  Optical activation of material properties illustrates the potentials held by
tuning light-matter interactions with impacts ranging from basic science to
technological applications. Here, we demonstrate for the first time that
composite nanostructures providing nonlocal environments can be engineered to
optically trigger photoinduced charge transfer dynamic (CTD) modulations in the
solid state. The nanostructures herein explored lead to unprecedented
out-of-phase behaviour between charge separation and recombination dynamics,
along with linear CTD variations with the optical-field amplitude. Using
transient absorption spectroscopy, up to 270 % increase in charge separation
rate is obtained in organic semiconductor thin films. We provide evidences that
composite nanostructures allow for surface photovoltages to be created, which
kinetics vary with the composite architecture and last beyond optical pulse
temporal characteristics. Furthermore, by generalizing Marcus theory framework,
we explain why CTD modulations can only be unveiled when optic field effects
are enhanced by nonlocal image dipole interactions. Demonstrating that
composite nanostructures can be designed to use optical fields as CTD remote
actuators opens the path for their use in practical and original applications
ranging from photochemistry to optoelectronics.
