Theoretical investigations on exploring Si-based heterostructures with cubic and ground-state perovskites

• This work develops CaTiO 3 and CaZrO 3 as the candidate of gate dielectric, and realize their orthorhombic structures deposited on Si (001) substrate, through the lattice transformation of “strained bulk” method. • Two Si-based heterostructures of cubic and orthorhombic CaZrO 3 with half monolayer of interfacial layer and two unit-cell perovskite thicknesses show semiconductivity and the straddling gap with type-I character through their band alignment, and the heterostructure with orthorhombic CaZrO 3 obtains excellent electrical property with larger ΔEv and ΔEc than 1.0 eV, to effectively block carrier and reduce leakage current. • With the increases of interfacial layer to one monolayer and perovskite thickness to four unitcells, both will all trigger the semiconductivity of perovskite/Si heterostructure into metallicity, which causes the loss of switch characteristics of the heterostructure. First principles calculations in the framework of density functional theory (DFT) are performed to exploit replaceable perovskite oxides against the instability of traditional cubic SrTiO 3 grown on silicon substrate. In this work, we consider more thermostable CaTiO 3 and CaZrO 3 with cubic and ground-state phase as the candidates to perform the gate dielectric. After the calibration of total energy and lattice transformation of ground-state perovskites to match with Si substrate, three categories of 2 × 2 heterostructures have been constructed and investigated through the geometrical change, atom displacement around interfacial layer, total energy and electronic structure change, under the variations on perovskite species, the concentration of interfacial layer and the thickness of perovskite film. And the results demonstrate that the category with half a monolayer of Ca/Sr atoms in interfacial layer and two unit-cell perovskite thicknesses show the type-I band alignment through their band alignment. Among this category, the heterostructure with Pnma CaZrO 3 shows semiconductivity and excellent electrical property with larger band offset for the candidate of gate dielectric. This work provides a creative perspective to expand the perovskite diversity for the booming growth of integrated circuit technology.