The electronic band structure of quasi-one-dimensional van der Waals semiconductors: the effective hole mass of ZrS compared to TiS.

The band structure of the quasi-one-dimensional transition metal trichalcogenide ZrS(001) was investigated using nanospot angle resolved photoemission spectroscopy (nanoARPES) and shown to have many similarities with the band structure of TiS(001). We find that ZrS, like TiS, is strongly n-type with the top of the valence band ∼1.9 eV below the Fermi level, at the center of the surface Brillouin zone. The nanoARPES spectra indicate that the top of the valence band of the ZrS(001) is located at [Formula: see text]. The band structure of both TiS and ZrS exhibit strong in-plane anisotropy, which results in a larger hole effective mass along the quasi-one-dimensional chains than perpendicular to them.