Role of Main Group Nonmetal Dopants on the Electronic Properties of the TcS2 Monolayer Revealed by Density Functional Theory

The electronic properties of n- and p-type semiconductors using nonmetals (H, B, C, N, O, Si, P, Se, F, Cl, Br, and I) to substitute sulfur in the TcS2 monolayer were investigated using first-principles methods based on the density functional theory. The H-, B-, C-, N-, Si-, and P-doped systems were p-type, whereas the F-doped systems were n-type semiconductors. Numerical results showed that these nonmetals induced magnetic properties through the dopant p orbital and neighboring Tc atom d orbitals. H-, B-, N-, P-, and F-doped systems exhibited semiconducting magnetic nanomaterial features, whereas Cl-, Br-, and I-doped systems exhibited half-metallic magnetic features. The formation energy of the C-doped system was the lowest followed by the O-doped system, compared to that of the other examined systems. Under Tc-rich growth conditions, the preparation of nonmetal-doped TcS2 was facile and stable because of its negative impurity formation energy. A more significant change was observed at the band edges of the doped systems compared to the pristine TcS2 monolayer. These results provided fundamental insights into the doped TcS2 monolayer for application as photocatalysts and spintronic, optoelectronic, and electronic devices.