Copper indium diselenide (CIS) is electrodeposited in a single step on chemical bath deposited cadmium sulfide layers in order to form a superstrate cell structure. The influence of the electrodeposition potential on junction formation is studied by solid-state photocurrent voltage and photocurrent spectral responses. Secondary ion mass spectroscopy depth profiling shows that cadmium and sulfur diffusion from the CdS layer into the CIS layer is small up to annealing temperatures of 320 degrees C. The diffusion process is found to be related to the composition of the CIS film, which in rum is determined by the electrodeposition potential. Interdiffusion processes are hindered in indium CIS films. A preliminary CTS superstrate cell characteristic is presented yielding an efficiency of 1.5%.