scholarly journals Effects of cluster diffusion on the island density and size distribution in submonolayer island growth

2011 ◽  
Vol 83 (4) ◽  
Author(s):  
Y. A. Kryukov ◽  
Jacques G. Amar
Keyword(s):  
Size Distribution ◽  
Island Growth ◽  
Cluster Diffusion ◽  
Island Density

scholarly journals Cathodoluminescence Wavelength Imaging Study of Clustering in InAs/GaAs Self-Assembled Quantum Dots

2000 ◽  
Vol 618 ◽  
Author(s):  
D. H. Rich ◽  
C. Zhang ◽  
I. Mukhametzhanov ◽  
A. Madhukar
Keyword(s):  
Quantum Dots ◽  
Spatial Scale ◽  
Size Distribution ◽  
Imaging Study ◽  
Island Growth ◽  
Spectral Lineshape ◽  
Force Microscopy ◽  
Self Organized ◽  
Atomic Force ◽  
Self Assembled

ABSTRACTCathodoluminescence wavelength imaging (CLWI) of InAs/GaAs self-assembled quantum dots (SAQDs) was performed to study the spatial variation in the spectral lineshape of the broadened quantum dot (QD) ensemble. The lineshape was found to vary on a scale of ∼μm, revealing attendant variations in the size distribution of SAQD clusters on this spatial scale. Energy variations in clusters of SAQDs are found to exhibit a spatial correlation with the efficiency of luminescence and the activation energy for thermal re-emission of carriers. A reduction in the energy variation of the QD clusters occurs when the thickness of the spacer layers in vertically self-organized samples is reduced or the number of stacks is increased. SAQDs were also prepared by punctuated island growth (PIG), in which deposition of the total desired amount is broken into two or more stages each separated by time delays. CLWI reveals a reduced variation in the energy of the dominant CL emission on a ∼μm spatial scale, correlating with a narrower size distribution of larger QDs for PIG, as measured in atomic force microscopy.

scholarly journals Island Growth of Poly(chloro-p-xylylene) Coatings

2021 ◽  
Vol 63 (1) ◽  
pp. 22-30
Author(s):  
A. S. Medvedeva ◽  
D. R. Streltsov ◽  
P. V. Dmitryakov ◽  
A. A. Nesmelov ◽  
A. I. Buzin ◽  
...  
Keyword(s):  
Size Distribution ◽  
Surface Coverage ◽  
Dynamic Scaling ◽  
Silicon Substrates ◽  
Island Growth ◽  
Force Microscopy ◽  
Atomic Force ◽  
Capture Zones ◽  
Average Size ◽  
Low Degrees

Abstract The evolution of the morphology of island poly(chloro-p-xylylene) films formed on silicon substrates by vapor deposition polymerization is investigated by atomic force microscopy. The dependences of the effective thickness of the island coating, the number density of polymer islands, and their average size on the surface coverage are studied. The maximal density of polymer islands and the surface coverage corresponding to the transition to the coalescence regime are estimated. Within the framework of the theory of dynamic scaling, the size distribution of islands and the size distribution of their “capture zones” are analyzed. It is shown that, at low degrees of filling of the substrate, before the coalescence of islands, these distributions are described by scaling functions corresponding to the model of reaction-limited aggregation. The size of the critical nucleus is estimated from the size distributions of the “capture zones” of polymer islands.

PHENOMENOLOGICAL VIEW OF NUCLEATION AND GROWTH OF Si ON THE Si(111)-(7×7) SUPERLATTICE

2000 ◽  
Vol 07 (01n02) ◽  
pp. 61-66 ◽  
Author(s):  
YUKICHI SHIGETA
Keyword(s):  
Activation Energy ◽  
Free Energy ◽  
Surface Structure ◽  
Epitaxial Growth ◽  
Size Distribution ◽  
Nucleation And Growth ◽  
Island Growth ◽  
Rearrangement Process ◽  
Phenomenological Consideration ◽  
The Difference

The influence of surface structure on epitaxial growth, which has not been considered before in the crystal growth theory, is discussed for the case of epitaxial growth of Si on Si(111)-(7×7) substrate. Since the rearrangement of surface structure is essential for progressing the epitaxial growth, the activation energy for the rearrangement is considered into the free energy change in the nucleation and growth processes. From a phenomenological consideration, some features of island shape and size distribution, which had been observed, are clearly explained. The size distribution is discontinuous according to the size of the unit cell of the superlattice and the shape will be almost triangular. These features are caused by prevention of the lateral growth at the faulted half in the 7×7 structure. After the evaporation has been stopped, the detachment of atoms from corners of the triangular island starts and the island shows a rounded shape. The detachment after the deposition is also explained by the difference in the free energy changes between during and after deposition. It is suggested that the activation energy for the rearrangement process of the 7×7 structure with island growth is much higher than that for the formation process with thermal decay of the Si island.

The extinction time of a general birth and death process with catastrophes

1986 ◽  
Vol 23 (04) ◽  
pp. 851-858 ◽  
Author(s):  
P. J. Brockwell
Keyword(s):  
Laplace Transform ◽  
Size Distribution ◽  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Death Process ◽  
Extinction Time ◽  
Birth And Death Process ◽  
Different Types ◽  
The Laplace Transform ◽  
Necessary And Sufficient

The Laplace transform of the extinction time is determined for a general birth and death process with arbitrary catastrophe rate and catastrophe size distribution. It is assumed only that the birth rates satisfyλ0= 0,λj> 0 for eachj> 0, and. Necessary and sufficient conditions for certain extinction of the population are derived. The results are applied to the linear birth and death process (λj=jλ, µj=jμ) with catastrophes of several different types.

Macrostructure and microphysics of Saturn's E-ring

1984 ◽  
Vol 75 ◽  
pp. 607-613 ◽  
Author(s):  
Kevin D. Pang ◽  
Charles C. Voge ◽  
Jack W. Rhoads
Keyword(s):  
Size Distribution ◽  
Spherical Shape ◽  
Mie Scattering ◽  
Narrow Size Distribution ◽  
Electrostatic Levitation ◽  
Volcanic Origin ◽  
Micron Diameter

Abstract.All observed optical and infrared properties of Saturn's E-ring can be explained in terms of Mie scattering by a narrow size distribution of ice spheres of 2 - 2.5 micron diameter. The spherical shape of the ring particles and their narrow size distribution imply a molten (possibly volcanic) origin on Enceladus. The E-ring consists of many layers, possibly stratified by electrostatic levitation.

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