Characterization of Porous Silicon Layers by Reflectance Spectroscopy

1992 ◽  
Vol 283 ◽  
Author(s):  
W. Theiβ ◽  
P. Grosse ◽  
H. Münder ◽  
H. Lüth ◽  
R. Herino ◽  
...  
Keyword(s):  
Optical Properties ◽  
Porous Silicon ◽  
Reflectance Spectroscopy ◽  
Experimental Results ◽  
Porous System ◽  
Optical Reflectance

ABSTRACTThe characterization of porous silicon layers by optical reflectance spectroscopy in the infrared, visible and UV is presented. A fit of simulated to measured spectra is used to interprete the experimental results. We stress that the microgeometry of the porous system determines the optical properties to a large extent and must be taken into account in a correct way in order to achieve reliable results.

Microstructural Characterization of Photoluminescent Porous Silicon

1991 ◽  
Vol 256 ◽  
Author(s):  
J. M. Macaulay ◽  
F. M. Ross ◽  
P. C. Searson ◽  
S. K. Sputz ◽  
R. People ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Optical Properties ◽  
Porous Silicon ◽  
Microstructural Characterization ◽  
Photoluminescence Spectroscopy ◽  
Experimental Results ◽  
Visible Luminescence ◽  
Wide Range ◽  
The Impact

ABSTRACTWe have used electron microscopy to examine the microstructure of porous silicon films over a wide range of doping levels, and photoluminescence spectroscopy to study their optical properties. We discuss the impact of our experimental results on models from the literature which were proposed to explain visible luminescence from porous silicon.

Lattice Relaxation Effects in Si and GaAs Nanocrystals

1994 ◽  
Vol 358 ◽  
Author(s):  
X. S. Zhao ◽  
Y. R. Ge ◽  
J. Schroeder ◽  
P. D. Persans
Keyword(s):  
Gallium Arsenide ◽  
Optical Properties ◽  
Porous Silicon ◽  
Raman Scattering ◽  
Lattice Relaxation ◽  
Experimental Results ◽  
Vibrational Modes ◽  
Strain Effects ◽  
Relaxation Effects ◽  
Almost All

ABSTRACTRaman scattering results on porous silicon, and silicon and gallium arsenide nanocrystals show that almost all vibrational modes become Raman active and remarkably soft in these nanocrystal systems. The experimental results further demonstrate that the carrier-induced strain effects play an important role on the optical properties of such nanocrystal systems.

Characterization of optical properties of Porous Silicon using Photoacoustic Technique

2008 ◽  
Vol 153 (1) ◽  
pp. 199-202 ◽  
Author(s):  
S. Abdallah ◽  
T. A. El-Brolossy ◽  
S. Negm ◽  
H. Talaat
Keyword(s):  
Optical Properties ◽  
Porous Silicon ◽  
Photoacoustic Technique

Reverse engineering of AlxGa1−xAs/GaAs structures composition by reflectance spectroscopy

2011 ◽  
Vol 19 (4) ◽  
Author(s):  
M. Wośko ◽  
B. Paszkiewicz ◽  
K. Tarnowski ◽  
B. Ściana ◽  
D. Radziewicz ◽  
...  
Keyword(s):  
Reverse Engineering ◽  
Reflectance Spectrum ◽  
Reflectance Spectroscopy ◽  
Experimental Results ◽  
Spectral Measurements ◽  
Spectrum Matching ◽  
Non Destructive ◽  
Sensitive Method

AbstractThe paper presents the application of non-modulation reflectance method for composition profiling of epitaxial AlxGa−xAs/GaAs structures. This non-destructive method is based on spectral measurements and theoretical reflectance spectrum matching. This is a very accurate and sensitive method of determining the Al composition in AlxGa1−xAs layers and structures with resolution down to 1 nm. In this work, the authors describe theoretic principles of this method and present experimental results of characterization of different AlGaAs structures to prove the potential of the worked out method.

scholarly journals Impact of thermal oxidation on the structural and optical properties of porous silicon microcavity

2017 ◽  
Vol 7 ◽  
pp. 184798041773570 ◽  
Author(s):  
A A El-Gamal ◽  
Sh M Ibrahim ◽  
M Amin
Keyword(s):  
Optical Properties ◽  
Porous Silicon ◽  
Thermal Oxidation ◽  
Structural Changes ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Resonance Position ◽  
One Dimensional ◽  
Degree Of Oxidation

We report the structural and optical characterization of one-dimensional porous silicon microcavities. These structures are based on a planar resonator formed by two high-reflectance mirrors separated by a thin active optical spacer. In order to simulate and predict the optical properties of the microcavity, the transfer matrix method is used. A strong correlation between the formation parameters and the reflectance spectra is introduced. The prepared microcavities are exposed to thermal oxidation. The resonance position of the microcavity exhibits a blueshift proportional to the degree of oxidation. Structural changes of the microcavities after oxidation are investigated and analyzed using X-ray diffraction and Raman spectroscopy. The observed shift of characteristic silicon peak is attributed to the reduction of silicon crystallites as the oxidation increases.

Preparation and Characterization of Ag Nanoparticles on Porous Silicon for Photo Conversion

2019 ◽  
Vol 50 (3) ◽  
pp. 82-95
Author(s):  
RAFID SABBAR ZAMEL ◽  
BAN KHALID MOHAMMED ◽  
ALAULDEEN SALAH YASEEN ◽  
HAITHAM T. HUSSEIN ◽  
UDAY MUHSIN NAYEF
Keyword(s):  
Porous Silicon ◽  
Ag Nanoparticles

scholarly journals Comparison of ISS–CATS and CALIPSO–CALIOP Characterization of High Clouds in the Tropics

2020 ◽  
Vol 12 (23) ◽  
pp. 3946
Author(s):  
Pasquale Sellitto ◽  
Silvia Bucci ◽  
Bernard Legras
Keyword(s):  
Optical Properties ◽  
Space Station ◽  
Satellite Observation ◽  
Observation Data ◽  
Upper Troposphere ◽  
Cloud Properties ◽  
Synchronous Orbit ◽  
The Tropics ◽  
High Clouds

Clouds in the tropics have an important role in the energy budget, atmospheric circulation, humidity, and composition of the tropical-to-global upper-troposphere–lower-stratosphere. Due to its non-sun-synchronous orbit, the Cloud–Aerosol Transport System (CATS) onboard the International Space Station (ISS) provided novel information on clouds from space in terms of overpass time in the period of 2015–2017. In this paper, we provide a seasonally resolved comparison of CATS characterization of high clouds (between 13 and 18 km altitude) in the tropics with well-established CALIPSO (Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observation) data, both in terms of clouds’ occurrence and cloud optical properties (optical depth). Despite the fact that cloud statistics for CATS and CALIOP are generated using intrinsically different local overpass times, the characterization of high clouds occurrence and optical properties in the tropics with the two instruments is very similar. Observations from CATS underestimate clouds occurrence (up to 80%, at 18 km) and overestimate the occurrence of very thick clouds (up to 100% for optically very thick clouds, at 18 km) at higher altitudes. Thus, the description of stratospheric overshoots with CATS and CALIOP might be different. While this study hints at the consistency of CATS and CALIOP clouds characterizaton, the small differences highlighted in this work should be taken into account when using CATS for estimating cloud properties and their variability in the tropics.

scholarly journals Transparent TiO2/Cu/TiO2 Multilayer for Electrothermal Application

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1024
Author(s):  
Jingjing Peng ◽  
Changshan Hao ◽  
Hongyan Liu ◽  
Yue Yan
Keyword(s):  
Optical Properties ◽  
Heating Rate ◽  
Figure Of Merit ◽  
Annealing Temperature ◽  
Critical Thickness ◽  
Experimental Results ◽  
Tio2 Layer ◽  
Electrical And Optical Properties ◽  
Partial Crystallization

Highly transparent indium-free multilayers of TiO2/Cu/TiO2 were obtained by means of annealing. The effects of Cu thickness and annealing temperature on the electrical and optical properties were investigated. The critical thickness of Cu mid-layer with optimal electrical and optical properties was 10 nm, with the figure of merit reaching as high as 5 × 10−3 Ω−1. Partial crystallization of the TiO2 layer enhanced the electrical and optical properties upon annealing. Electrothermal experiments showed that temperatures of more than 100 °C can be reached at a heating rate of 2 °C/s without any damage to the multilayers. The experimental results indicate that reliable transparent TiO2/Cu/TiO2 multilayers can be used for electrothermal application.

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