Effect of geometry on the screened acceptor binding energy in a quantum wire

2014 ◽  
Author(s):  
R. Vijaya Shanthi ◽  
P. Nithiananthi
Keyword(s):  
Binding Energy ◽  
Quantum Wire ◽  
Acceptor Binding Energy

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)  

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.

BARRIER THICKNESS DEPENDENCE OF OPTICAL ABSORPTION OF EXCITONS IN GaAs COUPLED QUANTUM WIRE

2004 ◽  
Vol 11 (01) ◽  
pp. 49-55 ◽  
Author(s):  
E. KASAPOGLU ◽  
M. GUNES ◽  
H. SARI ◽  
I. SÖKMEN
Keyword(s):  
Binding Energy ◽  
Optical Absorption ◽  
Quantum Wire ◽  
Variational Approach ◽  
Quantum Wires ◽  
Binding Energies ◽  
Barrier Thickness ◽  
Mass Approximation ◽  
Quantum Well Wires ◽  
Coupled Quantum Well

We have calculated the binding energy of excitons, and the interband optical absorption in rectangular coupled quantum-well wires of GaAs surrounded by Ga 1-x Al x As in effective-mass approximation, using the variational approach. Results obtained show that the exciton binding energies and optical absorption depend on the sizes of the wire and barrier thickness. To the best of our knowledge the exciton binding energy and interband optical absorption in the rectangular coupled quantum wires have not been clarified yet.

Effect of polarization charges on impurity binding energy in elliptical quantum wire

2013 ◽  
Vol 58 ◽  
pp. 165-170 ◽  
Author(s):  
E. Sadeghi ◽  
F. Vahdatnejad ◽  
M. Moradi LM
Keyword(s):  
Binding Energy ◽  
Quantum Wire

scholarly journals Beryllium acceptor binding energy in AlN

2008 ◽  
Vol 93 (14) ◽  
pp. 141104 ◽  
Author(s):  
A. Sedhain ◽  
T. M. Al Tahtamouni ◽  
J. Li ◽  
J. Y. Lin ◽  
H. X. Jiang
Keyword(s):  
Binding Energy ◽  
Acceptor Binding Energy

scholarly journals Acceptor binding energy in δ-doped GaAs/AlAs multiple-quantum wells

2002 ◽  
Vol 92 (10) ◽  
pp. 6039-6042 ◽  
Author(s):  
W. M. Zheng ◽  
M. P. Halsall ◽  
P. Harmer ◽  
P. Harrison ◽  
M. J. Steer
Keyword(s):  
Binding Energy ◽  
Quantum Wells ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Acceptor Binding Energy

Acceptor Binding Energy And Band Lineup Of III-V Nitride Alloys And Mocvd Growth Of GaN On GaAs - Or GaP-Coated Si

1994 ◽  
Vol 339 ◽  
Author(s):  
Yoshihiro Ueta ◽  
Shiro Sakai ◽  
Yasushi Kamiya ◽  
Hisao Sato
Keyword(s):  
Binding Energy ◽  
Bulk Modulus ◽  
Intermediate Layer ◽  
Group Iv ◽  
Si Substrate ◽  
Acceptor Impurity ◽  
Mocvd Growth ◽  
Nitride Alloys ◽  
Group Iv Elements ◽  
Acceptor Binding Energy

ABSTRACTThe acceptor binding energy is calculated to find out the best acceptor impurity in InN, GaN and AlN. Be is predicted to be the shallowest acceptor and the next are Mg and Zn. Group IV elements such as C or Si are very deep. Band lineup is calculated to be ΔEc : ΔEv = 2.1 eV : 0.76 eV = 0.73 : 0.27 = 2.8 : 1 for GaN/AlN and ΔEc : ΔEv = 0.88 eV : 0.66 eV = 0.57 : 0.43 = 1.3 : 1 for GaN/InN. GaN is grown on GaAs and GaP-coated Si substrate by MOCVD. GaAs intermediate layer gives better GaN compared to GaP intermediate layer. It is suggested that the lower bulk modulus of GaAs than that of GaP gives this difference.

Exciton binding energy in a quantum wire in the presence of a magnetic field

1995 ◽  
Vol 77 (3) ◽  
pp. 1097-1104 ◽  
Author(s):  
Gang Li ◽  
Spiros V. Branis ◽  
K. K. Bajaj
Keyword(s):  
Magnetic Field ◽  
Binding Energy ◽  
Quantum Wire ◽  
Exciton Binding Energy

Impurity Binding Energy of a Cylindrical Quantum Wire in a Magnetic Field

1995 ◽  
Vol 191 (2) ◽  
pp. 401-408 ◽  
Author(s):  
Zhigang Xiao ◽  
Jiqian Zhu ◽  
Fenglai He
Keyword(s):  
Magnetic Field ◽  
Binding Energy ◽  
Quantum Wire
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