Interface Structure and Doping of Chemical Vapor Deposition‐Grown MoS2 on 4H–SiC by Microscopic Analyses and Ab Initio Calculations

The interface structure and electronic properties of monolayer (1L) MoS 2 domains grown by chemical vapor deposition on 4H–SiC(0001) are investigated by microscopic/spectroscopic analyses combined with ab initio calculations. The triangular domains are epitaxially oriented on the (0001) basal plane, with the presence of a van der Waals (vdW) gap between 1L–MoS 2 and the SiC terraces. The high crystalline quality of the domains is confirmed by photoluminescence emission. Furthermore, a very low tensile strain ( ε ≈ 0.03%) of 1L–MoS 2 , consistent with the small in‐plane lattice mismatch, and a p‐type doping of (0.45 ± 0.11) × 10 13 cm −2 , is evaluated by Raman mapping. Density functional theory (DFT) calculations of the MoS 2 /4H–SiC(0001) system are also performed, considering different levels of refinement of the model: 1) the simple case of the junction between Si‐terminated SiC and MoS 2 , showing a covalent bond between the Si–S atoms and n‐type doping of MoS 2 ; 2) the complete passivation of Si dangling bonds with a monolayer (1 ML) of oxygen atoms, resulting in a vdW bond with d Si–S ≈ 3.84 Å bond length and p‐type doping of MoS 2 ; and 3) partial (¼ ML and ½ ML) oxygen coverages of the 4H–SiC surface, resulting in intermediate values of d Si–S and doping behavior.