Different to isotropic materials, photonic crystals (PCs) exhibit extraordinary optical properties, which are quite helpful for enhancing light absorption and boosting solar cells' photovoltaic conversion efficiency. In our work, the advantages of applying PCs on DSSC were systemically analyzed with theoretical calculations and experimental verifications, a series of formula were also proposed accordingly, to predict PCs' optical properties and select the most suitable PC for DSSC. Based on these work, a double-layer DSSC (a nanocrystalline layer ahead of a PC layer) with an optimized PC geometric structure was fabricated, I V tests showed that its photovoltaic conversion efficiency was 30% higher than the traditional DSSC. (C) 2012 Elsevier Ltd. All rights reserved.