Emission-Wavelength Extension of InAs/GaAs Quantum Dots by Controlling Lattice-Mismatch Strain

Author(s):  
T. Inoue ◽  
K. Matsushita ◽  
M. Kikuno ◽  
T. Kita ◽  
O. Wada ◽  
...  
RSC Advances ◽  
2015 ◽  
Vol 5 (98) ◽  
pp. 80122-80128 ◽  
Author(s):  
Mengmeng Yang ◽  
Yuanjun Yang ◽  
Bin Hong ◽  
Liangxin Wang ◽  
Zhenlin Luo ◽  
...  

The surface growth mode can induce the anomalous compressive strain in thicker VO2/Al2O3 epitaxial films, which can't be explained by conventional epitaxial lattice-mismatch. Strain may be an effective tool for manipulating MIT of the VO2 films.


2018 ◽  
Vol 759 ◽  
pp. 71-75 ◽  
Author(s):  
Peter L. Bishay ◽  
Bhavin Sampat ◽  
Jan Sladek ◽  
Ernian Pan ◽  
Vladimir Sladek

A fully coupled thermo-electro-mechanical models of cylindrical and truncated conical GaN/AlN Functionally Graded Quantum Dot (FGQD) systems with and without WL are analyzed in this study to determine the effect of lattice mismatch strain grading on the electromechanical behavior of the FGQD system. This has a technological and fundamental importance because the production methodology adopted for manufacturing QDs enables the composition of the QD material to be graded in the growth direction, so the material properties as well as the induced mismatch strain between the QD and the carrier matrix are accordingly graded. The power law is used to describe the grading function. Based on the obtained results, grading of material properties and lattice mismatch strain have significant effect on the distribution of the electromechanical quantities inside the QD and can be used as another tuning parameter in the design of QD systems.


2001 ◽  
Vol 695 ◽  
Author(s):  
Zhaohua Feng ◽  
Edward G. Lovell ◽  
Roxann L. Engelstad ◽  
Thomas F. Kuech

ABSTRACTAs films heteroepitaxially grow on substrates, lattice mismatch strain at the interfaces causes stresses in the films and substrates. These stresses can have deleterious effects on film quality. To facilitate an understanding of defect production and control during growth of films on compliant substrates, transient finite element models were developed to simulate the complete mechanical stress and strain fields. Effects of constraints between the template and handle wafer on the film stresses were examined. The investigation showed that different types of constraints caused stress variations over a large range. Other factors affecting the stresses, such as lattice mismatch strain, wafer radius, film and template thickness, were also assessed.


2007 ◽  
Vol 90 (1) ◽  
pp. 012509 ◽  
Author(s):  
Guanyin Gao ◽  
Shaowei Jin ◽  
Wenbin Wu

2001 ◽  
Vol 696 ◽  
Author(s):  
Zhaohua Feng ◽  
Edward G. Lovell ◽  
Roxann L. Engelstad ◽  
Peter D. Moran ◽  
Thomas F. Kuech

AbstractLattice mismatch strain between films and substrates causes stresses in each and degrades the film quality. Compliant substrates can decrease the stresses and dislocation density in the film. A particular type of compliant substrate, which consists of a thin template, a handle wafer and a glass interlayer, is discussed here. Three-dimensional axisymmetric finite element models were developed to simulate the film-substrate structure and analyze stress generation and relaxation. The materials of film and template were considered as elastic but the glass interlayer was viscoelastic at the film growth temperature. Factors affecting stress generation and relaxation are reported.


1999 ◽  
Vol 14 (4) ◽  
pp. 1560-1569 ◽  
Author(s):  
F. B. Mancoff ◽  
J. F. Bobo ◽  
O. E. Richter ◽  
K. Bessho ◽  
P. R. Johnson ◽  
...  

We have sputter deposited NiMnSb/PtMnSb Heusler alloy superlattices with bilayer periods from 9–160 Å. X-ray diffraction and cross-sectional transmission electron microscopy (TEM) measurements indicate that even for short bilayer periods, the superlattices are compositionally modulated, epitaxial, and maintain the Heusler alloy C1b structure. Low- and high-angle diffraction profiles are in agreement with simulations of the superlattice peaks. TEM images reveal defects, including stacking faults, which help relieve lattice mismatch strain. Energy minimization calculations of the stacking fault density are within a factor of 3 of the density observed by TEM. The saturation magnetization of the superlattices is close to bulk PtMnSb and NiMnSb, with a tendency for perpendicular magnetization at short bilayer periods.


2010 ◽  
Vol 645-648 ◽  
pp. 363-366 ◽  
Author(s):  
Kazuaki Seki ◽  
Kai Morimoto ◽  
Toru Ujihara ◽  
Tomoharu Tokunaga ◽  
Katsuhiro Sasaki ◽  
...  

6H-SiC hetero-epitaxially grown on a (111) 3C-SiC was observed with TEM. High-density stacking faults were formed around the hetero-interface, and the density of stacking faults decreased with increasing distance from interface. On the other hand, when 3C-SiC was homo-epitaxially grown on a 3C-SiC, any stacking faults did not exist at the interface between the grown crystal and the seed crystal. Thus, the stacking faults formation started from the 6H/3C hetero-interface. Considering the lattice-mismatch strain between 3C-SiC and 6H-SiC, the strain energy is equivalent to the stacking fault energy of 6H-SiC. This similarity suggests that the stacking faults formation could be caused by the relaxation of the lattice-mismatch strain.


Sign in / Sign up

Export Citation Format

Share Document