Evaluation of Optical Properties for Nanocrystal Si Dot Layers Fabricated by CVD as a Function of Size Reduction

2012 ◽  
Vol 725 ◽  
pp. 251-254
Author(s):  
Yuki Mizukami ◽  
D. Kosemura ◽  
M. Takei ◽  
Y. Numasawa ◽  
Y. Ohshita ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Optical Properties ◽  
Quantum Confinement ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
X Ray Diffraction ◽  
Confinement Effects ◽  
Quantum Confinement Effects ◽  
Transmission Electron

Raman spectroscopy and photoluminescence were performed in order to understand the optical properties of nanocrystal Si in relation to quantum confinement effects. The nanocrystal Si (nc-Si) dots in the SiO2 layer were fabricated by the H2 plasma treatment and chemical vapour deposition followed by the oxidation of the nc-Si dots surface. The post-annealing was also performed to improve the crystalline quality of nc-Si at 1050 °C for 5 and 10 min. There is a good correlation of the quantum confinement effects between the results of Raman spectroscopy and photoluminescence. The Raman spectra from nc-Si were analysed using the model of Richter et al. As a result, the sizes of the nc-Si dots were consistent with those obtained by transmission electron microscopy and X-ray diffraction. Moreover, the compressive stress in the nc-Si dots were evaluated which was induced by the SiO2 surroundings.

Structural and optical characterization of Si quantumdots in a SiC matrix

2010 ◽  
Vol 1260 ◽  
Author(s):  
Matthias Kuenle ◽  
Philipp Loeper ◽  
Marcel Rothfelder ◽  
Stefan Janz ◽  
Oliver Eibl ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Si Nanocrystals ◽  
Controlled Crystallization ◽  
Size Controlled ◽  
Field Imaging

AbstractAmorphous hydrogenated Si1-xCx/SiC multilayers consisting of alternating Si1-xCx and stoichiometric SiC layers were prepared using Plasma Enhanced Chemical Vapour Deposition (PECVD). Annealing at temperatures up to 1100°C was done targeting the size controlled crystallization of Si nanocrystals (NCs) in a SiC matrix. The influence of annealing temperature on the nanostructure of the multilayers was studied using Glancing Incidence X-ray Diffraction (GIXRD), Raman spectroscopy and Transmission Electron Microscopy (TEM). GIXRD reveal the crystallization of Si and SiC, when annealing temperatures exceed 900°C. The crystallization of Si and SiC was confirmed by TEM bright-field imaging and electron diffraction. Annealing at 900°C, leads to the formation of Si NCs with a size of 3 nm, whereas the SiC NCs also have a size of 3 nm. However, a large amount of Si is still amorphous as shown by Raman spectroscopy. Annealing at temperatures exceeding 900°C reduces the amorphous phase and a further growth of Si NCs occurs.

Synthesis and Photoluminescence Properties of Novel SnO2 Zigzag Nanoribbons

2010 ◽  
Vol 97-101 ◽  
pp. 4213-4216
Author(s):  
Jian Xiong Liu ◽  
Zheng Yu Wu ◽  
Guo Wen Meng ◽  
Zhao Lin Zhan
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Ceramic Boat

Novel single-crystalline SnO2 zigzag nanoribbons have been successfully synthesized by chemical vapour deposition. Sn powder in a ceramic boat covered with Si plates was heated at 1100°C in a flowing argon atmosphere to get deposits on a Si wafers. The main part of deposits is SnO2 zigzag nanoribbons. They were characterized by means of X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). SEM observations reveal that the SnO2 zigzag nanoribbons are almost uniform, with lengths near to several hundred micrometers and have a good periodically tuned microstructure as the same zigzag angle and growth directions. Possible growth mechanism of these zigzag nanoribbons was discussed. A room temperature PL spectrum of the zigzag nanoribbons shows three peaks at 373nm, 421nm and 477nm.The novel zigzag microstructures will provide a new candidate for potential application.

QUANTUM CONFINEMENT EFFECTS ON THE OPTICAL PROPERTIES OF ION BEAM SPUTTERED NICKEL OXIDE THIN FILMS

2001 ◽  
Vol 15 (02) ◽  
pp. 191-200 ◽  
Author(s):  
M. GHANASHYAM KRISHNA ◽  
A. K. BHATTACHARYA
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Nickel Oxide ◽  
Band Gap ◽  
Quantum Confinement ◽  
Ion Beam ◽  
Confinement Effects ◽  
Oxide Thin Films ◽  
Quantum Confinement Effects ◽  
Nickel Oxide Thin Films

Quantum confinement effects on the optical properties of ion beam sputtered nickel oxide thin films are reported. Thin films with crystallite sizes in the range 9 to 14 nm have been deposited on to fused silica substrates. There is an increase in band gap, from 3.4 to 3.9 eV, and a decrease in refractive index, from 2.4 to 1.6, with decrease in crystallite size, that can be attributed to quantum confinement effects. The effective mass approximation has been used to explain the observed behaviour in band gap variation.

Examination of Titanium Oxides, Lead Oxides and Lead Titanates Using X-Ray Diffraction and Raman Spectroscopy

1993 ◽  
Vol 310 ◽  
Author(s):  
Lynnette D. Madsen ◽  
Louise Weaver
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Vapour Deposition ◽  
Mixed Oxides ◽  
Chemical Vapour ◽  
Titanium Oxides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lead Oxides ◽  
Metalorganic Chemical Vapour Deposition

AbstractSingle oxides (with titanium or lead) deposited as thin films by low pressure metalorganic chemical vapour deposition were investigated by x-ray diffraction and Raman spectroscopy. Examination of mixed oxides (titanates) and silicates were also carried out using these techniques. The crystallographic nature of these thin films were examined and comparisons made to their bulk counterparts. The deposition and anneal conditions 600 for producing cubic PbTiO3 films are discussed briefly.

Structural Properties of Microcrystalline Si Solar Cells

2001 ◽  
Vol 664 ◽  
Author(s):  
M. Luysberg ◽  
C. Scholten ◽  
L. Houben ◽  
R. Carius ◽  
F. Finger ◽  
...  
Keyword(s):  
Solar Cells ◽  
Structural Properties ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Special Importance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Si Solar Cells ◽  
Transmission Electron

ABSTRACTThe structural properties of nip-µc-Si:H solar cells are investigated by transmission electron microscopy, X-ray diffraction and Raman spectroscopy. Different structural compositions are obtained by variation of the gas mixture during preparation by plasma enhanced chemical vapour deposition. Nucleation and growth of the n-layer onto textured TCO substrate was found to be similar to the growth on glass substrates. The growth of the i-layer follows a local epitaxy. This implies that the structure of the n-layer is of special importance regarding the control of the microstructure in microcrystalline Si nip solar cells.

Quantum size effects on the optical properties of nc-Si QDs embedded in an a-SiOx matrix synthesized by spontaneous plasma processing

2015 ◽  
Vol 17 (7) ◽  
pp. 5063-5071 ◽  
Author(s):  
Debajyoti Das ◽  
Arup Samanta
Keyword(s):  
Optical Properties ◽  
Size Effects ◽  
Quantum Confinement ◽  
Plasma Processing ◽  
Blue Shift ◽  
Quantum Size Effects ◽  
Confinement Effects ◽  
Quantum Size ◽  
Quantum Confinement Effects ◽  
Stokes Shifts

An energy blue shift due to quantum confinement effects in tiny nc-Si QDs accompanied by larger Stokes shifts in PL at smaller dimensions.

scholarly journals Quantum Confinement Effects of Thin Co3O4 Films

Atoms ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 70
Author(s):  
Alexandros Barnasas ◽  
Christos S. Garoufalis ◽  
Dimitrios I. Anyfantis ◽  
Nikolaos Bouropoulos ◽  
Panagiotis Poulopoulos ◽  
...  
Keyword(s):  
Quantum Confinement ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Confinement Effects ◽  
Force Microscopy ◽  
Air Atmosphere ◽  
Mass Approximation ◽  
Corning Glass ◽  
Atomic Force ◽  
Quantum Confinement Effects

Thin Co films were deposited on quartz and Corning glass by radio frequency magnetron sputtering. The films were postannealed at 500 °C in a furnace in air atmosphere. The resulting samples were examined with X-ray diffraction experiments, which revealed that they consist of single-phase, polycrystalline Co3O4. The morphology of selected samples was recorded by atomic force microscopy. Ultraviolet-visible light absorption spectroscopy experiments probed the absorbance of the films in the wavelength range 200–1,100 nm. Two types of transitions (energy gaps) were clearly identified. Both of them were found to be “blue shifted” with decreasing film thickness; this is interpreted as evidence of quantum confinement effects. For the case of the first gap value, this was corroborated by calculations based on a combination of the Potential Morphing Method and the effective mass approximation.

Optical properties of thePb2+-based aggregated phase in a CsCl host crystal: Quantum-confinement effects

1995 ◽  
Vol 51 (8) ◽  
pp. 5192-5199 ◽  
Author(s):  
M. Nikl ◽  
K. Nitsch ◽  
K. Polak ◽  
G. P. Pazzi ◽  
P. Fabeni ◽  
...  
Keyword(s):  
Optical Properties ◽  
Quantum Confinement ◽  
Host Crystal ◽  
Confinement Effects ◽  
Quantum Confinement Effects
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