Abstract

The effect of open-core screw dislocations on photoluminescence in n -doped wurtzite GaN epilayer is studied computationally and compared with experimental data. A kp Hamiltonian calculation domain is set up to contain a dipole of open-core screw dislocations, and its size is varied according to the desired dislocation density. Using the finite element method, energy levels and wave functions for conduction and valence states are determined in three-dimensional real space; the emission spectrum is then evaluated. The void associated with the dislocation core and the deformation potential due to the strain surrounding the core perturb the density of states and reduce the photoluminescence (PL) spectrum intensity accordingly. For dislocation densities below a transition density of around 108 cm-2, the deformation potential effect dominates in reducing the PL intensity; above this dislocation density the effect of the missing material at the core dominates. The calculated photoluminescence results agree with experimental near-band edge PL intensity data well. Both the experimental and calculated PL spectra indicate a significant reduction in the optical response for a dislocation density larger than 107 cm-2.

Original languageEnglish (US)
Article number023516
JournalJournal of Applied Physics
Volume101
Issue number2
DOIs
StatePublished - Mar 13 2007

Fingerprint

screw dislocations
wurtzite
photoluminescence
optical properties
voids
finite element method
emission spectra
energy levels
wave functions
dipoles
valence
conduction

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Effect of screw dislocation density on optical properties in n -type wurtzite GaN. / You, Jeong Ho; Johnson, H. T.

In: Journal of Applied Physics, Vol. 101, No. 2, 023516, 13.03.2007.

Research output: Contribution to journalArticle

@article{c37d0e738b0a46fdab72ae8f3ed53a07,
title = "Effect of screw dislocation density on optical properties in n -type wurtzite GaN",
abstract = "The effect of open-core screw dislocations on photoluminescence in n -doped wurtzite GaN epilayer is studied computationally and compared with experimental data. A kp Hamiltonian calculation domain is set up to contain a dipole of open-core screw dislocations, and its size is varied according to the desired dislocation density. Using the finite element method, energy levels and wave functions for conduction and valence states are determined in three-dimensional real space; the emission spectrum is then evaluated. The void associated with the dislocation core and the deformation potential due to the strain surrounding the core perturb the density of states and reduce the photoluminescence (PL) spectrum intensity accordingly. For dislocation densities below a transition density of around 108 cm-2, the deformation potential effect dominates in reducing the PL intensity; above this dislocation density the effect of the missing material at the core dominates. The calculated photoluminescence results agree with experimental near-band edge PL intensity data well. Both the experimental and calculated PL spectra indicate a significant reduction in the optical response for a dislocation density larger than 107 cm-2.",
author = "You, {Jeong Ho} and Johnson, {H. T.}",
year = "2007",
month = "3",
day = "13",
doi = "10.1063/1.2407455",
language = "English (US)",
volume = "101",
journal = "Journal of Applied Physics",
issn = "0021-8979",
publisher = "American Institute of Physics Publising LLC",
number = "2",

}

TY - JOUR

T1 - Effect of screw dislocation density on optical properties in n -type wurtzite GaN

AU - You, Jeong Ho

AU - Johnson, H. T.

PY - 2007/3/13

Y1 - 2007/3/13

N2 - The effect of open-core screw dislocations on photoluminescence in n -doped wurtzite GaN epilayer is studied computationally and compared with experimental data. A kp Hamiltonian calculation domain is set up to contain a dipole of open-core screw dislocations, and its size is varied according to the desired dislocation density. Using the finite element method, energy levels and wave functions for conduction and valence states are determined in three-dimensional real space; the emission spectrum is then evaluated. The void associated with the dislocation core and the deformation potential due to the strain surrounding the core perturb the density of states and reduce the photoluminescence (PL) spectrum intensity accordingly. For dislocation densities below a transition density of around 108 cm-2, the deformation potential effect dominates in reducing the PL intensity; above this dislocation density the effect of the missing material at the core dominates. The calculated photoluminescence results agree with experimental near-band edge PL intensity data well. Both the experimental and calculated PL spectra indicate a significant reduction in the optical response for a dislocation density larger than 107 cm-2.

AB - The effect of open-core screw dislocations on photoluminescence in n -doped wurtzite GaN epilayer is studied computationally and compared with experimental data. A kp Hamiltonian calculation domain is set up to contain a dipole of open-core screw dislocations, and its size is varied according to the desired dislocation density. Using the finite element method, energy levels and wave functions for conduction and valence states are determined in three-dimensional real space; the emission spectrum is then evaluated. The void associated with the dislocation core and the deformation potential due to the strain surrounding the core perturb the density of states and reduce the photoluminescence (PL) spectrum intensity accordingly. For dislocation densities below a transition density of around 108 cm-2, the deformation potential effect dominates in reducing the PL intensity; above this dislocation density the effect of the missing material at the core dominates. The calculated photoluminescence results agree with experimental near-band edge PL intensity data well. Both the experimental and calculated PL spectra indicate a significant reduction in the optical response for a dislocation density larger than 107 cm-2.

UR - http://www.scopus.com/inward/record.url?scp=33847745039&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33847745039&partnerID=8YFLogxK

U2 - 10.1063/1.2407455

DO - 10.1063/1.2407455

M3 - Article

AN - SCOPUS:33847745039

VL - 101

JO - Journal of Applied Physics

JF - Journal of Applied Physics

SN - 0021-8979

IS - 2

M1 - 023516

ER -