Nitrides and oxynitrides isostructural to α-SiN (-α-SiAlON, = Sr, Ca, Li) possess superb thermally stable photoluminescence (PL) properties, making them reliable phosphors for high-power solid-state lighting. However, the synthesis of phase-pure Sr-α-SiAlON still remains a great challenge and has only been reported for Sr below 1.35 at.
View Article and Find Full Text PDFVisible light is a universal and user-friendly excitation source; however, its use to generate persistent luminescence (PersL) in materials remains a huge challenge. Herein, the concept of intermolecular charge transfer (xCT) is applied in typical host-guest molecular systems, which allows for a much lower energy requirement for charge separation, thus enabling efficient charging of near-infrared (NIR) PersL in organics by visible light (425-700 nm). Importantly, NIR PersL in organics occurs via the trapping of electrons from charge-transfer aggregates (CTAs) into constructed trap states with trap depths of 0.
View Article and Find Full Text PDFMechanoluminescence (ML) sensing technologies open up new opportunities for intelligent sensors, self-powered displays and wearable devices. However, the emission efficiency of ML materials reported so far still fails to meet the growing application requirements due to the insufficiently understood mechano-to-photon conversion mechanism. Herein, we propose to quantify the ability of different phases to gain or lose electrons under friction (defined as triboelectric series), and reveal that the inorganic-organic interfacial triboelectricity is a key factor in determining the ML in inorganic-organic composites.
View Article and Find Full Text PDFLow-dimensional (LD) organic metal halides (OMHs) have a bright future due to their excellent photoelectric characteristics and unique structure. However, the synthesis and emission control of LD-OMHs are still unclear. Herein, the different dimensional (zero-dimensional (0D), one-dimensional (1D), and three-dimensional (3D)) of OMHs were obtained by the reaction of 1,4-diazabicyclo (2.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2024
Water-soluble quantum dots (QDs) are necessary to prepare patterned pixels or films for high-resolution displays with less environmental burden but are very limited by the trade-off between photoluminescence and stability of QDs. In this work, we proposed synthesizing water-soluble QDs with simultaneous excellent luminescence properties and high stability by coating the amphiphilic poly(maleic anhydride--1-octadecene)-ethanol amine (PMAO-EA) polymer on the surface of silane-treated QDs. These coated QDs show a photoluminescence quantum yield (PLQY) as high as 94%, and they have good photoluminescence stability against light irradiation and thermal attacks, owing to the suppression of the nonradiative recombination by the polymer layer and the isolation of oxygen and water by the silica layer.
View Article and Find Full Text PDFCorrection for 'A super-high brightness and excellent colour quality laser-driven white light source enables miniaturized endoscopy' by Shuxing Li , , 2023, , 4581-4588, https://doi.org/10.1039/D3MH01170D.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2023
With increasing ecological and environmental concerns, tin (Sn)-based perovskite light-emitting diodes (PeLEDs) are competitive candidates for future displays because of their environmental friendliness, excellent photoelectric properties, and low-cost solution-processed fabrication. Nonetheless, their electroluminescence (EL) performance still lags behind that of lead (Pb)-based PeLEDs due to the fast crystallization rate of Sn-based perovskite films and undesired oxidation from Sn to Sn , leading to poor film morphology and coverage, as well as high density defects. Here, we propose a ligand engineering strategy to construct high-quality phenethylammonium tin iodide (PEA SnI ) perovskite films by using L-glutathione reduced (GSH) as surface ligands toward efficient pure red PEA SnI -based PeLEDs.
View Article and Find Full Text PDFA laser-driven white light source promises intrinsic advantages for miniaturized endoscopic illumination. However, it remains a great challenge to simultaneously achieve high brightness and excellent colour rendition due to the shortage of highly efficient and thermally robust red-emitting laser phosphor converters. Here, we designed CaAlSiN:Eu@Al (CASN@Al) converters with neglectable efficiency loss by tightly bonding all-inorganic phosphor films on an aluminium substrate.
View Article and Find Full Text PDFLead halide perovskite nanocrystals (NCs) have been the star material in lighting and displays owing to their excellent photoelectrical properties, but they have not simultaneously realized high photoluminescence quantum yield (PLQY) and high stability. To solve this problem, we propose a perovskite/linear low-density polyethylene (perovskite/LLDPE) core/shell NC by the synergistic role of the pressure effect and steric effect. Green CsPbBr/LLDPE core/shell NCs with near-unity PLQY and nonblinking behavior were synthesized through an in situ hot-injection process.
View Article and Find Full Text PDFPerovskite light-emitting diodes (PeLEDs) are strong candidates for next-generation display and lighting technologies due to their high color purity and low-cost solution-processed fabrication. However, PeLEDs are not superior to commercial organic light-emitting diodes (OLEDs) in efficiency, as some key parameters affecting their efficiency, such as the charge carrier transport and light outcoupling efficiency, are usually overlooked and not well optimized. Here, ultrahigh-efficiency green PeLEDs are reported with quantum efficiencies surpassing a milestone of 30% by regulating the charge carrier transport and near-field light distribution to reduce electron leakage and achieve a high light outcoupling efficiency of 41.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2022
Herein, we report a new X-type ligand, i.e., organic sulfonium bromide, for high-efficiency CsPbBr and MAPbBr (MA=methylammonium) perovskite nanocrystals (PNCs).
View Article and Find Full Text PDFProportionally converting the applied mechanical energy into photons by individual mechanoluminescent (ML) micrometer-sized particles opens a new way to develop intelligent electronic skins as it promises high-resolution stress distribution visualization and fast response. However, a big challenge for ML sensing technology is its low sensitivity in detecting stress. In this work, a novel stress distribution sensor with the detection sensitivity enhanced by two orders of magnitude is developed by combining a proposed near-distance ML imaging scheme with an improved mechano-to-photon convertor.
View Article and Find Full Text PDFThe discovery of X-ray-charged persistent luminescence (PersL) in fluoride nanoparticles enables these materials to emit photons without real-time excitation, which provides a great possibility for the development of new luminescent nanotechnologies. In this work, we developed NaLuF:Mn nanoparticles with intense green PersL and functionalized surfaces and accordingly achieved time-gated imaging of latent fingerprints (LFPs) with Level 3 details. These surface-modified NaLuF:Mn nanoparticles exhibited near-spherical morphology, long-lasting emission for several hours, appropriate trap depth distribution, and tight chemical bonding with amino acids from fingerprints, thus greatly improving the accuracy of LFP imaging in a variety of environments.
View Article and Find Full Text PDFPerovskite light-emitting diodes (PeLEDs) are promising candidates used for superthin emissive displays with high resolution, high brightness, and wide color gamut, but the CsPbI nanocrystal (NC) based ones usually have an external quantum efficiency (EQE) of less than 20%, which needs further enhancement to minimize the gap between their counterparts. Herein, we propose to improve optical properties of the CsPbI:Sr emissive layer (EML) by inserting an additional potassium iodide (KI) passivation layer between the hole transport layer and EML to increase the film quality, photoluminescence quantum yield, and thermal stability of the EML. The KI layer can also increase the carrier mobility to balance the charge injection in PeLEDs, leading to a reduction in Auger recombination and Joule heating.
View Article and Find Full Text PDFInkjet-printed perovskite quantum dot (PQD) color conversion films (CCFs) have great potentials for mini/micro-LED displays because of their ultrahigh color purity, tunable emissions, high efficiency, and high-resolution. However, current PQD inks mainly use expensive, toxic, and flammable organic substances as solvents. In this work, water is proposed to be used as the solvent for inkjet printing PQD/polymer CCFs.
View Article and Find Full Text PDFNaYF:Ln, due to its outstanding upconversion characteristics, has become one of the most important luminescent nanomaterials in biological imaging, optical information storage, and anticounterfeiting applications. However, the large specific surface area of NaYF:Ln nanoparticles generally leads to serious nonradiative transitions, which may greatly hinder the discovery of new optical functionality with promising applications. In this paper, we report that monodispersed nanoscale NaYF:Ln, unexpectedly, can also be an excellent persistent luminescent (PersL) material.
View Article and Find Full Text PDFAdv Mater
December 2021
The emergence of new applications, such as in artificial intelligence, the internet of things, and biotechnology, has driven the evolution of stress sensing technology. For these emerging applications, stretchability, remoteness, stress distribution, a multimodal nature, and biocompatibility are important performance characteristics of stress sensors. Mechanoluminescence (ML)-based stress sensing has attracted widespread attention because of its characteristics of remoteness and having a distributed response to mechanical stimuli as well as its great potential for stretchability, biocompatibility, and self-powering.
View Article and Find Full Text PDFLithium-sulfur (Li-S) batteries are regarded as one of the most promising next-generation battery technologies owing to their ultrahigh energy density up to 2600 W h kg and low cost. However, major challenges still remain in the application of Li-S batteries, such as shuttle effect and sluggish redox kinetics. Herein, it is demonstrated that phosphorus doping can not only significantly improve the polysulfide adsorption but also enhance the catalysis effects of metal-organic framework-derived CoS nanoboxes in Li-S batteries.
View Article and Find Full Text PDFAs symmetry-breaking interfaces, edges inevitably influence material properties, particularly for low-dimensional materials such as two-dimensional (2D) graphene and black phosphorus (BP). Hence, exploiting pristine edge structures and the associated edge reconstruction is important. In this study, we revealed edge reconstruction and evolution in monolayer BP (ML-BP) via in situ high-resolution transmission electron microscopy.
View Article and Find Full Text PDFLow-dimensional metal halide hybrids (OIMHs) have recently been explored as single-component white-light emitters for use in solid-state lighting. However, it still remains challenging to realize tunable white-light emission in lead-free zero-dimensional (0D) hybrid system. Here, a combination strategy has been proposed through doping Sb enabling and balancing multiple emission centers toward the multiband warm white light.
View Article and Find Full Text PDFStress sensing is the basis of human-machine interface, biomedical engineering, and mechanical structure detection systems. Stress sensing based on mechanoluminescence (ML) shows significant advantages of distributed detection and remote response to mechanical stimuli and is thus expected to be a key technology of next-generation tactile sensors and stress recorders. However, the instantaneous photon emission in ML materials generally requires real-time recording with a photodetector, thus limiting their application fields to real-time stress sensing.
View Article and Find Full Text PDFLight Sci Appl
September 2020
A brighter near-infrared (NIR) phosphor is achieved by inhibiting the oxidation of Cr and reducing the surface defects of phosphor particles, enabling the realization of smarter and more sensitive light sources for night vision.
View Article and Find Full Text PDFMicro light-emitting diodes (μLEDs) have been considered an excellent candidate for next-generation display technology because of their promising optical properties, outstanding power efficiency, fast response time, high reliability, etc. However, the μLED displays based on individual red-green-blue (RGB) primary chips suffer from severe issues in mass production, such as difficulty in mass transfer, high cost, and low reproducibility. To overcome these issues, an alternative approach has been proposed to achieve full-color μLEDs by assembling ultraviolet- or blue-μLEDs with QD color conversion films (CCFs).
View Article and Find Full Text PDFLow dimensional semiconductor nanomaterials show great promise for a variety of applications due to their size-dependent and excellent optoelectronic properties. In this work, we developed a strategy to synthesize uniform and very thin CsPbBr perovskite nanoplates (NPls) by introducing additional metal bromides. The CsPbBr NPls, self-assembled into a face-to-face stacked state, had a thickness of 4.
View Article and Find Full Text PDFRed emitters based on CaAlO:Mn have been attracting extensive attention due to their advantages of being rare-earth-free and chemically stable. However, their relatively low luminescence efficiencies will seriously hinder their application in light-emitting diodes (LEDs). In this regard, the promising red phosphors of CaAlO:Mn were synthesized with enhanced luminous efficiency by introducing the coexisting phase of MgAlO.
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