The solar-to-elec. power-conversion efficiency (η) of dye-sensitized solar cells can be greatly enhanced by integrating a mesoporous, nanoparticle-based, one-dimensional photonic crystal as a coherent scattering layer in the device. The photogenerated current is greatly improved without altering the open-circuit voltage of the cell, while keeping the transparency of the cell intact. Improved av. power-conversion efficiency values between 15% and 30% are attained.