Broken-gap type-III band alignment in monolayer halide perovskite/antiperovskite oxide van der Waals heterojunctions

We show that Rb 2 CdCl 4 /Ba 4 OSb 2 van der Waals heterostructures exhibit a rare type-III band alignment with a broken gap, which can be tuned by applying strain or an external electric field, paving the way for the novel tunnel field-effect transistors.