Controllable Colloidal Synthesis of MAPbI₃ Perovskite Nanocrystals for Dual-Mode Optoelectronic Applications

This study demonstrates an acetate ligand (AcO^-)-assisted strategy for the controllable and tunable synthesis of colloidal methylammonium lead iodide (MAPbI₃) perovskite nanocrystals (PNCs) for efficient photovoltaic and photodetector devices. The size of colloidal MAPbI₃ PNCs can be tuned from 9 to 20 nm by changing the AcO^-/MA ratio in the reaction precursor. In situ observations and detailed characterization results show that the incorporation of the AcO^- ligand alters the formation of PbI₆ octahedral cages, which controls PNC growth. A well-optimized AcO^-/MA ratio affords MAPbI₃ PNCs with a low defect density, a long carrier lifetime, and unique solid-state isotropic properties, which can be used to fabricate solution-processed dual-mode photovoltaic and photodetector devices with a conversion efficiency of 13.34% and a detectivity of 2 × 10¹¹ Jones, respectively. This study provides an avenue to further the precisely controllable synthesis of hybrid PNCs for multifunctional optoelectronic applications.