Enhanced photovoltaic properties of dye-sensitized solar cells using three-component CNF/TiO2/Au heterostructure

Abstract

To further increase the photoelectric efficiency of dye-sensitized solar cell (DSSC), enhancing the light adsorption of photoanode and suppressing the recombination of photo-generated charges are of great importance. Motivated by this, a novel and efficient three-component CNF/TiO2/Au heterostructure was successfully constructed and employed as an alternative photoanode material. The as-prepared CNF/TiO2/Au is characterized by conductive carbon nanofiber (CNF) core, uniform TiO2 outer shell assembled by upright nanorods, and surface modification with well-dispersed Au nanoparticles. To demonstrate the potential application of such material in DSSC, a comparison of photoelectric properties with commercial P25 and binary composite CNF/TiO2 was carried out. By contrast, the ternary composite CNF/TiO2/Au exhibited the highest short-circuit photocurrent density of 15.47 mA cm−2 and photoelectric conversion efficiency of 6.45%, which is about 31% higher than that of the commercial P25-based DSSCs. The great improvement of photoelectric properties for ternary composite CNF/TiO2/Au might be attributed to not only the conspicuous light adsorption ability derived from the sufficient dye loading of CNF/TiO2/Au and the surface plasmon resonance of Au nanoparticles, but also the reduced recombination endowed by the conductive CNF core and the heterojunctions at the interface.