Characterization of the Plasmonic Fluorescence Enhancement of Poly (3-hexylthiophene) for Organic Solar Cell Applications

The dependence of surface-enhanced fluorescence of the semiconducting polymer poly (3-hexylthiophene) on the diameter of silver nanoparticles was studied. Particle suspensions with a high degree of monodispersity, ranging in diameter from 15 to 153 nm, were synthesized. Polymer films were spin-cast onto substrates containing immobilized silver particles. Fluorescence enhancement factors ranged from 0.9 to 4.9 and generally improved with increasing particle size. Normalization of the fluorescence enhancement to the number of interrogated particles showed an 800-fold increase in enhancement between the smallest and largest particles.