基于DFT研究2D WTe_(2)的晶体构型和吸附机理

Crystal Configuration and Adsorption Mechanism of 2D WTe_(2) Based on DFT

过渡金属硫系化合物(TMDs)作为一类典型的二维材料,因其具有半导体、半金属、超导等性质而受到广泛关注。WTe_(2)不仅具备TMDs的通性,其独特的电学和光学性能使WTe_(2)在各种电子器件中有着广泛的应用潜力。本文对WTe的三种主要晶格构型(2H、1T、Td)进行了结构分析和性能对比。2H相具有六边形对称性,力学性能和热力学稳定性较好,适宜作为电极材料,因此选用了2H构型进一步研究。以Li^(+)、Na^(+)、K^(+)、Mg^(2+)、Ca^(2+)、Al^(3+)为吸附对象,考虑三个高对称吸附位点,基于密度泛函理论(DFT)对WTe吸附金属原子的构型进行仿真计算。优化后的吸附键长与两吸附离子键长进行对比,初步判断吸附键的类型,并预测了吸附构型的稳定性,从而了解WTe_(2)作为电极材料的可行性,为研究WTe_(2)在电极材料中的应用奠定模型基础。

Transition metal chalcogenides (TMDs),as a typical class of two-dimensional materials,have attracted extensive attention due to their semiconducting,semi-metallic,and superconducting properties.WTe_(2)not only possesses the general properties of TMDs,but also has unique electrical and optical properties that make WTehave a wide range of potential applications in various electronic devices.In this paper,the structure analysis and performance comparison of three main lattice configurations (2H,1T,Td) of WTe_(2)were carried out.The 2H phase has hexagonal symmetry,good mechanical properties and thermodynamic stability,and is suitable as an electrode material.Therefore,the 2H configuration is selected for further research.Taking Li^(+),Na^(+),K^(+),Mg^(2+),Ca^(2+),and Al^(3+) as adsorption objects,considering three highly symmetric adsorption sites,the configuration of WTe_(2)adsorbed metal atoms was simulated based on density functional theory (DFT).The optimized adsorption bond length is compared with the two adsorbed ionic bond lengths,the type of adsorption bond is preliminarily determined,and the stability of the adsorption configuration is predicted,so as to understand the feasibility of WTe_(2)as an electrode material.The application lays the foundation for the model.