STRUCTURAL AND OPTICAL PROPERTIES OF LARGE-SCALE ZnO NANOWIRES AND NANOSHEETS PREPARED BY DRY THERMAL OXIDATION

2009 ◽  
Vol 16 (06) ◽  
pp. 901-904 ◽  
Author(s):  
S. S. TNEH ◽  
H. ABU HASSAN ◽  
K. G. SAW ◽  
F. K. YAM ◽  
Z. HASSAN
Keyword(s):  
Optical Properties ◽  
Thermal Oxidation ◽  
Large Scale ◽  
Gas Flow ◽  
Deep Level ◽  
Exciton Peak ◽  
Interstitial Oxygen ◽  
Energy Dispersion Spectroscopy ◽  
Zno Nanostructure ◽  
Annealing Conditions

In this work, we report the morphology and optical properties of zinc oxide ( ZnO ) layers prepared by dry thermal oxidation at different annealing conditions. Morphology studies using scanning electron microscope (SEM) show that the amount of nanowires and nanosheets increases with the introduction of a flow of O2 gas. High-resolution X-ray diffraction (HR-XRD) data show that typical polycrystalline ZnO nanostructure layers have been deposited. Near-perfect stoichiometry of Zn and O atom vacancies has been observed from energy dispersion spectroscopy (EDS) spectrum. Photoluminescence (PL) spectra show strong peaks at UV and green regions. An increase in the stoichiometry of ZnO has been achieved with the oxygen gas flow during annealing indicating that deep-level defects represented by interstitial oxygen and antisite oxygen are gas pressure dependent. A single exciton peak with binding energy 60 meV has been observed at room temperature.

Research of Structural and Optical Properties of MgZnO Films Annealed at Different Oxygen Partial Pressures

2015 ◽  
Vol 1096 ◽  
pp. 54-61 ◽  
Author(s):  
Wei Wei Liu ◽  
Zhen Zhong Zhang
Keyword(s):  
Optical Properties ◽  
Oxygen Content ◽  
Interstitial Oxygen ◽  
Photoluminescence Spectra ◽  
Structural And Optical Properties ◽  
Annealing Conditions ◽  
Partial Pressures ◽  
High Annealing ◽  
Mgzno Film ◽  
Annealing Pressure

Structural and optical properties of MgZnO films were investigated by annealing in oxygen at different pressures. The crystalline quality of the annealed films improves with increasing annealing pressure. After annealing at 3.03×105Pa, the grain size became larger and oxygen content in the annealed films increased. This was attributed to the recrystallization of the films under high annealing pressure. However, a decreased oxygen content was found by annealing the films at 1.01×105or 2.05×10-3Pa. According to the defect levels and the relationship between photoluminescence spectra and annealing conditions, it was suggested that the emission peak located at 2.270 eV in photoluminescence spectra was related to interstitial oxygen (Oi) which will compensate the donor defects (Znior/and VO) and lead to the MgZnO film transforming into ap-type conduction under the annealing pressure of 3.03×105Pa.

Two-Dimensional Local Deep-Level Transient Spectroscopy Imaging Using Super-Higher-Order Scanning Nonlinear Dielectric Microscopy

2016 ◽  
Author(s):  
N. Chinone ◽  
Y. Cho ◽  
R. Kosugi ◽  
Y. Tanaka ◽  
S. Harada ◽  
...  
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Higher Order ◽  
Trap Density ◽  
New Technique ◽  
Two Dimensional ◽  
Nonlinear Dielectric ◽  
Annealing Conditions ◽  
Transient Spectroscopy ◽  
A New Technique

Abstract A new technique for local deep level transient spectroscopy (DLTS) imaging using super-higher-order scanning nonlinear dielectric microscopy is proposed. Using this technique. SiCVSiC structure samples with different post oxidation annealing conditions were measured. We observed that the local DLTS signal decreases with post oxidation annealing (POA), which agrees with the well-known phenomena that POA reduces trap density. Furthermore, obtained local DLTS images had dark and bright areas, which is considered to show the trap distribution at/near SiCVSiC interface.

Cuprous oxide thin films prepared by thermal oxidation of copper layer. Morphological and optical properties

2015 ◽  
Vol 159 ◽  
pp. 325-332 ◽  
Author(s):  
Artak Karapetyan ◽  
Anna Reymers ◽  
Suzanne Giorgio ◽  
Carole Fauquet ◽  
Laszlo Sajti ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Thermal Oxidation ◽  
Cuprous Oxide ◽  
Copper Layer ◽  
Oxide Thin Films

Large-scale synthesis and optical properties of hexagonal GaN micropyramid/nanowire homostructures

2005 ◽  
Vol 17 (1) ◽  
pp. 30-34 ◽  
Author(s):  
Xu Xiang ◽  
Chuanbao Cao ◽  
Yajie Xu ◽  
Hesun Zhu
Keyword(s):  
Optical Properties ◽  
Large Scale ◽  
Large Scale Synthesis

Large-scale, single-oriented ZnO nanostructure on h-BN films for flexible inorganic UV sensors

2021 ◽  
Vol 130 (22) ◽  
pp. 223105
Author(s):  
Hongseok Oh ◽  
Youngbin Tchoe ◽  
Heehun Kim ◽  
Jiyoung Yun ◽  
Mingi Park ◽  
...  
Keyword(s):  
Large Scale ◽  
Zno Nanostructure ◽  
Uv Sensors

Effect of Nitrogen Doping on the Structure and Optical Properties of N-Type Hydrogenated Amorphous Silicon Thin Films

2011 ◽  
Vol 383-390 ◽  
pp. 6980-6985
Author(s):  
Mao Yang Wu ◽  
Wei Li ◽  
Jun Wei Fu ◽  
Yi Jiao Qiu ◽  
Ya Dong Jiang
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Amorphous Silicon ◽  
Photoelectron Spectroscopy ◽  
Gas Flow ◽  
Hydrogenated Amorphous Silicon ◽  
Chemical Vapor ◽  
Silicon Thin Films ◽  
Frequency Plasma ◽  
Hydrogenated Amorphous

Hydrogenated amorphous silicon (a-Si:H) thin films doped with both Phosphor and Nitrogen are deposited by ratio frequency plasma enhanced chemical vapor deposition (PECVD). The effect of gas flow rate of ammonia (FrNH3) on the composition, microstructure and optical properties of the films has been investigated by X-ray photoelectron spectroscopy, Raman spectroscopy and ellipsometric spectra, respectively. The results show that with the increase of FrNH3, Si-N bonds appear while the short-range order deteriorate in the films. Besides, the optical properties of N-doped n-type a-Si:H thin films can be easily controlled in a PECVD system.

Tuning Hierarchical Cluster Assembly in Pulsed Laser Deposition of Al-doped ZnO

2013 ◽  
Vol 1497 ◽  
Author(s):  
Paolo Gondoni ◽  
Valeria Russo ◽  
Carlo E. Bottani ◽  
Andrea Li Bassi ◽  
Carlo S. Casari
Keyword(s):  
Optical Properties ◽  
Pulsed Laser Deposition ◽  
Gas Flow ◽  
Mass Density ◽  
Pulsed Laser ◽  
Hierarchical Cluster ◽  
Laser Deposition ◽  
Cluster Assembly ◽  
Hierarchical Assembly ◽  
Doped Zno

ABSTRACTThe synthesis of hierarchically assembled Al-doped ZnO layers by Pulsed Laser Deposition (PLD) at room temperature was investigated. PLD was performed in a background pressure of 100 Pa O2 to deposit clusters in a low energy regime and obtain nano- and mesostructures resulting from a hierarchical assembly of nanoclusters. We here analyzed the effects of varying the gas flow rate on mesoscale morphology, mass density and optical properties. The variation of the target-to-substrate distance was also investigated, identifying its effects on mass density and film morphology. The optimization of optical properties in terms of transparency and light scattering capability is of potential interest for photovoltaic applications.

Study on Effective Radial Thermal Conductivity of Gas Flow through a Methanol Reactor

2015 ◽  
Vol 13 (1) ◽  
pp. 103-112 ◽  
Author(s):  
Kun Lei ◽  
Hongfang Ma ◽  
Haitao Zhang ◽  
Weiyong Ying ◽  
Dingye Fang
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Reynolds Number ◽  
Temperature Distribution ◽  
Large Scale ◽  
Gas Flow ◽  
Fixed Bed ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Particle Reynolds Number

Abstract The heat conduction performance of the methanol synthesis reactor is significant for the development of large-scale methanol production. The present work has measured the temperature distribution in the fixed bed at air volumetric flow rate 2.4–7 m3 · h−1, inlet air temperature 160–200°C and heating tube temperature 210–270°C. The effective radial thermal conductivity and effective wall heat transfer coefficient were derived based on the steady-state measurements and the two-dimensional heat transfer model. A correlation was proposed based on the experimental data, which related well the Nusselt number and the effective radial thermal conductivity to the particle Reynolds number ranging from 59.2 to 175.8. The heat transfer model combined with the correlation was used to calculate the temperature profiles. A comparison with the predicated temperature and the measurements was illustrated and the results showed that the predication agreed very well with the experimental results. All the absolute values of the relative errors were less than 10%, and the model was verified by experiments. Comparing the correlations of both this work with previously published showed that there are considerable discrepancies among them due to different experimental conditions. The influence of the particle Reynolds number on the temperature distribution inside the bed was also discussed and it was shown that improving particle Reynolds number contributed to enhance heat transfer in the fixed bed.

Structural and Optical Properties of TiO2 Thin Films Prepared by Thermal Oxidation of Ti Thin Films

2013 ◽  
Vol 770 ◽  
pp. 225-228
Author(s):  
L. Uttayan ◽  
K. Aiempanakit ◽  
M. Horprathum ◽  
P. Eiamchai ◽  
V. Pattantsetakul ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Thermal Oxidation ◽  
Annealing Temperature ◽  
Oxidation Process ◽  
Structural And Optical Properties ◽  
X Ray ◽  
Wafer Substrate ◽  
Uv Visible ◽  
Ti Films

Titanium dioxide (TiO2) films were prepared by thermal oxidation from Ti films. The Ti films were deposited on glass and silicon (100) wafer substrate by dc magnetron sputtering and subsequent with thermal oxidation process. The crystal structure and morphology of TiO2 films were estimated by using X-ray diffractometry (XRD) and field-emission scanning electron microscopy (FE-SEM), respectively. The optical property of TiO2 films was determined by UV-Visible spectrophotometer. The influences of annealing temperature between 200 to 500°C in air for 1 hour on the structure and optical properties of TiO2 films were investigated. The increasing of annealing temperature was directly affected the phase transition from Ti to TiO2. The optical and structural properties of TiO2 films are the best exhibited with increasing the annealing temperature at 500 °C.

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