Impact of dark excitons on F\"orster type resonant energy transfer between dye molecules and atomically thin semiconductors

TL;DR

This paper presents a microscopic theoretical study of F"orster energy transfer from dye molecules to TMDC monolayers, highlighting the influence of dark excitons on transfer rates in layered nanostructures.

Contribution

It introduces a self-consistent microscopic model combining Bloch and Maxwell equations to analyze F"orster transfer, including dark exciton effects in TMDCs.

Findings

Transfer rates are in the meV range for typical dye molecules.

Dark excitons significantly affect the F"orster transfer rate.

The transfer rate depends non-trivially on molecular transition energy.

Abstract

Interfaces of dye molecules and two-dimensional transition metal dichalcogenides (TMDCs) combine strong molecular dipole excitations with high carrier mobilities in semiconductors. F\"orster type energy transfer is one key mechanism for the coupling between both constituents. We report microscopic calculations of a spectrally resolved F\"orster induced transition rate from dye molecules to a TMDC layer. Our approach is based on microscopic Bloch equations which are solved self-consistently together with Maxwells equations. This approach allows to incorporate the dielectric environment of a TMDC semiconductor, sandwiched between donor molecules and a substrate. Our analysis reveals transfer rates in the meV range for typical dye molecules in closely stacked structures, with a non-trivial dependence of the F\"orster rate on the molecular transition energy resulting from unique signatures of dark, momentum forbidden TMDC excitons.