In Situ Zwitterionic Ligands Consolidated Surface Matrix of Perovskite Quantum Dots for Efficient Red LEDs

Abstract Perovskite quantum dots (PQDs) attract significant attention for high‐performance light‐emitting diodes (LEDs) due to their remarkable optoelectronic properties and solution processability. However, the surface matrix of PQDs generally suffers from the dynamic binding of ligands, ineluctably producing numerous surface vacancies and thus leading to serious nonradiative recombination and structural lability. Herein, an in situ surface matrix consolidation (ISMC) strategy is introduced for the synthesis of PQDs, which can generate adequate zwitterionic ligands and create an iodide‐rich environment for the synthesis of the PQDs with substantially diminished surface vacancies. Meanwhile, the zwitterionic ligands can also strongly anchor on the PQD surface, which mitigates the dynamic binding of ligands and thus allows PQDs with improved optoelectronic properties and stability. Moreover, the PQD solid with a preferred stacking orientation is achieved due to the complete surface matrix in PQDs, subsequently facilitating charge carrier transport in the PQD solids with suppressed nonradiative recombination. Consequently, the red PQD‐LEDs yield a remarkable maximum external quantum efficiency of up to 23.36% with the highest luminance of 15096 cd m −2 . This work provides new insights into the surface matrix regulation of PQDs through precursor engineering toward high‐performance optoelectronic devices.