Antisolvent Etching-Driven Surface Reconstruction of Perovskite Quantum Dots Enabling Efficient Light-Emitting Diodes

Achieving a balance between removing surface ligands and stabilizing perovskite quantum dots (PQDs) is crucial for the development of efficient electroluminescent light-emitting diodes (LEDs), yet it has always been a challenging task. Herein, we devised an antisolvent etching-driven surface reconstruction strategy. A mixed antisolvent solution (isopropanol/methyl acetate) with zinc iodide (ZnI2) and 1-dodecylthiol (1-DT) was introduced in the purification stage for removing native surface ligands of PQDs. The antisolvent solution etched the surface of PQDs, thereby disrupting the [PbI6]4– octahedral structure, removing the native ligands, and facilitating the surface reconstruction. 1-DT stabilized the [PbI6]4– octahedron through robust coordination between the thiol group and Pb2+. ZnI2 passivated vacancies formed by purification and increased the PQD film conductivity. The LED based on such PQDs exhibited high champion and average external quantum efficiencies of 23.7% and 21.4%, respectively, representing a 2.2-fold enhancement compared to the control devices.