Charge Mobility and Strain Engineering in Two-Step MS-Grown MoS₂/Seed Layer Heterointerface and Photo-Excitation Mechanism

Abstract

Two-dimensional (2D) materials have potential application and wide development prospects in photoelectron and spintronic devices. However, the properties of different growth conditions are challenging to study in the future. This, in turn, hinders further research into 2D materials and the manufacture of high-quality devices. A comprehensive understanding of the ultrafast laser spectroscopy and dynamics that take into account the substrate-transition metal dichalcogenide (TMD) interaction is lacking. Here, the strain effect is elucidated by systematically investigating the interfacial interaction between different substrates and MoS2. The strain and interface engineering of MoS2/seeds layer heterointerface and light-matter coupling are discussed in the Raman and photoluminescence spectra. The dramatic enhanced PL originates from the phase transition of MoS2 on different substrates and electron–hole pairs dissociated by exciton screening effect. Finite-difference time-domain simulation confirmed that the electric field, magnetic field, and polarization field of the heterojunction system changed after the strain was applied. In addition, based on the dependence of physical parameters of MoS2, the relative numerical changes of physical parameters of MoS2 films on different substrates as well as the photoelectric transfer, strain, and charge doping levels on the surface or interface will provide a direction for optimizing the selection of various devices.

Photogenerated Carrier Separation and Localized Surface Plasmon Resonance in MoS2/Metal Nanocomposites: Implications for Photoelectric Devices

“…The presence of an emission peak at 440 nm is because of the transition among the above conduction band (CB) electrons as well as valence band (VB) holes (Figure S1ai,bi). This peak appears at the high energy side, which we refer to as C-excitons . Two obvious luminous peaks at 640 and 550 nm are attributed to direct transitions of A and B excitons, as shown in Figure f ii .…”

“…This peak appears at the high energy side, which we refer to as C-excitons. 52 Two obvious luminous peaks at 640 and 550 nm are attributed to direct transitions of A and B excitons, as shown in Figure 4f ii . Peak A represents the direct exciton transition among the top VB K and bottom CB K of the Brillouin region, while peak B corresponds to the direct transition of an exciton among CB and a lower VB.…”