Photoelectron spectroscopic study of the interaction of thin Fe films with the MoS₂(0001) surface

Abstract

The Fe/MoS2(0001) interface has been studied by high-resolution photoelectron spectroscopy using synchrotron radiation. The evolution of the Mo3d, Fe3p, and S2p core levels and of the valence band spectra (hν = 152 eV) during growth of vapor-deposited Fe films (1-10 Å) indicates the production of sulfur vacancy defects in the MoS2(0001) surface. Several submonolayer sulfur surface species were formed, including sulfur adsorbed on the Fe surface and a reacted Fe-S species. The MoS2 surface was found to be covered for Fe film thicknesses of ~10 Å. Annealing a 10 Å film to 600 K resulted in the Fe film beginning to agglomerate, while annealing to 700-900 K resulted in further agglomeration of the Fe film. Annealing to 700-900 K also resulted in reformation of a partially disordered MoS2(0001)-1 × 1 surface with ~5% defects, as determined from photoelectron spectroscopy and low-energy electron diffraction. The overlayer film remained primarily in the form of metallic Fe, before and after annealing to temperatures ≲ 900 K, which was shown by the behavior of the Fe3p core level spectra and valence band spectra. Annealing the sample to 1200 K resulted in decomposition of the MoS2(0001) surface. The results indicate that the Fe/MoS2(0001) system exhibits some interfacial reactivity but does not form bulk Fe-S compounds. The results have been compared to those of previous studies of the Fe/MoS2(0001) system. © 1989.