Efficient Ohmic contacts and built-in atomic sublayer protection in MoSi2N4 and WSi2N4 monolayers

Metal contacts to two-dimensional (2D) semiconductors are often plagued by the strong Fermi level pinning (FLP) effect which reduces the tunability of the Schottky barrier height (SBH) and degrades the performance of 2D semiconductor devices. Here, we show that MoSi 2 N 4 and WSi 2 N 4 monolayers—an emerging 2D semiconductor family with exceptional physical properties—exhibit strongly suppressed FLP and wide-range tunable SBH. An exceptionally...