The influence of substrate temperature on the morphology, optical and electrical properties of thermal-evaporated ZnSe thin films

BACAKSIZ E., Aksu S., POLAT İ., YILMAZ Ş., Altunbas M.

JOURNAL OF ALLOYS AND COMPOUNDS, vol.487, pp.280-285, 2009 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 487
  • Publication Date: 2009
  • Doi Number: 10.1016/j.jallcom.2009.07.102
  • Journal Name: JOURNAL OF ALLOYS AND COMPOUNDS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.280-285
  • Keywords: ZnSe thin films, Vacuum evaporation, Substrate temperature, Annealing temperature, Optical band gap, Electrical resistivity, CHEMICAL BATH DEPOSITION, CADMIUM, GROWTH
  • Karadeniz Technical University Affiliated: Yes

Abstract

The structural, optical and electrical properties of ZnSe films deposited by evaporation were investigated as a function of substrate temperature (at -73 and 275 degrees C) and post-deposition annealing temperature (at 200, 300 and 400 degrees C). XRD studies showed that films deposited at both substrate temperatures were polycrystalline in nature with zinc-blende structure and a strong (1 1 1) texture. There was not a substantial increase in the grain size with increasing substrate temperature. SEM studies showed that the substrate temperature induced changes in the morphology of the as-deposited samples, which could be explained in terms of the "Structure Zone Model". Post-deposition annealing induced grain growth in all cases but resulted in different morphological changes depending on the substrate temperature. The optical band gap energy values were obtained and two direct transitions were observed, arising possibly from the spin-orbit splitting of the valence band. The room temperature resistivity values were found to be 9.0 x 10(6) and 3.1 x 10(6) Omega cm for the films grown at -73 and 275 degrees C, respectively. (C) 2009 Elsevier B.V. All rights reserved.