Dielectric Band Edge Enhancement of Energy Conversion Efficiency in Photonic Crystal Dye-Sensitized Solar Cell

We present evidence for the enhancement of light-to-electrical energy conversion efficiency (IPCE) in photonic crystal dye-sensitized solar cells due to an amplified light field at the dielectric band edge. Under angle-resolved monochromatic irradiance along the LU direction, the IPCE enhancement peaks match well with the blue shift in the dielectric band edge. The numerical simulation indicates that the photon localization effect at the dielectric band edge causes the intensification of the light field in the dielectric matrix. Using a Maxwell−Bloch two-level atom model to quantify the dye absorption of light and photocurrent generation, we show that the improvement in IPCE is due to an enhanced light−matter interaction between the dye atom and the amplified field.