First-principles study of the quasi-two-dimensional electron gas at LaInO₃/BaSnO₃ interfaces

We investigate atomic and electronic properties of LaInO₃/BaSnO₃ (LIO/BSO) heterostructures using first-principles density functional theory and tight-binding modeling of the frontier orbitals. The charge transfer from the topmost layer of LIO to the interfacial BSO is observed as increasing the thickness of the LIO layers. The spatial distribution of the interfacial charge density profile as a function of LIO thickness is also investigated. The charge density profile as a function of the charge transfer is further investigated by a tight-binding model considering Hartree potential in which the model parameters, such as the effective mass of Sn-s bands and dielectric constants, are obtained by fitting the charge density profile from the first-principles calculations. Our results by solving the Poisson-Schrödinger equation with a thick BSO limit show that there is a significant change in the spatial extent of the interfacial electron gas with the degree of the charge transfer. We believe that our results provide the electronic structures and charge-density profiles by varying charge transfer in thick BSO limits, which could be useful for understanding the properties of the quasi-two-dimensional electron gas formed at the LIO/BSO interface.