Quantum Dot Growth in the Si-Ge-C System Through Multi-Step Procedure

2000 ◽  
Vol 618 ◽  
Author(s):  
Yutaka Wakayama ◽  
Gerhard Gerth ◽  
Peter Werner ◽  
Leonid V. Sokolov

ABSTRACTTo fabricate nanometer-sized Ge dots on Si(100), we have investigated multi-step procedure, involving low temperature deposition of a Ge layer, a sub-monolayer C on a Ge wetting layer, a Ge top layer for three-dimensional (3D) dot formation and post-annealing. Effects of each procedure were discussed on the basis of an atomic force microscope study. 10nm-sized Ge dots with a high number density in the order of 1011 cm−2 were grown on the Si(100) substrate by combining each procedure and optimizing experimental conditions, such as deposition temperature, the C layer thickness and post-annealing temperature.

2012 ◽  
Vol 576 ◽  
pp. 602-606
Author(s):  
Samsiah Ahmad ◽  
N.D.M. Sin ◽  
M.N. Berhan ◽  
Mohamad Rusop Mahmood

Zinc Oxide (ZnO) films were prepared on unheated glass substrate by radio frequency (RF) magnetron sputtering technique and post deposition annealing of the ZnO thin film were performed at 350, 400, 450 and 500°C. Post annealing temperature was found to improve the structural and electrical characteristics of the deposited films. The structural properties of the films were carried out by the surface profiler, X-Ray diffraction (XRD), atomic force microscopy (AFM) and field emission scanning electron microscope (FESEM) while the electrical properties were measured using current voltage (I-V) probe measurement system. All samples exhibit the (002) peak and the sample annealed at 500°C gives the highest crystalline quality, highest Rms roughness (1.819 nm) and highest electrical conductivity (3.28 x 10-3 Sm-1).


Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1802
Author(s):  
Dan Liu ◽  
Peng Shi ◽  
Yantao Liu ◽  
Yijun Zhang ◽  
Bian Tian ◽  
...  

La0.8Sr0.2CrO3 (0.2LSCO) thin films were prepared via the RF sputtering method to fabricate thin-film thermocouples (TFTCs), and post-annealing processes were employed to optimize their properties to sense high temperatures. The XRD patterns of the 0.2LSCO thin films showed a pure phase, and their crystallinities increased with the post-annealing temperature from 800 °C to 1000 °C, while some impurity phases of Cr2O3 and SrCr2O7 were observed above 1000 °C. The surface images indicated that the grain size increased first and then decreased, and the maximum size was 0.71 μm at 1100 °C. The cross-sectional images showed that the thickness of the 0.2LSCO thin films decreased significantly above 1000 °C, which was mainly due to the evaporation of Sr2+ and Cr3+. At the same time, the maximum conductivity was achieved for the film annealed at 1000 °C, which was 6.25 × 10−2 S/cm. When the thin films post-annealed at different temperatures were coupled with Pt reference electrodes to form TFTCs, the trend of output voltage to first increase and then decrease was observed, and the maximum average Seebeck coefficient of 167.8 µV/°C was obtained for the 0.2LSCO thin film post-annealed at 1100 °C. Through post-annealing optimization, the best post-annealing temperature was 1000 °C, which made the 0.2LSCO thin film more stable to monitor the temperatures of turbine engines for a long period of time.


2018 ◽  
Vol 7 (3.11) ◽  
pp. 48
Author(s):  
Kevin Alvin Eswar ◽  
Mohd Husairi Fadzillah Suhaimi ◽  
Muliyadi Guliling ◽  
Zuraida Khusaimi ◽  
Mohamad Rusop ◽  
...  

ZnO Nanostructures have been successfully deposited on of Porous silicon (PSi) via wet colloid chemical approach. PSi was prepared by electrochemical etching method. ZnO/PSi thin films were annealed in different temperature in the range of 300 °C to 700 °C. Surface morphology studies were conducted using field emission scanning microscopy (FESEM). Flower-like structures of ZnO were clearly seen at annealing temperature of 500 °C. The X-ray diffraction spectra (XRD) have been used to investigate the structural properties. There are three dominant peaks referred to plane (100), (002) and (101) indicates that ZnO has a polycrystalline hexagonal wurtzite structures. Plane (002) shows the highest intensities at annealing temperature of 500 °C. Based on plane (002) analysis, the sizes were in range of 30.78 nm to 55.18. In addition, it was found that the texture coefficient of plane (002) is stable compared to plane (100) and (101). 


2010 ◽  
Vol 10 (10) ◽  
pp. 6419-6423 ◽  
Author(s):  
Sharul Ashikin Kamaruddin ◽  
Mohd Zainizan Sahdan ◽  
Kah-Yoong Chan ◽  
Mohamad Rusop ◽  
Hashim Saim

2009 ◽  
Vol 67 ◽  
pp. 65-70 ◽  
Author(s):  
Gaurav Shukla ◽  
Alika K. Khare

TiO2 is a widely studied material for many important applications in areas such as environmental purification, photocatalyst, gas sensors, cancer therapy and high effect solar cell. However, investigations demonstrated that the properties and applications of titanium oxide films depend upon the nature of the crystalline phases present in the films, i.e. anatase and rutile phases. We report on the pulsed laser deposition of high quality TiO2 thin films. Pulsed Laser deposition of TiO2 thin films were performed in different ambient viz. oxygen, argon and vacuum, using a second harmonic of Nd:YAG laser of 6 ns pulse width. These deposited films of TiO2 were further annealed for 5hrs in air at different temperatures. TiO2 thin films were characterized using x-ray diffraction, SEM, photoluminescence, transmittance and reflectance. We observed effect of annealing over structural, morphological and optical properties of TiO2 thin films. The anatase phase of as-deposited TiO2 thin films is found to change into rutile phase with increased annealing temperature. Increase in crystalline behaviour of thin films with post-annealing temperature is also observed. Surface morphology of TiO2 thin films is dependent upon ambient pressure and post- annealing temperature. TiO2 thin films are found to be optically transparent with very low reflectivity hence will be suitable for antireflection coating applications.


2013 ◽  
Vol 63 (12) ◽  
pp. 1328-1332
Author(s):  
D. Y. Lee ◽  
C. -W. Cho ◽  
S. H. Lee ◽  
J. W. Kim ◽  
H. K. Kim ◽  
...  

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