Fabrication and Characterization of Ni-, Co-, and Rb-Incorporated CH3NH3PbI3 Perovskite Solar Cells.

Ni- and Co-incorporated CH₃NH₃PbI₃ perovskite solar cells were fabricated and characterized to optimize the photovoltaic and optical properties related to surface morphology, crystal growth and orientation, and electronic structures. Partially replacing Pb with Ni or Co in the perovskite crystals improved the photovoltaic performance and carrier mobility based on the effective mass in the band structure. In particular, the addition of both Ni and Rb compounds to perovskite improved the long-term stability of the photovoltaic cells, which depended on surface modification and coverage, crystal growth, and the high (100) orientation in the perovskite layer. The short-circuit current density of the cells was increased by promoting the generation and mobility of photoinduced carriers, which were inversely proportional to the effective mass ratio. Electron correlation was associated with the promotion of charge transfer owing to the hybridization between the 3d orbitals of Ni and the 5p orbitals of the I atoms near the valence band state. [ABSTRACT FROM AUTHOR]