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 ㎚ to 750 ㎚. Its incident photon-to-current efficiency (IPCE) was determined to be 18.6% around 500 ㎚, 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.