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.

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.

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.

Enhancement of efficiency in graphene/porous silicon solar cells by co-doping graphene with gold nanoparticles and bis(trifluoromethanesulfonyl)-amide

2017 ◽  
Vol 5 (35) ◽  
pp. 9005-9011 ◽  
Author(s):  
Ju Hwan Kim ◽  
Dong Hee Shin ◽  
Ha Seung Lee ◽  
Chan Wook Jang ◽  
Jong Min Kim ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Solar Cells ◽  
Porous Silicon ◽  
Au Nanoparticles ◽  
Silicon Solar Cells ◽  
Porous Si ◽  
Co Doping ◽  
Si Solar Cells ◽  
First Time

The co-doping of graphene with Au nanoparticles and bis(trifluoromethanesulfonyl)-amide is employed for the first time to enhance the performance of graphene/porous Si solar cells.

EFFECT OF ETCHING TIME ON OPTICAL AND MORPHOLOGICAL FEATURES OF N-TYPE POROUS SILICON PREPARED BY PHOTO-ELECTROCHEMICAL METHOD

2016 ◽  
Vol 78 (3) ◽  
Author(s):  
Asad A. Thahe ◽  
Noriah Bidin ◽  
Mohammed A. Al-Azawi ◽  
Naser M. Ahmed
Keyword(s):  
Porous Silicon ◽  
Gravimetric Method ◽  
Constant Current ◽  
Etching Time ◽  
Absorption Data ◽  
Time Duration ◽  
Constant Current Density ◽  
Force Microscopy ◽  
Atomic Force ◽  
Structure Properties

Achieving efficient visible photoluminescence from porous-silicon (PSi) is demanding for optoelectronic and solar cells applications. Improving the absorption and emission features of PSi is challenging. Photo-electro-chemical etching assisted formation of PSi layers on n-type (111) silicon (Si) wafers is reported. Samples are prepared at constant current density (~30 mA/cm2) under varying etching times of 10, 15, 20, 25, and 30 min. The influence of etching time duration on the growth morphology and spectral properties are inspected. Room temperature photoluminescence (PL) measurement is performed to determine the optical properties of as-synthesized samples. Sample morphologies are imaged via Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The thickness and porosity of the prepared samples are estimated using the gravimetric method. The emission and absorption data is further used to determine the samples band gap and electronic structure properties. Results and analyzed, interpreted with different mechanisms and compared.  

Visible Electro- and Photoluminescence from Porous Silicon and its Related Optoelectronic Properties

1991 ◽  
Vol 256 ◽  
Author(s):  
Nobuyoshi Koshida ◽  
Hideki Koyama
Keyword(s):  
Porous Silicon ◽  
Optical Absorption ◽  
Size Effect ◽  
Band Gap ◽  
Visible Region ◽  
Optoelectronic Properties ◽  
Porous Si ◽  
Quantum Size ◽  
Effect Model ◽  
Injection Type

ABSTRACTThe optoelectronic properties of porous Si (PS) are presented in terms of electroluminescence (EL), photoluminescence (PL), photoconduction (PC), and optical absorption. Observations of injection-type EL, efficient PL, band-gap widening, and photosensitivities In the visible region are consistent with the quantum size effect model in PS.

scholarly journals Morphology and FT IR spectra of porous silicon

2017 ◽  
Vol 68 (7) ◽  
pp. 53-57 ◽  
Author(s):  
Martin Kopani ◽  
Milan Mikula ◽  
Daniel Kosnac ◽  
Jan Gregus ◽  
Emil Pincik
Keyword(s):  
Porous Silicon ◽  
Ir Spectra ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Layer Formation ◽  
Porous Si ◽  
Ft Ir ◽  
P Type ◽  
Type Sample ◽  
Ftir Investigation

AbstractThe morphology and chemical bods of p-type and n-type porous Si was compared. The surface of n-type sample is smooth, homogenous without any features. The surface of p-type sample reveals micrometer-sized islands. FTIR investigation reveals various distribution of SiOxHycomplexes in both p-and n-type samples. From the conditions leading to porous silicon layer formation (the presence of holes) we suggest both SiOxHyand SiFxHycomplexes in the layer.

Gas Sensor Using an Aluminium-Porous Silicon Junction Application to the Detection of Non-Zero Molecular Dipole Moment

1994 ◽  
Vol 358 ◽  
Author(s):  
D. Stievenard ◽  
D. Deresmes
Keyword(s):  
Dipole Moment ◽  
Porous Silicon ◽  
Silicon Oxide ◽  
Surface States ◽  
Dangling Bonds ◽  
Porous Si ◽  
Adsorbed Gas ◽  
Dipole Layer ◽  
Dc Current ◽  
Partial Depletion

ABSTRACTPorous silicon is known to be sensitive to moisture. Using an aluminium-porous p+ silicon junction, we have realized a sensor which dc current increases up to two orders of magnitude in the presence of ammoniac. We have tested a series of various gases and we show that if the dipole moment of the molecule is zero, there is no effect on the dc current. To interpret quantitatively this phenomenon, we assume that the conductivity is governed by the width of a channel resulting from the partial depletion of silicon located between two pores. This depleted region is due to the charges trapped on surface states associated with the Si-SiO2 interface where SiO2 is the native silicon oxide. When some gas is adsorbed, we propose there is a passivation of the interface states (mainly dangling bonds), leading to a decrease of the depleted region, i.e. an increase of the width of the channel and thus an increase of the current. The adsorbed gas gives a dipole layer at the surface of the pore. This layer has no influence on the depleted region. It stabilizes electrons or holes at the porous Si surface, allowing a stable charge state of the dangling bonds.

Photoluminescence Excitation Spectroscopy Of Porous Silicon

1994 ◽  
Vol 358 ◽  
Author(s):  
A. Kux ◽  
M. Ben Chorin
Keyword(s):  
Particle Size ◽  
Porous Silicon ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Photoluminescence Excitation ◽  
Size Dispersion ◽  
Different Parts ◽  
Extract Information

ABSTRACTWe combine photoluminescence excitation spectroscopy and photoconductivity to extract information about the bandgap and particle size distribution of porous silicon. This allows us to specify the influence of size dispersion and to show that different methods to determine absorption probe different parts of the size distribution.

Lithium effect on the electronic properties of porous silicon for energy storage applications: a DFT study

2018 ◽  
Vol 47 (22) ◽  
pp. 7505-7514 ◽  
Author(s):  
I. González ◽  
A. N. Sosa ◽  
A. Trejo ◽  
M. Calvino ◽  
A. Miranda ◽  
...  
Keyword(s):  
Energy Storage ◽  
Porous Silicon ◽  
Electronic Properties ◽  
Theoretical Study ◽  
Dft Study ◽  
Porous Si ◽  
Energy Storage Applications

A theoretical study on the effect of Li on the electronic properties of porous Si; these properties change drastically if the Li is superficial or interstitial.

High performance of porous silicon/carbon/RGO network derived from rice husks as anodes for lithium-ion batteries

2018 ◽  
Vol 42 (24) ◽  
pp. 19811-19817 ◽  
Author(s):  
Kaifeng Yu ◽  
Hanxiang Zhang ◽  
Hui Qi ◽  
Jicai Liang ◽  
Ce Liang
Keyword(s):  
Porous Silicon ◽  
Lithium Ion Batteries ◽  
High Performance ◽  
Lithium Ion ◽  
Reduction Reaction ◽  
Magnesiothermic Reduction ◽  
Rice Husks ◽  
Porous Si ◽  
Silicon Carbon ◽  
Battery Anode

Rice husk-derived porous Si/C synthesized via activation and magnesiothermic reduction reaction possesses excellent electrochemistry performance as a lithium-ion battery anode.

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