Far-infrared and Raman Spectroscopy of CdTe0.97Se0.03(In)

Nebojsa Romcevic 1Maja Romcevic 1Jelena Trajic 1Dusanka Stojanovic 1Zorica Lazarevic 1Branka Hadzic 1Andrzej Mycielski 2

1. Institute of Physics (IF), Pregrevica 118, Belgrade 11080, Serbia
2. Polish Academy of Sciences, Institute of Physics, al. Lotników 32/46, Warszawa 02-668, Poland


Far-infrared reflectivity and Raman spectra of CdTe0.97Se0.03(In) single crystals were measured in 40-500cm-1 spectral range at 80 and 300K temperatures. Studied material had been produced with the Bridgman method at the Institute of Physics, Polish Academy of Science, Warsaw. The analysis of the far-infrared spectra was made by a fitting procedure based on the dielectric function which includes spacious distribution of free carrier influence on plasmon-phonon interaction. In undoped sample (CdTe0.97Se0.03) two optical mode frequencies (TO/LO pairs) at about 147/169 and 173/177 cm-1 were obtained. Plasmon-phonon interaction is weak.

            In doped sample concentration of free carriers increasing and plasmon-phonon interaction is stronger. In that case, like in some other II-VI semiconductors[1], with high free carrier concentration, a surface layer with a low concentration of free carriers (depleted region) could be formed. Then, from this surface layer we can clearly see phonons. While the light penetration depth is greater than the surface layer thickness, we see both, coupled and non-coupled modes of the mixed crystals in the reflection spectra. In the Raman spectra we did not registered any influence of doping. The excellent agreement between the experimental data and theoretical spectra supports this assumption.

[1] N. Romcevic, M. Romcevic, A. Golubovic, Le Van Khoi, A. Mycielski, D. Jovanovic, D. Stojanovic, S. Nikolic, S. Duric, Journal of Alloys and Compounds 397 (2005) 52-57.

Related papers
  1. (Cd, Mn)Te Crystals for X and Gamma Radiation Detectors - an Alternative Material to CdTe and (Cd,Zn)Te. 
  2. SEM studies of the etched surface of (Cd,Mn)Te
  3. The influence of growth atmosphere on the self-selection of the grains during ZnO crystal growth
  4. Raman scattering from ZnO doped with Fe, Mn and Co nanoparticles
  5. Influence of hydrogen on hydrogenated cadmium telluride optical spectra
  6. Raman scattering study of polycrystalline BiFeO3 obtained by mechanochemical synthesis
  7. Low-frequency Raman scattering from transition-metal-doped ZnO nanoparticles
  8. Raman spectroscopy of multiphonon emission process in Ni-doped PbTe
  9. Raman spectroscopy of Pb0.85Sn0.15Te (In) single crystal
  10. Resonant and non-resonant Raman spectra of CdTe/ZnTe self-assembled quantum dots
  11. Additional  Phonon Modes related to intrinsic defects in CdHgTe
  12. Phonon and vibrational spectra of real crystals obtained using the synchrotron radiation
  13. ZnO homoepitaxial growth by Atomic Layer Epitaxy technique.
  14. Preparation of the ZnO substrate surface
  15. Electrical contacts to semi-insulating (Cd,Mn)Te:V
  16. Influence of hydrogen on optical spectra of hydrogenated CdTe
  17. Effect of the Annealing Atmosphere on the Quality of ZnO Crystal Surface
  18. Structure properties of bulk ZnO crystals
  19. Materials requirements in the group - CdTe, CdZnTe and CdMnTe - and recent advances for X-ray and gamma-ray applications.
  20. Applications of the II-VI semimagnetic semiconductors
  21. Is the (Cd,Mn)Te crystal a prospective material for X-ray and γ-ray detectors?
  22. The local crystalline structure of ZnCdTe alloys obtained by Far Infrared Synchrotron Radiation measurements
  23. Defects induced by oxygen and hydrogen in CdTe crystals
  25. Structural and optical characterization of epitaxial layers of CdTe/PbTe grown on BaF2 (111) substrates
  26. Low-frequency magnons and phonons in hexagonal MnTe
  28. CVT contactless growth of ZnO crystals
  29. Mn doped ZnTe (110) (1x1) surface in Resonant Photoemission study
  30. Differential Reflectivity and Photoemission study of ZnTe and CdTe(110) surface

Presentation: Poster at E-MRS Fall Meeting 2009, Symposium C, by Nebojsa Romcevic
See On-line Journal of E-MRS Fall Meeting 2009

Submitted: 2009-05-08 14:41
Revised:   2009-06-07 00:48
Web science24.com
© 1998-2018 pielaszek research, all rights reserved Powered by the Conference Engine