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CsPbBr3perovskite nanocrystal embedded glasses (PNEGs) based on the borosilicate system were synthesized with varying compositions to obtain a chemically stable PNEG compared with a PNEG based on the germanate system. Photo-luminescence (PL) and structural characteristics were examined to find the proper heat-treatment conditions for high quantum efficiency under a 450 nm blue light emitting diode (LED) excitation. The CsPbBr3within the glass matrix was observed by transmission electron microscope (TEM). Comparative studies on the thermal, photonic and water stabilities of the obtained borosilicate PNEG with those of a germanate PNEG were carried out. The borosilicate CsPbBr3PNEG was employed as a green phosphor along with K2SiF6:Mn4+as a red phosphor to compose a white LED with phosphor in silicone (PiS) and a remote PiS structure, whose color gamut was examined for display applications.

Perovskite nanocrystals (PNCs) based on cesium lead halide CsPbX3(X = Cl, Br, I) have rapidly emerged as one of the most promising photonic materials in recent years due to their characteristic high quantum efficiency and narrow emission bandwidth. However, their poor stability against external influences such as moisture, oxygen, heat, and light irradiation has hindered their practical photonic applications in light-emitting diodes, displays, and photovoltaic cells. Among various attempts to overcome their shortcomings, an inorganic glass matrix can be an effective and practical solution, providing chemically stable encapsulation of the PNCs. Significant improvements in chemical, thermal, and photo-stabilities compared with the colloidal PNCs have been reported, without degrading their unique optical properties. Perovskite nanocrystal-embedded glasses (PNEGs) can be fabricated using conventional melt-quenching methods followed by heat treatment. Various combinations of glass and PNC compositions have been reported, demonstrating practical feasibility in various photonic applications.

Two-dimensional (2D) transition metal dichalcogenides have received considerable attention due to their exotic electrical, chemical, and physical properties. Here, we report a layer-dependent band structure of a 2D semiconducting ternary metal chalcogenide (TMC), hexagonal FeIn2S4(hFIS), which is prepared through thickness-controlled colloidal solution synthesis. The controlled dissociation rate of chalcogen precursors caused the growth of the different thicknesses of hFIS, which is coincident with mechanisms established in conventional 2D nanomaterial colloidal synthesis. The various thickness-dependent band structures of hFIS were investigated from the corresponding optical band gap and redox potentials. The unveiled layer-dependent band structure of hFIS showed band gaps of approximately 1.02, 1.26, and 1.52 eV, corresponding to synthesis of the 7–8, 5–6, and 2–3 layers, respectively. This study will contribute to the exploration of other layer-dependent TMCs (MIn2X4, M = Fe, Co, Mn, and Zn and X = S, Se, and Te) for new optical and electronic device applications.

In this study, the resistive switching and synaptic properties of a complementary metal-oxide semiconductor-compatible Ti/a-BN/Si device are investigated for neuromorphic systems. A gradual change in resistance is observed in a positive SET operation in which Ti diffusion is involved in the conducting path. This operation is extremely suitable for synaptic devices in hardware-based neuromorphic systems. The isosurface charge density plots and experimental results confirm that boron vacancies can help generate a conducting path, whereas the conducting path generated by a Ti cation from interdiffusion forms is limited. A negative SET operation causes a considerable decrease in the formation energy of only boron vacancies, thereby increasing the conductivity in the low-resistance state, which may be related to RESET failure and poor endurance. The pulse transient characteristics, potentiation and depression characteristics, and good retention property of eight multilevel cells also indicate that the positive SET operation is more suitable for a synaptic device owing to the gradual modulation of conductance. Moreover, pattern recognition accuracy is examined by considering the conductance values of the measured data in the Ti/a-BN/Si device as the synaptic part of a neural network. The linear and symmetric synaptic weight update in a positive SET operation with an incremental voltage pulse scheme ensures higher pattern recognition accuracy.

Assembled amyloid beta (Aβ) peptides have been considered pathological assemblies involved in human brain diseases, and the electron transfer or electron transport characteristics of Aβ are important for the formation of structured assemblies. Here, we report the electrical characteristics of surface-assembled Aβ peptides similar to those observed in Alzheimer’s patients. These characteristics correlate to their electron transfer characteristics. Electrical current–voltage plots of Aβ vertical junction devices show the Aβ sequence dependence of the current densities at both Aβ monomers (mono-Aβs) and Aβ oligomers (oli-Aβs), while Aβ sequence dependence is not clearly observed in the electrical characteristics of Aβ planar field effect transistors (FETs). In particular, surface oligomerization of Aβ peptides drastically decreases the activity of electron transfer, which presents a change in the electron transport pathway in the Aβ vertical junctions. Electron transport at oli-Aβ junctions is symmetric (tunneling/tunneling) due to the weak and voltage-independent coupling of the less redox-reactive oli-Aβ to the contacts, while that at mono-Aβ junctions is asymmetric (hopping/tunneling) due to redox levels of mono-Aβ voltage-dependently coupled with contact electrodes. Consequently, through vertical junctions, the sequence- and conformation-dependent electrical characteristics of Aβs can reveal their electron transfer activities.

The role of hydrogen-containing species in the alkaline dissolution of aluminum was studied by secondary ion mass spectrometry (SIMS). Large number densities of submicron particles nucleated and then disappeared during dissolution, at intervals of approximately 3 min. The particles were composed of aluminum hydride, with an aluminum hydroxide surface layer. When particles first appeared, the aluminate ion concentration near the surface was at the solubility of Al(OH)3, and the potential was close to the Nernst potential for oxidation of AlH3 to Al(OH)3. The observed formation of AlH3 indicates that the dissolving Al surface was poised near this equilibrium potential, i. e. that a hydride species serves as an intermediate in the dissolution process.

Formation of interfacial nanoscale voids in Al during room-temperature caustic corrosion was characterized by positron annihilation spectroscopy (PAS) and compared with measurements of deuterium absorption using secondary ion mass spectrometry (SIMS). The hypothesis was investigated that voids are created from vacancy-hydrogen (Vac-H) defects introduced during corrosion. Evidence for both mobile and immobile forms of absorbed hydrogen was obtained, the latter present within distances of 50 nm from the metal-oxide interface, where voids were also found. During corrosion, the immobile hydrogen was found only during discrete 1-2 min intervals of time separated by periods of 1-2 min when it was not present. Model calculations suggested that this transient behavior is consistent with repeated nucleation and dissolution of clusters of Vac-H defects. Only some aspects of the time-dependence of the void concentration from PAS corresponded with that of absorbed hydrogen; the former is believed to be influenced by metallic impurities.

Ginsenosides have beneficial effects on several airway inflammatory disorders primarily through glucocorticosteroid-like anti-inflammatory activity. Among inflammatory cells, eosinophils play a major pathogenic role in conferring a risk of severe refractory diseases including chronic rhinosinusitis (CRS). However, the role of ginsenosides in reducing eosinophilic inflammation and CRS pathogenesis is unexplored.

The role of hydrogen-containing surface species in the alkaline dissolution of aluminum was studied by secondary ion mass spectrometry (SIMS) and atomic force microscopy (AFM). The measurements revealed quasi-periodic nucleation and dissolution of large number densities of 10–100nmsize particles, during open-circuit dissolution in 1MNaOH(D) at room temperature. SIMS results using deuterated solutions, and prior Auger microprobe measurements, indicated that the particles were composed of aluminum hydride (deuteride), with an aluminum hydroxide (deuteroxide) surface layer. The measured open-circuit potential during dissolution was close to the Nernst potential of hydride oxidation. It was concluded that AlH3forms continuously during dissolution by reaction of cathodically generated hydrogen with the Al metal and is oxidized to aluminate ions [Al(OH)4−]in the accompanying anodic process. The present results are a direct confirmation of hydride formation on Al accompanying corrosion.

The role of hydrogen-containing species in the alkaline dissolution of aluminum was studied by secondary ion mass spectrometry (SIMS). Large number densities of submicron particles nucleated and then disappeared during dissolution, at intervals of approximately 3 min. The particles were composed of aluminum hydride, with an aluminum hydroxide surface layer. When particles first appeared, the aluminate ion concentration near the surface was at the solubility of Al(OH)3, and the potential was close to the Nernst potential for oxidation of AlH3 to Al(OH)3. The observed formation of AlH3 indicates that the dissolving Al surface was poised near this equilibrium potential, i. e. that a hydride species serves as an intermediate in the dissolution process.

Formation of interfacial nanoscale voids in Al during room-temperature caustic corrosion was characterized by positron annihilation spectroscopy (PAS) and compared with measurements of deuterium absorption using secondary ion mass spectrometry (SIMS). The hypothesis was investigated that voids are created from vacancy-hydrogen (Vac-H) defects introduced during corrosion. Evidence for both mobile and immobile forms of absorbed hydrogen was obtained, the latter present within distances of 50 nm from the metal-oxide interface, where voids were also found. During corrosion, the immobile hydrogen was found only during discrete 1-2 min intervals of time separated by periods of 1-2 min when it was not present. Model calculations suggested that this transient behavior is consistent with repeated nucleation and dissolution of clusters of Vac-H defects. Only some aspects of the time-dependence of the void concentration from PAS corresponded with that of absorbed hydrogen; the former is believed to be influenced by metallic impurities.