In this review, we present an update on the methods for screening 2D materials suitable for valleytronic applications. We begin with an introduction to the field highlighting some of the latest findings and seminal works. Then we provide a brief background on the physics of valley- and layer- pseudospins in layered 2D materials such as transition metal dichalcogenides. This is followed by a detailed survey of a number of key techniques commonly employed to elucidate valley properties in such materials, highlighting in particular their capability for discriminating valley pseudospins, their key advantages and current limitations. Finally, we conclude by summarising the state-of-the-art assessing materials for valleytronic applications and point the reader to the current open questions that could have critical influence on the technological impact that may be derived from such materials.

MoS2/WS2 2D heterostructures grown by in-situ reactive sputtering deposition exhibit a strong interlayer coupling and associated exciton relaxation at the interface.

Atomically precise dangling-bond (DB) lines are constructed dimer-by-dimer on a hydrogen-passivated Ge( 001)-( 2×1):H surface by an efficient scanning tunneling microscope (STM) tip-induced desorption protocol. Due to the smaller surface band gap of the undoped Ge(001) substrate compared to Si(001), states associated with individually created DBs can be characterized spectroscopically by scanning tunneling spectroscopy (STS). Corresponding dI /dV spectra corroborated by first-principle modeling demonstrate that DB dimers introduce states below the Ge(001):H surface conduction band edge. For a DB line parallel to the surface reconstruction rows, the DB-derived states near the conduction band edge shift to lower energies with increasing number of DBs. The coupling between the DB states results in a dispersive band spanning 0.7 eV for an infinite DB line. For a long DB line perpendicular to the surface reconstruction rows, a similar band is not formed since the interdimer coupling is weak. However, for a short DB line (2-3 DBs) perpendicular to the reconstruction rows a significant shift is still observed due to the more flexible dimer buckling.