Chemical bath deposition of CdS quantum dots onto mesoscopic TiO ₂ films for application in quantum-dot-sensitized solar cells

Alcohol, instead of water, was used as a solvent in a chemical bath deposition process for the in situ synthesis of CdS quantum dots onto mesoporous Ti O2 films. Due to low surface tension, the alcohol solutions have high wettability and superior penetration ability on the mesoscopic Ti O2 film, leading to a well-covered CdS on the surface of mesopores. The CdS-sensitized Ti O2 electrode prepared using the alcohol system not only has a higher incorporated amount of CdS but also greatly inhibits the recombination of injected electrons. The efficiency of a CdS quantum-dots-sensitized solar cell prepared using the present method is as high as 1.84% under the illumination of one sun (AM1.5, 100 mW cm2).