Electrodeposition of Stoichiometric CdTe from a Reusable Ionic Liquid Bath

摘要

Electrodeposition (ED) from ionic liquid (IL) medium is of much importance because a variety of architectures can be synthesized by IL assisted growth. However, these liquids are relatively new for the fabrication of compounds and alloys with a great control over the stoichiometry and thickness. In this regard a well-defined route needs to be established for their wider acceptance as greener alternatives to deposit materials like CdTe, CdS, CdSe, etc. via ED. In this article, we have discussed the prerequisites, tricks and methodology to develop stoichiometric CdTe thin films from IL medium with required thicknesses in a highly controlled way compared to conventional ED techniques. This method provides a greener alternative to aqueous electrolytes which are considered to be hazardous media for the ED of CdTe films. We have found that the required precursor ratio of Te:Cd can be lower down to 1:10 for [Bmim]Cl IL medium which is 1:1000 for the aqueous electrolytes. As-grown nanostructured CdTe films can be directly utilized for the devices like IR sensors, Schottky rectifiers and Solar cells without any post-annealing. Moreover, the aspect ratio of nanostructures can be tuned by changing the precursors' ratio in IL bath. Nevertheless, IL can be reused multiple times to develop identical thin films which guarantee the low cost pathway.