Investigation into Photoconductivity in Single CNF/TiO(2)-Dye Core-Shell Nanowire Devices

A vertically aligned carbon nanofiber array coated with anatase TiO(2) (CNF/TiO(2)) is an attractive possible replacement for the sintered TiO(2) nanoparticle network in the original dye-sensitized solar cell (DSSC) design due to the potential for improved charge transport and reduced charge recombination. Although the reported efficiency of 1.1% in these modified DSSC's is encouraging, the limiting factors must be identified before a higher efficiency can be obtained. This work employs a single nanowire approach to investigate the charge transport in individual CNF/TiO(2) core-shell nanowires with adsorbed N719 dye molecules in dark and under illumination. The results shed light on the role of charge traps and dye adsorption on the (photo) conductivity of nanocrystalline TiO(2) CNF's as related to dye-sensitized solar cell performance.