Neutron scattering study on the phonon spectra of two-dimensional metal chalcogenide InSe

Two dimensional (2D) metal chalcogenides are constituted by covalently/ionically bonded atomic layers that are held together via interlayer van der Waals (vdW) forces, and induce the interesting anomaly in electrical, optical and thermal properties. Therefore, this 2D material is a promising candidate in the next-generation electronic devices for energy conversion and information communication. InSe is a typical 2D vdW compounds and an n-type semiconductor with a band gap around 1.3 eV. The structure is hexagonal or trigonal. Although the physical and mechanical properties of InSe are fundamentally related to the features of chemical bonding and lattice vibration, the complete lattice dynamics are still missing. In this proposal, we want to apply inelastic neutron scattering to obtain the phonon dispersion spectra of InSe and explain the thermal, thermoelastic and transport properties.

二维（2D）金属硫族化合物由共价/离子键合的原子层构成，层间依靠范德瓦尔斯（van der Waals, vdW）力结合，并呈现出电学、光学及热学性质方面的新奇反常特性。因此，这类二维材料是用于能源转换与信息通信的下一代电子器件的极具潜力的候选材料。硒化铟（InSe）是典型的二维范德瓦尔斯化合物，同时也是禁带宽度约1.3 eV的n型半导体，其晶体结构为六方相或三方相。尽管硒化铟的物理与力学性质本质上与其化学键合特征及晶格振动特性密切相关，但目前其完整的晶格动力学行为仍未被阐明。在本研究提案中，我们拟采用非弹性中子散射技术获取硒化铟的声子色散谱，以此阐释其热学、热弹性以及输运性质。