Forming ohmic contacts between metals and semiconductors is critical to achieving high-performance and energy-efficient electronics. Here we investigate the interface properties of WSi2N4 contacted by Mo2B, O-modified Mo2B (Mo2BO2) and OH-modified Mo2B (Mo2B(OH)(2)) nanosheets using density functional theory simulations. We show that WSi2N4 and Mo2B form n-type Schottky contacts with barrier heights that are robust against external electric fields. In contrast, functionalizing Mo2B with O and OH causes the work function to energetically down- and up-shift significantly, thus forming both n-typ...