Exciton

Chemistry

Materials science

Electric field

Chemical physics

Physics

Valence band

Nanotechnology

Magnetization

Janus

Quantum mechanics

Molecule

Magnetic field

Band gap

Monolayer

Condensed matter physics

van der Waals force

Physical chemistry

Polarization (electrochemistry)

Band offset

Polarization density

The Journal of Physical Chemistry Letters

Focusing on two-dimensional (2D) Janus MoSSe monolayers, we show that simultaneously existing in-plane and out-of-plane intrinsic electric fields cause Zeeman- and Rashba-type spin splitting, respectively. In MoSSe van der Waals (vdW) structures, intrinsic electric field results in a large interlayer band offset. Therefore, large interlayer band offset, being the driving force for interlayer excitons, endows ultralong lifetimes to excitons and might dissociate excitons into free carriers. In comparison to its parent structure (i.e., MoS2), MoSSe vdW structures are rather appealing for new concepts in light-electricity interconversion. In addition, the Rashba effects could be tuned by changing the interlayer distances due to the competition between the intralayer and interlayer electric field. Due to the large band offset, valley polarization relaxation is markedly reduced, promising enhanced valley polarization and ultralong valley lifetimes. As a result, MoSSe vdW structures harbor strong valley-contrasting physics, making them competitive systems to their parent structures.

Intrinsic Electric Field-Induced Properties in Janus MoSSe van der Waals Structures