Comparison of Porous Silicon Etched Gently and Under Illumination

1994 ◽  
Vol 358 ◽  
Author(s):  
Adam A. Filios ◽  
Raphael Tsu
Keyword(s):  
Porous Silicon ◽  
Thermal Annealing ◽  
Raman Line ◽  
Quantum Confinement ◽  
Blue Shift ◽  
The Other ◽  
Bulk Silicon ◽  
Dominant Mechanism ◽  
Peak Energy ◽  
Photoluminescence Peak

ABSTRACTPorous silicon samples prepared in the dark under "gentle" etching conditions clearly demonstrate effects of quantum confinement, such as a correlation of the photoluminescence peak energy with the downshift of the Raman line from 521 cm−1 for bulk silicon, and a blue shift in the remaining weak photoluminescence after thermal annealing. On the other hand, samples prepared under illumination as well as those heavily etched in the dark, though luminesce brightly, show no significant effects of quantum confinement, suggesting a different dominant mechanism for the observed luminescence.

Effect of Preparation Conditions on the Silicon L-Edge In Electrochemically Prepared Porous Silicon

1993 ◽  
Vol 298 ◽  
Author(s):  
T. Van Buuren ◽  
T. Tiedje ◽  
W. Weydanz
Keyword(s):  
Electronic Structure ◽  
High Resolution ◽  
Porous Silicon ◽  
Quantum Confinement ◽  
Light Exposure ◽  
Blue Shift ◽  
Bulk Silicon ◽  
Preparation Conditions ◽  
P Type ◽  
Confinement Model

AbstractHigh resolution measurements of the silicon L-edge absorption in electrochemically prepared porous silicon show that the absorption threshold is shifted to higher energy relative to bulk silicon, and that the shift is dependent on how the porous silicon is prepared. When the porous silicon is made from n-type material with light exposure, the blue shift increases logarithmically with the anodizing current. Porous silicon prepared by anodizing p-type silicon exhibits a blue shift in the L-edge which increases with the time spent in the HF solution after the anodizing potential is turned off. The data are consistent with the quantum confinement model for the electronic structure of porous silicon.

Pholuminuksence Studies on Porous Silioon Quantum Confinement Mechanism

1993 ◽  
Vol 298 ◽  
Author(s):  
Shulin Zhang ◽  
Kuoksan He ◽  
Yangtian Hou ◽  
Xin Wang ◽  
Jingjian Li ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Current Density ◽  
Quantum Wire ◽  
Quantum Confinement ◽  
Mechanism Model ◽  
Peak Energy ◽  
P Type ◽  
Silicon Based ◽  
First Time ◽  
Photoluminescence Peak

AbstractA novel step—like and pinning behavior of photoluminescence peak energy connected with changes in the concentration of HIF and current density were for the first time observed for p— type porous silicon. Based on a theoretical calculation of the electron structure of the silicon quantum wire it is argued that these behaviors can be explained in terms of a novel formation mechanism model of porous silicon.

Effect of Thermal Annealing on the Photoluminescence Properties of a GaInNAs/GaAs Single Quantum Well

2000 ◽  
Vol 639 ◽  
Author(s):  
Laurent Grenouillet ◽  
Catherine Bru-Chevallier ◽  
Gérard Guillot ◽  
Philippe Gilet ◽  
Philippe Ballet ◽  
...  
Keyword(s):  
Quantum Well ◽  
Thermal Annealing ◽  
Low Temperatures ◽  
Blue Shift ◽  
Emission Peak ◽  
Single Quantum ◽  
Photoluminescence Properties ◽  
Single Quantum Well ◽  
Peak Energy ◽  
Strong Blue Shift

ABSTRACTWe report on the effect of thermal annealing on the photoluminescence properties of a Ga0.65In0.35N0.02As0.98/GaAs single quantum well. Thermal annealing is shown to decrease the strong nitrogen-induced localization effects observed at low temperatures and to reduce the full width at half maximum of the emission peak. It also induces a strong blue shift of the emission peak energy, which is thought not to arise from an In-Ga interdiffusion alone, as it is much larger than in a nitrogen-free reference single quantum well.

Steplike behavior of photoluminescence peak energy and formation ofp‐type porous silicon

1993 ◽  
Vol 62 (6) ◽  
pp. 642-644 ◽  
Author(s):  
Shu‐Lin Zhang ◽  
Kuok‐san Ho ◽  
Yongtian Hou ◽  
Bidong Qian ◽  
Peng Diao ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Peak Energy ◽  
Photoluminescence Peak

Preparation and Characterization of ZnS/ZnO Compound Grown on Porous Silicon Substrate Using CVD Method

2010 ◽  
Vol 663-665 ◽  
pp. 393-396
Author(s):  
Fu Ru Zhong ◽  
Xiao Yi Lv ◽  
Zhen Hong Jia
Keyword(s):  
Electron Microscopy ◽  
Porous Silicon ◽  
Room Temperature ◽  
Zinc Sulphide ◽  
Cvd Method ◽  
Peak Energy ◽  
Porous Silicon Substrate ◽  
Photoluminescence Peak ◽  
Scanning Electron

We have investigated the morphology and photoluminescence (PL) of Zinc Oxide (ZnO) and Zinc sulphide (ZnS) compound grown on porous silicon at room temperature. Under different excitation wavelengths (320 nm, 340nm, 370 nm), the photoluminescence (PL) spectra of PS-ZnS-ZnO composites were different, and at 550nm there is a strong photoluminescence peak. Energy dispersive spectroscopy (EDS) has been carried out to evaluate the existing of ZnO/ZnS compound. In addition, the scanning electron microscopy (SEM) observation shows that the morphology of the PS-ZnS-ZnO composites was well grown on porous silicon.

Relationships Between Photoluminescence Spectra and Porosity of Porous Silicon

1994 ◽  
Vol 332 ◽  
Author(s):  
H.Z. Song ◽  
L.Z. Zhang ◽  
B.R. Zhang ◽  
G.G. Qin
Keyword(s):  
Porous Silicon ◽  
Quantum Confinement ◽  
Light Emission ◽  
Photoluminescence Spectra ◽  
Lower Side ◽  
Si Substrates ◽  
Peak Energy ◽  
P Type ◽  
Confinement Model

ABSTRACTIt was found that porous silicon (PS) layers formed on 0.01 Ωcm (111) and 0.02 Ωcm (100) Si substrates show high photoluminescence (PL) peak energies on both lower and higher porosity sides and a minimum of PL peak energy at the moderate porosity, while those formed on 0.8 and 10Ωcm (111) p-type Si substrates show an increase of PL peak energy with porosity on the lower side and a saturation of PL peak energy with porosity on the higher side. These experimental facts are not consistent with the quantum confinement model for light emission of PS, which predicts a monotonous increase of PL peak energy with PS porosity.

Photoluminescence peak energy evolution for porous silicon during photo-oxidation and gamma -ray oxidation

1995 ◽  
Vol 7 (3) ◽  
pp. 697-704 ◽  
Author(s):  
L Z Zhang ◽  
B Q Zong ◽  
B R Zhang ◽  
Z H Xu ◽  
J Q Li ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Gamma Ray ◽  
Energy Evolution ◽  
Photo Oxidation ◽  
Peak Energy ◽  
Photoluminescence Peak

The Effect of Surface Roughness on Photoluminescence of Porous Silicon

2000 ◽  
Vol 638 ◽  
Author(s):  
Shunsuke Ogawa ◽  
Nobutomo Uehara ◽  
Masato Ohmukai ◽  
Yasuo Tsutsumi
Keyword(s):  
Surface Roughness ◽  
Porous Silicon ◽  
Blue Shift ◽  
The Other ◽  
Quantum Size ◽  
Silicon Nanostructure ◽  
Pl Emission ◽  
Ftir Absorption Spectra ◽  
Porous Silicon Nanostructure ◽  
Effect Of Surface

AbstractWe studied the effect of surface roughness of Si wafers on porous silicon by means of photoluminescence (PL), Fourier transformed infrared (FTIR) absorption and Raman spectroscopy. We prepared several kinds of Si wafers with a different surface roughness, and then the anodization was performed at a same condition. PL spectra show a blue shift with the increase of surface roughness. The particle size of porous silicon nanostructure becomes the smaller with increasing surface roughness at the same time. On the other hand, FTIR absorption spectra show no difference regardless of surface roughness. The PL emission dependent on the surface roughness originates from a quantum size effect. We infer that the surface roughness causes the concentration of the current during anodization in the area where the radius of the curvature at the surface is small.

Raman and Optical Characterization of Porous Silicon

1991 ◽  
Vol 256 ◽  
Author(s):  
J. F. Harvey ◽  
H. Shen ◽  
R. A. Lux ◽  
M. Dutita ◽  
J. Pamulapati ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Quantum Confinement ◽  
Room Temperature ◽  
Thermal Dissociation ◽  
Life Time ◽  
High Energy ◽  
Bulk Silicon ◽  
Energy Peak ◽  
Time Changes

ABSTRACTRaman spectra from electrochemically etched porous silicon are correlated with photoluminescence (PL) data from the same spots of the sample. This correlation is consistent with optical properties of quantum confinement. The dielectric constant determined from angle resolved ellipsometry gives values far below that of bulk silicon. This reduction is due to the combined effects of voids as well as quantum confinement. The PL spectrum shows a weak high energy peak around 2.8eV in addition to the strong broad peak at 1.5 to 1.9eV. The temperature dependence of PL resembles that of bound excitons such as Si:S, having a thermal dissociation energy of 100 meV near room temperature. The radiation life time changes from tens of microseconds near room temperature to a few milliseconds at liquid helium temperatures. The rapid increase in lifetime and decrease in PL intensity at low temperatures indicates that phonons are probably involved.

Synthesis and Characterization of Si Nanoparticles Obtained on Sonication of Porous Silicon Multilayer Films

2012 ◽  
Vol 17 ◽  
pp. 13-25 ◽  
Author(s):  
Paresh G. Kale ◽  
Sharma Pratibha ◽  
Chetan S. Solanki
Keyword(s):  
Surface Modification ◽  
Porous Silicon ◽  
Current Density ◽  
Quantum Confinement ◽  
Blue Shift ◽  
Vis Spectroscopy ◽  
Si Nanoparticles ◽  
Confinement Behavior ◽  
Si Quantum Dots

Synthesis of Si quantum dots (QDs), useful for multi-junction crystalline Si solar cells, using porous Silicon (PS) is presented in this paper. Four types of freestanding PS structures are fabricated by anodization method with modulation of current density between two levels. The level-1 current density is kept constant at 20 mA/cm2 (for reference monolayer structure - sample A) and 10 mA/cm2 (for all multilayer structures samples B, C, D). The level-2 is varied between 0 to 50 mA/cm2 (0, 20, 30, 50 mA/cm2 as sample A, B, C and D respectively). In order to obtain Si QDs from PS films, the films are subjected to sonication (120 W, 42 kHz) for 6 hours. HRTEM images confirm presence of Si nanoparticles in the range of 2 to 8 nm. Various spectroscopic analyses of Si nanoparticles are performed in order to evaluate quantum confinement behavior and surface modification observed during sonication. Analysis of de-convoluted Raman peaks shows frequency downshift and increase in full width half maximum due to formation of QDs. After sonication, PL spectroscopy indicates blue shift from 2.54 eV (sample A) to 2.85 eV (sample D_6HR), similar to the observations made by UV-Vis spectroscopy. FTIR spectra show oxidation of Si QDs during sonication. Spectroscopic and microscopic results are explained using quantum confinement and surface modification phenomenon.

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