Structural, morphological and optical properties of Bi2-xSbxSe3 thin films grown by electrodeposition

Abstract

Ternary single-phase Bi2-xSbxSe3 alloy thin films were synthesized onto Au(1 1 1) substrates from an aqueous solution containing Bi(NO3)(3), SbCl3, and SeO2 at room temperature for the first time via the electrodeposition technique. The electrodeposition of the thin films was studied using cyclic voltammetry, compositional, structural, optical measurements and surface morphology. It was found that the thin films with different stoichiometry can be obtained by controlling the electrolyte composition. The as-deposited films were crystallized in the preferential orientation along the (0 1 5) plane. The SEM investigations show that the film growth proceeds via nucleation, growth of film layer and formation of spherical particles on the film layer. The particle size and shape of Bi2-xSbxSe3 films could be changed by tuning the electrolyte composition. The optical absorption spectra suggest that the band gap of this alloy varied from 0.24 to 0.38 eV with increasing Sb content from x = 0 to x = 0.2. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.