Visible Luminescence from Porous Silicon and Siloxene: Recent Results

1992 ◽  
Vol 283 ◽  
Author(s):  
H. D. Fuchs ◽  
M. Rosenbauer ◽  
M. S. Brandt ◽  
S. Ernst ◽  
S. Finkbeiner ◽  
...  
Keyword(s):  
Optical Properties ◽  
Magnetic Resonance ◽  
Porous Silicon ◽  
Time Dependent ◽  
Photoluminescence Excitation ◽  
Porous Si ◽  
Green Luminescence ◽  
Visible Luminescence ◽  
Optically Detected ◽  
Insight Into

ABSTRACTThe optical properties of porous Si (p-Si) are compared to those of siloxene and its derivatives in order to gain more insight into the mechanism of the luminescence observed in p-Si. We report new results of photoluminescence (PL), photoluminescence excitation (PLE), time-dependent and pressure-dependent photoluminescence, and optically detected magnetic resonance (ODMR). Important information about the structural, electronic, and microscopic nature of the two classes of materials are deduced from these experiments. Annealed siloxene and p-Si show very similar properties, suggesting that siloxene-related structures, e.g. electrically isolated Si6-rings, might be responsible for the luminescence in p-Si. The Si-planes in as-prepared siloxene, with their green luminescence, are metastable and are readily oxidized into red-luminescent siloxene configurations.

Two-Dimensional Excitons in Siloxene

1993 ◽  
Vol 298 ◽  
Author(s):  
M. S. Brandt ◽  
M. Rosenbauer ◽  
M. Stutzmann
Keyword(s):  
Magnetic Resonance ◽  
Porous Silicon ◽  
Dipolar Coupling ◽  
Luminescence Properties ◽  
Two Dimensional ◽  
Photoluminescence Excitation ◽  
Luminescence Process ◽  
Optically Detected ◽  
Gaussian Line ◽  
Triplet Excitons

AbstractThe luminescence properties of two different modifications of siloxene are studied with photoluminescence excitation spectroscopy (PLE) und optically detected magnetic resonance (ODMR). The luminescence of as prepared siloxene, which consists of isolated silicon planes, is resonantly excited at the bandgap, indicating a direct bandstructure. The observation of Δm = ±2 transitions in ODMR shows that triplet excitons contribute to the luminescence process. In contrast, annealed siloxene consisting primarily of six-membered silicon rings shows a PLE typical of a material with an indirect bandgap. The ODMR signal of annealed siloxene and of porous silicon show the same Gaussian line with a typical width of 400 G, which can arise from strong dipolar coupling of an electron and a hole ≈ 5Å apart.

Optically Detected Magnetic Resonance and Double Beam Photoluminescence of CdS/HgS/CdS Nanoparticles

1998 ◽  
Vol 536 ◽  
Author(s):  
H. Porteanu ◽  
A. Glozman ◽  
E. Lifshitz ◽  
A. Eychmüller ◽  
H. Weller
Keyword(s):  
Optical Properties ◽  
Magnetic Resonance ◽  
Cds Nanoparticles ◽  
Electron Hole ◽  
Cladding Layer ◽  
Double Beam ◽  
Optically Detected Magnetic Resonance ◽  
Optically Detected ◽  
Cladding Layers ◽  
Hole Recombination

AbstractCdS/HgS/CdS nanoparticles consist of a CdS core, epitaxially covered by one or two monolayers of HgS and additional cladding layers of CdS. The present paper describes our efforts to identify the influence of CdS/HgS/CdS interfaces on the localization of the photogenerated carriers deduced from the magneto-optical properties of the materials. These were investigated by the utilization of optically detected magnetic resonance (ODMR) and double-beam photoluminescence spectroscopy. A photoluminescence (PL) spectrum of the studied material, consists of a dominant exciton located at the HgS layer, and additional non-excitonic band, presumably corresponding to the recombination of trapped carriers at the interface. The latter band can be attenuated using an additional red excitation. The ODMR measurements show the existence of two kinds of electron-hole recombination. These electron-hole pairs maybe trapped either at a twin packing of a CdS/HgS interface, or at an edge dislocation of an epitaxial HgS or a CdS cladding layer.

Optical Properties of Microcrystalline Silicon in Oxide Matrix through Partial Oxidation of Anodized Porous Silicon

1991 ◽  
Vol 256 ◽  
Author(s):  
Toshimichi Ito ◽  
Toshimichi Ohta ◽  
Osamu Arakaki ◽  
Akio Hiraki
Keyword(s):  
Optical Properties ◽  
Porous Silicon ◽  
Partial Oxidation ◽  
Silicon Oxide ◽  
Light Emission ◽  
Wavelength Region ◽  
Microcrystalline Silicon ◽  
Quantum Size ◽  
Visible Luminescence ◽  
Oxide Matrix

ABSTRACTMicrocrystalline silicon embedded in silicon oxide has been prepared by means of partial oxidation of porous silicon produced anodically from degenerate p-Si wafers. Their optical properties such as absorption coefficients and luminescence have been characterized. Results show blue shifts in absorption and photoluminescence spectra in a visible wavelength region with decreasing size of the microcrystalline Si in the Si oxide matrix. The quantum size effect is discussed as well as possible origins of the observed visible luminescence, including light emission from as-anodized (or H-chemisorbed) porous silicon.

Insight into the Spin Properties in Undoped and Mn-Doped CdSe/CdS-Seeded Nanorods by Optically Detected Magnetic Resonance

ACS Nano ◽  
2020 ◽  
Vol 14 (10) ◽  
pp. 13478-13490 ◽  
Author(s):  
Joanna Dehnel ◽  
Yahel Barak ◽  
Itay Meir ◽  
Adam K. Budniak ◽  
Anjani P. Nagvenkar ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Optically Detected Magnetic Resonance ◽  
Spin Properties ◽  
Optically Detected ◽  
Mn Doped ◽  
Insight Into

Optical Properties of Deuterium Terminated Porous Silicon

1996 ◽  
Vol 452 ◽  
Author(s):  
Takahiro Matsumoto ◽  
Yasuaki Masumoto ◽  
Nobuyoshi Koshida
Keyword(s):  
Optical Properties ◽  
Absorption Spectrum ◽  
Porous Silicon ◽  
Photoluminescence Spectrum ◽  
Porous Si ◽  
Surface Vibration ◽  
Quantum Confined

AbstractWe have studied the optical properties of deuterium-terminated porous silicon. The photoluminescence spectrum was different from that of usual hydrogen-terminated porous Si despite porous Si showing both the same structure and the same absorption spectrum. These results indicate that the surface vibration of terminated atoms couples to the quantum confined states.

Photoluminescence Excitation Spectroscopy (PLE) of Porous Silicon

1991 ◽  
Vol 256 ◽  
Author(s):  
Lei Wang ◽  
M. T. Wilson ◽  
M. S. Goorsky ◽  
N. M. Haegel
Keyword(s):  
Porous Silicon ◽  
Absorption Coefficient ◽  
Strong Increase ◽  
Photoluminescence Excitation ◽  
Porous Si ◽  
Absorption Data ◽  
Direct Bandgap ◽  
Alternative Method ◽  
Thin Samples

ABSTRACTPLE spectroscopy was performed on samples of porous Si at temperatures of 300 and 4.2 K. PLE provides information about the absorption coefficient in the limit of optically thin samples and is an alternative method for determining absorption data on porous Si without removal of the substrate. The spectra obtained correspond closely to the relative changes in absorption coefficient for bulk Si between 2.0 and 3.5 eV, with a strong increase above 3.0 eV which is due to the direct bandgap transition.

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.

CONTINUOUS-WAVE PHOTOLUMINESCENCE AND NANOSTRUCTURAL PROPERTIES OF POROUS SILICON

2009 ◽  
Vol 08 (03) ◽  
pp. 311-318
Author(s):  
ADWAN Al-AJILI
Keyword(s):  
Electron Microscopy ◽  
Porous Silicon ◽  
Continuous Wave ◽  
Structural Information ◽  
Photoluminescence Excitation ◽  
Porous Si ◽  
X Ray ◽  
Diffraction Patterns ◽  
Silicon Based ◽  
X Ray Absorption

The photoluminescence (PL) emitted by porous silicon has been investigated by using the continuous tuneable UV Synchrotron Radiation Source. One sample was investigated for orange PL emission wavelength at temperatures 77–295 K. The PL peak is found to shift to higher frequency with decreasing temperature. Information about the nanostructure of porous silicon has been determined from PL and Extended X-ray Absorption Fine Structure (EXAFS), as well as from electron microscopy. In particular, the optical properties of silicon-based nanostructured materials, obtained from PL and photoluminescence excitation measurements, have been correlated with structural information from Si –K-edge EXAFS. Electron microscopy was used to study the relation between the nanostructure and PL of porous Si , and to investigate porous Si structure. Platelet Si and Si crystallites in porous Si layers were observed. The size of crystallites ranged from 4 to 6.5 nm. Diffraction patterns show these porous Si samples have a crystalline structure.

Structural Characterization of Porous Silicon Fabricated by Electrochemical and Chemical Dissolution of Si Wafers

1991 ◽  
Vol 256 ◽  
Author(s):  
S. Miyazaki ◽  
T. Yasaka ◽  
K. Okamoto ◽  
K. Shiba ◽  
K. Sakamoto ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Electron Beam Irradiation ◽  
Complete Recovery ◽  
Porous Si ◽  
Beam Irradiation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Disordered Structure ◽  
Visible Luminescence

ABSTRACTThe structure of porous silicon exhibiting efficient visible photoluminescence has been characterized by using Fourier transformed infrared absorption, Raman scattering and x-ray diffraction. It is shown that the lattice spacing in the porous Si layer expands by about 0.3% in the direction perpendicular to the surface and also a partially disordered structure is existing. Electron beam irradiation causes desorption of hydrogen and fluorine bonds which terminate the surface, resulting in the quenching of the visible luminescence. The chemical etching of such layer has led to complete recovery of the luminescence intensity as well as the hydrogen and fluorine bonds termination.

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