Tunable Schottky Barrier and Contact Types in Janus MoSH/MoGeSiN₄ Contacts

The Janus MoGeSiN4 monolayer presents outstanding electronic properties and is expected to be used as a channel material for field-effect transistors (FETs). However, the interface between MoGeSiN4 and the metal electrode remains an urgent issue that needs to be solved. Herein, we use two-dimensional (2D) metallic Janus MoSH as an electrode to form a contact with the Janus MoGeSiN4 monolayer and investigate the interfacial electronic properties of MoSH/MoGeSiN4 by density functional theory (DFT) calculations. Depending on the specific configurations, MoSH/MoGeSiN4 contacts can form an n- or p-type Schottky contact. When the H side of MoSH is close to the Ge–N side of MoGeSiN4, the n-type Schottky barrier height (SBH) is 0.23 eV, which is lower than that of most 2D metal/MoSi2N4 contacts. In addition, when an external electric field is applied, the MoSH/MoGeSiN4 contacts change from a Schottky contact to an Ohmic contact and transition from an n-type Schottky contact to a p-type Schottky contact. This study not only demonstrates a method for modulating SBH values and contact types of MoSH/MoGeSiN4 contacts but also provides a guide into electronic devices based on the MoSH/MoGeSiN4 contacts design.