Photoluminescence from Donor-Acceptor Molecular Systems via Long Distance Energy Transfer Mediated by Surface Plasmons

摘要

We have studied the energy transfer from p-sexiphenyl (p-6P) to 5,5'-bis(4-biphenylyl)-2,2'-bithiophene (BP2T) mediated by surface plasmons (SPs) on a thin silver layer sandwiched between two MgF_2 spacers. The SP-mediated fluorescence of the BP2T acceptor is observed at the donor-acceptor distance beyond 200 nm, which is much longer than the Forster distance. The photoluminescence of BP2T is maximized at silver thickness of roughly 40 nm, where the silver layer is transformed from segregated nanoparticles into a continuous film, at an MgF_2 thickness of 10.5 to 52.5 nm.