Band edge modulation and interband optical transition in AlN:Mg$_{{\rm{Al}}}$-O$_{{\rm{N}}}$ nanotubes

2014 ◽  
Vol 1 (2) ◽  
pp. 025030
Author(s):  
Pu Huang ◽  
Jun-jie Shi ◽  
Min Zhang ◽  
Xin-he Jiang ◽  
Hong-xia Zhong ◽  
...  
Keyword(s):  
Optical Transition ◽  
Band Edge ◽  
Interband Optical Transition

scholarly journals Positive and Negative Donor Impurity in an InAs/AlAs Quantum Wire

2010 ◽  
Vol 2 (3) ◽  
pp. 433
Author(s):  
N. Arunachalam ◽  
A. J. Peter
Keyword(s):  
Binding Energy ◽  
Quantum Wire ◽  
Optical Transition ◽  
Binding Energies ◽  
Impurity Level ◽  
Wire Radius ◽  
Emission Energy ◽  
Interband Optical Transition ◽  
Mass Approximation ◽  
Charged Donor

Binding energies of positive and negative charged donor impurities in an InAs/AlAs cylindrical quantum wire are investigated. Numerical calculations are performed using the variational procedure within the single band effective mass approximation. We assume that the impurity is located at the axis of the wire. The interband optical transition with and without the exciton is computed as a function of wire radius. The valence-band anisotropy is included in our theoretical model by using different hole masses in different spatial directions. Neutral shallow donors comprise a positively charged donor and a single bound electron. It is observed that (i) negative trions have a higher binding energy than positive trions, (ii) the binding energy of the heavy-hole exciton is much larger than that of the light-hole exciton due to different hole mass values (iii) the exciton binding energy and the interband emission energy are both increased when the radius of the cylindrical quantum wire is decreased and (iv) the effect of exciton influences the interband emission energy. Our results are in good agreement with the recent published results. Keywords: Quantum wire; Impurity level; Binding energy; Excitons. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i3.4715                 J. Sci. Res. 2 (3), 433-441 (2010)  

Calculated interband optical transition spectra of GdN

2008 ◽  
Vol 78 (19) ◽  
Author(s):  
Chandrima Mitra ◽  
Walter R. L. Lambrecht
Keyword(s):  
Optical Transition ◽  
Interband Optical Transition

TUNING OF THE MAGNETIC FIELD INDUCED SHARP BAND-EDGE OPTICAL ABSORPTION IN EUROPIUM CHALCOGENIDES

2004 ◽  
Vol 18 (27n29) ◽  
pp. 3813-3816 ◽  
Author(s):  
A. B. HENRIQUES ◽  
L. K. HANAMOTO ◽  
E. TER HAAR ◽  
E. ABRAMOF ◽  
A. Y. UETA ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Optical Absorption ◽  
Low Temperatures ◽  
Optical Transition ◽  
Band Edge ◽  
Near Band Edge ◽  
High Magnetic Fields ◽  
Sharp Band ◽  
The Magnetic Field

The near band-edge polarized optical optical absortion spectra of EuTe at low temperatures and high magnetic fields were investigated. The samples were grown by MBE on BaF 2 substrates, and the thickness varied in the 0.18-2.0 μm range. At high magnetic fields, the well-known 4f7→4f65d(t2g) optical transition splits into two well resolved lines at σ+ and two lines for σ-. These lines can be described by localized transitions tunable by the d-f exchange interaction, with a quadratic dependence on the intensity of the external magnetic field. Comparative measurements of the magnetization and the optical absorption as a function temperature provides a further test of the model of a localized excitation extending over a few lattice sites.

Interband optical transition spectra in GaAs quantum wires with rectangular cross sections

1997 ◽  
Vol 56 (4) ◽  
pp. 1958-1966 ◽  
Author(s):  
T. Sogawa ◽  
H. Ando ◽  
S. Ando ◽  
H. Kanbe
Keyword(s):  
Cross Sections ◽  
Quantum Wires ◽  
Optical Transition ◽  
Interband Optical Transition

Light Emission Induced by the Indium Distribution in InGaN Nanowires

2013 ◽  
Vol 815 ◽  
pp. 148-153
Author(s):  
Jun Jie Shi ◽  
Tie Cheng Zhou ◽  
Hong Xia Zhong ◽  
Xin He Jiang ◽  
Pu Huang
Keyword(s):  
First Principles ◽  
Electronic Structures ◽  
Light Emission ◽  
Optical Transition ◽  
Laser Diodes ◽  
Optoelectronic Devices ◽  
Surface States ◽  
First Principles Calculations ◽  
Light Emitting ◽  
Interband Optical Transition

The InGaN nanowires (NWs) have attracted intense attention for their huge potential in applications such as light emitting diodes, laser diodes and solar cells. Although lots of work are focused on improving their optical performance, little is known about the influence of the In distribution and the surface states on the microscopic light emission mechanism. In order to give an atomic level understanding, we investigate the electronic structures of the wurtziteGa-rich InGaN NWs with different In distributions using first-principles calculations. We find that the In-atoms are apt to distribute on the surface of the NWs and the short surface In-N chains can be easily formed. For the unsaturated NWs, several new bands are induced by the surface states, which can be modified by the surface In microstructures. The randomly formed surface In-N chains can highly localize the electrons/holes at the band edges and dominate the interband optical transition. For the saturated NWs, the band edges are determined by the inner atoms. Our work is useful to improve the performance of the InGaN NW-based optoelectronic devices.

Interband Light Absorption in Semiconductor Quantum Dots Connected with the Charged and Neutral Exciton - Donor Complexes

2005 ◽  
Vol 277-279 ◽  
pp. 893-898
Author(s):  
A.P. Djotyan ◽  
A.A. Avetisyan ◽  
E.M. Kazaryan
Keyword(s):  
Quantum Dots ◽  
Oscillator Strength ◽  
Ground State ◽  
Light Absorption ◽  
Quantum Confinement ◽  
Optical Transition ◽  
Semiconductor Quantum Dots ◽  
Spherical Quantum Dot ◽  
Interband Optical Transition ◽  
Interband Light Absorption

The interband light absorption in spherical quantum dot (QD) of semiconductors connected with the charged and neutral exciton-donor complexes are studied theoretically. The oscillator strength for interband optical transition from valence band to the ground state of excitondonor complex in spherical QD has been investigate. The calculations were performed in the cases of infinite and finite potential barrier of QD. The dependences of the oscillator strength on the radius of the QD were obtained. It was shown that the quantum confinement gives rise a giant oscillator strength per impurity.

The optical bandgap and band-edge positions of semiconducting p-type CuYO2

1985 ◽  
Vol 63 (10) ◽  
pp. 1306-1308 ◽  
Author(s):  
F. A. Benko ◽  
F. P. Koffyberg
Keyword(s):  
Valence Band ◽  
Optical Transition ◽  
Optical Bandgap ◽  
Band Edge ◽  
Valence Band Edge ◽  
Vacuum Level ◽  
Type Semiconductor ◽  
P Type

CuYO2, doped with calcium, is a low-mobility p-type semiconductor. From photoelectrochemical measurements it is found that the valence band edge is 5.3 eV below the vacuum level, typical for oxides with a metal-3d valence band. The lowest bandgap is 1.20 eV and the transition is indirectly allowed. An optical transition at 3.60 eV indicates an oxygen-2p valence band at 7.7 eV below vacuum. The results are discussed with the help of a simplified band scheme.

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