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.