  In the present work, we introduce the anodic growth of conical shaped TiO2
nanotube arrays. These titania nanocones provide a scaffold for dye-sensitized
solar cell (DSSC) structures with significantly improved photon management,
providing an optimized absorption profile compared with conventional
cylindrical nanotube arrays. Finite difference time domain (FDTD) modelling
demonstrates a drastically changed power-absorption characteristic over the
tube length. When used in a back-side illumination DSSC configuration, nanocone
structures can reach over 60 % higher solar cell conversion efficiency than
conventional tubes. The resulting {\eta} of ca. 8 % represents one of the
highest reported values for Graetzel type DSSCs used under back-side
illumination.
