Tuning the Interfacial Electronic Structure of MoS2 by Adsorption of Cobalt Phthalocyanine Derivatives

We investigate the interfacial electronic structure of n-type bulk MoS2 upon the adsorption of CoPc and CoPcF16 mono- and few-layers using advanced spectroscopic techniques. These include X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), angle-resolved photoelectron spectroscopy (ARPES), and ultraviolet photoelectron spectroscopy (UPS). Our findings indicate that the adsorption of CoPc enhances the degree of n-doping at the interface with MoS2. In contrast, CoPcF16 results in a nearly intrinsic position of the Fermi level. Furthermore, we note the formation of an induced gap state near the valence band maximum for monolayer CoPcF16 on MoS2. These observations underscore the potential to fine-tune the interfacial electronic properties of transition metal dichalcogenides through molecular functionalization for tailored electronic applications.