Surface Defect Passivation by 2-(Anthracene-9-carboxamido)ethan-1-aminium Methylammonium in Lead Iodide Mixed-Dimensional Perovskites

Researchers are actively exploring ways to effectively link organic chromophores with bulk semiconductors to facilitate efficient energy transfer between the two materials. However, this goal is usually hindered by poor interface formation between organic-molecular materials and inorganic semiconductors. Mixed-dimensional metal halide perovskites represent a potential solution to this problem, as they intimately connect the organic and inorganic constituents in the crystal lattice. In this study, we present our research into the integration of an anthracene derivative into narrow-bandgap mixed-dimensional lead iodide perovskites. While looking for evidence of energy transfer, we instead found that bulk thin films of methylammonium lead iodide can suffer from defect states that affect charge carriers of a particular energy, resulting in excitation energy-dependent photoluminescent lifetimes and photoluminescence quantum yields. The incorporation of anthracene and conversion into a mixed-dimensional perovskite reduced the detrimental effects of this defect, highlighting another beneficial aspect of reduced dimensionality, which has meaningful implications for potential photovoltaic devices based on these types of materials.