We have developed dye-sensitized nanocrystalline CdS and ZnS solar cells (DSSCs)
based on crystal violet, methylene blue, and fluorescein photosensitizers. Nanocrystalline
CdS and ZnS were synthesized by a green synthesis method using starch as the capping
agent. Characterization of nanocrystalline CdS and ZnS was carried out by optical
absorption and x-ray diffraction. The results indicate that CdS and ZnS prepared by this
method may be used as photoelectodes in photo-electro-chemical energy conversion
systems. DSSCs have been built and their photocurrent, open-circuit voltage, fill factor,
and efficiency have been measured under direct sunlight illumination (1000 Wcm

2).
The efficiency of the cells made from dye-CdS was much higher than that of the cells
made from dye-ZnS. This can be attributed to the particle size effect. Among the prepared
dye-sensitized solar cells, a DSSC based on fluorescein dye as the photosensitizer
produced the highest overall light solar energy to electricity conversion efficiency