Indium doped Cd0.6Hg0.4Se thin films have been prepared using simple chemical bath deposition technique with the objectives to Study structural, optical, electrical changes taking place upon doping and to test their electrochemical properties. The 'as deposited' thin films were characterized by XRD, AAS, EDAX SEM, optical absorption, thermo-electrical techniques and photo-electrochemical studies. The donor atoms were found to dissolve substitutionally in the lattice of Cd0.6Hg0.4Se up to a certain range of doping concentration. The films were polycrystalline in the single cubic phase without appreciable lattice distortion. The crystallinity, grain size, band gap, conductivity were found to increase with increase in indium content up to 0.1 mol%. The carrier concentration and mobility were found to depend on indium content and temperature. An enhancement in the PEC efficiency, Voc, Is, and the fill factor has been found. (c) 2006 Published by Elsevier B.V.