Computer study of the structure and thermal stability of a monolayer MoS₂ film on a diamond substrate
 

Letters on Materials 9 (3), 2019 pp. 270-275

A.Y. Galashev, K.A. Ivanichkina

Abstract — MoS₂ is a promising candidate for next-generation electrical and optoelectronic devices. The use of chemical vapor deposition allows obtaining high-quality MoS₂ monolayers on a diamond substrate. However, it is not clear how firmly the MoS₂ monolayer is held on the diamond substrate at a high temperature and how the structure of the MoS₂ monolayer changes after its deposition on the diamond substrate and subsequent heating on it. In this paper, the molecular dynamics method is used to study the stability of single-layer MoS₂ in the temperature range of 250–550 K. The molybdenum disulfide film on a diamond substrate structure is studied by constructing Voronoi polyhedra. Polyhedra were built around Mo atoms, and faces are formed by neighboring S atoms. The distributions of polyhedrons by the number of faces were found. These distributions were also calculated for truncated polyhedra obtained by eliminating small geometric elements. A comparison of the obtained statistical distributions for a MoS₂ monolayer on a diamond substrate with the corresponding characteristics of an autonomous monolayer MoS₂ indicates a significant change in the structure of the monolayer. This change is a result of its deposition on the diamond substrate. When the temperature reaches 550 K, the MoS₂ film is completely separated from the substrate. There is a singularity near this temperature, which indicates the thermal instability of the system under investigation

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