FACILE AND CONTROLLED SYNTHESIS OF 2D ORGANOMETAL HALIDE PEROVSKITE PURE BA2MAPb2I7 AND HETEROSTRUCTURED BA2PbI4/BA2MAPb2I7 SINGLE CRYSTALS

Abstract

Two dimensional (2D) organometal halide perovskites (OHPs) have attracted intensive interest for their diverse optoelectronic applications. However, a practical and controllable solution-based way particularly for the synthesis of pure BA2MAPb2I7 and heterostructured BA2PbI4/BA2MAPb2I7 single crystals, which are of great importance for high performance photodetectors, is still lacking. In this study, we report the efficient synthesis route of large-area high-quality BA2MAPb2I7 and BA2PbI4/BA2MAPb2I7 single crystals. We show that the combined method of solution temperature lowering and limiting reagent approaches yields rapid and controllable synthesis. In addition, the correct determination of the BAI:MAI:PbI2 molarity ratios in the synthesis process was revealed to be highly significant. These results provide fundamental insight and useful guideline for obtaining the presented 2D OHPs with regard to high practicality and controllability.