scholarly journals Atomic Self-Ordering in Heteroepitaxially Grown Semiconductor Quantum Dots Due to Relaxation of External Lattice Mismatch Strains

2001 ◽  
Vol 707 ◽  
Author(s):  
Peter Möck ◽  
Teya Topuria ◽  
Nigel D. Browning ◽  
Robin J. Nicholas ◽  
Roger G. Booker
Keyword(s):  
Quantum Dots ◽  
Low Temperatures ◽  
Short Range ◽  
Lattice Mismatch ◽  
Life Time ◽  
Semiconductor Quantum Dots ◽  
Quantum Dot Lasers ◽  
Atomic Order ◽  
Transmission Electron ◽  
Gaas Quantum Dot

ABSTRACTThermodynamic arguments are presented for the formation of atomic order in heteroepitaxially grown semiconductor quantum dots. From thermodynamics several significant properties of these systems can be derived, such as an enhanced critical temperature of the disorder-order transition, the possible co-existence of differently ordered domains of varying size and orientation, the possible existence of structures that have not been observed before in semiconductors, the occurrence of atomic order over time, and the occurrence of short range order when the growth proceeds at low temperatures. Transmission electron microscopy results support these predictions. Finally, we speculate on the cause for the observed increase in life time of (In,Ga)As/GaAs quantum dot lasers [H-Y. Liu et al., Appl. Phys. Lett. 79, 2868 (2001)].

scholarly journals Atomic Self-ordering in Heteroepitaxially Grown Semiconductor Quantum Dots due to Relaxation of External Lattice Mismatch Strains

2001 ◽  
Vol 696 ◽  
Author(s):  
Peter Möck ◽  
Teya Topuria ◽  
Nigel D. Browning ◽  
Robin J. Nicholas ◽  
Roger G. Booker
Keyword(s):  
Quantum Dots ◽  
Low Temperatures ◽  
Short Range ◽  
Lattice Mismatch ◽  
Life Time ◽  
Semiconductor Quantum Dots ◽  
Quantum Dot Lasers ◽  
Atomic Order ◽  
Transmission Electron ◽  
Gaas Quantum Dot

AbstractThermodynamic arguments are presented for the formation of atomic order in heteroepitaxially grown semiconductor quantum dots. From thermodynamics several significant properties of these systems can be derived, such as an enhanced critical temperature of the disorder-order transition, the possible co-existence of differently ordered domains of varying size and orientation, the possible existence of structures that have not been observed before in semiconductors, the occurrence of atomic order over time, and the occurrence of short range order when the growth proceeds at low temperatures. Transmission electron microscopy results support these predictions. Finally, we speculate on the cause for the observed increase in life time of (In,Ga)As/GaAs quantum dot lasers [H-Y. Liu et al., Appl. Phys. Lett. 79, 2868 (2001)].

Ordering in Ni4Mo by TEM and APFIM

1987 ◽  
Vol 45 ◽  
pp. 214-215
Author(s):  
E.A. Kenik ◽  
T.A. Zagula ◽  
M.K. Miller ◽  
J. Bentley
Keyword(s):  
Electron Irradiation ◽  
Low Temperatures ◽  
Short Range ◽  
Atom Probe ◽  
Range Order ◽  
Considerable Time ◽  
Probe Field ◽  
Disordered Phase ◽  
Transmission Electron ◽  
Diffraction Patterns

The state of long-range order (LRO) and short-range order (SRO) in Ni4Mo has been a topic of interest for a considerable time (see Brooks et al.). The SRO is often referred to as 1½0 order from the apparent position of the diffuse maxima in diffraction patterns, which differs from the positions of the LRO (D1a) structure. Various studies have shown that a fully disordered state cannot be retained by quenching, as the atomic arrangements responsible for the 1½0 maxima are present at temperatures above the critical ordering temperature for LRO. Over 20 studies have attempted to identify the atomic arrangements associated with this state of order. A variety of models have been proposed, but no consensus has been reached. It has also been shown that 1 MeV electron irradiation at low temperatures (∼100 K) can produce the disordered phase in Ni4Mo. Transmission electron microscopy (TEM), atom probe field ion microscopy (APFIM), and electron irradiation disordering have been applied in the current study to further the understanding of the ordering processes in Ni4Mo.

scholarly journals Wafer-Scale Epitaxial Low Density InAs/GaAs Quantum Dot for Single Photon Emitter in Three-Inch Substrate

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 930
Author(s):  
Xiaoying Huang ◽  
Rongbin Su ◽  
Jiawei Yang ◽  
Mujie Rao ◽  
Jin Liu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Single Photon ◽  
Growth Parameters ◽  
Life Time ◽  
Correlation Factor ◽  
Low Density ◽  
Wafer Scale ◽  
Two Photon ◽  
Gaas Quantum Dot ◽  
Highly Uniform

In this work, we successfully achieved wafer-scale low density InAs/GaAs quantum dots (QDs) for single photon emitter on three-inch wafer by precisely controlling the growth parameters. The highly uniform InAs/GaAs QDs show low density of μ0.96/μm2 within the radius of 2 cm. When embedding into a circular Bragg grating cavity on highly efficient broadband reflector (CBR-HBR), the single QDs show excellent optoelectronic properties with the linewidth of 3± 0.08 GHz, the second-order correlation factor g2(τ)=0.0322 ±0.0023, and an exciton life time of 323 ps under two-photon resonant excitation.

An X-ray scattering study on inverted Ge–Si huts grown at low temperatures

2004 ◽  
Vol 19 (4) ◽  
pp. 347-351
Author(s):  
J. Xu ◽  
X. S. Wu ◽  
B. Qian ◽  
J. F. Feng ◽  
S. S. Jiang ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Lattice Strain ◽  
Lattice Mismatch ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Large Lattice ◽  
Scattering Study

Ge–Si inverted huts, which formed at the Si∕Ge interface of Si∕Ge superlattice grown at low temperatures, have been measured by X-ray diffraction, grazing incidence X-ray specular and off-specular reflectivities, and transmission electron microscopy (TEM). The surface of the Si∕Ge superlattice is smooth, and there are no Ge–Si huts appearing on the surface. The roughness of the surfaces is less than 3 Å. Large lattice strain induced by lattice mismatch between Si and Ge is found to be relaxed because of the intermixing of Ge and Si at the Si∕Ge interface.

Transmission electron microscopy of semiconductor quantum dots

2000 ◽  
Vol 199 (2) ◽  
pp. 130-140 ◽  
Author(s):  
C.-P. Liu ◽  
P. D. Miller ◽  
W. L. Henstrom ◽  
J. M. Gibson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Quantum Dots ◽  
Semiconductor Quantum Dots ◽  
Transmission Electron

Photochromism and magneto-optic response of ZnO:Mn semiconductor quantum dots fabricated by microemulsion route

Open Physics ◽  
2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Nirmal Misra ◽  
Mohendra Roy ◽  
Dambarudhar Mohanta ◽  
Kishor Baruah ◽  
Amarjyoti Choudhury
Keyword(s):  
Quantum Dots ◽  
Quantum Confinement Effect ◽  
Colour Change ◽  
Underlying Mechanism ◽  
Semiconductor Quantum Dots ◽  
Transmission Electron ◽  
Photochromic Effect ◽  
Diluted Magnetic ◽  
Average Size ◽  
Magneto Optic

AbstractZnO:Mn semiconductor quantum dots were prepared by solution casting led microemulsion route. Quantum dots of average size ∼2 nm were noticed in transmission electron micrographs. The present work highlights colour change phenomena (photochromic effect) of quantum dots while subjected to photon illumination. The magneto-optic measurements e.g. magnetic field (H) vs angle of rotation (θ) show step like behavior and is ascribed to the quantum confinement effect of diluted magnetic ZnO:Mn nanostructures. Further, underlying mechanism responsible for exhibiting photochromism and magneto-optic effects are also discussed.

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