Incorporation of Functionalized Single-Wall Carbon Nanotubes in Dye-Sensitized TiO2 Solar Cells

Effects of incorporation of acid-treated single-wall carbon nanotubes (a-SWCNs) in TiO2 film and of anchorage of dye-linked, a-SWCNs (hereafter dye-SWCNs) to the TiO2/electrolyte interface on photocurrent−voltage characteristics of dye-sensitized solar cells were studied. Compared with an unmodified cell, the modified cell with the a-SWCNs in TiO2 film showed a 25% increase in short-circuit photocurrent (J sc). The J sc increase is correlated with improved connectivity between the a-SWCNs and the TiO2 particles and with enhanced light scattering by TiO2 clusters formed in the presence of the a-SWCNs. In the case of anchoring dye-SWCNs to the TiO2/electrolyte interface, the open-circuit voltage (V oc) increased by as much as 0.1 V, possibly due to the basicity of the TiO2 surface from NH groups of ethylenediamine moieties of the anchored dye-SWCNs.