Tunable electronic structures, Rashba splitting, and optical and photocatalytic responses of MSSe-PtO2 (M = Mo, W) van der Waals heterostructures

Abstract

Binding energies, AIMD simulation and phonon spectra confirm both the thermal and dynamical stabilities of model-I and model-II of MSSe-PtO₂ (M = Mo, W) vdWHs. An indirect type-II band alignment in both the models of MSSe-PtO₂ vdWHs and a larger Rashba spin splitting in model-II than in model-I provide a platform for experimental design of MSSe-PtO₂ vdWHs for optoelectronics and spintronic device applications. Transfer of electrons from the MSSe layer to the PtO₂ layer at the interface of MSSe-PtO₂ vdWHs makes MSSe (PtO₂) p(n)-type. Large absorption in the visible region of MoSSe-PtO₂ vdWHs, while blue shifts in WSSe-PtO₂ vdWHs are observed. In the case of model-II of MSSe-PtO₂ vdWHs, a further blue shift is observed. Furthermore, the photocatalytic response shows that MSSe-PtO₂ vdWHs cross the standard water redox potentials confirming their capability to split water into H⁺/H₂ and O₂/H₂O.