Directional photoluminescence enhancement of organic emitters via surface plasmon coupling

In this paper, we had quantitatively investigated the photoluminescence of organic emitter on a Si substrate with periodically corrugated metal thin film experimentally and theoretically. Due to the plasmonic coupling by the metal gratings, 4.3 times and 1.7 times enhancements in optical intensities were observed at specified and full viewing angles at certain wavelengths, respectively. Good agreement of angular-frequency versus in-plane wavevector (omega-k) curves between experiments and calculations were obtained when varying organic materials, metal materials, and grating pitches. Two different metal materials were used, which show slight shift in omega-k curves due to the high sensitivity of the surface plasmon to the relative permittivity.