Complexity of mixed allotropes of MoS2 unraveled by first-principles theory

Article

关键词: TOTAL-ENERGY CALCULATIONS;    PHASE-TRANSITION;    PHOTOLUMINESCENCE;    NANOPARTICLES;    DYNAMICS;   

DOI  :  10.1103/PhysRevB.102.165412

来源: SCIE

【 摘 要 】

Two-dimensional MoS2 forms stable and several metastable allotropes of semimetallic, metallic, and semiconducting characters, depending on the experimental growth conditions. In this paper we consider intergrowth of the two most frequently reported metastable phases of MoS2 (1T and 1T') within the stable 1H phase to establish the effect of geometric and electronic reconstructions of the interface region between 1H and T/1T' phases using first-principles density functional calculations. We show that a complex structural reconstruction at the interfaces is responsible for the opening of an energy gap driving the electronic and geometric structures to resemble that of the 1T' phase. It is also found that the size of the patches inside the 1H matrix crucially controls the geometry and electronic structure close to the Fermi level. These results establish that remarkable properties of chemically exfoliated MoS2 with patches of metastable structures are to be understood as arising fundamentally from intergrowths necessarily strained due to lattice mismatch across the interface between the H and the distorted T phase, rather than in terms of any pure metastable phase.

【 授权许可】

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