Model dielectric function spectra of GaAsN for far-infrared and near-infrared to ultraviolet wavelengths

G. Leibiger, V. Gottschalch, B. Rheinländer, J. Šik, M. Schubert

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

We study the optical properties of tensile strained GaAs1-yNy (0%≤y≤3.7%) single layers for photon energies from 0.75 to 4.5 eV and for wave numbers from 100 to 600 cm-1 using spectroscopic ellipsometry. The intentionally undoped GaAsN layers were grown pseudomorphically on top of undoped GaAs buffer layers deposited on Te-doped (001) GaAs substrates by metalorganic vapor phase epitaxy. We provide parametric model functions for the dielectric function spectra of GaAsN for both spectral ranges studied here. The model functions for photon energies from 0.75 to 4.5 eV excellently match dielectric function data obtained from a numerical wavelength-by-wavelength inversion of the experimental data (point-by-point fit). Critical-point analysis of the point-by-point fitted dielectric function is performed in the spectral regions of the fundamental band gap and the critical-point transitions E1 and E1 + Δ1. The band-gap energy is redshifted whereas the E1 and E1 + Δ1 transition energies are blueshifted with increasing y. For y≤1.65% the observed blueshift of the E1 energy is well explained by the sum of the effects of biaxial (001) strain and alloying. The GaAsN layers show a two-mode phonon behavior in the spectral range from 100 to 600 cm-1. We detect the transverse GaAs- and GaN-sublattice phonon modes at wave numbers of about 267 and 470 cm-1, respectively. The oscillator strength of the GaN-sublattice resonance increases linearly due to alloying and tensile strain. We compare our results from the single layers with those obtained previously from tensile and compressively strained GaAsN/GaAs and GaAsN/InAs/GaAs superlattices.

Original languageEnglish (US)
Pages (from-to)4927-4938
Number of pages12
JournalJournal of Applied Physics
Volume89
Issue number9
DOIs
StatePublished - May 1 2001

Fingerprint

wavelengths
sublattices
alloying
critical point
energy
photons
vapor phase epitaxy
oscillator strengths
ellipsometry
superlattices
buffers
inversions
optical properties

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Model dielectric function spectra of GaAsN for far-infrared and near-infrared to ultraviolet wavelengths. / Leibiger, G.; Gottschalch, V.; Rheinländer, B.; Šik, J.; Schubert, M.

In: Journal of Applied Physics, Vol. 89, No. 9, 01.05.2001, p. 4927-4938.

Research output: Contribution to journalArticle

Leibiger, G. ; Gottschalch, V. ; Rheinländer, B. ; Šik, J. ; Schubert, M. / Model dielectric function spectra of GaAsN for far-infrared and near-infrared to ultraviolet wavelengths. In: Journal of Applied Physics. 2001 ; Vol. 89, No. 9. pp. 4927-4938.
@article{032053c7ee044aa89b0c0172ccfb05bd,
title = "Model dielectric function spectra of GaAsN for far-infrared and near-infrared to ultraviolet wavelengths",
abstract = "We study the optical properties of tensile strained GaAs1-yNy (0{\%}≤y≤3.7{\%}) single layers for photon energies from 0.75 to 4.5 eV and for wave numbers from 100 to 600 cm-1 using spectroscopic ellipsometry. The intentionally undoped GaAsN layers were grown pseudomorphically on top of undoped GaAs buffer layers deposited on Te-doped (001) GaAs substrates by metalorganic vapor phase epitaxy. We provide parametric model functions for the dielectric function spectra of GaAsN for both spectral ranges studied here. The model functions for photon energies from 0.75 to 4.5 eV excellently match dielectric function data obtained from a numerical wavelength-by-wavelength inversion of the experimental data (point-by-point fit). Critical-point analysis of the point-by-point fitted dielectric function is performed in the spectral regions of the fundamental band gap and the critical-point transitions E1 and E1 + Δ1. The band-gap energy is redshifted whereas the E1 and E1 + Δ1 transition energies are blueshifted with increasing y. For y≤1.65{\%} the observed blueshift of the E1 energy is well explained by the sum of the effects of biaxial (001) strain and alloying. The GaAsN layers show a two-mode phonon behavior in the spectral range from 100 to 600 cm-1. We detect the transverse GaAs- and GaN-sublattice phonon modes at wave numbers of about 267 and 470 cm-1, respectively. The oscillator strength of the GaN-sublattice resonance increases linearly due to alloying and tensile strain. We compare our results from the single layers with those obtained previously from tensile and compressively strained GaAsN/GaAs and GaAsN/InAs/GaAs superlattices.",
author = "G. Leibiger and V. Gottschalch and B. Rheinl{\"a}nder and J. Šik and M. Schubert",
year = "2001",
month = "5",
day = "1",
doi = "10.1063/1.1359422",
language = "English (US)",
volume = "89",
pages = "4927--4938",
journal = "Journal of Applied Physics",
issn = "0021-8979",
publisher = "American Institute of Physics Publising LLC",
number = "9",

}

TY - JOUR

T1 - Model dielectric function spectra of GaAsN for far-infrared and near-infrared to ultraviolet wavelengths

AU - Leibiger, G.

AU - Gottschalch, V.

AU - Rheinländer, B.

AU - Šik, J.

AU - Schubert, M.

PY - 2001/5/1

Y1 - 2001/5/1

N2 - We study the optical properties of tensile strained GaAs1-yNy (0%≤y≤3.7%) single layers for photon energies from 0.75 to 4.5 eV and for wave numbers from 100 to 600 cm-1 using spectroscopic ellipsometry. The intentionally undoped GaAsN layers were grown pseudomorphically on top of undoped GaAs buffer layers deposited on Te-doped (001) GaAs substrates by metalorganic vapor phase epitaxy. We provide parametric model functions for the dielectric function spectra of GaAsN for both spectral ranges studied here. The model functions for photon energies from 0.75 to 4.5 eV excellently match dielectric function data obtained from a numerical wavelength-by-wavelength inversion of the experimental data (point-by-point fit). Critical-point analysis of the point-by-point fitted dielectric function is performed in the spectral regions of the fundamental band gap and the critical-point transitions E1 and E1 + Δ1. The band-gap energy is redshifted whereas the E1 and E1 + Δ1 transition energies are blueshifted with increasing y. For y≤1.65% the observed blueshift of the E1 energy is well explained by the sum of the effects of biaxial (001) strain and alloying. The GaAsN layers show a two-mode phonon behavior in the spectral range from 100 to 600 cm-1. We detect the transverse GaAs- and GaN-sublattice phonon modes at wave numbers of about 267 and 470 cm-1, respectively. The oscillator strength of the GaN-sublattice resonance increases linearly due to alloying and tensile strain. We compare our results from the single layers with those obtained previously from tensile and compressively strained GaAsN/GaAs and GaAsN/InAs/GaAs superlattices.

AB - We study the optical properties of tensile strained GaAs1-yNy (0%≤y≤3.7%) single layers for photon energies from 0.75 to 4.5 eV and for wave numbers from 100 to 600 cm-1 using spectroscopic ellipsometry. The intentionally undoped GaAsN layers were grown pseudomorphically on top of undoped GaAs buffer layers deposited on Te-doped (001) GaAs substrates by metalorganic vapor phase epitaxy. We provide parametric model functions for the dielectric function spectra of GaAsN for both spectral ranges studied here. The model functions for photon energies from 0.75 to 4.5 eV excellently match dielectric function data obtained from a numerical wavelength-by-wavelength inversion of the experimental data (point-by-point fit). Critical-point analysis of the point-by-point fitted dielectric function is performed in the spectral regions of the fundamental band gap and the critical-point transitions E1 and E1 + Δ1. The band-gap energy is redshifted whereas the E1 and E1 + Δ1 transition energies are blueshifted with increasing y. For y≤1.65% the observed blueshift of the E1 energy is well explained by the sum of the effects of biaxial (001) strain and alloying. The GaAsN layers show a two-mode phonon behavior in the spectral range from 100 to 600 cm-1. We detect the transverse GaAs- and GaN-sublattice phonon modes at wave numbers of about 267 and 470 cm-1, respectively. The oscillator strength of the GaN-sublattice resonance increases linearly due to alloying and tensile strain. We compare our results from the single layers with those obtained previously from tensile and compressively strained GaAsN/GaAs and GaAsN/InAs/GaAs superlattices.

UR - http://www.scopus.com/inward/record.url?scp=0035340643&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0035340643&partnerID=8YFLogxK

U2 - 10.1063/1.1359422

DO - 10.1063/1.1359422

M3 - Article

AN - SCOPUS:0035340643

VL - 89

SP - 4927

EP - 4938

JO - Journal of Applied Physics

JF - Journal of Applied Physics

SN - 0021-8979

IS - 9

ER -