Electrochemical behavior of InSb thin films with different crystal structure in alkaline solution

Abstract

Indium antimonide is a semiconducting material with a wide range of potential applications which narrows down when a highly oxidative surface of InSb is considered. Particularly advantageous is the use of InSb in the form of nanowires. One of the most affordable methods used for their synthesis is a template-assisted electrodeposition within the pores of anodic aluminum oxide (AAO). After electrodeposition of nanowires, the AAO template is typically dissolved in a NaOH solution. The possible and undesirable dissolution of InSb nanowires can weaken electrical transport properties of nanowires. Therefore, it is essential to study corrosion behavior of InSb, which can depend on the semiconductor structure and composition. To achieve this goal, we investigated the effect of crystal size and morphology of pulse electrodeposited indium antimonide thin films on their corrosion behavior in a 0.5 M NaOH aqueous solution. Furthermore, to collect a complete set of data and to explain sometimes complicated electrochemical behavior of semiconducting films, corrosion experiments on metallic films consisting of indium or antimony were also performed. The results were compared with the electrochemical behavior of the single components - indium and antimony which were used as a reference. The open circuit potential, cyclic polarization curves, and Tafel plots were recorded in order to characterize electrochemical properties of thin films such as corrosion potential, corrosion current density, corrosion rate. The obtained results indicate that thin films composed of the single metallic component are less resistant to the corrosion than indium antimonide. Moreover, the corrosion resistance of InSb thin films depends on the crystal size of InSb which can be tuned by the duration of pulse “on”.