The Study on Microstructural and Optical Properties of Nanocrystalline Germanium Films

2010 ◽  
Vol 663-665 ◽  
pp. 324-327
Author(s):  
Chao Song ◽  
Rui Huang
Keyword(s):  
Multilayer Structure ◽  
Room Temperature ◽  
Multilayer Film ◽  
Volume Fraction ◽  
Raman Scattering Spectroscopy ◽  
Force Microscopy ◽  
Room Temperature Photoluminescence ◽  
Atomic Force ◽  
Lower Volume Fraction ◽  
Lower Volume

The germanium film and Ge/Si multilayer structure were fabricated by magnetron sputtering technique on silicon substrate at temperatures of 500°C. Raman scattering spectroscopy measurements reveal that the nanocrystalline Ge occurs in both kinds of samples. Furthermore, from the atomic force microscopy (AFM) results, it is found that the grain size as well as spatially ordering distribution of the nc-Ge can be modulated by the Ge/Si multilayer structure. The room temperature photoluminescence was also observed in the samples. However, compared with that from the nc-Ge film, the intensity of PL from the nc-Ge/a-Si multilayer film becomes weaker, which is attributed to its lower volume fraction of crystallized component.

Correlation of Structural and Optical Properties of nc-Ge/a-Si Multilayers Grown by Ion Beam Sputtering

2011 ◽  
Vol 306-307 ◽  
pp. 1300-1303
Author(s):  
Chao Song ◽  
Rui Huang ◽  
Xiang Wang ◽  
Jie Song ◽  
Yan Qing Guo
Keyword(s):  
Room Temperature ◽  
Volume Fraction ◽  
Ion Beam ◽  
Silicon Substrates ◽  
Ion Beam Sputtering ◽  
Raman Scattering Spectroscopy ◽  
Force Microscopy ◽  
Room Temperature Photoluminescence ◽  
Atomic Force ◽  
Beam Sputtering

The nc-Ge/a-Si multilayer structures were fabricated by ion beam sputtering technique on silicon substrates at temperature of 400 °C. Raman scattering spectroscopy, atomic force microscopy (AFM) and room temperature photoluminescence were used to characterize the structure and optical property of the samples. It was found that the nc-Ge/a-Si multilayer sample can be obtained when the Ge sublayer is 3 nm. The room temperature photoluminescence was observed and the luminescent peak is located at 685 nm. Compared with the a-Ge/a-Si film, the intensity of PL of the nc-Ge/a-Si multilayer film becomes stronger due to the higher volume fraction of crystallized component.

Estimation of the Crystallinity of P-type Hydrogenated Nanocrystalline Cubic Silicon Carbide by Conductive Atomic Force Microscopy

2012 ◽  
Vol 1426 ◽  
pp. 347-352
Author(s):  
Daisuke Hamashita ◽  
Yasuyoshi Kurokawa ◽  
Makoto Konagai
Keyword(s):  
Silicon Carbide ◽  
Atomic Force Microscopy ◽  
Volume Fraction ◽  
Crystalline Silicon ◽  
Conductive Atomic Force Microscopy ◽  
Raman Scattering Spectroscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
P Type ◽  
Cubic Silicon Carbide

ABSTRACTP-type hydrogenated nanocrystalline cubic silicon carbide is a promising material for the emitter of n-type crystalline silicon heterojunction solar cell due to its lower light absorption and wider bandgap of 2.2 eV. The electrical properties of hydrogenated nanocrystalline cubic silicon carbide can be influenced by its crystallinity. In this study, we propose the use of conductive atomic force microscopy (Conductive-AFM) to evaluate the crystalline volume fraction (fc) of p-nc-3C-SiC:H thin films (20∼30 nm) as a new method instead of Raman scattering spectroscopy, X-ray diffraction, and spectroscopic ellipsometry.

scholarly journals Morphology and luminescence of photo-electrochemically synthesized porous silicon: Influence of varying current density

2017 ◽  
Vol 13 (4) ◽  
pp. 708-710
Author(s):  
Asad Thahe ◽  
Hazri Bakhtiar ◽  
Noriah Bidin ◽  
Zainuriah Hassan ◽  
Zainal Abidin Talib ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Current Density ◽  
Room Temperature ◽  
Gravimetric Method ◽  
Etching Time ◽  
Time Duration ◽  
High Quality ◽  
Force Microscopy ◽  
Room Temperature Photoluminescence ◽  
Atomic Force

Achieving high quality porous silicon (PSi) materials with desired porosity remains challenging. Three good qualities of PSi samples are prepared by Photo electro-chemically etching a piece of n-type Si inside the solution of 20 M HF, 10 M C2H5OH and 10 M H2O2 at fixed etching time duration (30 min) and varying current density (15 mA/cm2, 30 mA/cm2 and 45 mA/cm2). As-prepared sample morphologies are characterized via scanning electron microscopy (SEM) and atomic force microscopy (AFM). The gravimetric method is used to estimate the thickness and porosity of the prepared samples. Current density (etching time) dependent morphologies, electronic bandgap and room temperature photoluminescence (PL) properties of such PSi nanostructures are evaluated. These PSi structures revealed enhanced rectifying characteristics with increasing current density. 

Indentation of AlN/CrN Multilayers from Room Temperature to 400 °C

2005 ◽  
Vol 492-493 ◽  
pp. 335-340 ◽  
Author(s):  
F. Giuliani ◽  
A. Goruppa ◽  
S.J. Lloyd ◽  
Dennis Teer ◽  
W.J. Clegg
Keyword(s):  
Multilayer Structure ◽  
Room Temperature ◽  
Deformation Behaviour ◽  
Dislocation Motion ◽  
Effect Of Temperature ◽  
Columnar Microstructure ◽  
Cross Sectional ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

Observations elsewhere have shown that multilayer structures with layers ~10 nm thick can be harder than monolithic ones. Here we see whether these effects can be observed at high temperatures and investigate the effect of temperature on the manner of deformation. The hardness of an AlN/CrN multilayer structure with a range of wavelengths from 6-200 nm has been measured at temperatures from room temperature to 400 oC. The changes in hardness have been related to the deformation behaviour observed by cross-sectional transmission electron microscopy and atomic force microscopy. These observations suggest that the mechanical properties of the coatings are dominated by the refinement in the columnar microstructure rather than directly by an effect of the layer interfaces on dislocation motion.

Structural and Optical Properties of In0.27Ga0.73N/Si (111) Film Grown Using PA-MBE Technique

2012 ◽  
Vol 620 ◽  
pp. 368-372 ◽  
Author(s):  
Saleh H. Abud ◽  
Hassan Zainuriah ◽  
Fong Kwong Yam ◽  
Alaa J. Ghazai
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Molecular Beam ◽  
Grown Film ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
X Ray ◽  
Force Microscopy ◽  
Room Temperature Photoluminescence ◽  
Atomic Force

In this paper, InGaN/GaN/AlN/Si (111) structure was grown using a plasma-assisted molecular beam epitaxy (PA-MBE) technique. The structural and optical properties of grown film have been characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), high resolution X-ray diffraction (HR-XRD) and photoluminescence (PL). Indium-mole fraction has been computed to be 0.27 using XRD data and Vegards law with high grain size and low tensile strain. Room-temperature photoluminescence revealed an intense peak at 534 nm (2.3 eV) related to our sample In0.27Ga0.73N.

Cryogenic atomic force microscopy

1991 ◽  
Vol 49 ◽  
pp. 54-55
Author(s):  
K. A. Fisher ◽  
M. G. L. Gustafsson ◽  
M. B. Shattuck ◽  
J. Clarke
Keyword(s):  
Room Temperature ◽  
Rapid Freezing ◽  
Cryogenic Temperatures ◽  
Soft Or ◽  
Electrically Conductive ◽  
Force Microscopy ◽  
Flexible Molecules ◽  
Advantages And Disadvantages ◽  
Atomic Force ◽  
Chemical Perturbation

The atomic force microscope (AFM) is capable of imaging electrically conductive and non-conductive surfaces at atomic resolution. When used to image biological samples, however, lateral resolution is often limited to nanometer levels, due primarily to AFM tip/sample interactions. Several approaches to immobilize and stabilize soft or flexible molecules for AFM have been examined, notably, tethering coating, and freezing. Although each approach has its advantages and disadvantages, rapid freezing techniques have the special advantage of avoiding chemical perturbation, and minimizing physical disruption of the sample. Scanning with an AFM at cryogenic temperatures has the potential to image frozen biomolecules at high resolution. We have constructed a force microscope capable of operating immersed in liquid n-pentane and have tested its performance at room temperature with carbon and metal-coated samples, and at 143° K with uncoated ferritin and purple membrane (PM).

Hydrogen Transport and Hydrogen-Assisted Cracking in SUS304 Stainless Steel During Deformation at Low Temperatures

2015 ◽  
Author(s):  
Lin Zhang ◽  
Bai An ◽  
Takashi Iijima ◽  
Chris San Marchi ◽  
Brian Somerday
Keyword(s):  
Stainless Steel ◽  
Hydrogen Embrittlement ◽  
Room Temperature ◽  
Hydrogen Release ◽  
Hydrogen Transport ◽  
Force Microscopy ◽  
Atomic Force ◽  
Strain Induced Martensite ◽  
Hydrogen Assisted Cracking ◽  
Slip Planes

The behaviors of hydrogen transport and hydrogen-assisted cracking in hydrogen-precharged SUS304 austenitic stainless steel sheets in a temperature range from 177 to 298 K are investigated by a combined tensile and hydrogen release experiment as well as magnetic force microscopy (MFM) based on atomic force microscopy (AFM). It is observed that the hydrogen embrittlement increases with decreasing temperature, reaches a maximum at around 218 K, and then decreases with further temperature decrease. The hydrogen release rate increases with increasing strain until fracture at room temperature but remains near zero level at and below 218 K except for some small distinct release peaks. The MFM observations reveal that fracture occurs at phase boundaries along slip planes at room temperature and twin boundaries at 218 K. The role of strain-induced martensite in the hydrogen transport and hydrogen embrittlement is discussed.

ATOMIC FORCE MICROSCOPY AND XRD ANALYSIS OF SILVER FILMS DEPOSITED BY THERMAL EVAPORATION

2006 ◽  
Vol 20 (02) ◽  
pp. 217-231 ◽  
Author(s):  
MUHAMMAD MAQBOOL ◽  
TAHIRZEB KHAN
Keyword(s):  
Atomic Force Microscopy ◽  
Grain Size ◽  
Surface Characterization ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
Xrd Analysis ◽  
Force Microscopy ◽  
Atomic Force ◽  
Average Grain Size ◽  
20 Nm

Thin films of pure silver were deposited on glass substrate by thermal evaporation process at room temperature. Surface characterization of the films was performed using X-ray diffraction (XRD) and atomic force microscopy (AFM). Thickness of the films varied between 20 nm and 72.8 nm. XRD analysis provided a sharp peak at 38.75° from silver. These results indicated that the films deposited on glass substrates at room temperature are crystalline. Three-dimension and top view pictures of the films were obtained by AFM to study the grain size and its dependency on various factors. Average grain size increased with the thickness of the deposited films. A minimum grain size of 8 nm was obtained for 20 nm thick films, reaching 41.9 nm when the film size reaches 60 nm. Grain size was calculated from the information provided by the XRD spectrum and averaging method. We could not find any sequential variation in the grain size with the growth rate.

scholarly journals An Experimental Validation Study of Ferrofluid Evaporation

2021 ◽  
Author(s):  
Wenjuan YU ◽  
Decai Li ◽  
Sifang Niu
Keyword(s):  
Base Fluid ◽  
Experimental Validation ◽  
Magnetic Particles ◽  
Evaporation Rate ◽  
Volume Fraction ◽  
Test Tube ◽  
Weight Losses ◽  
Lower Volume Fraction ◽  
Lower Volume ◽  
The Magnetic Field

Abstract Kerosene based ferrofluid was put into a test tube to evaporate under different conditions. The weight losses of samples were measured and the evaporation rates were calculated. The predictions of evaporation rates were made based on Bolotov’s model. It was found that the magnetic particles prevent the base fluid from evaporation and lower volume fraction leaded to higher evaporation rate. Bolotov’s model had a certain deviation but still well responsive to different variables. It was also found that the magnetic field made a difference to the evaporation rate.

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