Thin films of cadmium oxide (CdO) were synthesized by layer-by-layer deposition method on indium doped tin oxide (ITO) substrates. Post-deposition annealing at 250 degrees C for 24 h produced pure phase CdO films by removal of trace amount of cadmium hydroxide, as confirmed from X-ray diffractogram. First time employment of CdO in place of TiO2 in dye-sensitized solar cells is reported to check feasibility and cell performance. A dye-sensitized nanocrystalline CdO photo-electrode was obtained by adsorbing cis-dithiocyanato (4,4'-dicarboxylic acid-2,2'-bipyridide) ruthenium (II) (N3) dye by keeping at 45 degrees C for 20 h. The efficiency of dye-sensitized nanocrystalline CdO thin film solar cell was increased from 0.24% to 2.95% due to dye adsorption. This must be highest reported conversion efficiency for other metal oxides than TiO2 based dye-sensitized solar cells. (c) 2005 Elsevier Ltd. All rights reserved.