Fröhlich potential of the A2" phonon mode in MoS2. (October 2020)

• Record Type: Journal Article
• Authors: Singh, Ramji; Mohamed, Ahmed; Dutta, Mitra; Stroscio, Michael A.
• Is Part Of: Solid state communications. Volume 320(2020)
• Publication Date: 2020-10
• Subjects: MoS2 -- Fröhlich potential -- Phonon modes -- Polar materials; Solid state chemistry -- Periodicals; Solid state physics -- Periodicals; Chimie de l'état solide -- Périodiques; Physique de l'état solide -- Périodiques; 530.41
• DOI: 10.1016/j.ssc.2020.114015
• Languages: English
• ISSNs: 0038-1098

Abstract

Abstract: The use of 2D transition metal-dichalcogenide (TMDC) layers in solid state structures has received increasing attention in recent times. Molybdenum disulfide (MoS2 ) is one of the most technologically important graphene-like two-dimensional (2D) transition metal dichalcogenides (TMDCs). They have been extensively studied, in part, because they do not have the small bandgap limitations in graphene. As an important and illustrative 2D TMDC material, here we analyze the Fröhlich potentials for MoS2 with special emphasis on the A 2 " mode. This mode has historically received little attention compared to the E ' mode which is known to play a dominant role in 2D materials for in-plane transport. In contrast, for carrier transport perpendicular to the 2D layer, it is the A 2 " mode that interacts strongly with carriers through the Fröhlich potential. In this paper, an analytical expression for the Fröhlich potential is derived for the A 2 " mode. We show that the potential falls off exponentially in the direction normal to the plane of the MoS2 . These results are used to derive the electron-phonon coupling for the A 2 " mode in MoS2 to better understand the electron scattering mechanisms in this material as well as the amplitude of the Fröhlich interaction. Highlights: Theoretical analysis of the Fröhlich potentials for MoS2 with special emphasis on the A 2 " mode. Evaluation of the out-of-plane field generated by the A 2 " optical phonon mode (usually referred to as the ZO phonons) in MoS2 . Examination of the potential decay from the plane of the TMD layer.