Photoelectrochemical solar cell properties of heteropolytungstic acid-incorporated TiO2 nanodisc thin films

Thin film of heteropolytungstic acid (HPA)-incorporated TiO2 nanodisc was fabricated, and its photovoltaic performances were observed as a function of irradiation wavelength from 400 nm to 750 nm. Its incident photon-to-current efficiency (IPCE) was determined to be 18.6% around 500 nm, with energy conversion efficiency of 6.9%, which were observed to be further enhanced to 23% and 9%, respectively, by adsorption of ruthenium or porphyrin dyes. Complementary electron transports from both HPA and dyes to TiO2 nanodisc seems to avoid most of the backward electron or hole transfer reactions to enhance the photoelectrochemical efficiencies of dye-sensitized solar cells.