TY - JOUR
T1 - Infrared reflectance and transmission spectra in II-VI alloys and superlattices
AU - Talwar, Devki N.
AU - Yang, Tzuen Rong
AU - Feng, Zhe Chuan
AU - Becla, P.
PY - 2011/11/8
Y1 - 2011/11/8
N2 - Room temperature measurements of the far-infrared (FIR) reflectance spectra are reported for the polar optical phonons in a series of bulk Cd xZn1-xTe (0 ≤ x ≤ 1) and CdSexTe 1-x (0 < x ≤ 0.35) crystals grown by Bridgman technique. The composition-dependent spectra exhibited many fundamental aspects of lattice vibrations, while the results of long-wavelength optical modes for the end member binary compounds displayed phonon values in good agreement with the existing inelastic neutron scattering and/or Raman spectroscopy data. Using a standard methodology of multilayer optics with effective-medium dielectric tensors, we simulated the FIR transmission and reflectivity spectra at oblique incidence (Berreman's effect) in many II-VI free-standing thin films, epilayers and superlattices. Berreman's approach provided us with a strong basis for analyzing the infrared experimental data and offered an effective means of estimating the zone-center transverse and longitudinal optical (ωTO, ωLO) phonon frequencies in polar-semiconductor thin films and heterostructure materials of increasing technological importance.
AB - Room temperature measurements of the far-infrared (FIR) reflectance spectra are reported for the polar optical phonons in a series of bulk Cd xZn1-xTe (0 ≤ x ≤ 1) and CdSexTe 1-x (0 < x ≤ 0.35) crystals grown by Bridgman technique. The composition-dependent spectra exhibited many fundamental aspects of lattice vibrations, while the results of long-wavelength optical modes for the end member binary compounds displayed phonon values in good agreement with the existing inelastic neutron scattering and/or Raman spectroscopy data. Using a standard methodology of multilayer optics with effective-medium dielectric tensors, we simulated the FIR transmission and reflectivity spectra at oblique incidence (Berreman's effect) in many II-VI free-standing thin films, epilayers and superlattices. Berreman's approach provided us with a strong basis for analyzing the infrared experimental data and offered an effective means of estimating the zone-center transverse and longitudinal optical (ωTO, ωLO) phonon frequencies in polar-semiconductor thin films and heterostructure materials of increasing technological importance.
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U2 - 10.1103/PhysRevB.84.174203
DO - 10.1103/PhysRevB.84.174203
M3 - Article
AN - SCOPUS:82455203995
SN - 1098-0121
VL - 84
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 17
M1 - 174203
ER -