Synthesis of calcium monosilicide nanowires by reactive deposition technique

Abstract The CaSi nanowires were synthesized on Si substrate by reactive deposition technique. A great amount of Ca vapor reacted with surface of cleaned Si substrate, and CaSi nanowires was grown on the as-synthesized CaSi film. The diameter of nanowires could achieve with a minimum value about 25 nm. The CaSi nanowire was self-orient along the <001> direction. We can control the length of nanowires by experimental parameter settings, such as quantity of Ca source, duration time and temperature. The formation mechanism of Ca-silicides on Si substrate was discussed in detail. Raman spectroscopy shows that the nanosized character for CaSi phase was confirmed. Meanwhile, the Ca-silicides layer showed a strong absorption in the ultraviolet (UV) region of the solar spectrum, indicating their potential applications.

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The Potential Applications of Raman Spectroscopy in Unravelling Complex Palaeowildfire Ecosystems

10.5194/egusphere-egu21-2626 ◽

2021 ◽

Author(s):

Thomas Theurer ◽

David Muirhead ◽

David Jolley ◽

Dmitri Mauquoy

Keyword(s):

Raman Spectroscopy ◽

Carbonaceous Material ◽

Complex Interactions ◽

Intensity Changes ◽

Potential Applications ◽

Ecosystem Studies ◽

History Of ◽

The Impact ◽

Unique Relationship

<p>Raman spectroscopy represents a novel methodology of characterising plant-fire interactions through geological history, with enormous potential. Applications of Raman spectroscopy to charcoal have shown that this is an effective method of understanding intensity changes across palaeofire regimes. Such analyses have relied on the determination of appropriate Raman parameters, given their relationship with temperature of formation and microstructural changes in reference charcoals. Quantitative assessments of charcoal microstructure have also been successfully applied to the assessment of carbonaceous maturation under alternate thermal regimes, such as pyroclastic volcanism. Palaeowildfire systems in association with volcanism may present a complex history of thermal maturation, given interactions between detrital charcoals and volcanogenic deposition. However, whilst palaeofire and volcanic maturation of carbonaceous material are well understood individually, their interaction has yet to be characterised. Here we present the first analysis of palaeofire charcoals derived from volcanic ignition utilising Raman spectroscopy. Our results indicate that complex interactions between volcanism and palaeofire systems may be better understood by the characterisation of charcoal microstructure, alongside palaeobotanical and ecosystem studies. Understanding the unique relationship between wildfires and volcanism, and the impact that this has on the fossil record, may better assist our understanding of wildfire systems in deep history. Further still, this highlights the potential for better understanding the socioecological impacts of modern and future wildfire systems closely associated with volcanic centres.&#160;</p>

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A study on the formation mechanism of graphite fluorides by Raman spectroscopy

Journal of Fluorine Chemistry ◽

10.1016/s0022-1139(02)00323-8 ◽

2003 ◽

Vol 120 (2) ◽

pp. 143-150 ◽

Cited By ~ 44

Author(s):

Vinay Gupta ◽

Tsuyoshi Nakajima ◽

Yoshimi Ohzawa ◽

Boris Žemva

Keyword(s):

Raman Spectroscopy ◽

Formation Mechanism

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Characterization of layers produced by a reactive deposition technique: An EDAX and ESCA study

Fresenius Zeitschrift für Analytische Chemie ◽

10.1007/bf00469181 ◽

1987 ◽

Vol 329 (2-3) ◽

pp. 400-402

Author(s):

K. Bange ◽

G. Weinberg ◽

S. Krause ◽

K. Horn

Keyword(s):

Deposition Technique ◽

Reactive Deposition

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Ultraviolet Raman spectroscopy for understanding structure and formation mechanism of amyloid fibrils

Vibrational Spectroscopy in Protein Research ◽

10.1016/b978-0-12-818610-7.00014-1 ◽

2020 ◽

pp. 415-434

Author(s):

Joseph Handen ◽

Igor K. Lednev

Keyword(s):

Raman Spectroscopy ◽

Formation Mechanism ◽

Amyloid Fibrils

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Thickness dependence study of multiferroic PbTi 0.5 Fe 0.5 O 3 thin films grown on Si substrate by using pulsed laser deposition technique

Thin Solid Films ◽

10.1016/j.tsf.2017.03.002 ◽

2017 ◽

Vol 628 ◽

pp. 61-67 ◽

Cited By ~ 4

Author(s):

S Nawaz ◽

Snehlata Aggarwal ◽

A A Tulapurkar ◽

V R Palkar

Keyword(s):

Thin Films ◽

Pulsed Laser Deposition ◽

Pulsed Laser ◽

Thickness Dependence ◽

Laser Deposition ◽

Deposition Technique ◽

Si Substrate

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Formation of Al2O3 Film on Si Substrate by Microwave Generated Remote Plasma Assisted Atomic Layer Deposition Technique

ECS Meeting Abstracts ◽

10.1149/ma2010-02/30/1878 ◽

2010 ◽

Keyword(s):

Atomic Layer Deposition ◽

Atomic Layer ◽

Deposition Technique ◽

Si Substrate ◽

Remote Plasma ◽

Al2o3 Film ◽

Layer Deposition ◽

Atomic Layer Deposition Technique

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Solar Spectrum Splitting Parallel Junction High Efficiency Concentrating Photovoltaics

MRS Proceedings ◽

10.1557/opl.2012.690 ◽

2012 ◽

Vol 1391 ◽

Cited By ~ 3

Author(s):

Lirong Z. Broderick ◽

Marco Stefancich ◽

Dario Roncati ◽

Brian R. Albert ◽

Xing Sheng ◽

...

Keyword(s):

Solar Cells ◽

High Efficiency ◽

Linear Array ◽

Low Cost ◽

Spectral Band ◽

Solar Spectrum ◽

Optical Loss ◽

Single Element ◽

Si Substrate ◽

Spectrum Splitting

ABSTRACTA compact, single element concentrator comprising a near linear array of prisms has been designed to simultaneously split and concentrate the solar spectrum. Laterally aligned solar cells with different bandgaps are devised to be fabricated on a common Si substrate, with each cell absorbing a different spectral band optimized for highest overall power conversion efficiency. Epitaxial Ge on Si is used as a low cost virtual substrate for III-V materials growth. Assuming no optical loss for the prism concentrator, no shadowing and perfect carrier collection for the solar cells, simulations show that 39% efficiency can be achieved for a parallel four-junction (4PJ) InGaP-GaAs-Si-Ge cell under 200X concentration, and higher efficiency is possible with more junctions.

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The mechanism of sunlight-mediated inactivation of Bacillus thuringiensis crystals

Biochemical Journal ◽

10.1042/bj2730043 ◽

1991 ◽

Vol 273 (1) ◽

pp. 43-47 ◽

Cited By ~ 61

Author(s):

M Pusztai ◽

P Fast ◽

L Gringorten ◽

H Kaplan ◽

T Lessard ◽

...

Keyword(s):

Raman Spectroscopy ◽

Bacillus Thuringiensis ◽

Time Course ◽

Solar Spectrum ◽

Oxygen Species ◽

Biological Assays ◽

Fermentation Liquor ◽

Crystal Damage ◽

Singlet Oxygen Species ◽

Nm Range

Detailed photostability studies were carried out using purified delta-endotoxin crystals from Bacillus thuringiensis subspecies HD-1 and HD-73. The mechanism and time course of sunlight inactivation was investigated by: (a) monitoring the tryptophan damage in the intact crystals by Raman spectroscopy, (b) amino acid analysis and (c) biological assays using insects. The results demonstrate that, for purified HD-1 or HD-73 crystals, the 300-380 nm range of the solar spectrum is largely responsible for bringing about crystal damage and consequent loss of toxicity. Purified Bacillus thuringiensis crystals that were exposed to fermentation liquor after cell lysis were more quickly degraded by sunlight than were crystals from cells that were lysed in water. This effect is attributed to adsorption of chromophores by crystals exposed to the fermenter liquor and the subsequent ability of these chromophores to act as photosensitizers. The importance of a photosensitization mechanism in crystal degradation was further emphasized by irradiating Bacillus thuringiensis crystals in vacuo. The latter crystals were found to be less damaged (20% tryptophan loss after 24 h irradiation by the solar spectrum) compared with crystals from the same sample irradiated in air (60% (60% tryptophan loss). Other methods of decreasing exposure of the crystals to oxygen, e.g. by using glycerol as a humectant, were also found to be successful in controlling photodamage. The results concerning photodegradation support a photosensitization mechanism involving the presence of exogenous (and possibly endogenous) chromophores which create singlet oxygen species upon irradiation by light.

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