One-Step Aerosol Synthesis of Thiocyanate Passivated Hybrid Perovskite Microcrystals : Impact of (Pseudo-)Halide Additives on Crystallization and Access to a Novel Binary Model

Abstract

Hybrid Perovskite materials have gone through an astonishing development due to their unique optoelectronic behavior, leading to the creation of a wide range of synthetic strategies. As the materials’ surface is found to play a crucial role with respect to the properties, e.g. hydration, stability and carrier mobilities, considerable efforts have been made to optimize the surface through various approaches. Especially the passivation of the perovskite surface attracted a lot of attention in this field, often resulting in more complex, multi-step synthetic processes. In this study, a simple one-step aerosol-assisted synthetic approach is presented to obtain thiocyanate (SCN) passivated single-crystal MAPbBr3 microcrystals. To elucidate the role of the additive in the crystallization process, mixed (pseudo-)halide precursors are systematically investigated. The as processed, passivated microcrystals exhibit enhanced stability and charge carrier lifetimes. Additionally, a decrease in surface photovoltage, attributed to the presence of the SCN additive, is observed. Furthermore, the aerosol process is further developed resulting in a novel binary system containing MAPbBr3-SCN perovskite microcrystals and Au nanostructures. This system serves as a promising model for further investigations into potential interactions between plasmonic and semiconducting materials, with initial results indicating prolonged charge carrier lifetimes.