Moiré-induced bandgap tuning by varying electric dipole in InSe/CuSe vertical heterostructure

The stacked two layered materials with a lattice constant mismatch and/or twist angle relative to each other can create moir\'e pattern, modulating the electronic properties of pristine materials. Here, we combine scanning tunneling microscopy/spectroscopy and density functional theory calculations investigate potential induced bandgap tuning in InSe/CuSe vertical heterostructure synthesized by two-step molecular beam epitaxy. Scanning microscopy measurements demonstrate superlattice periodicity ~3.48nm about 11{\deg} between monolayers. spectroscopy record on different stacking sites reveals InSe is location-dependent variation 400 meV observed. Density reveal that moir\'e-induce electric dipole monolayer key factor for bandgap. Besides, charge transfer CuSe also contributes due its related. We show not only tune but vanish Dirac nodal line some stackings. Our explorations provide valuable information understanding twodimensional