Hybrids with Intercalated Zerovalent Metals for Optoelectronics

The intercalation of layered compounds is a promising route for scalable synthesis of 2D heterostructures with novel emergent optoelectronic properties. Here, we investigate, via first principles calculations, the intercalation of zerovalent metals within the van der Waals gap of bulk MoS₂. Specifically, we focus on a novel Cu-MoS₂ hybrid that accommodates uniform, continuous 2D layers of metallic Cu within the vdW gap of MoS₂. We study the evolution of the Cu-MoS₂ hybrid with increasing Cu content and examine the consequences for intercalation energetics and optoelectronic properties as the intercalated Cu evolves from disordered clusters to contiguous layers. We identify an emergent plasmon resonance (~1eV) that is unique to the Cu-MoS₂hybrid, arising from resonant 2D Cu states within the MoS₂ band gap. Our calculations are shown to be in good agreement with experiments and help explain the enhanced infrared absorption of the Cu-MoS₂ hybrids. We also compare and contrast the Cu-MoS₂ hybrid with Sn-MoS₂ hybrids that are less amenable to complete intercalation but can nevertheless display enhanced infrared absorption with the intercalation of small Sn clusters. Overall, our results indicate that intercalation of zerovalent metals in layered materials offers a facile and scalable approach for designing hybrid 2D heterostructures with tunable optoelectronic properties for device applications.