Interfacial electronic properties of 2D/3D (PtSe2/CsPbX3) perovskite heterostructure

Interfacial electronic properties are greatly significant to study the photoelectric properties of semiconductor heterostructures. The novel heterostructures are constructed using perovskite 3D CsPbX3(X = Cl, Br, I) and 2D PtSe2, and the structural and photoelectrical properties are studied by density functional theory. The band levels transform and interfacial charge transfer have serious differences at the interface of the CsPbX3-PtSe(2)heterostructures. The CsPbCl3-PtSe(2)and CsPbBr3-PtSe(2)heterostructures show the type-I band arrangement, however, the CsPbI3-PtSe(2)heterostructure demonstrate the type-II band arrangement. The difference in work function of the two semiconductors causes electrons to flow spontaneously at the interface. Moreover, the monolayer PtSe(2)can broaden the absorption spectrum of the CsPbX3-PtSe(2)heterostructures, that effectively enhance absorption capability of the heterostructures, especially the CsPbI3-PtSe(2)heterostructure. These results demonstrate PtSe(2)semiconductor materials can effectively improve the photoelectric performance of all-inorganic metal halide perovskite.