We have fabricated antimony sulfide (Sb2S3) sensitized nano-structured solar cells prepared by chemical bath deposition. By incorporating a surface treatment on the antimony sulfide films, an improvement in solar cell performance is observed. The influence of the TiO2 photoanode structure on solar cell efficiencies is also studied by varying the TiO2 nanoparticle size. Although smaller nanoparticle size provides a much larger effective surface area for sensitizer attachment, the smaller pore size lead to an over-aggregation of Sb2S3 particles on the surface pores. Devices fabricated on particles of size similar to 100 nm exhibited an efficiency of 2.3%. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.007203jes] All rights reserved.