Energy Level Alignment at the C ₆₀ /Monolayer‐WS ₂ Interface on Insulating and Conductive Substrates

Abstract Combining a transition metal dichalcogenide monolayer (ML) and molecular semiconductors is an attractive route for forming nanoscale hybrid van der Waals heterostructures with potentially novel (opto‐)electronic properties. The energy level alignment at the interface governs these properties, but precise determination of interfacial electronic structure challenging due to pronounced excitonic nature both components non‐trivial band inorganic ML. For instance, dielectric screening by supporting substrate such heterostructure may impact levels, very few experiments have attended this important issue date. Here, it shown how photoelectron spectroscopy can be used unravel line‐up C 60 /ML‐WS 2 supported on insulating (sapphire) semi‐metallic (graphite) substrates. On substrates, almost identical staggered type‐II determined. However, exhibits stronger n‐type characteristics sapphire, which suggested native donor‐type defects ML‐WS . While remain occupied active substrate, they are emptied into charge reservoir conductive substrate. These insights should considered in future design functional ML semiconductor materials.