Ions-induced Assembly of Perovskite Nanocomposites for Highly Efficient Light-Emitting Diodes with EQE Exceeding 30.

Metal halide perovskites, a cost-effective class of semiconductos, hold great promise for display technologies that demand high-efficiency, color-pure light-emitting diodes (LEDs). Early research on three-dimensional (3D) perovskites showed low radiative efficiencies due to modest exciton binding energies. To inprove luminescence, reducing dimensionality or grain size has been a common approach.

Efficient Green Spin Light-Emitting Diodes Enabled by Ultrafast Energy- and Spin-Funneling in Chiral Perovskites.

Introducing molecular chirality into perovskite crystal structures has enabled the control of carrier spin states, giving rise to circularly polarized luminescence (CPL) in thin films and circularly polarized electroluminescence (CPEL) in LEDs. Spin-LEDs can be fabricated either through a spin-filtering layer enabled by chiral-induced spin selectivity or a chiral emissive layer. The former requires a high degree of spin polarization and a compatible spinterface for efficient spin injection, which might not be easily integrated into LEDs.

Construction of Standardized Procedure for Early Activity After Cardiac Surgery in Elderly Based on Critical Care Scoring System and Effect Analysis.

Objective: To analyze the construction and effect of standardized procedure of early activity after cardiac surgery in elderly patients based on the critical illness scoring system.

Methods: A total of 65 elderly patients who underwent cardiac surgery in our hospital from January 2020 to January 2022 were selected as the research objects and divided into the control group (n = 32) and the observation group (n = 33) according to the admission time. The standardized procedure for the early activity after cardiac surgery was implemented based on the critical illness scoring system.

Synergistic Halide- and Ligand-Exchanges of All-Inorganic Perovskite Nanocrystals for Near-Unity and Spectrally Stable Red Emission.

All-inorganic perovskite nanocrystals (NCs) of CsPbX (X = Cl, Br, I) are promising for displays due to wide color gamut, narrow emission bandwidth, and high photoluminescence quantum yield (PLQY). However, pure red perovskite NCs prepared by mixing halide ions often result in defects and spectral instabilities. We demonstrate a method to prepare stable pure red emission and high-PLQY-mixed-halide perovskite NCs through simultaneous halide-exchange and ligand-exchange.

Efficient Quasi-2D Perovskite Light-Emitting Diodes Enabled by Regulating Phase Distribution with a Fluorinated Organic Cation.

Metal halide perovskites have become a research highlight in the optoelectronic field due to their excellent properties. The perovskite light-emitting diodes (PeLEDs) have achieved great improvement in performance in recent years, and the construction of quasi-2D perovskites by incorporating large-size organic cations is an effective strategy for fabricating efficient PeLEDs. Here, we incorporate the fluorine meta-substituted phenethylammonium bromide (-FPEABr) into CsPbBr to prepare quasi-2D perovskite films for efficient PeLEDs, and study the effect of fluorine substitution on regulating the crystallization kinetics and phase distribution of the quasi-2D perovskites.

Low-dimensional phase suppression and defect passivation of quasi-2D perovskites for efficient electroluminescence and low-threshold amplified spontaneous emission.

Quasi-2D metal halide perovskites are promising candidates for light-emitting applications owing to their large exciton binding energy and strong quantum confinement effect. Usually, quasi-2D perovskites are composed of multiple phases with various numbers of layers () of metal halide octahedron sheets, enabling light emission from the lowest-bandgap phase by cascade energy transfer. However, the energy transfer processes are extremely sensitive to the phase distribution and trap density in the quasi-2D perovskite films, and the insufficient energy transfer between different- phases and the defect-induced traps would result in nonradiative losses.

Rearranging Low-Dimensional Phase Distribution of Quasi-2D Perovskites for Efficient Sky-Blue Perovskite Light-Emitting Diodes.

Metal halide perovskites have received much attention for their application in light-emitting diodes (LEDs) in the past several years. Rapid progress has been made in efficient green, red, and near-infrared perovskite LEDs. However, the development of blue perovskite LEDs is still lagging far behind.