Structures and Electronic Properties of Different CH(3)NH(3)PbI(3)/TiO(2) Interface: A First-Principles Study

Methylammonium lead iodide perovskite, CH(3)NH(3)PbI(3), has attracted particular attention due to its fast increase in efficiency in dye sensitization TiO(2) solid-state solar cells. We performed first-principles calculations to investigate several different types of CH(3)NH(3)PbI(3)/TiO(2) interfaces. The interfacial structures between the different terminated CH(3)NH(3)PbI(3) and phase TiO(2) are thoroughly explored, and the calculated results suggest that the interfacial Pb atoms play important roles in the structure stability and electronic properties. A charge transfer from Pb atoms to the O atoms of TiO(2) lead to the band edge alignment of Pb-p above Ti-d about 0.4 eV, suggesting a better carries separation. On the other hand, for TiO(2), rutile (001) is the better candidate due to the better lattice and atoms arrangement match with CH(3)NH(3)PbI(3).