  Two new ultimately thin vanadium rich 2D materials based on VS2 are created
via molecular beam epitaxy and investigated using scanning tunneling
microscopy, X-ray photoemission spectroscopy and density-functional theory
calculations. The controlled synthesis of stoichiometric single-layer VS2 or
either of the two vanadium-rich materials is achieved by varying the sample
coverage and the sulphur pressure during annealing. Through annealing of small
stoichiometric single-layer VS2 islands without S pressure, S-vacancies
spontaneously order in 1D arrays, giving rise to patterned adsorption. Via the
comparison of density-functional theory calculations with scanning tunneling
microscopy data, the atomic structure of the S-depleted phase, with a
stoichiometry of V4S7, is determined. By depositing larger amounts of vanadium
and sulphur, which are subsequently annealed in a S-rich atmosphere,
self-intercalated ultimately thin V5S8-derived layers are obtained, which host
2x2 V-layers between sheets of VS2. We provide atomic models for the thinnest
V5S8-derived structures. Finally, we use scanning tunneling spectroscopy to
investigate the charge density wave observed in the 2D V5S8-derived islands.
