Comprehensive Interior/Surface Defect Management Strategy for Halide Perovskite Nanocrystal Light-Emitting Diodes

Perovskite nanocrystals (PeNCs) have emerged as highly promising materials for a wide range of optoelectronic applications due to their high color purity, tunable bandgap, and solution processability. However, labile nature and low stability, primarily caused by interior/surface defects of PeNCs, remain as a bottleneck for commercialization. To address these problems, we introduce two-steps strategy to efficiently passivate both internal and surface defects via compositional and surface ligand engineering. We carefully control tensile and compressive strains by incorporating A and B-site cations of varying radii to alleviate lattice strain, thereby reducing interior defects arising from size mismatches. Additionally, a simple and efficient surface ligand exchange method employing a short conjugated molecular ligand as a tridentate binding ligand effectively passivates surface defects in PeNCs. This comprehensive two-step defect passivation strategy results in a significant increase in the efficiency and stability of PeNCs light-emitting diodes (LEDs), demonstrating its potential for advancing the practical application of PeNCs in optoelectronic devices.