Effects of Transition Metal Substituents on Interfacial and Electronic Structure of CH(3)NH(3)PbI(3)/TiO(2) Interface: A First-Principles Comparative Study

To evaluate the influence of transition metal substituents on the characteristics of CH(3)NH(3)PbI(3)/TiO(2), we investigated the geometrical and electronic properties of transition metal-substituted CH(3)NH(3)PbI(3)/TiO(2) by first-principles calculations. The results suggested that the substitution of Ti(4+) at the five-fold coordinated (Ti(5c)) sites by transition metals is energetically favored. The substituted interface has enhanced visible light sensitivity and photoelectrocatalytic activity by reducing the transition energies. The transition metal substitution can effectively tune the band gap of the interface, which significantly improves the photo-reactivity. The substituted systems are expected to be more efficient in separating the photo-generated electrons-holes and active in the visible spectrum.