Quasiparticle level alignment in anthracene-MoS2 heterostructures

TL;DR

This study uses $GW$ calculations to analyze how the electronic energy levels align in anthracene-MoS2 heterostructures, revealing configuration-dependent transitions between type-I and type-II alignments crucial for optoelectronic applications.

Contribution

It provides the first systematic $GW$ analysis of organic-inorganic heterostructures with various anthracene configurations, highlighting the impact of molecular arrangement on level alignment.

Findings

Sparse, horizontal anthracene adsorption results in type-I alignment.

Dense, head-on anthracene packing leads to type-II alignment.

Quasiparticle corrections are highly sensitive to interfacial molecular configurations.

Abstract

Heterostructures composed of transition metal dichalcogenides (TMDCs) and organic molecules have been extensively explored for optoelectronic devices. To maximize their application potential, it is essential to investigate the electronic band structures, which govern the charge response of the interfaces to external perturbations. Based on $GW$ calculations, we present a study of organic-inorganic heterostructures with anthracene molecules adsorbed on monolayer MoS2. Building on previous investigations of organic molecule self-assembly at surfaces, we systematically analyze anthracene configurations with various molecular orientations and surface coverages. Partially self-consistent $GW_0$ provides qualitatively different level alignments from those in DFT. Whereas the systems with sparse, horizontally adsorbed anthracenes exhibit type-I alignment, densely packed anthracenes in the head-on position lead to type-II alignment, which indicates the strong dependence of quasiparticle corrections on the interfacial configuration. These findings highlight the importance of level-alignment predictions for both interpreting experiments and guiding the design of organic-inorganic heterostructures.