Electron-phonon (e-ph) interaction in monolayer Janus MoSSe has been investigated using ab initio approach. We find that the asymmetric structure induced net dipole moment in MoSSe introduce an enhanced e-ph interaction compared to the symmetric MoS 2 . Through the mode resolved scattering analysis, we demonstrate that the out-of-plane optical mode in MoSSe contributing to the total eph scattering rates are much more than MoS 2 . Around the band edges, the maximum mean free paths (MFPs) of both electrons and holes along zigzag (ZZ) direction are found to be 4 nm in MoSSe, while the MFPs along armchair directions are significantly shorter than along ZZ direction, meaning the highly anisotropic transport properties in MoSSe.

The hot carrier relaxation dynamics in inorganic perovskites SrSnS3 and SrSnSe3 has been investigated using nonadiabatic molecular dynamics simulation. The results indicate that the hot carrier relaxation dynamics strongly depends on the chalcogenide element. It is found that the hot electrons and hot holes have a fast relaxation time in SrSnS3 than SrSnSe3 with the similar excess energy due to the strong nonadiabatic couplings. Moreover, the hot holes hold a dramatic faster decay time than hot electrons for both of the two systems because of the large density of states and the smaller energy level differences in the valence band. Generally, our findings here show that the hot carrier relaxation time in chalcogenide perovskites SrSnS3 and SrSnSe3 is longer than the organic–inorganic perovskites, indicating the present chalcogenide perovskites are promising candidates for solar cell applications.

The broken mirror symmetry of the two-dimensional (2D) Janus material brings novel quantum properties and various application prospects. Particularly, when stacking into heterostructure, its intrinsic dipole moments and large band...

Through first-principles calculations combining many-body perturbation theory, we investigate electron–phonon scattering and optical properties including the excitonic effects of T-carbon.

Stacking sequence of bilayer van der Waals transition metal dichalcogenides determines their electronic and related optical excitations. When the Janus monolayer structure has been taken to construct bilayer TMDs, it would introduce another degree of freedom, the out-of-plane intrinsic dipole moment, to tune the electronic and optical properties. Here we reveal that the electronic band structures and interlayer excitons can be dramatically tuned via the stacking sequence of the bilayer MoSSe with the different intrinsic dipole orientations. Moreover, the lowest energy interlayer excitons exhibit diverse spatial extensions, and the corresponding radiative lifetimes can be tailored within the range of ∼10−8 to ∼10−2 seconds at room temperature, by means of optimizing the dipole orientation and stacking sequence, and when the dipole moment keeps the same orientation for the constituent layer, it will slower the radiative recombination. Our findings shed a light on the applications of the interlayer excitons in Janus MoSSe on optoelectronics.