In this work, we use the atomically sharp metallic STM tip both as an atomically-precise electrode that allows adding electrons to the molecule on demand, and as an optical antenna to enhance the chromophore’s luminescence. Upon temporarily charging the molecule, it switches from a bright state, which features intense emission excited by a laser focused on the tip (left side of the figure), to a dark state where this fluorescence is quenched (right side).
K. Kaiser, S. Jiang, M. Romeo, F. Scheurer, G. Schull, A. Rosławska
Gating single-molecule fluorescence with electrons
Physical Review Letters, 133, 156902 (2024)