Self-organization mechanism of GalnP quantum wires in (GaP) m /(lnP) m short-period binary superlattices for GalnP/AllnP multi-quantum-wire (MQWR) lasers

1996 ◽  
Vol 28 (5) ◽  
pp. 547-556 ◽  
Author(s):  
J. Yoshida ◽  
K. Kishino ◽  
D. H. Jang ◽  
S. Nahm ◽  
I. Nomura ◽  
...  
Keyword(s):  
Quantum Wire ◽  
Quantum Wires ◽  
Self Organization ◽  
Short Period ◽  
Organization Mechanism

Strain measurement in In0.2Ga0.8As/GaAs quantum wires by convergent beam electron diffraction

1995 ◽  
Vol 53 ◽  
pp. 444-445
Author(s):  
S. Hillyard ◽  
Y.-P. Chen ◽  
J.D. Reed ◽  
W.J. Schaff ◽  
L.F. Eastman ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Semiconductor Lasers ◽  
Quantum Wire ◽  
Quantum Wires ◽  
Convergent Beam Electron Diffraction ◽  
Zero Order ◽  
Beam Electron ◽  
Local Lattice ◽  
Device Applications ◽  
Convergent Beam

The positions of high-order Laue zone (HOLZ) lines in the zero order disc of convergent beam electron diffraction (CBED) patterns are extremely sensitive to local lattice parameters. With proper care, these can be measured to a level of one part in 104 in nanometer sized areas. Recent upgrades to the Cornell UHV STEM have made energy filtered CBED possible with a slow scan CCD, and this technique has been applied to the measurement of strain in In0.2Ga0.8 As wires.Semiconductor quantum wire structures have attracted much interest for potential device applications. For example, semiconductor lasers with quantum wires should exhibit an improvement in performance over quantum well counterparts. Strained quantum wires are expected to have even better performance. However, not much is known about the true behavior of strain in actual structures, a parameter critical to their performance.

scholarly journals Strong and robust polarization anisotropy of site- and size-controlled single InGaN/GaN quantum wires

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hwan-Seop Yeo ◽  
Kwanjae Lee ◽  
Young Chul Sim ◽  
Seoung-Hwan Park ◽  
Yong-Hoon Cho
Keyword(s):  
Quantum Wire ◽  
Quantum Wires ◽  
Geometrical Shape ◽  
Optical Polarization ◽  
Polarization Anisotropy ◽  
Single Quantum ◽  
Group Iii ◽  
Highly Efficient ◽  
Group Iii Nitride ◽  
Size Controlled

Abstract Optical polarization is an indispensable component in photonic applications, the orthogonality of which extends the degree of freedom of information, and strongly polarized and highly efficient small-size emitters are essential for compact polarization-based devices. We propose a group III-nitride quantum wire for a highly-efficient, strongly-polarized emitter, the polarization anisotropy of which stems solely from its one-dimensionality. We fabricated a site-selective and size-controlled single quantum wire using the geometrical shape of a three-dimensional structure under a self-limited growth mechanism. We present a strong and robust optical polarization anisotropy at room temperature emerging from a group III-nitride single quantum wire. Based on polarization-resolved spectroscopy and strain-included 6-band k·p calculations, the strong anisotropy is mainly attributed to the anisotropic strain distribution caused by the one-dimensionality, and its robustness to temperature is associated with an asymmetric quantum confinement effect.

A short-period GaAs-AlGaAs quantum-wire array laser with a submicrometer current blocking layer

1997 ◽  
Vol 9 (1) ◽  
pp. 2-4 ◽  
Author(s):  
Tae-Geun Kim ◽  
Kyung-Hyun Park ◽  
Eun Kyu Kim ◽  
Suk-Ki Min ◽  
Jung-Ho Park
Keyword(s):  
Quantum Wire ◽  
Wire Array ◽  
Blocking Layer ◽  
Short Period ◽  
Current Blocking Layer ◽  
Current Blocking

Structural self-organization mechanism of ZnO nanoparticles in acrylate composites

2013 ◽  
Vol 80 (3) ◽  
pp. 187 ◽  
Author(s):  
Yu. É. Burunkova ◽  
I. Yu. Denisyuk ◽  
S. A. Sem’ina
Keyword(s):  
Zno Nanoparticles ◽  
Self Organization ◽  
Organization Mechanism

Variational Calculations of Donor Binding Energy in Rectangular Wurtzite Aluminium Gallium Nitride / Gallium Nitride Quantum Wires

2007 ◽  
Vol 1040 ◽  
Author(s):  
Choudhury Jayant Praharaj
Keyword(s):  
Gallium Nitride ◽  
Binding Energy ◽  
Electric Fields ◽  
Quantum Wire ◽  
Quantum Wires ◽  
Potential Profile ◽  
Nitride Semiconductors ◽  
Aluminium Gallium Nitride ◽  
Donor Binding Energy ◽  
Variational Calculations

AbstractWe present variational calculations of donor binding energy in rectangular wurtzite aluminium gallium nitride / gallium nitride quantum wires. We explicitly take into account the effect of spontaneous and piezoelectric polarization on the energy levels of donors in quantum wires. Wurtzite structure nitride semiconductors have spontaneous polarization even in the absence of externally applied electric fields. They also have large piezoelectric polarization when grown as pseudomorphic layers. The magnitude of both polarization components is of the order of 1013 electrons per cm2, and has a non-trivial effect on the potential profile seen by electrons. Due to the large built-in electric fields resulting from the polarization discontinuities at heterojunctions, the binding energies of donors is a strong function of the position inside the quantum wire. The potential profile in the 0001 direction can vary by as much as 1.5eV due to polarization effects for vertical dimensions of the quantum wire up to 20 angstroms. The probability density of electrons tends to concentrate near the minimum of the conduction band profile in the 0001 direction. Donors located close to this minimum tend to have a larger concentration of electron density compared to those located closer to the maximum. As a consequence, the binding energy of the former are higher compared to the latter. We use Lorentzian variational wavefunctions to calculate the binding energy as a function of donor position. The confinement potential enhances the binding by a factor of about 3 compared to donors in bulk nitride semiconductors, from about 30 meV to about 90 meV. The variation of binding energy with position is calculated to be more than 50% for typical compositions of the quantum wire regions. Our calculations will be useful for understanding device applications involving n-type doped nitride semiconductor quantum wires.

Silicon Self-Interstitial Clusters

1998 ◽  
Vol 538 ◽  
Author(s):  
L. Colombo ◽  
A. Bongiorno ◽  
M. ROSATI
Keyword(s):  
Molecular Dynamics ◽  
Tight Binding ◽  
Self Organization ◽  
Interstitial Atoms ◽  
Organization Mechanism

AbstractA tight-binding molecular dynamics investigation on the structure and energetics of self-interstitial clusters in silicon is presented. We discuss how a small number of self-interstitial atoms give rise to the formation of tedrahedally-shaped clusters, while a larger number of defects exhibit a self-organization mechanism driving the system to form rod-like defects.

scholarly journals Energy Levels in Nanowires and Nanorods with a Finite Potential Well

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
G. Gulyamov ◽  
A. G. Gulyamov ◽  
A. B. Davlatov ◽  
Kh. N. Juraev
Keyword(s):  
Electron Energy ◽  
Quantum Wire ◽  
Quantum Wires ◽  
Energy Levels ◽  
Electron Energy Spectrum ◽  
Constant Thickness ◽  
Potential Well ◽  
Discrete Level ◽  
Effective Masses ◽  
Internal Radius

The energy of electrons and holes in cylindrical quantum wires with a finite potential well was calculated by two methods. An analytical expression is approximately determined that allows one to calculate the energy of electrons and holes at the first discrete level in a cylindrical quantum wire. The electron energy was calculated by two methods for cylindrical layers of different radius. In the calculations, the nonparabolicity of the electron energy spectrum is taken into account. The dependence of the effective masses of electrons and holes on the radius of a quantum wires is determined. An analysis is made of the dependence of the energy of electrons and holes on the internal and external radii, and it is determined that the energy of electrons and holes in cylindrical layers with a constant thickness weakly depends on the internal radius. The results were obtained for the InP/InAs heterostructures.

POLAR INTERFACE-OPTICAL VIBRATIONAL SPECTRA IN A WURTZITE GaN/AlN RECTANGULAR QUANTUM WIRE

2006 ◽  
Vol 13 (01) ◽  
pp. 75-80 ◽  
Author(s):  
L. ZHANG
Keyword(s):  
Quantum Wells ◽  
Quantum Wire ◽  
Quantum Wires ◽  
Uniaxial Crystal ◽  
Wave Number ◽  
Phonon Modes ◽  
Crystal Model ◽  
Limited Frequency ◽  
Dielectric Continuum ◽  
Dielectric Continuum Model

Under the dielectric continuum model and Loudon's uniaxial crystal model, the interface optical (IO) phonon modes in a quasi-one-dimensional (Q1D) wurtzite rectangular quantum wire are deduced and analyzed. Numerical calculation on a wurtzite GaN/AlN rectangular wurtzite quantum wire was performed. Results reveal that the dispersion frequencies of IO modes sensitively depend on the geometric structures of the Q1D wurtzite rectangular quantum wires. The degenerating behavior of the IO phonon modes in the Q1D wurtzite rectangular quantum wire has been clearly observed for small free wave number kz in z-direction. The limited frequency behaviors of IO modes have been analyzed deeply, and detailed comparisons with those in wurtzite planar quantum wells and cylindrical quantum wires are also done. Moreover, once the anisotropy of the wurtzite material has been ignored, the present theories can be naturally reduced to the situation of Q1D cubic rectangular quantum wire systems.

ONE-PHONON-ASSISTED ELECTRON RESONANT RAMAN SCATTERING IN FREE-STANDING QUANTUM WIRES

2007 ◽  
Vol 21 (17) ◽  
pp. 2989-3000
Author(s):  
XIANG-FU ZHAO ◽  
CUI-HONG LIU
Keyword(s):  
Raman Scattering ◽  
Quantum Wire ◽  
Quantum Wires ◽  
Longitudinal Optical ◽  
Phonon Modes ◽  
Free Standing ◽  
Surface Optical ◽  
Resonant Raman ◽  
Resonant Raman Scattering ◽  
Valence Bands

The scattering intensity (SI) for an electron resonant Raman scattering (ERRS) process in a free-standing semiconductor quantum wire of cylindrical geometry associated with bulk longitudinal optical (LO) phonon modes or the surface optical (SO) phonon modes is calculated for T=0 K . The Fröhlich interaction is considered to illustrate the theory for a GaAs system. Electron states are confined within a free-standing quantum wire (FSW). Single parabolic conduction and valence bands are assumed. The selection rules are studied. Numerical results and a discussion are also presented for various radii of the cylindrical quantum wires.

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