Epitaxial growth of single-orientation high-quality MoS2monolayers

We present a study on the growth and characterization of high-quality single-layer MoS2 with a single orientation, i.e. without the presence of mirror domains. This single orientation of the MoS2 layer is established by means of x-ray photoelectron diffraction. The high quality is evidenced by combining scanning tunneling microscopy with x-ray photoelectron spectroscopy measurements. Spin- and angle-resolved photoemission experiments performed on the sample revealed complete spin- polarization of the valence band states near the K and -K points of the Brillouin zone. These ndings open up the possibility to exploit the spin and valley degrees of freedom