Conversion of Electrochemically Deposited Aragonite Crystallites to Perovskite through In Situ Ion Exchange

The unique and broadly applicable optoelectronic properties of metal-halide perovskite materials are determined by structural dimensionality. Conversion of scaffold supported carbonate salts to perovskite with microstructure retention has previously been shown to act as a gateway to unique morphologies. In the present work, calcium carbonate microstructures are electrochemically deposited on a transparent conducting oxide substrate. Through a series of ion-exchange reactions the microstructures are decorated with a layer of surface localized perovskite nanocrystals, indicating that this ion exchange process occurs at the microstructure surface. Throughout the conversion process, electron microscopy confirms that the microstructures retain their overall morphology while cubic perovskite nanocrystals exhibiting characteristic photoluminescence and photoblinking are formed at the interface. This work confirms a synthetic pathway in which perovskites can be made in shapes previously inaccessible, which may lead to enhanced optoelectronic properties.