Microstructuring of 2D perovskites via ion-exchange fabrication

In recent years, two dimensional (2D) perovskites have attracted growing interest as a material for optoelectronic applications, combining the defect tolerance and strong absorption of bulk perovskites with enhanced material stability. Moreover, the possibility to tune their bandgap via control of the thickness of the perovskite layers allows precise optimization of the energy levels in these materials, making them ideal candidates for rationally designed semiconductor heterojunctions. However, despite the advances in the synthesis of 2D perovskites, typical fabrication strategies produce either uniform thin-films or isolated single crystals, severely hindering the prospect of patterning these materials. We demonstrate an ion-exchange synthesis of 2D perovskites, starting from a lead carbonate host material and converting it to 2D perovskites via a solution-based treatment. The process allows for the fabrication of 2D perovskites spanning a range of halide compositions and 2D layer thicknesses and yields highly crystalline luminescent materials. We demonstrate the potential of this approach for 2D perovskite patterning, spatially localizing 2D perovskite structures via the conversion of pre-patterned lead carbonate structures. These results significantly expand the possibilities of 2D perovskite material design toward controllable integration of 2D perovskites in complex device architectures.