AbstractWe demonstrate monochromatic and white light optical amplification of the photo-oxidation of adsorbed methylene blue using an inverse colloidal photonic crystal fashioned from anatase nanocrystals, denoted i-nc-TiO2-o. Enhanced photo-activity that drives the oxidation of the dye is attributed to slow photons in i-nc-TiO2-o. When the slow photon wavelength is optimized with respect to the electronic excitation energy of i-nc-TiO2-o, the photo-oxidation rate of the dye is doubled compared to conventional nc-TiO2. By increasing the probability of absorbing photons in i-nc-TiO2-o relative to nc-TiO2, a larger population of electron-hole pairs is generated enabling more efficient photo-oxidation. Slow photons in photonic crystals portend a myriad of opportunities for amplified photo-processes in chemistry and biology.
Optical amplification enhancement in photonic crystals