We describe a design for a photonic crystal dye-sensitized solar cell (DSSC) that can attain at least a factor of one-third enhancement in solar light absorption relative to a conventional cell. The design consists of a periodic array of modulated-diameter TiO2 nanotubes filled with TiO2 nanoparticles and interstitial regions filled with electrolyte. Using nanotubes filled with nanoparticles provides not only light trapping and absorption enhancement, but offers improved electrical transport through the nanotube walls. Keeping the volume of dye-coated TiO2 nanoparticles in the cell constant, our design gives a maximum achievable photocurrent density (MAPD) of over 21mA/cm2 in 2D simulations, well beyond the current record for C101-based cells. The design is shown to be feasible using current manufacturing techniques.