Effect of direct interlayer coupling on the moire<acute accent> potentials in twisted WSe2/ MoSe2 heterobilayers

The shift of band edges in twisted van der Waals bilayers due to interlayer coupling can be divided into direct and indirect (strain-induced) contributions. However, experimental methods face challenges in isolating the effects of direct interlayer coupling on moire<acute accent> potentials because lattice deformation within the layers is unavoidable in twisted bilayers. In this study, we employed density functional theory (DFT) to investigate the electronic structure of a strain-free, rigidly twisted WSe2/ MoSe2 bilayer, focusing specifically on the influence of direct interlayer coupling on moire<acute accent> potentials. Our findings show that even without strain, direct interlayer coupling induces significant moire<acute accent> potential, particularly at small twist angles. In the R-stacking configuration, at a twist angle of [specific angle], the moire<acute accent> potential depths for the conduction band minimum and valence band maximum are 32 meV and 55 meV, respectively. We attribute this pronounced spatial variation in interlayer coupling strength to intralayer charge redistribution, which plays a key role in shaping the moire<acute accent> potential.