DFT study of structural and electronic properties of MoS2(1-x)Se2x alloy (x = 0.25)

• Main Authors: Gusakova, Julia, Gusakov, Vasilii, Tay, Beng Kang
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2019
• Subjects: Density Functional Theory; Monolayer Alloy; DRNTU::Engineering::Electrical and electronic engineering
• Online Access: https://hdl.handle.net/10356/89103; http://hdl.handle.net/10220/47653
• Institution: Nanyang Technological University

First-principles calculations have been performed to study the structural features of the monolayer MoS2(1-x)Se2x (x = 0.25) alloy and its electronic properties. We studied the effects of the relative positions of Se atoms in a real monolayer alloy. It was demonstrated that the distribution of the Se atoms between the top and bottom chalcogen planes was most energetically favorable. For a more probable distribution of Se atoms, a MoS2(1-x)Se2x (x = 0.25) monolayer alloy is a direct semiconductor with a fundamental band gap equal to 2.35 eV (calculated with the GVJ-2e method). We also evaluated the optical band gap of the alloy at 77 K (1.86 eV) and at room temperature (1.80 eV), which was in good agreement with the experimentally measured band gap of 1.79 eV.