Thomson Effect ◽  
Sem Images ◽  
Heat Diffusion Equation ◽  
Electrothermal Effects

AbstractAsymmetric melting was observed in electrically pulsed n-type (phosphorus) nanocrystalline silicon (nc-Si) wires fabricated lithographically. Scanning electron microscope (SEM) images taken from the pulsed wires showed that melting initiates from the ground terminal end of the wires instead of the center as initially expected. Asymmetry in the temperature profile is caused by heat exchanged between charge carriers and phonons when an electrical current is passed along a temperature gradient. This effect is known as Thomson effect, a thermoelectric heat transfer mechanism. One dimensional (1D) time dependent heat diffusion equation including Thomson heat term was solved to model the temperature profile on our structures. The modeling results show that Thomson effect introduces significant shifts in the temperature distribution. The effect of Thomson heat is modeled for various electrical pulse conditions and wires dimensions. Our results indicate that Thomson effect is significant in small scale electronic devices operating under high current densities.

Cytoplasmic Tubules in Cells Infected with Laryngotracheitis Virus

1969 ◽  
Vol 27 ◽  
pp. 376-377
Author(s):  
A. M. Watrach
Keyword(s):  
Tissue Culture ◽  
Small Proportion ◽  
Chicken Embryo ◽  
Culture Cells ◽  
Tissue Culture Cells ◽  
Morphologic Characteristics ◽  
Infectious Laryngotracheitis ◽  
Laryngotracheitis Virus ◽  
In Cells

During a study of the development of infectious laryngotracheitis (LT) virus in tissue culture cells, unusual tubular formations were found in the cytoplasm of a small proportion of the affected cells. It is the purpose of this report to describe the morphologic characteristics of the tubules and to discuss their possible association with the development of virus.The source and maintenance of the strain of LT virus have been described. Prior to this study, the virus was passed several times in chicken embryo kidney (CEK) tissue culture cells.

Effect of Some Metabolic Inhibitors on Vinblastine-Induced Ribosomal-Granular Material Complexes

1971 ◽  
Vol 29 ◽  
pp. 548-549
Author(s):  
Awtar Krishan ◽  
Dora Hsu
Keyword(s):  
Granular Material ◽  
Rna Synthesis ◽  
Culture Medium ◽  
Actinomycin D ◽  
Metabolic Inhibitors ◽  
Protein And Rna Synthesis ◽  
Apparent Reduction ◽  
Plant Alkaloids ◽  
In Cells

Cells exposed to antitumor plant alkaloids, vinblastine and vincristine sulfate have large proteinacious crystals and complexes of ribosomes, helical polyribosomes and electron-dense granular material (ribosomal complexes) in their cytoplasm, Binding of H3-colchicine by the in vivo crystals shows that they contain microtubular proteins. Association of ribosomal complexes with the crystals suggests that these structures may be interrelated.In the present study cultured human leukemic lymphoblasts (CCRF-CEM), were incubated with protein and RNA-synthesis inhibitors, p. fluorophenylalanine, puromycin, cycloheximide or actinomycin-D before the addition of crystal-inducing doses of vinblastine to the culture medium. None of these compounds could completely prevent the formation of the ribosomal complexes or the crystals. However, in cells pre-incubated with puromycin, cycloheximide, or actinomycin-D, a reduction in the number and size of the ribosomal complexes was seen. Large helical polyribosomes were absent in the ribosomal complexes of cells treated with puromycin, while in cells exposed to cycloheximide, there was an apparent reduction in the number of ribosomes associated with the ribosomal complexes (Fig. 2).

Detection of Nucleic Acids in Cells or Tissue Sections Using In situ Polymerase Chain Reaction (PCR)

1996 ◽  
Vol 54 ◽  
pp. 16-17
Author(s):  
J. R. Hully ◽  
K. R. Luehrsen ◽  
K. Aoyagi ◽  
C. Shoemaker ◽  
R. Abramson
Keyword(s):  
Nucleic Acids ◽  
Viral Infections ◽  
Anatomical Location ◽  
Rt Pcr ◽  
Reverse Transcription Pcr ◽  
Cellular Source ◽  
Gene Transcripts ◽  
Initial Description ◽  
In Cells

The development of PCR technology has greatly accelerated medical research at the genetic and molecular levels. Until recently, the inherent sensitivity of this technique has been limited to isolated preparations of nucleic acids which lack or at best have limited morphological information. With the obvious exception of cell lines, traditional PCR or reverse transcription-PCR (RT-PCR) cannot identify the cellular source of the amplified product. In contrast, in situ hybridization (ISH) by definition, defines the anatomical location of a gene and/or it’s product. However, this technique lacks the sensitivity of PCR and cannot routinely detect less than 10 to 20 copies per cell. Consequently, the localization of rare transcripts, latent viral infections, foreign or altered genes cannot be identified by this technique. In situ PCR or in situ RT-PCR is a combination of the two techniques, exploiting the sensitivity of PCR and the anatomical definition provided by ISH. Since it’s initial description considerable advances have been made in the application of in situ PCR, improvements in protocols, and the development of hardware dedicated to in situ PCR using conventional microscope slides. Our understanding of the importance of viral latency or viral burden in regards to HIV, HPV, and KSHV infections has benefited from this technique, enabling detection of single viral copies in cells or tissue otherwise thought to be normal. Clearly, this technique will be useful tool in pathobiology especially carcinogenesis, gene therapy and manipulations, the study of rare gene transcripts, and forensics.

Absence of temporal ordering of apoptotic features in heat-shock treated leukemia and lymphoma cell lines

1996 ◽  
Vol 54 ◽  
pp. 758-759
Author(s):  
D. W. Fairbain ◽  
M.D. Standing ◽  
K.L. O'Neill
Keyword(s):  
Heat Shock ◽  
Cell Lines ◽  
Chromatin Condensation ◽  
Membrane Integrity ◽  
Resistant Cell ◽  
Membrane Blebbing ◽  
Late Loss ◽  
Induced Apoptosis ◽  
Dying Cells ◽  
In Cells

Apoptosis is a genetically defined response to physiological stimuli that results in cellular suicide. Features common to apoptotic cells include chromatin condensation, oligonucleosomal DNA fragmentation, membrane blebbing, nuclear destruction, and late loss of ability to exclude vital dyes. These characteristics contrast markedly from pathological necrosis, in which membrane integrity loss is demonstrated early, and other features of apoptosis, which allow a non-inflammatory removal of dead and dying cells, are absent. Using heat shock-induced apoptosis as a model for examining stress response in cells, we undertook to categorize a variety of human leukemias and lymphomas with regard to their response to heat shock. We were also interested in determining whether a common temporal order was followed in cells dying by apoptosis. In addition, based on our previous results, we investigated whether increasing heat load resulted in increased apoptosis, with particular interest in relatively resistant cell lines, or whether the mode of death changed from apoptosis to necrosis.

Umatilla Virus Association with Fibrils and Tubules in Cultured Cells

1980 ◽  
Vol 38 ◽  
pp. 476-477
Author(s):  
Neil M. Foster ◽  
Ruth D. Breckon
Keyword(s):  
Bluetongue Virus ◽  
Linear Array ◽  
Cultured Cells ◽  
Intimate Association ◽  
Infected Cells ◽  
Dark Staining ◽  
In Cells

Macrotubules have been described1 in cells infected with Umatilla virus (UMAV), an orbivirus for which bluetongue virus (BTV) is the protype. Macrotubules, often in linear array, were observed in the cytoplasm and in intimate association with viroplasms of infected cells. Macrotubules had outside and inside diameters of 20 and 15 nm and many had dark-staining centers with diameters similar to the interiors of the tubules. UMAV was 60 nm and the RNA core was 30 nm in diameter. This report describes the association of UMAV with macrotubules and two types of microtubules.

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