Fabrication of red-emitting perovskite LEDs by stabilizing their octahedral structure.

Light-emitting diodes (LEDs) based on metal halide perovskites (PeLEDs) with high colour quality and facile solution processing are promising candidates for full-colour and high-definition displays. Despite the great success achieved in green PeLEDs with lead bromide perovskites, it is still challenging to realize pure-red (620-650 nm) LEDs using iodine-based counterparts, as they are constrained by the low intrinsic bandgap. Here we report efficient and colour-stable PeLEDs across the entire pure-red region, with a peak external quantum efficiency reaching 28.

Tautomeric mixture coordination enables efficient lead-free perovskite LEDs.

Lead halide perovskite light-emitting diodes (PeLEDs) have demonstrated remarkable optoelectronic performance. However, there are potential toxicity issues with lead and removing lead from the best-performing PeLEDs-without compromising their high external quantum efficiencies-remains a challenge. Here we report a tautomeric-mixture-coordination-induced electron localization strategy to stabilize the lead-free tin perovskite TEASnI (TEAI is 2-thiopheneethylammonium iodide) by incorporating cyanuric acid.

Deep-Blue Electroluminescence of Perovskites with Reduced Dimensionality Achieved by Manipulating Adsorption-Energy Differences.

The lagging development of deep-blue perovskite light-emitting diodes (PeLEDs) heavily impedes their practical applications in full-color display due to the absence of spectrally stable emitters and the mismatch of carrier injection capacity. Herein, we report highly efficient deep-blue PeLEDs through a new chemical strategy that addresses the dilemma for simultaneously constant electroluminescence (EL) spectra and high-purify phase in reduced-dimensional perovskites. The success lies in the control of adsorption-energy differences between phenylbutylamine (PBA) and ethylamine (EA) interacting with perovskites, which facilitates narrow n-value distribution.

Growing MASnIperovskite single-crystal films by inverse temperature crystallization.

Perovskite single-crystal films are promising candidates for high-performance perovskite optoelectronic devices due to their optoelectrical properties. However, there are few reports of single-crystal films of tin based perovskites. Here, for the first time, we realize the controllable growth and preparation of lead-free tin perovskite MASnIsingle crystals via inverse temperature crystallization (ITC) strategy with γ-butyrolactone (GBL) as solvent.

Two-step synthesis of hole structure bastnasite (RECOF RE = Ce, La, Pr, Nd) sub-microcrystals with tunable luminescence properties.

A two-step synthetic route using RE(OH)CO3 colloid spheres as the sacrificial template was designed to prepare monodisperse, pure bastnasite (RECO3F: RE = Ce, La, Pr, Nd) with a hole structure for the first time. A variety of morphologies, including jujube core-like, stacked nanoblocks, and stacked nanosheets were obtained through changing the ratio of reactants. The phase, structure, shapes, and photoluminescence properties of samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy.

A novel color-tunable phosphor, NaGdF:Ln (Ln = Eu, Tb, Dy, Sm, Ho) sub-microcrystals: structure, luminescence and energy transfer properties.

Ln3+-Doped fluorides are economical and highly efficient luminescent materials, which play a crucial role in LEDs, biolabeling, and sensors. Therefore, Na5Gd9F32:Ln3+ sub-microspheres with tunable multicolor emissions were successfully synthesized via a simple water bath method employing colloidal Gd(OH)CO3 spheres as precursors. Samples were characterized by XRD, SEM, TEM, EDS and PL.

Facile synthesis and color-tunable properties of monodisperse β-NaYF:Ln (Ln = Eu, Tb, Tm, Sm, Ho) microtubes.

In this study, monodisperse and uniform β-NaYF hexagonal microtubes were successfully synthesized via a simple hydrothermal method without any organic surfactants, employing Y(OH)CO colloid spheres as precursors. The possible formation mechanism was studied on the basis of a series of time-dependent control experiments and its intrinsic crystal structure. The integrated emission intensity of β-NaYF:0.

Fabrication of CeO nanoparticles decorated three-dimensional flower-like BiOI composites to build p-n heterojunction with highly enhanced visible-light photocatalytic performance.

Three-dimensional (3D) flower-like CeO/BiOI heterostructures with different Ce/Bi molar ratio were successfully synthesized via a hydrothermal method using polyvinylpyrrolidone (PVP) as surfactant. The X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) results indicate that the CeO nanoparticles were successfully loaded on the surface of the flower-like BiOI. The photodegradation experiment demonstrated that the photocatalytic efficiency of CeO/BiOI samples were higher than that of pure BiOI and CeO, and CeO/BiOI heterostructure showed the best photocatalytic performance when the amount of CeO located at BiOI up to 15%.