Abstract

Compared to bulk gold, nanoparticles show significantly higher quantum yield of photoluminescence (PL) from d-band hole recombination [1]. It makes them attractive for cell imaging and biosensing. The underlying mechanism of the PL is a subject of intensive debates, although there are numerous reports on single-photon and multi-photon-induced PL of plasmonic particles and nanoparticle systems. Here, we experimentally and numerically show that the hot-spot intensity between two gold bipyramids anticorrelates with the one-photon photoluminescence from the dimers, where the plasmonic coupling is adjusted mechanically by seesawing the bipyramids and by varying the interparticle distance with the tip of an atomic force microscope [2]. This mechanical manipulation allows us not only to directly control the interparticle distance, but also to control the strength of the hot-spot in the gap of a dimer.

© 2017 IEEE