Electrodeposition of Bi-Se thin films involving ethylene glycol based electrolytes

Abstract

The work is devoted to the electrochemical deposition of Bi-Se thin films from ethylene glycol-based electrolytes. The studies have been carried out by potentiodynamic and galvanostatic methods under various conditions, using Pt and Ni electrodes. By recording cyclic and linear polarization curves, the potential range of deposition of thin Bi-Se films on Pt (-0.75 to -1.2 V) and Ni (0.2 to -0.85 V) electrodes was determined. A comparison of the polarization curves of two electrodes showed that co-electrodeposition of Bi and Se occurs in approximately the same potential range. In order to find the optimal mode and composition of the electrolyte, the effect of various factors (concentration of initial components, temperature, etc.) on the process of co-electrodeposition of Bi with Se was studied. In addition, the samples of Bi-Se thin films obtained on Ni electrodes using the galvanostatic method were studied by scanning electron microscope (SEM) and X-ray phase analysis. The results of X-ray phase analysis confirmed the formation of thin Bi₂Se₃ films with and without additional heat treatment step. Elemental analysis of obtained films carried out by EDS shows that films contained 62.79 wt. % Bi and 37.21 wt. % Se.