Electrodeposition of Iron Selenide Films: Electrochemical and Morphological Characterizations

In recent years, iron-based superconductors have attracted attention due to their interesting electromagnetic properties that open wide application prospects. Among these, FeSe is particularly studied since it is both a superconductor with a bulk critical transition temperature, Tc, of 8 K and a semiconductor used in solar cells. For the design of an iron-based superconductor, the preparation of larger samples is envisaged, and the possibility of maintaining low manufacturing costs is extremely appealing. One possible technique suitable for this purpose is electrodeposition, which combines inexpensive equipment to the easy scaling towards larger/longer samples. In this work, we study the possibility of using electrodeposition as a method for FeSe film growth. We start by analyzing the electrochemical behaviour of the precursor solution via cyclic voltammetry before attempting electrodeposition. We find out that the main drawback of this technique is the microstructure of the deposited film, which is made mostly of unconnected grains. This issue does not rule out this technique for the preparation of superconducting thin films, but it has to be addressed in view of a potential application of this technique to the preparation of an iron-based coated conductor.