Electronic properties of two-dimensional van der Waals GaS/GaSe heterostructures

On the basis of density functional electronic calculations, heterostructures of single-layer GaS and GaSe were found to exhibit novel physical properties due to their specific interfacing effects and versatile structural features. We verified that electrons and holes can be distributed on the opposite constituent of the heterostructures, forming a type-II band alignment and enabling physical separation of excitons, which is highly desirable in applications such as solar energy conversion. We found the Rashba effects in the two-dimensional GaS/GaSe heterostructures due to the breaking of inversion symmetry and the intrinsic polarization, which reveals new possibility in applications in spintronic and electronic nanodevices. In addition, we confirmed that the electronic properties of GaS/GaSe van der Waals heterostructures can be continuously tuned by external strain.