Spongy structure of CdS nanocrystals decorated with dye molecules for semiconductor sensitized solar cells

We exploit a new structure of semiconductor sensitized solar cells, where CdS nanocrystals are assembled into a spongy structure and decorated with organic molecules to serve as photoanode. UV-vis absorption, Nyquist impedance spectra, combining with photocurrent density-voltage characterization demonstrate that the assembled CdS nanocrystals with porous architecture can effectively capture the incoming light and allow thorough infiltration of electrolyte, while the decoration of organic molecules helps to accelerate hole-transfer. As a result, the solar cells with spongy structure show higher absorption, short-circuit-current density, open-circuit voltage, and final performance than traditional semiconductor sensitized solar cells. Our results indicate that it is essential to develop reasonable semiconductor structures for constructing solar cells with high efficiency.