Sb-doped CdS single crystal was used as a photoanode to fabricate a photoelectrochemical solar (PECS) cell. The three organic dyes; eosin, thymol blue and rhodamin 6G were used as sensitizers in (PECS) cell, In the absence of the dye, the results showed that with Sb-doped CdS single crystal electrode, a higher power conversion efficiency similar to9.27% has been achieved compared to similar to5.7-7.4% for pure crystal, Application of the dye in PECS cell increases the efficiency to about 13%. The efficiency reaches its maximum value when the dye concentration is (2.5 x 10(-5))M, sufficient to cover the surface of the semiconductor electrode with a continuous monolayer of the dye. Exceeding this value resulted in a gradual decrease of the efficiency from its maximum value. Mott-Schottky plots gave a doping density of 3.14 x 10(17) cm(-3) and a space charge width of similar to4.95 x 10(-6) cm for the sample used, A flat-band potential equal to -0.84 V, independent of both frequency and pH, was also predicted. Cyclic voltammetry (c.v.) measurements showed an anodic current peak at 0.4 V vs. SCE. The disappearance of this peak after excess addition of the reducing agent Na2S, indicates that this peak is due to the PEC corrosion of the semiconductor electrode. (C) 2002 Elsevier Science B.V. All rights reserved.