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Title: Structural and optical properties of polycrystalline CdSe{sub x}Te{sub 1-x} (0{<=}x{<=}0.4) thin films

Abstract

CdSe{sub x}Te{sub 1-x} (0{<=}x{<=}0.4) ternary thin films have been deposited on quartz substrates at room temperature by a single source thermal evaporation. X-ray diffraction patterns and transmission electron microscope micrographs of these films showed that the films were of polycrystalline texture over the whole range studied and exhibit predominant cubic (zinc blende) structure with strong preferential orientation of the crystallites along (111) direction. Linear variation of the lattice constant with mole fraction x is observed obeying Vegard's law. The dependence of the optical constants, the refractive index n and extinction coefficient k, of the films on the mole fraction x was studied in the spectral range of 400-2500nm. The normal dispersion of the refractive index of the films could be described using the Wemple-DiDomenco single-oscillator model. CdSe{sub x}Te{sub 1-x} thin films of different composition have two direct and indirect transitions corresponding to energy gaps E{sub g}{sup d} and E{sub g}{sup ind}. The variation in either E{sub g}{sup d} or E{sub g}{sup ind} with x indicates that this system belongs to the amalgamation type. The variation follows a subquadratic dependence and the bowing parameters were found to be 0.36 and 0.48eV for the direct, and indirect energy gaps, respectively. Direct linearmore » variation of the ratio N/m* with x is observed.« less

Authors:
 [1];  [2];  [1];  [1]
  1. Physics Department, Faculty of Education, Ain Shams University, Cairo (Egypt)
  2. Physics Department, Faculty of Science, Ain Shams University, Cairo (Egypt). E-mail: mohamedm_sallam@yahoo.com
Publication Date:
OSTI Identifier:
21000597
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 42; Journal Issue: 2; Other Information: DOI: 10.1016/j.materresbull.2006.05.022; PII: S0025-5408(06)00231-5; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ENERGY GAP; LATTICE PARAMETERS; OSCILLATORS; POLYCRYSTALS; QUARTZ; REFRACTIVE INDEX; SUBSTRATES; THIN FILMS; TRANSMISSION ELECTRON MICROSCOPY; VARIATIONS; VEGARD LAW; X-RAY DIFFRACTION; ZINC SULFIDES

Citation Formats

El-Nahass, M.M., Sallam, M.M., Afifi, M.A., and Zedan, I.T. Structural and optical properties of polycrystalline CdSe{sub x}Te{sub 1-x} (0{<=}x{<=}0.4) thin films. United States: N. p., 2007. Web. doi:10.1016/j.materresbull.2006.05.022.
El-Nahass, M.M., Sallam, M.M., Afifi, M.A., & Zedan, I.T. Structural and optical properties of polycrystalline CdSe{sub x}Te{sub 1-x} (0{<=}x{<=}0.4) thin films. United States. doi:10.1016/j.materresbull.2006.05.022.
El-Nahass, M.M., Sallam, M.M., Afifi, M.A., and Zedan, I.T. Thu . "Structural and optical properties of polycrystalline CdSe{sub x}Te{sub 1-x} (0{<=}x{<=}0.4) thin films". United States. doi:10.1016/j.materresbull.2006.05.022.
@article{osti_21000597,
title = {Structural and optical properties of polycrystalline CdSe{sub x}Te{sub 1-x} (0{<=}x{<=}0.4) thin films},
author = {El-Nahass, M.M. and Sallam, M.M. and Afifi, M.A. and Zedan, I.T.},
abstractNote = {CdSe{sub x}Te{sub 1-x} (0{<=}x{<=}0.4) ternary thin films have been deposited on quartz substrates at room temperature by a single source thermal evaporation. X-ray diffraction patterns and transmission electron microscope micrographs of these films showed that the films were of polycrystalline texture over the whole range studied and exhibit predominant cubic (zinc blende) structure with strong preferential orientation of the crystallites along (111) direction. Linear variation of the lattice constant with mole fraction x is observed obeying Vegard's law. The dependence of the optical constants, the refractive index n and extinction coefficient k, of the films on the mole fraction x was studied in the spectral range of 400-2500nm. The normal dispersion of the refractive index of the films could be described using the Wemple-DiDomenco single-oscillator model. CdSe{sub x}Te{sub 1-x} thin films of different composition have two direct and indirect transitions corresponding to energy gaps E{sub g}{sup d} and E{sub g}{sup ind}. The variation in either E{sub g}{sup d} or E{sub g}{sup ind} with x indicates that this system belongs to the amalgamation type. The variation follows a subquadratic dependence and the bowing parameters were found to be 0.36 and 0.48eV for the direct, and indirect energy gaps, respectively. Direct linear variation of the ratio N/m* with x is observed.},
doi = {10.1016/j.materresbull.2006.05.022},
journal = {Materials Research Bulletin},
number = 2,
volume = 42,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}