The structure and electronic properties of bilayer, trilayer, and multilayer vertical Janus heterostructures are studied by first-principles calculation. By comparing the electronic structure of monolayer SMoS, monolayer SeMoS, and SMoS/SeMoS heterostructures, it has been found that, when SMoS forms heterostructures with more than two layers of Janus SeMoS, the band gap of the system changes from direct to indirect. In the Janus heterostructure system, significant charge transfer occurs between layers and a certain built-in electric field occurs. Due to the different contribution of Mo-d orbit...
