Centimeter-Sized CsPbBr Single-Crystal Films for Energy-Resolved Radiation Detection.

Metal halide perovskites (MHPs) are promising materials for radiation detection. Compared with polycrystalline films, single crystals (SCs) have lower defect density, higher carrier mobility, and lifetime. However, the direct synthesis of MHP SCs for large-area flat panel imaging detectors remains challenging.

CsPbBr Superstructures with Circularly Polarized Photolumines-Cence Obtained by the Self-Assembly and Annealing of Nanoclusters.

We report a two-step approach to fabricate CsPbBr superstructures with strongly circularly polarized photoluminescence by self-assembly of nanoclusters on a substrate, followed by their annealing. In the first step, the nanoclusters self-assemble upon solvent evaporation, a process that forms mesoscopic superstructures whose geometrical arrangement at the μm-scale confers them optical chirality. In the second step, mild annealing of such superstructures induces the coalescence of the nanoclusters, accompanied by a continuous red shift of the photoluminescence up to 530 nm, with preservation of the μm-scale wires bundles and the chiral properties of the sample (g=0.

Breaking the Boundaries of the Goldschmidt Tolerance Factor with Ethylammonium Lead Iodide Perovskite Nanocrystals.

We report the synthesis of ethylammonium lead iodide (EAPbI) colloidal nanocrystals as another member of the lead halide perovskites family. The insertion of an unusually large -cation (274 pm in diameter) in the perovskite structure, hitherto considered unlikely due to the unfavorable Goldschmidt tolerance factor, results in a significantly larger lattice parameter compared to the Cs-, methylammonium- and formamidinium-based lead halide perovskite homologues. As a consequence, EAPbI nanocrystals are highly unstable, evolving to a nonperovskite δ-EAPbI polymorph within 1 day.

Size-Dependent Multiexciton Dynamics Governs Scintillation From Perovskite Quantum Dots.

The recent emergence of quantum-confined nanomaterials in the field of radiation detection, in particular lead halide perovskite nanocrystals, offers scalability and performance advantages over conventional materials. This development raises fundamental questions about the mechanism of scintillation itself at the nanoscale and the role of particle size, arguably the most defining parameter of quantum dots. Understanding this is crucial for the design and optimization of future nanotechnology scintillators.

Cooling-Induced Order-Disorder Phase Transition in CsPbBr Nanocrystal Superlattices.

Perovskite nanocrystal superlattices are being actively studied after reports have emerged on collective excitonic properties at cryogenic temperatures, where energetic disorder is minimized due to the frozen lattice vibrations. However, an important issue related to structural disorder of superlattices at low temperatures has received little attention to date. In this work, it is shown that CsPbBr nanocrystal superlattices undergo a reversible order-disorder transition upon cooling to 90 K.

Additive-Driven Enhancement of Crystallization: Strategies and Prospects for Boosting Photoluminescence Quantum Yields in Halide Perovskite Films for Light-Emitting Diodes.

Halide perovskite light-emitting diodes (PeLEDs) hold great potential for applications in displays and lighting. To enhance the external quantum efficiency (EQE) of PeLEDs, it is crucial to boost the photoluminescence quantum yield (PLQY) of the perovskite films. The use of additives has emerged as a powerful chemical strategy to control the crystallization process in solution-processed perovskite films.

Fate of Optical Excitons in FAPbI Nanocube Superlattices.

Understanding the nature of the photoexcitation and ultrafast charge dynamics pathways in organic halide perovskite nanocubes and their aggregation into superlattices is key for potential applications as tunable light emitters, photon-harvesting materials, and light-amplification systems. In this work, we apply two-dimensional coherent electronic spectroscopy (2DES) to track in real time the formation of near-infrared optical excitons and their ultrafast relaxation in CH(NH)PbI nanocube superlattices. Our results unveil that the coherent ultrafast dynamics is limited by the combination of the inherent short exciton decay time (≃40 fs) and the dephasing due to the coupling with selective optical phonon modes at higher temperatures.

Investigation of the Octahedral Network Structure in Formamidinium Lead Bromide Nanocrystals by Low-Dose Scanning Transmission Electron Microscopy.

Metal halide perovskites (MHP) are highly promising semiconductors. In this study, we focus on FAPbBr nanocrystals, which are of great interest for green light-emitting diodes. Structural parameters significantly impact the properties of MHPs and are linked to phase instability, which hampers long-term applications.

Exciton-photocarrier interference in mixed lead-halide-perovskite nanocrystals.

The use of semiconductor nanocrystals in scalable quantum technologies requires characterization of the exciton coherence dynamics in an ensemble of electronically isolated crystals in which system-bath interactions are nevertheless strong. In this communication, we identify signatures of Fano-like interference between excitons and photocarriers in the coherent two-dimensional photoluminescence excitation spectral lineshapes of mixed lead-halide perovskite nanocrystals in dilute solution. Specifically, by tuning the femtosecond-pulse spectrum, we show such interference in an intermediate coupling regime, which is evident in the coherent lineshape when simultaneously exciting the exciton and the free-carrier band at higher energy.

Medullary Thyroid Cancer: Epidemiology and Characteristics According to Data From the Marne-Ardennes Register 1975-2018.

Context: Medullary thyroid cancer (MTC) is a rare disease.

Objective: The main objective of our study was to analyze the incidence evolution of MTC with a follow-up of more than 40 years. Further, a descriptive and survival analysis was performed according to the Kaplan-Meier analysis.

High-Efficiency and Stable Colloidal One-Dimensional Core/Shell Nanorod Light-Emitting Diodes.

Anisotropic nanocrystals such as nanorods (NRs) display unique linearly polarized emission, which is expected to break the external quantum efficiency (EQE) limit of quantum dot-based light-emitting diodes (LEDs). However, the progress in achieving a higher EQE using NRs encounters several challenges, primarily involving a low photoluminescence quantum yield (PLQY) of NRs and imbalanced charge injection in NR-LEDs. In this work, we investigated NR-LEDs based on CdSe/CdZnS/ZnS rod-in-rod NRs with a high PLQY and higher linear polarization compared to those of dot-in-rod NRs.

Near Infrared Light-Emitting Diodes Based on Colloidal InAs/ZnSe Core/Thick-Shell Quantum Dots.

Heavy-metal-free III-V colloidal quantum dots (QDs) exhibit promising attributes for application in optoelectronics. Among them, InAs QDs are demonstrating excellent optical performance with respect to absorption and emission in the near-infrared spectral domain. Recently, InAs QDs attained a substantial improvement in photoluminescence quantum yield, achieving 70% at a wavelength of 900 nm through the strategic overgrowth of a thick ZnSe shell atop the InAs core.

Illegal products containing selective androgen receptor modulators purchased online from Italy: health risks for consumers.

Background: Selective androgen receptor modulators (SARMs) are small synthetic drug molecules that are still not approved as medicine in Europe or the United States but are sold on illegal websites to improve sport performance, particularly bodybuilding.

Aim: To address the quality issues of illegal SARM products and their increasing diffusion in Italy with their potential health risks for consumers.

Methods: Web-based tools were used to investigate retail websites, trending searches, and information exchange via social media.

A screening method for the quantitative determination of selective androgen receptor modulators (SARMs) in capsules by high resolution F- and H-NMR spectroscopy.

A new method for rapid determination of the content of selective androgenic receptor modulators (SARMs) andarine, cardarine, ligandrol, ostarine and S-23 in capsules by H- and F-high resolution nuclear magnetic resonance spectroscopy was described and validated. Specificity, linearity, accuracy, precision, detection and quantification limits were considered as validation parameters. Full H-, C- and F-NMR structural assignment of the SARMs is provided as a tool for self-standing identification without a reference standard.

A Robust Anti-Thermal-Quenching Phosphor Based on Zero-Dimensional Metal Halide RbInCl:Sb.

High-power phosphor-converted white light-emitting diodes (hp-WLEDs) have been widely involved in modern society as outdoor lighting sources. In these devices, due to the Joule effect, the high applied currents cause high operation temperatures (>500 K). Under these conditions, most phosphors lose their emission, an effect known as thermal quenching (TQ).

Partial Ligand Stripping from CsPbBr Nanocrystals Improves Their Performance in Light-Emitting Diodes.

Halide perovskite nanocrystals (NCs), specifically CsPbBr, have attracted considerable interest due to their remarkable optical properties for optoelectronic devices. To achieve high-efficiency light-emitting diodes (LEDs) based on CsPbBr nanocrystals (NCs), it is crucial to optimize both their photoluminescence quantum yield (PLQY) and carrier transport properties when they are deposited to form films on substrates. While the exchange of native ligands with didodecyl dimethylammonium bromide (DDAB) ligand pairs has been successful in boosting their PLQY, dense DDAB coverage on the surface of NCs should impede carrier transport and limit device efficiency.

Near-Infrared Light Emitting Metal Halides: Materials, Mechanisms, and Applications.

Near-Infrared (NIR) light emitting metal halides are emerging as a new generation of optical materials owing to their appealing features, which include low-cost synthesis, solution processability, and adjustable optical properties. NIR-emitting perovskite-based light-emitting diodes (LEDs) have reached an external quantum efficiency (EQE) of over 20% and a device stability of over 10,000 h. Such results have sparked an interest in exploring new NIR metal halide emitters.

Stainless Steel Activation for Efficient Alkaline Oxygen Evolution in Advanced Electrolyzers.

Designing robust and cost-effective electrocatalysts for efficient alkaline oxygen evolution reaction (OER) is of great significance in the field of water electrolysis. In this study, an electrochemical strategy to activate stainless steel (SS) electrodes for efficient OER is introduced. By cycling the SS electrode within a potential window that encompasses the Fe(II)↔Fe(III) process, its OER activity can be enhanced to a great extent compared to using a potential window that excludes this redox reaction, decreasing the overpotential at current density of 100 mA cm by 40 mV.

Pervasiveness of inorganic gunshot residue (IGSR) in handguns after cleaning and conditioning procedures.

Memory effect in firearms that is, the possibility for a weapon to release inorganic particles whose elemental composition depends on its entire shooting history, is responsible for most of the interpretation difficulties encountered in forensic gunshot residue analysis. The presence of residues chemically inconsistent with the last discharged round, the creation of particles having unusual elemental profiles, and the dependence of residue population composition on the collection point are all manifestations of memory effect. The experimental results reported in this paper highlight the ineffectiveness of a wide number of gun cleaning procedures in reducing memory effect.

Combinatorial immune checkpoint blockade increases myocardial expression of NLRP-3 and secretion of H-FABP, NT-Pro-BNP, interleukin-1β and interleukin-6: biochemical implications in cardio-immuno-oncology.

Background: Immune checkpoint blockade in monotherapy or combinatorial regimens with chemotherapy or radiotherapy have become an integral part of oncology in recent years. Monoclonal antibodies against CTLA-4 or PD-1 or PDL-1 are the most studied ICIs in randomized clinical trials, however, more recently, an anti-LAG3 (Lymphocyte activation gene-3) antibody, Relatlimab, has been approved by FDA in combination with Nivolumab for metastatic melanoma therapy. Moreover, Atezolizumab is actually under study in association with Ipilimumab for therapy of metastatic lung cancer.