Electrochemical co-deposition of gallium and antimonide from the 1-butyl-1-methylpyrrolidinium dicyanamide room temperature ionic liquid

Low temperature electrodeposition of Ga-Sb film is investigated from the 1-butyl-1-methylpyrrolidinium dicyanamide room temperature ionic liquid containing anhydrous GaCl₃ and SbCl₃. Voltammetry shows that the redox potential of Ga(III)/Ga is more negative than that of the Sb(III)/Sb. While the deposited Sb can be easily anodized, the deposited Ga is difficult to oxidize. Electrodeposition of Ga-Sb films are attempted at various potentials and temperatures in solutions containing different Ga(III)/Sb(III) concentration ratios. To obtain GaSb film with a Ga:Sb ratio of 1:1 the electrolyte must contains a Ga(III) concentration higher than that of Sb(III). Scanning electron microscopy, energy dispersive X-ray analysis and X-ray photoelectron spectroscopy are used to characterize the morphologies, composition and the chemical bonding of the deposited GaSb films.