AMiner finds ligand reconstruction cuts defects in quantum dot light emitters

Researchers have achieved a 34.3% external quantum efficiency (EQE) in pixel-less quantum dot light-emitting diodes (QLEDs) by reconstructing the surface of quantum dots with zirconium acetylacetonate (Zr(acac)4). This approach precisely repairs defects, overcoming limitations imposed by traditional long-chain ligands and markedly improving both efficiency and stability. The optimized QLEDs demonstrated an operational T95@1000 cd/m2 lifetime of 19,450 hours, more than quadrupling the 4974 hours observed in unmodified devices, a result stemming from suppressed exciton quenching and reduced carrier leakage. Researchers detailed a method for addressing residual surface defects on quantum dots, a long-standing limitation imposed by the steric hindrance of traditional long-chain ligands. This innovative approach focuses on the chemical solution Zr(acac)4 to solve a materials science problem, demonstrating a surprising level of control over quantum dot surface chemistry. The core challenge in maximizing QLED efficiency…