Soochow University Liao Liangsheng (Fang Sheng Optoelectronic CTO) Latest Nature: Long-range Order MKs Quantum Dot Light Emitting Diodes Stable

the external quantum efficiency (EQE) of light-emitting diodes (LEDs) based on perovskite quantum dots exceeds 25% and has narrow-band emission, these LEDs have limited operating lifetimes. Perovskitequantum dotfilms (variations in dot size, surface ligand density, and point-to-point stacking) inhibits carrier injection, resulting in poor operational stability because of the larger bias required to produce emission in these LEDs. In view of this, May 8, 2024(Fang Sheng Optoelectronic CTO)to Nature, which published the research results of long-range order to stabilize quantum dot light-emitting diodes: the diffraction intensity of repeated quantum dot units increased by three times compared with the control.

using a synergistic dual-ligand approach: an iodide-rich reagent for anion exchange (aniline hydroiodide) and a chemical reactant (bromotrimethylsilane) that generates a strong acid that dissolves smaller quantum dots in situ to tune the size and remove fewer quantum dots more efficiently. Conductive ligands can form dense, uniform and defect-free thin films. These films exhibit high conductivity (4 x10^−4Sm^−1), 2.5 times higher than the control,is the highest conductivity ever recorded in a perovskite quantum dot. The high conductivity ensures efficient charge transport, enabling the red perovskite QD-LED to generate 1,000 at a record low voltage of 2.8V.cd m^−2brightness at which the EQE exceeds 20%. In addition, when the EQE exceeds 20%, the operating stability of the device is 100 times better than that of the previous red perovskite LED.