Impact of gold nanoparticle shape on quantum coherent interactions and the efficiency of hot carrier injection in titanium dioxide under modal strong coupling

We recently discovered that when a monolayer of gold nanoparticles is supported on titanium dioxide electrodes with nanocavity functionality, modal strong coupling occurs between the localized surface plasmon resonance (LSPR) mode of the gold nanoparticles and the nanocavity mode, leading to an enhancement in the internal quantum efficiency of photocurrent generation using water as the electron source. Furthermore, we elucidated that this enhancement mechanism is attributed to quantum coherent interactions among the LSPR modes of multiple gold nanoparticles mediated by the nanocavity. In this presentation, we report on the effects of introducing gold nanoparticles with different shapes within the quantum coherence region on quantum coherent interactions, as well as their impact on the efficiency of hot carrier injection into titanium dioxide.