Robust Delocalized Frenkel Excitons in Two-Dimensional Supramolecular Assemblies

Efficient energy transport in nanoscale photonic and optoelectronic systems requires excitons that remain delocalized despite structural or environmental disorder, a key challenge for real-world applications such as artificial light harvesting and quantum information processing. Here, we demonstrate that Frenkel excitons in two-dimensional supramolecular assemblies can maintain extensive delocalization even in the presence of embedded molecular defects that act as deep-energy traps. Using fluorescent dopant molecules introduced during the self-assembly of double-wall molecular nanotubes, we created a model system where exciton traps are integrated without compromising the host lattice’s structural integrity. Two-dimensional electronic spectroscopy directly revealed energy transfer from delocalized host excitons to the dopants, while time-resolved photoluminescence confirmed that exciton delocalization remains largely intact. Theoretical simulations using realistic molecular geometries, Redfield theory, and Monte Carlo analysis reproduced the observed dynamics and showed that excitons adaptively redistribute to avoid trap sites. These findings highlight the potential of multidimensional supramolecular architectures to support efficient exciton transport under fabrication-relevant conditions, with resilience to structural imperfections arising from their non-1D nature, a feature likely shared by 3D excitonic systems.