"

Cookies ussage consent

Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our site without changing the browser settings you grant us permission to store that information on your device.

I agree, do not show this message again.

Raman study of ZnSe/SiOx multilayers

M. J. ŠĆEPANOVIĆ1,* , M. GRUJIĆ-BROJČIN1, I. BINEVA2, D. NESHEVA2, Z. ANEVA2, Z. LEVI2, Z. V. POPOVIĆ1

Affiliation

  1. Center for Solid State Physics and New Materials, Institute of Physics, Pregrevica 118, 11080 Belgrade, Serbia
  2. Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia, Bulgaria

Abstract

Multilayers of ZnSe/SiOx having different ZnSe layer thicknesses (2.0, 3.5, 4.0, 5.0, 7.0 and 10 nm) have been prepared by thermal evaporation in vacuum. Raman scattering measurements have been performed at room temperature using the 442 nm line of a He-Cd laser. Two bands, which appear at about 250 and 500 cm-1, have been attributed to the 1LO and 2LO modes from “pure” ZnSe in multilayers. Both modes show a large homogeneous broadening. The 1LO Raman mode displays an asymmetric shape and redshift, which can be related to the phonon confinement effect, due to the nanometric size of the ZnSe layers. The size effect on the band shape has been simulated by using a one-dimensional phonon confinement model for ZnSe nanolayers. The comparison of experimental and calculated data also implies the existence of surface phonon modes. Moreover, a change in the intensity of Raman scattering with ZnSe layer thickness points to the resonant enhancement of the Raman bands when the photon energy of the exciting light (2.8 eV) approaches the energy band gap of some samples..

Keywords

ZnSe multilayers, Raman spectroscopy, Phonon confinement, Numeric simulation.

Submitted at: Nov. 1, 2006
Accepted at: Jan. 15, 2007

Citation

M. J. ŠĆEPANOVIĆ, M. GRUJIĆ-BROJČIN, I. BINEVA, D. NESHEVA, Z. ANEVA, Z. LEVI, Z. V. POPOVIĆ, Raman study of ZnSe/SiOx multilayers, Journal of Optoelectronics and Advanced Materials Vol. 9, Iss. 1, pp. 178-181 (2007)