Electronic Interactions in Coulombic Associated Photoactive Macrocycles to Chemically Modified MoS2 Nanosheets

Abstract

Whilst functionalization of transition metal dichalcogenides (TMDs), and more specifically MoS₂, has flourished the past decade, the accommodation of photoactive molecules on their lattice has unlocked the potentiality of this family of materials in a series of optoelectronic and energy related applications. The electronic communication between the chromophore and MoS₂, in such systems, has been thoroughly studied, in cases where the grafting of the former on the latter is secured through covalent bonding. However, comparatively less attention has been drawn in cases where the chromophore is electrostatically anchored on MoS₂, a means that potentially provides alternative ways of spatially accommodating the ligand on the TMD's extended environment, which directly affects the electronic communication between the two entities. In this work, we comparatively study the photophysical characteristics of three separate nanoensembles, where MoS₂ is electrostatically hosting a Zn-phthalocyanine, a Zn-porphyrin, and a boron-dipyrromethene, that complementary cover a wide range of visible absorption, via UV-Vis and photoluminescence spectroscopy. The results highlight the strong interactions in the excited state across all chromophores, while the ground-state interactions vary from chromophore to chromophore, indicating a distinct energy exchange dependent on the specific nanoensemble.