Red-Emitting CsPbI/ZnSe Colloidal Nanoheterostructures with Enhanced Optical Properties and Stability.

Producing heterostructures of cesium lead halide perovskites and metal-chalcogenides in the form of colloidal nanocrystals can improve their optical features and stability, and also govern the recombination of charge carriers. Herein, the synthesis of red-emitting CsPbI/ZnSe nanoheterostructures is reported via an in situ hot injection method, which provides the crystallization conditions for both components, subsequently leading to heteroepitaxial growth. Steady-state absorption and photoluminescence studies alongside X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy analysis evidence on a type-I band alignment for CsPbI/ZnSe nanoheterostructures, which exhibit photoluminescence quantum yield of 96% due to the effective passivation of surface defects, and an enhancement in carrier lifetime.

Near-infrared two-photon excited photoluminescence from Yb-doped CsPbClBr perovskite nanocrystals embedded into amphiphilic silica microspheres.

Nonlinear absorption of metal-halide perovskite nanocrystals (NCs) makes them an ideal candidate for applications which require multiphoton-excited photoluminescence. By doping perovskite NCs with lanthanides, their emission can be extended into the near-infrared (NIR) spectral region. We demonstrate how the combination of Yb doping and bandgap engineering of cesium lead halide perovskite NCs performed by anion exchange (from Cl to Br) leads to efficient and tunable emitters that operate under two-photon excitation in the NIR spectral region.

Trap-Mediated Sensitization Governs Near-Infrared Emission from Yb-Doped Mixed-Halide CsPbClBr Perovskite Nanocrystals.

Understanding the photosensitization mechanisms in Yb-doped perovskite nanocrystals is crucial for developing their anticipated photonic applications. Here, we address this question by investigating near-infrared photoluminescence of Yb-doped mixed-halide CsPbClBr nanocrystals as a function of temperature and revealing its strong dependence on the stoichiometry of the host perovskite matrix. To explain the observed experimental trends, we developed a theoretical model in which energy transfer from the perovskite matrix to Yb ions occurs through intermediate trap states situated beneath the conduction band of the host.

Obviating Ligand Exchange Preserves the Intact Surface of HgTe Colloidal Quantum Dots and Enhances Performance of Short Wavelength Infrared Photodetectors.

A large volume, scalable synthesis procedure of HgTe quantum dots (QDs) capped initially with short-chain conductive ligands ensures ligand exchange-free and simple device fabrication. An effective n- or p-type self-doping of HgTe QDs is achieved by varying cation-anion ratio, as well as shifting the Fermi level position by introducing single- or double-cyclic thiol ligands, that is, 2-furanmethanethiol (FMT) or 2,5-dimercapto-3,4-thiadiasole (DMTD) in the synthesis. This allows for preserving the intact surface of the HgTe QDs, thus ensuring a one order of magnitude reduced surface trap density compared with HgTe subjected to solid-state ligand exchange.

Accumulation of Dystrophin-Positive Muscle Fibers and Improvement of Neuromuscular Junctions in mdx Mouse Muscles after Bone Marrow Transplantation under Different Conditions.

Duchenne muscular dystrophy (DMD) is a severe muscular disorder caused by mutations in the dystrophin gene. It leads to respiratory and cardiac failure and premature death at a young age. Although recent studies have greatly deepened the understanding of the primary and secondary pathogenetic mechanisms of DMD, an effective treatment remains elusive.

Near-Infrared Emission of HgTe Nanoplatelets Tuned by Pb-Doping.

Doping the semiconductor nanocrystals is one of the most effective ways to obtain unique materials suitable for high-performance next-generation optoelectronic devices. In this study, we demonstrate a novel nanomaterial for the near-infrared spectral region. To do this, we developed a partial cation exchange reaction on the HgTe nanoplatelets, substituting Hg cations with Pb cations.

Engineering the Optical Properties of CsPbBr Nanoplatelets through Cd Doping.

Lead halide perovskite nanoplatelets (NPls) attract significant attention due to their exceptional and tunable optical properties. Doping is a versatile strategy for modifying and improving the optical properties of colloidal nanostructures. However, the protocols for B-site doping have been rarely reported for 2D perovskite NPls.

Beyond Charge Transfer: The Impact of Auger Recombination and FRET on PL Quenching in an rGO-QDs System.

PL intensity quenching and the PL lifetime reduction of fluorophores located close to graphene derivatives are generally explained by charge and energy transfer processes. Analyzing the PL from PbS QDs in rGO/QD systems, we observed a substantial reduction in average PL lifetimes with an increase in rGO content that cannot be interpreted solely by these two processes. To explain the PL lifetime dependence on the rGO/QD component ratio, we propose a model based on the Auger recombination of excitations involving excess holes left in the QDs after the charge transfer process.

Tunable Mie Resonances of Tin-based Iodide Perovskite Islandlike Films with Enhanced Infrared Photoluminescence.

The ability of light manipulation at a sub-wavelength scale of metal halide perovskite-based nanostructures through nanophotonic design were employed for advanced optical and optoelectronic applications. While these nanostructures could be efficiently tuned in the visible spectral range, their operation at infrared wavelengths is still challenging. Herein, we illustrate that islandlike films of lead-free CHNHSnI can generate strong and tunable Mie-type resonances in the near-infrared spectral range.

Enhanced stability of the optical responses from all-inorganic perovskite nanocrystals embedded in a synthetic opal matrix.

Nanostructured luminescent materials based on perovskite nanocrystals (p-NCs) are attractive since their optical properties can be tuned in a wide spectral range with high luminescence quantum yields and lifetimes, however, they lack stability. In this work, the optical properties of highly luminescent colloidal p-NCs (CsPbX, where X = Cl/Br, Br, I) embedded in porous opal matrices are presented. It is shown that the photoluminescence of the p-NCs embedded into opal matrices possess increased longtime stability of its spectral and kinetic parameters under ambient conditions.