Photoelectrochemical solar cells fabricated from porous CdSe and CdS layers

Porous CdSe layers were prepared by spray pyrolysis deposition using sodium selenosulfate as a selenium source and its surface area and porosity were increased by the dissolution of sodium sulfate formed as by-product. The porous CdSe as both photoanode and absorber could efficiently transport electrons to fluorine-doped tin oxide electrode and extract holes to the electrolyte. The cells were optimized by controlling the number of spray pyrolysis deposition cycles and then etching with sodium sulfate. An efficient solar cell having a power conversion efficiency of 2.6% at 1 sun illumination (100 mW cm⁻¹) was fabricated. Further, we extend this approach to fabricate an efficient porous CdS-sensitized solar cell with power conversion efficiency greater than 1.0% at 1 sun illumination.