Rectangular bunched rutile TiO ₂ nanorod arrays grown on carbon fiber for dye-sensitized solar cells

Because of their special application in photovoltaics, the growth of one-dimensional single-crystalline TiO ₂ nanostructures on a flexible substrate is receiving intensive attention. Here we present a study of rectangular bunched TiO ₂ nanorod (NR) arrays grown on carbon fibers (CFs) from titanium by a "dissolve and grow" method. After a corrosion process in a strong acid solution, every single nanorod is etched into a number of small nanowires. Tube-shaped dye-sensitized solar cells are fabricated by using etched TiO ₂ NRs-coated CFs as the photoanode. An absolute energy conversion efficiency of 1.28% has been demonstrated under 100 mW cm ^-2 AM 1.5 illumination. This work demonstrates an innovative method for growing bunched TiO ₂ NRs on flexible substrates that can be applied in flexible devices for energy harvesting and storage.