A eutectic mixture of choline chloride and urea (commercially known as Reline) has been used as a medium from which US, CdSe, and ZnS thin films have been clectrodeposited for the first time. Reline is a conductive room temperature ionic liquid (RTIL) with a wide electrochemical window, which is suitable for use as a medium for electrodeposition. The voltarnmetric behaviour of the Reline-Ccl(II)-sulfur system has been investigated. Thin films of US deposited at constant potential were characterized by photocurrent and electrolyte electroabsorbance spectroscopies. Thin films of CdSe and ZnS have also been prepared, and their photocurrent excitation spectra have been measured. (C) 2007 Flsevier B.V. All rights reserved.