  Semiconductor quantum dot (QD) assemblies are utilized in solar cells and
light-harvesting devices because of their distinct physical and optical
properties. Recent experiments have successfully synthesized QD molecules,
arrays, and assemblies with precision by directly attaching QDs. These systems
demonstrate high carrier mobility while preserving the optical properties of
the individual QD components. However, despite advancements in fabricating
these superstructures, a comprehensive understanding of the charge transfer
process at the microscopic level is still lacking. Here, we theoretically
investigated the electron transfer dynamics across finite 1-dimensional
CdSe-CdS core-shell QD arrays, with $N_{\rm dot}=2,3, \cdots$ QDs. The
electronic and vibronic properties of the QD arrays were calculated using a
semiempirical pseudopotential method and the electron transfer dynamics were
studied using a mixed quantum-classical mapping approach. We find that as
$N_{\rm dot}$ increases, the superlattice bending and the symmetric stretch
modes can significantly localize electron transfer in the nonadiabatic regime,
particularly when the connecting neck between the QDs is narrow, resulting in
charge localization for large values of $N_{\rm dot}$. This behavior is quite
different in the adiabatic limit when the neck connecting the QDs is wide,
where such modes can facilitate electron transfer, partially governed by
decoherence times. The interplay between electronic and super-lattice couplings
is thus crucial for designing high-mobility devices based on QD superlattices
and avoiding charge localization.
