Infrared reflectance and transmission spectra in II-VI alloys and superlattices

Article

关键词: MOLECULAR-BEAM EPITAXY;    LATTICE-DYNAMICS;    RAMAN-SCATTERING;    OPTICAL-PROPERTIES;    PROPAGATING PHONONS;    MIXED-CRYSTALS;    QUANTUM DOTS;    BAND-GAP;    GROWTH;    ZNSE;   

DOI  :  10.1103/PhysRevB.84.174203

来源: SCIE

【 摘 要 】

Room temperature measurements of the far-infrared (FIR) reflectance spectra are reported for the polar optical phonons in a series of bulk CdxZn1-xTe (0 <= x <= 1) and CdSex Te1-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 (omega(TO), omega(LO)) phonon frequencies in polar-semiconductor thin films and heterostructure materials of increasing technological importance.

【 授权许可】

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