Optical characterization of CdTe nanoparticles embedded in a nanoparticulate SnO2 matrix

Authors

  • E. Campos-González Facultad de Química, Materiales, Universidad Autónoma de Quer´etaro, Quer´etaro, 76010, M´exico.
  • M. Becerril Departamento de Física, Centro de Investigación y de Estudios Avanzados del I.P.N. Apartado Postal 14-740, México D.F. 07360, México.
  • J. Santoyo-Salazar Departamento de Física, Centro de Investigación y de Estudios Avanzados del I.P.N. Apartado Postal 14-740, México D.F. 07360, México.
  • H. Silva-López Departamento de Física, Centro de Investigación y de Estudios Avanzados del I.P.N. Apartado Postal 14-740, México D.F. 07360, México.
  • F. de Moure Flores Facultad de Química, Materiales, Universidad Autónoma de Querétaro, Querétaro, 76010, México.
  • O. Zelaya-Ángel Departamento de Física, Centro de Investigación y de Estudios Avanzados del I.P.N. Apartado Postal 14-740, México D.F. 07360, México.

DOI:

https://doi.org/10.31349/RevMexFis.64.61

Keywords:

Semiconductors, quantum dots, Raman, II-VI.

Abstract

Cadmium telluride (CdTe) nanoparticles were grown in the interior of a SnO2 transparent matrix by means of the r.f. sputtering technique.
X-ray diffraction (XRD) patterns reveal that the CdTe quantum dots (QD) grow in the hexagonal wurtzite (W) phase. Diffraction data show
that SnO2 is constituted by nanoparticles also, with size of the same order of the W-CdTe QD. The broad bands of the XRD patterns and the
Scherrer formula allowed, by assuming a spherical shape, the W-CdTe QD size calculation, which have average diameters in the range 4.8
- 14.0 nm. These data were confirmed by electron microscopy images. Optical absorbance gives information to calculate the energy of the
two lowest excitonic states (band gap). The Raman spectra show several broad bands in the range 100 - 200 cm-1, on which deconvolution
allows separate five modes in the 100 - 200 cm-1 interval. The bands correspond to CdTe and tetragonal Te. The transversal optic (TO) and
longitudinal optic (LO) modes of CdTe at the Γ point of the first Brillouin zone, for phonons in nanoparticles, follow the expected behavior
if the radius of crystal decreases, taking into account that the selection rules for momentum conservation are relaxed.

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Published

2018-02-07

How to Cite

[1]
E. Campos-González, M. Becerril, J. Santoyo-Salazar, H. Silva-López, F. de Moure Flores, and O. Zelaya-Ángel, “Optical characterization of CdTe nanoparticles embedded in a nanoparticulate SnO2 matrix”, Rev. Mex. Fís., vol. 64, no. 1 Jan-Feb, pp. 61–66, Feb. 2018.

Issue

Vol. 64 No. 1 Jan-Feb (2018): Revista Mexicana de Física

Section

05 Condensed Matter

License

Authors retain copyright and grant the Revista Mexicana de Física right of first publication with the work simultaneously licensed under a CC BY-NC-ND 4.0 that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.