Exciton and Trion Dynamics in Bilayer MoS₂

Abstract

The control of exciton and triondynamics in bilayer MoS2 is demonstrated, via the comodulations by both temperature and electric field. The calculations here show that the band structure of bilayer MoS2 changes from indirect at room temperature toward direct nature as temperature decreases, which enables the electrical tunability of the K-K direct PL transition in bilayer MoS2 at low temperature.

Gate‐Tunable Resonant Raman Spectroscopy of Bilayer MoS2

“…The Davydov split Raman-inactive A 2u mode is displayed in red triangles. Davydov splitting is more pronounced at resonance, which is consistent with previous reports on WS 2 and MoTe 2 . [17,30] In the moderate/heavy electron doping region when there is no splitting, increases of V tg causes A 1g mode to blue-shifts when excitation wavelength is 612.2 nm while red-shifts when 632.9 nm is used.…”

Many‐Body Complexes in 2D Semiconductors

“…Through electrical/optical doping, switching between exciton, trion, and biexciton emissions have been observed in monolayer 2D semiconductors, depending on the injected carrier types and carrier densities (Figure c–e). Trion and biexciton binding energies are therefore extracted based on the energy differences of PL emissions.…”

Microscopic Origin of the Valley Hall Effect in Transition Metal Dichalcogenides Revealed by Wavelength-Dependent Mapping

“…33,34 Therefore, for this experiment we use a device based on a 3R-stacked MoS 2 bilayer, in which the splitting between excitons and trions could be resolved experimentally (see Figure 4a, black curve). 35 Owing to their stacking, 3R TMD multilayers have broken inversion symmetry regardless of the number of layers 36 and are expected to show a large VHE in all cases. This is a crucial difference from the commonly investigated 2H polytype of TMD multilayers, 15 in which the crystal inversion symmetry is strongly broken only in odd multilayers [17][18][19] (in even 2H multilayers, inversion symmetry can still be broken -but much more weakly-by the presence of an underlying substrate 37,38 ).…”