Rutile TiO2-modified multi-wall carbon nanotubes in TiO2 film electrodes for dye-sensitized solar cells

The beneficial influence of incorporation of acid-treated and rutile TiO2 (r-TiO2)-modified multi-wall carbon nanotubes (MWNTs) in TiO2 films on photocurrent-voltage characteristics of dye-sensitized solar cells (DSSCs) was studied. Two different routes were adopted for the modification of acid-treated MWNTs (a-MWNTs) with r-TiO2. The films and MWNTs were characterized by electron microscopy, energy dispersive X-ray spectroscopy, XRD and Raman spectroscopy. In the case of incorporation of a-MWNTs with r-TiO2 modification, short-circuit photocurrent (J(sc)) of the pertinent DSSC increased by 35% compared with that of a cell with bare TiO2 film. The open-circuit voltage remained almost the same for all cases. The enhanced J(sc) is explained by the increased surface area of the film, enhanced cluster formation of TiO2 particles around a-MWNTs, and improved interconnectivity of TiO2 particles in the presence of a-MWNTs.