The electrodeposition of cadmium telluride on cadmium sulphide deposited from a chemical bath is investigated with the aim of improving the structural and optical properties of the CdTe layers for solar cell applications. The CdTe layers are characterized by X-ray diffraction spectroscopy, optical transmission measurements and photoelectrochemical measurements. The influence of the electrodeposition potential on the conductivity type of the deposited CdTe is demonstrated. Spectral response measurements are used as an analytical method to study the optoelectronic properties of CdTe. Thickness-dependent spectral responses reflect a change of doping type for electrodeposition potentials more positive than +5 mV vs. the deposition potential of elemental cadmium. A front- and back-side illumination technique is used to determine the position of the active junction which varies between a n-CdS/p-CdTe and a n-CdTeelectrolyte junction. The width of the space charge layers and the doping concentrations are determined by using the Gartner equation for fitting the quantum efficiency vs. absorption coefficient plots.