scholarly journals 1 ML Wetting Layer upon Ga(As)Sb Quantum Dot (QD) Formation on GaAs Substrate Monitored with Reflectance Anisotropy Spectroscopy (RAS)

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Henning Fouckhardt ◽  
Johannes Strassner ◽  
Thomas H. Loeber ◽  
Christoph Doering
Keyword(s):  
Gaas Substrate ◽  
Semiconductor Quantum Dots ◽  
Ex Situ ◽  
Difference Spectroscopy ◽  
Wetting Layer ◽  
Reflectance Anisotropy ◽  
Atomic Force ◽  
Monitoring Technique ◽  
Scientific Dispute

III/V semiconductor quantum dots (QD) are in the focus of optoelectronics research for about 25 years now. Most of the work has been done on InAs QD on GaAs substrate. But, e.g., Ga(As)Sb (antimonide) QD on GaAs substrate/buffer have also gained attention for the last 12 years. There is a scientific dispute on whether there is a wetting layer before antimonide QD formation, as commonly expected for Stransky-Krastanov growth, or not. Usually ex situ photoluminescence (PL) and atomic force microscope (AFM) measurements are performed to resolve similar issues. In this contribution, we show that reflectance anisotropy/difference spectroscopy (RAS/RDS) can be used for the same purpose as an in situ, real-time monitoring technique. It can be employed not only to identify QD growth via a distinct RAS spectrum, but also to get information on the existence of a wetting layer and its thickness. The data suggest that for antimonide QD growth the wetting layer has a thickness of 1 ML (one monolayer) only.

In situ X-ray Scattering Study of the Formation of Au Nano Crystals During Thermal Annealing

2007 ◽  
Vol 1027 ◽  
Author(s):  
Do Young Noh ◽  
Ki-Hyun Ryu ◽  
Hyon Chol Kang
Keyword(s):  
Thermal Annealing ◽  
Bragg Reflection ◽  
Ex Situ ◽  
X Ray ◽  
Force Microscopy ◽  
X Ray Scattering ◽  
Atomic Force ◽  
Au Thin Films ◽  
Ray Scattering

AbstractThe transformation of Au thin films grown on sapphire (0001) substrates into nano crystals during thermal annealing was investigated by in situ synchrotron x-ray scattering and ex situ atomic force microscopy (AFM). By monitoring the Au(111) Bragg reflection and the low Q reflectivity and comparing them with ex situ AFM images, we found that polygonal-shape holes were nucleated and grow initially. As the holes grow larger and contact each other, their boundary turns into Au nano crystals. The Au nano crystals have a well-defined (111) flat top surface and facets in the in-plane direction.

Ex Situ and In Situ Thermal Transformations of M-50 Pitch Revealed by Non-contact Atomic Force Microscopy

2021 ◽  
Author(s):  
Pengcheng Chen ◽  
Jordan N. Metz ◽  
Adam S. Gross ◽  
Stuart E. Smith ◽  
Steven P. Rucker ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Ex Situ ◽  
Thermal Transformations ◽  
Force Microscopy ◽  
Atomic Force

(G03 Best Paper Award Winner) Analysis of Sn Behavior During Ni/GeSn Solid-State Reaction by Correlated X-ray Diffraction, Atomic Force Microscopy, and Ex-situ/In-situ Transmission Electron Microscopy

2020 ◽  
Vol MA2020-02 (24) ◽  
pp. 1750-1750
Author(s):  
Andrea Quintero Colmenares ◽  
Patrice Gergaud ◽  
Jean-Michel Hartmann ◽  
Vincent Delaye ◽  
Nicolas Bernier ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ex Situ ◽  
Paper Award ◽  
X Ray Diffraction ◽  
Award Winner ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

In-Situ and Ex-Situ Studies of Silicon Interfaces and Nanostructures by Ellipsometry and Rds

1995 ◽  
Vol 406 ◽  
Author(s):  
U. Rossowl ◽  
L. Mantese ◽  
U. Frotscher ◽  
D. E. Aspnes ◽  
W. Richter
Keyword(s):  
Dielectric Function ◽  
Electrochemical Etching ◽  
Chemical Species ◽  
Ex Situ ◽  
Silicon Nanostructures ◽  
Interface Properties ◽  
Difference Spectroscopy ◽  
Reflectance Difference Spectroscopy ◽  
Modified Surfaces

AbstractWe report surface-induced optical anisotropy (SIOA) spectra and dielectric function data of vicinal Si(001) surfaces using reflectance-difference spectroscopy (RDS) and spectroscopic ellipsometry (SE). To find the main contributions of the optical response we took data for clean and by hydrogen, oxygen, and arsenic modified surfaces. The SIOA lineshapes, as measured by reflectance-difference (RD) spectroscopy, can be either derivative-like or similar to the dielectric function as measured by SE. The derivative-like spectra appear to be associated with step contributions while the dielectric-function-like behavior appears to arise from terrace dimers and/or changes in chemical species bonded to the steps. In addition, we present SE data of silicon nanostructures formed by electrochemical etching and find that their behavior is dominated by interface properties.

Characterization of the Mechanical and Tribological Properties of Sputtered a:SiC Thin Films

1996 ◽  
Vol 436 ◽  
Author(s):  
T. W. Scharf ◽  
R. B. Inturi ◽  
J. A. Barnard
Keyword(s):  
Thin Films ◽  
Ex Situ ◽  
Root Mean Square Roughness ◽  
Wear Volume ◽  
Sphere Diameter ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
Atomic Force ◽  
Ar Gas

AbstractD.C. magnetron sputtering from a CVD β-SiC target has been utilized to deposit amorphous SiC thin films on various substrates (Coming 7059 glass, unoxidized Si (111), and sapphire). The approximately 1 μm thick films were grown under various Ar sputtering pressures and flow rates. In situ annealing during deposition in vacuum and ex situ post-deposition annealing in air, both at 500°C for two hours, were implemented to determine their effects on the properties of the films. The mechanical properties were assessed via nanoindentation. An accelerated sphere-on-flat(tape) wear tester was administered to measure the wear volume losses and resultant wear rates under 0.1 and 0.2N loads, a 0.024m/s tape speed, and a 1mm ruby sphere diameter. An atomic force microscope (AFM) established the wear scar volume losses as well as the surface arithmetic roughness (RA) and root mean square roughness (RMS) of the films. The amorphous microstructure was verified by X-ray diffractometry. There was a decreasing trend in the plastic contact damage resistance, hardness, elastic modulus, and wear resistance of the films with increased amounts of Ar gas pressure; on the other hand, annealing of the lower Ar content films generated an increase in these properties compared to the as-deposited films. Atomic force microscopy revealed a more pronounced change in surface features and roughness for the in situ annealed films.

Surface Structural Characterization and Mechanical Testing by Nanoindentation Measurements of Hybrid Polymer/clay Nanostructured Multilayer Films

2002 ◽  
Vol 17 (7) ◽  
pp. 1622-1633 ◽  
Author(s):  
Xiaowu Fan ◽  
Mi-Kyoung Park ◽  
Chuanjun Xia ◽  
Rigoberto Advincula
Keyword(s):  
Thin Films ◽  
Quartz Crystal ◽  
Ex Situ ◽  
Multilayer Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Diallyldimethylammonium Chloride

Nanostructured montmorillonite/poly(diallyldimethylammonium chloride) multilayer thin films were fabricated up to 100 layers thick by stepwise alternating polyelectrolyte and clay deposition from solution. The structure and morphology of the films were characterized by x-ray diffraction, ellipsometry, atomic force microscopy, and quartz crystal microbalance ex situ and in situ measurements. The mechanical properties were tested by nanoindentation. The hardness of the multilayer thin film was 0.46 GPa. The thin film's modulus was correlated to its ordering and anisotropic structure. Both hardness and modulus of this composite film were higher than those of several other types of polymer thin films.

scholarly journals Compared EC-AFM Analysis of Laser-Induced Graphene and Graphite Electrodes in Sulfuric Acid Electrolyte

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7333
Author(s):  
Claudia Filoni ◽  
Bahram Shirzadi ◽  
Marco Menegazzo ◽  
Eugenio Martinelli ◽  
Corrado Di Natale ◽  
...  
Keyword(s):  
Ex Situ ◽  
Oxidation Reactions ◽  
Acid Electrolyte ◽  
Spectroscopy Analysis ◽  
Graphite Electrodes ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Analysis ◽  
And Performance

Flexible and economic sensor devices are the focus of increasing interest for their potential and wide applications in medicine, food analysis, pollution, water quality, etc. In these areas, the possibility of using stable, reproducible, and pocket devices can simplify the acquisition of data. Among recent prototypes, sensors based on laser-induced graphene (LIGE) on Kapton represent a feasible choice. In particular, LIGE devices are also exploited as electrodes for sensing in liquids. Despite a characterization with electrochemical (EC) methods in the literature, a closer comparison with traditional graphite electrodes is still missing. In this study, we combine atomic force microscopy with an EC cell (EC-AFM) to study, in situ, electrode oxidation reactions when LIGE or other graphite samples are used as anodes inside an acid electrolyte. This investigation shows the quality and performance of the LIGE electrode with respect to other samples. Finally, an ex situ Raman spectroscopy analysis allows a detailed chemical analysis of the employed electrodes.

Electromigration of Silicon Adatoms on Silicon (111) Surface

2011 ◽  
Vol 6 (2) ◽  
pp. 65-76
Author(s):  
Ekaterina E. Rodyakina ◽  
Sergey S. Kosolobov ◽  
Aleksandr V. Latyshev
Keyword(s):  
Electron Microscopy ◽  
Experimental Data ◽  
Effective Charge ◽  
Ex Situ ◽  
Equilibrium Conditions ◽  
Force Microscopy ◽  
Homoepitaxial Growth ◽  
Atomic Force ◽  
Reflection Electron Microscopy

Existence of adatom gradient concentration on surface between step bunches was shown under sublimation, homoepitaxial growth and near equilibrium conditions on silicon (111) surface at above 900 ºС by means of in situ ultrahigh vacuum reflection electron microscopy and ex situ atomic force microscopy. It is experimentally confirmed that adatom have negative (at 1 100 ºС) and positive (at 1 300 ºС) effective charge. We found out the sign of adatom effective charge independent on the supersaturation volume on the surface. On the hasement of experimental data we evaluated the effective charge of adatom at 1 280ºС; this quantity is placed between 0,07 ± 0,01 and 0,17 ± 0,02 of electron unit

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