Ligand Engineering Achieves Suppression of Temperature Quenching in Pure Green Perovskite Nanocrystals for Efficient and Thermostable Electroluminescence.

Formamidinium lead bromide (FAPbBr) perovskite nanocrystals (NCs) are promising for display and lighting due to their ultra-pure green emission. However, the thermal quenching will exacerbate their performance degradation in practical applications, which is a common issue for halide perovskites. Here, we reported the heat-resistant FAPbBr NCs prepared by a ligand-engineered room-temperature synthesis strategy.

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.

Regulating the Grain-Growth Surface for Efficient Near-Infrared Perovskite Light-Emitting Diodes.

Metal halide perovskites hold great potential for next-generation light-emitting diodes (PeLEDs). Despite significant progress, achieving high-performance PeLEDs hinges on optimizing the interface between the perovskite crystal film and the charge transport layers, especially the buried interface, which serves as the starting point for perovskite growth. Here, we develop a bottom-up perovskite film modulation strategy using formamidine acetate (FAAc) to enhance the buried interface.

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.

Synergistic nucleation regulation using 4,4',4''-tris(carbazol-9-yl)-triphenylamine and moisture for stably air-processed high-performance perovskite photodetectors.

Perovskite photodetectors (PPDs) offer a promising solution with low cost and high responsivity, addressing the limitations of traditional inorganic photodetectors. However, there is still room for improvement in terms of the dark current and stability of air-processed PPDs. In this study, 4,4',4''-tris(carbazol-9-yl)-triphenylamine (TCTA) was utilized as a nucleation agent to enhance the quality of perovskite films.

Reblooming of the -Bis(2-phenylpyridine) Platinum(II) Complex: Synthesis Updating, Aggregation-Induced Emission, Electroluminescence, and Cell Imaging.

Studies on the syntheses, photophysical properties, and applications of -bis(2-phenylpyridine) platinum(II) complex (Pt(ppy)) family are of great importance, but very limited progress has been achieved to date. Herein, a one-pot method was established for the syntheses of Pt(ppy)-type complexes and . These two compounds were nonemissive in dilute solutions.

Understanding the degradation mechanism of TTA-based blue fluorescent OLEDs by exciton dynamics and transient electroluminescence measurements.

The lifetime of blue organic light-emitting diodes (OLEDs) has always been a big challenge in practical applications. Blue OLEDs based on triplet-triplet annihilation (TTA) up-conversion materials have potential to achieve long lifetimes due to fusing two triplet excitons to one radiative singlet exciton, but there is a lack of an in-depth understanding of exciton dynamics on degradation mechanisms. In this work, we established a numerical model of exciton dynamics to study the impact factors in the stability of doped blue OLEDs based on TTA up-conversion hosts.

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.

The Synergy of the Buried Interface Surface Energy and Temperature for Thermal Evaporated Perovskite Light-Emitting Diodes.

Multisource coevaporation is such a promising method for the preparation of perovskite films. However, there is limited research about the effects of the buried interface on thermal-evaporated perovskite light-emitting diodes (PeLEDs). In this study, the effects of buried interfaces on thermal-evaporated all-inorganic perovskite films are systematically investigated.

Increasing the operating lifetime of green phosphorescent organic light emitting diodes by reducing charge accumulation at the interface.

The stability and degradation mechanism of phosphorescent organic light emitting diodes (OLEDs) has been an unresolved problem in the past decades. Here, we found that electron accumulation at the interface between the electron blocking layer and the emitting layer is one of the reasons for device degradation. By inserting a thin layer with a shallower LUMO level than that of the electron transporting layer between the emitting layer and the electron transporting layer, we successfully reduced the density of electrons at the interface and greatly improved the lifetime of the resulting green phosphorescent OLEDs.

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.

Ternary Electrical Memory Devices Based on Polycarbazole: SnO Nanoparticles Composite Material.

In this paper, a D-A polymer (PIB) containing carbazole as the donor group in the main chain and benzimidazole benzisoindolinone as the acceptor group was synthesized by Suzuki reaction. The Suzuki reaction, also known as the Suzuki coupling reaction, is a relatively new organic coupling reaction in which aryl or alkenyl boronic acids or boronic acid esters react with chlorine, bromine, iodoaromatic hydrocarbons or alkenes under the catalysis of zerovalent palladium complexes cross-coupling. A series of devices were fabricated by a spin-coating approach, and the devices all exhibited ternary resistance switching storage behavior.

Ternary Flash Memory with a Carbazole-Based Conjugated Copolymer: WS Composites as Active Layers.

For nonvolatile memory devices, the design and synthesis of their substrate materials are very important. Due to the versatility and large-area fabrication of the low-temperature spin coating process, organic/inorganic nanomaterials as active layers of memory devices have been deeply studied. Inorganic nanoparticles can engage in interactions with polymers via external voltage.

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.

Reducing greenhouse gas emissions and enhancing carbon and nitrogen conversion in food wastes by the black soldier fly.

Currently, sustainable utilisation, including recycling and valorisation, is becoming increasingly relevant in environmental management. The wastes bioconversion by the black soldier fly larva (BSFL) has two potential advantages: the larvae can convert the carbon and nitrogen in the biomass waste, and improve the properties of the substrate to reduce the loss of gaseous carbon and nitrogen. In the present study, the conversion rate of carbon, nitrogen and the emissions of greenhouse gases and NH during BSFL bio-treatment of food waste were investigated under different pH conditions.

Effect of moisture content on greenhouse gas and NH emissions from pig manure converted by black soldier fly.

The effects of different moisture contents on greenhouse gas (GHG) emissions from pig manure (PM) digested by black soldier fly larvae (BSFL) as well as the accompanying changes of nitrogen and carbon contents in gaseous emissions and residues were studied. A mixture of PM and corncob at the ratio of 2.2:1 was prepared with a moisture content of 45%.

Superior Efficiency and Low-Efficiency Roll-Off White Organic Light-Emitting Diodes Based on Multiple Exciplexes as Hosts Matched to Phosphor Emitters.

Based on exciplexes as hosts, the monochromatic organic light-emitting diodes (OLEDs) have achieved high power and external quantum efficiencies. However, the high-quality white OLEDs (WOLEDs) with high color rendering index (CRI) have the unsatisfactory efficiencies at high luminance, particularly in terms of power efficiency (PE), resulting in high energy consumption. Here, a new design concept using multiple exciplexes as hosts to match different phosphors has been demonstrated to develop high-performance WOLEDs.

Strategic-tuning of radiative excitons for efficient and stable fluorescent white organic light-emitting diodes.

The emerging thermally activated delayed fluorescence materials have great potential for efficiencies in organic light-emitting diodes by optimizing molecular structures of the emitter system. However, it is still challenging in the device structural design to achieve high efficiency and stable device operation in white organic light-emitting diodes. Here we propose a universal design strategy for thermally activated delayed fluorescence emitter-based fluorescent white organic light-emitting diodes, establishing an advanced system of "orange thermally activated delayed fluorescence emitter sensitized by blue thermally activated delayed fluorescence host" combined with an effective exciton-confined emissive layer.

Experimental realization of sequential weak measurements of non-commuting Pauli observables.

Sequential weak measurements of non-commuting observables are not only fundamentally interesting in terms of quantum measurement but also show potential in various applications. Previously reported methods, however, can only make limited sequential weak measurements experimentally. In this article, we propose the realization of sequential measurements of non-commuting Pauli observables and experimentally demonstrate for the first time the measurement of sequential weak values of three non-commuting Pauli observables using genuine single photons.

High efficiency hybrid white organic light-emitting diodes based on a simple and efficient exciton regulation emissive layer structure.

It is well-known that hybrid white organic light-emitting diodes (WOLEDs) are constructed by blue fluorophors and red-green or orange phosphors, therefore, theoretically exhibiting the advantages of long lifetime and high efficiency. However, the efficiency is far from reaching the expected values. Here, we designed a simple and efficient exciton regulation emissive layer (EML) structure to fabricate high efficiency hybrid WOLEDs.

Controlling excimer formation in indolo[3,2,1-]carbazole/9-carbazole based host materials for RGB PhOLEDs.

Three novel materials (, and ), based on the indolo[3,2,1-]carbazole and 9-carbazole building blocks, with high triplet energies ( > 2.80 eV) and good thermal stability ( > 101 °C) were synthesized, characterized and applied as host materials in PhOLED devices. In course of the preparation of the materials, an improved protocol for the synthesis of the indolo[3,2,1-]carbazole moiety has been developed.

Simultaneous observation of quantum contextuality and quantum nonlocality.

Quantum nonlocality and quantum contextuality are the most curious properties that change our understanding of nature, and were observed independently in recent decades. One important question is whether both properties can be observed simultaneously. In this paper, we show that in a qutrit-qutrit system we can observe quantum nonlocality and quantum contextuality at the same time.

In situ synthesis and macroscale alignment of CsPbBr perovskite nanorods in a polymer matrix.

We report an in situ catalyst-free strategy to synthesize inorganic CsPbBr3 perovskite nanorods in a polymer matrix (NRs-PM) with good dimensional control, outstanding optical properties and ultrahigh environmental stability. Polarization photoluminescence (PL) imaging with high spatial resolution was carried out for the first time on single nanorod (NR) and shows a relatively high local polarization ratio (∼0.4) consistent with theoretical predictions based on a dielectric contrast model.

Extremely Low Roll-Off and High Efficiency Achieved by Strategic Exciton Management in Organic Light-Emitting Diodes with Simple Ultrathin Emitting Layer Structure.

Phosphorescent organic light-emitting diodes (OLEDs) possess the property of high efficiency but have serious efficiency roll-off at high luminance. Herein, we manufactured high-efficiency phosphorescent OLEDs with extremely low roll-off by effectively locating the ultrathin emitting layer (UEML) away from the high-concentration exciton formation region. The strategic exciton management in this simple UEML architecture greatly suppressed the exciton annihilation due to the expansion of the exciton diffusion region; thus, this efficiency roll-off at high luminance was significantly improved.