Energy transfer from Rhodamine-B to Oxazine-170 in the presence of photonic stop band

Photonic crystals can effectively suppress spontaneous emission of embedded emitter in the direction were photonic stop band overlaps emission band of emitter. This property of PhC has been successfully exploited to enhance energy transfer from a donor Rhodamine-B dye to an acceptor Oxazine-170 dye by inhibiting the fluorescence emission of donor in a controlled manner. Self-assembled PhC were synthesized using RhB dye doped polystyrene microspheres subsequently infiltrated with O-170 dye molecules dissolved in ethanol. An angle dependent enhancement of emission intensity of acceptor via energy transfer in photonic crystal environment was observed. These results were compared with observations made on a dye mixture solution of the same two dyes. Restricted number of available modes in photonic crystal inhibited de-excitation of donor thereby enabling efficient transfer of energy from excited donor to acceptor dye molecules.