Doped ScC(OH) MXene: new type s-pd band inversion topological insulator.

The electronic structures of Si and Ge substitutionally doped ScC(OH) MXene monolayers are investigated in density functional theory. The doped systems exhibit band inversion, and are found to be topological invariants in Z theory. The inclusion of spin orbit coupling results in band gap openings. Our results point out that the Si and Ge doped ScC(OH) MXene monolayers are topological insulators. The band inversion is observed to have a new mechanism that involves s and pd states.