Deposition of Sb2Se3 thin films on Pt substrate via electro-chemical atomic layer epitaxy (EC-ALE)

Abstract

This work deals with the deposition of a Sb2Se3 thin film on a Pt substrate using Electro-Chemical Atomic Layer Epitaxy (EC-ALE). We first investigated the UPD of selenium on a Pt substrate. Two routes have been evidenced to get a UPD layer of Se, either the polarization of the Pt-substrate at around 0.35 V in the Se solution or the deposition of full UPD Se together with bulk deposition of Se and dissolution of the latter one at lower potentials. The following investigation on the electrochemical behavior of antimony on selenium-covered platinum electrode by cyclic voltammetry and anodic potentiodynamic studies led us to choose the two-steps procedure for the Se deposition. After an optimization of the deposition parameters, the alternate deposition of Sb and Se elements to form the Sb2Se3 compound by EC-ALE on platinum substrate has been performed. The stoichiometry of the deposited film has been evaluated by coulometry and it has been confirmed by atomic force microscopy (AFM).