In this talk, the effect of different types of periodic optical nanostructures on the conversion efficiency of dye solar cells will be presented and discussed. Both photonic crystals and surface relief patterns acting as optical gratings integrated in the nanocrystalline titania electrode of the cell give rise to a significant enhancement of the photogenerated current as a result of the longer path travelled by strongly back reflected light. At the same time, transparency of the device at frequencies below and above the absorption band of the dye is almost unaffected. Integration of optimized one-dimensional photonic crystals and surface optical gratings do not alter the porosity of the supporting electrode, thus not hindering dye loading or electrolyte diffusion through the cell, preserving the rest of electrical parameters of the photovoltaic device intact.
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