Structure and Optical Properties of Porous Silicon Formed on Silicon Substrates Treated with Compression Plasma Flow

2015 ◽  
Vol 245 ◽  
pp. 49-54
Author(s):  
Mikhail Victorovich Bozhenko ◽  
Evgeniy Anatolievich Chusovitin ◽  
Nikolay Gennadievich Galkin ◽  
Evgeny Vladislavovich Pustovalov ◽  
Vladimir Vadimovich Tkachev ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Plasma Flow ◽  
Wavelength Region ◽  
Peak Position ◽  
Silicon Substrates ◽  
Intensity Increase ◽  
Long Wavelength ◽  
Bond Density ◽  
Compression Plasma Flow ◽  
Pl Intensity

Porous silicon layers were formed on the silicon substrates treated with compression plasma flow. Pores density and lateral size on substrates treated with plasma is by 25% more than that on untreated substrates. The intensity of the PL of the PS layers, formed on the plasma treated substrates (PT PS), is twice more than that of the PS layers, formed on untreated substrates. Three month exposure of normal PS and PT PS layers to the air leads to the PL intensity increase by 3 and 5.7 times, respectively, as well as to the peak position shifting towards long wavelength region by 3.1 nm, in the case of PT PS layer. The PL intensity increase is attributable to the reduction of the dangling bond density as a result of passivation by oxygen.

ESR Study of Porous Silicon

1992 ◽  
Vol 283 ◽  
Author(s):  
W. Y. Cheung ◽  
S. P. Wong ◽  
I. H. Wilson ◽  
C. F. Kan ◽  
S. K. Hark
Keyword(s):  
Porous Silicon ◽  
Spin Density ◽  
Light Emission ◽  
Blue Shift ◽  
Esr Spectra ◽  
Peak Position ◽  
Silicon Substrates ◽  
Post Annealing ◽  
G Value ◽  
P Type

ABSTRACTA detailed ESR study has been performed on porous silicon on both <100> and <111> p-type silicon substrates prepared using anodization in HF under a range of conditions and the results are correlated with the light emission properties. It is found that the ESR spectra are dependent upon the orientation of the samples. The ESR defect centers are identified to be the Pb centers or Pbo centers of the Si-SiO2 system from the g-value anisotropy maps. The variation of the spin density Ns with annealing conditions has also been studied for samples annealed either in nitrogen or oxygen ambient at 200°C for various time intervals. It is concluded that the increase or decrease of Ns are due to the generation or elimination of the Pb or Pbo centers in conjunction with the oxidation process during annealing. From PL study of these samples, it is found that there is no simple correlation between the spin density and the PL intensity. However, a blue shift in the PL peak position was observed both in samples after a post-annealing etch in HF solution, and in samples annealed in oxygen without a post-annealing etch. This blue shift supports the quantum confinement model of light emission from porous silicon.

Reversible and Irreversible Light-Induced Change of Photoluminescence in Porous Silicon

1995 ◽  
Vol 378 ◽  
Author(s):  
Suk-Ho Choi ◽  
Byoung-Hun Mun
Keyword(s):  
Fourier Transform ◽  
Porous Silicon ◽  
Room Temperature ◽  
Irreversible Process ◽  
Laser Light ◽  
Light Exposure ◽  
Peak Position ◽  
Continuous Laser ◽  
Ftir Studies ◽  
Pl Intensity

AbstractWe have investigated the light-induced change of photoluminescence(PL) and its recovery in porous silicon. The exposure of the porous silicon to continuous laser light in vacuum results in the quenching of the PL intensity, which is almost fully recovered by simply keeping the samples in vacuum or in air at room temperature for a few days. When the light exposure is done in air, the PL spectra of the samples with initial PL peak at 800 nm are blue-shifted to the peak position at 740 nm and the samples with the initial PL spectrum peaked at 740 nm shows only a rise of PL intensity without any change of its peak position. Fourier transform infrared(FTIR) studies suggest that the light-induced change of PL in air is a irreversible process and occurs as a result of optically induced replacement of some of the Si-H bonds with O-Si-H bonds or adsorption of oxygen with hydrogen loss.

AUSTENITIC STEEL SURFACE ALLOYED WITH ZIRCONIUM USING COMPRESSION PLASMA FLOW

2012 ◽  
Vol 16 (4) ◽  
pp. 297-313 ◽  
Author(s):  
A. H. Sari ◽  
Valiantsin M. Astashynski ◽  
E. A. Kostyukevich ◽  
A. M. Kuzmitski ◽  
V. V. Uglov ◽  
...  
Keyword(s):  
Austenitic Steel ◽  
Plasma Flow ◽  
Steel Surface ◽  
Compression Plasma Flow

Non-linear optical properties of poly(phenylene vinylene) in porous silicon substrates

2005 ◽  
Vol 2 (9) ◽  
pp. 3222-3226 ◽  
Author(s):  
T. P. Nguyen ◽  
P. Le Rendu ◽  
C. Simos ◽  
P. X. Nguyen ◽  
V. Skarka ◽  
...  
Keyword(s):  
Optical Properties ◽  
Porous Silicon ◽  
Phenylene Vinylene ◽  
Silicon Substrates ◽  
Non Linear ◽  
Linear Optical Properties ◽  
Linear Optical

Enzyme immobilisation on planar and porous silicon substrates for biosensor applications

1999 ◽  
Vol 7 (1-4) ◽  
pp. 77-83 ◽  
Author(s):  
M. Thust ◽  
M.J. Schöning ◽  
P. Schroth ◽  
Ü. Malkoc ◽  
C.I. Dicker ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Silicon Substrates ◽  
Enzyme Immobilisation ◽  
Biosensor Applications

Relaxed Germanium on Porous Silicon Substrates

2012 ◽  
Author(s):  
Tobias F. Wietler ◽  
Eddy P. Rugeramigabo ◽  
Eberhard Bugiel ◽  
Enrique Garralaga Rojas
Keyword(s):  
Porous Silicon ◽  
Silicon Substrates

Combining the deep Earth and lithospheric gravity field to study the density structure of the upper mantle

2021 ◽  
Author(s):  
Bart Root ◽  
Javier Fullea ◽  
Jörg Ebbing ◽  
Zdenek Martinec
Keyword(s):  
Gravity Field ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Field Data ◽  
Wavelength Region ◽  
Density Structure ◽  
Long Wavelength ◽  
Global Gravity ◽  
Deep Earth

&lt;p&gt;Global gravity field data obtained by dedicated satellite missions is used to study the density distribution of the lithosphere. Different multi-data joint inversions are using this dataset together with other geophysical data to determine the physical characteristics of the lithosphere. The gravitational signal from the deep Earth is usually removed by high-pass filtering of the model and data, or by appropriately selecting insensitive gravity components in the inversion. However, this will remove any long-wavelength signal inherent to lithosphere. A clear choice on the best-suited approach to remove the sub-lithospheric gravity signal is missing.&amp;#160;&lt;/p&gt;&lt;p&gt;Another alternative is to forward model the gravitational signal of these deep situated mass anomalies and subtract it from the observed data, before the inversion. Global tomography provides shear-wave velocity distribution of the mantle, which can be transformed into density anomalies. There are difficulties in constructing a density model from this data. Tomography relies on regularisation which smoothens the image of the mantle anomalies. Also, the shear-wave anomalies need to be converted to density anomalies, with uncertain conversion factors related to temperature and composition. Understanding the sensitivity of these effects could help determining the interaction of the deep Earth and the lithosphere.&lt;/p&gt;&lt;p&gt;In our study the density anomalies of the mantle, as well as the effect of CMB undulations, are forward modelled into their gravitational potential field, such that they can be subtracted from gravity observations. The reduction in magnitude of the density anomalies due to the regularisation of the global tomography models is taken into account. The long-wavelength region of the density estimates is less affected by the regularisation and can be used to fix the mean conversion factor to transform shear wave velocity to density. We present different modelling approaches to add the remaining dynamic topography effect in lithosphere models. This results in new solutions of the density structure of the lithosphere that both explain seismic observations and gravimetric measurements. The introduction of these dynamic forces is a step forward in understanding how to properly use global gravity field data in joint inversions of lithosphere models.&lt;/p&gt;

Properties of thermal devices and sensors on porous silicon substrates

2012 ◽  
Author(s):  
Frieder Lucklum ◽  
Bernhard Jakoby ◽  
Alexander Schwaiger
Keyword(s):  
Porous Silicon ◽  
Silicon Substrates

scholarly journals UV Spectroscopy of the Novalike Variable TT Arietis

1982 ◽  
Vol 69 ◽  
pp. 453-454
Author(s):  
W. Wargau ◽  
H. Drechsel ◽  
J. Rahe ◽  
G. Klare ◽  
B. Wolf ◽  
...  
Keyword(s):  
Uv Spectroscopy ◽  
Wavelength Region ◽  
Apparent Magnitude ◽  
Long Wavelength ◽  
Dwarf Nova ◽  
Tt Ari ◽  
Visual Brightness

TT Ari was detected by Strohmeier et al. (1957) and is classified as a novalike variable. It was hitherto unclear whether TT Ari is a special type of dwarf nova (Warner, 1976) or an old nova (Cowley et al., 1975). Our group obtained a total of four IUE spectra between 1979 and 1981 in the short and long wavelength region. The first spectrum was taken in July 1979, when the system had a visual brightness of 11.3 magnitudes. The following two IUE observations in November 1980 revealed TT Ari in the lowest optical state (V = 14m.3) observed so far. The fourth spectrum was obtained during the rise to maximum in January 1981, when the system had an apparent magnitude of V = 11m.8. From this behavior, Krautter et al. (1981) concluded that TT Ari is a dwarf nova with extremely extended standstills as they are typical for Z Cam stars.

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