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Fluoride-ion conductors have attracted great attention as solid electrolytes for all-solid-state fluoride-ion batteries with high energy densities surpassing those of conventional lithium-ion batteries. Well-known examples include fluorite-type PbSnF4with intrinsic fluoride vacancies and tysonite-type La0.9Ba0.1F2.9(LBF) with extrinsic fluoride vacancies introduced by aliovalent substitution. In contrast to the conventional dynamics of fluoride ions through fluoride vacancies, an isolated anion sublattice could provide a unique means for interstitial fluoride-ion diffusion because of its rotational flexibility. In this study, we employed Tl4.5SnF8.5, which contains fluoride ions located between isolated SnF6octahedra, and investigated the relationship between the cell volume and the fluoride-ion conductivity upon varying the ionic radius of the tin site substituent with a fixed carrier amount. Tl4.5Sn0.9Y0.1F8.4exhibited the maximum fluoride-ion conductivity and minimum activation energy. Ball milling of this material led to high room-temperature fluoride-ion conductivity comparable to that of LBF. Neural-network potential molecular dynamics was also used to elucidate the fluoride-ion diffusion mechanism. The fluoride ions of the SnF6octahedra were found to undergo rotational motion, which mediated fluoride-ion diffusion and hopping of the interstitial fluoride ions. These dynamics of the isolated anion sublattice provide a new design strategy for fluoride-ion conductors to complement the previous approach based on the introduction of fluoride vacancies.

To investigate effect of stacking faults (SFs) on switching reliability, we carried out switching tests using SiC-MOSFETs containing expanded SFs. Before the switching test, current stress was applied to the internal body-diode devices under test (DUTs) to expand SFs. The circuit configuration of the switching test we used was a half-bridge type and a double-pulse gate signal was applied to the lower arm DUT. The switching-voltage was 1.8kV and switching-current increased in about 8A steps to breakdown. Reverse recovery safety operation area (RRSOA) breakdown switching-current decreased dependently on the degree of SiC-MOSFET degradation. Reverse bias SOA (RBSOA) did not decrease even if degraded SiC-MOSFETs were used.

A new lobane-type diterpenoid, loba-8,10,13(15)-triene-14,17,18-triol 17-acetate (1), and 5 known compounds, lobatriene (2), (17R)-loba-8,10,13(15)-triene-17,18-diol (3), loba-8,10,13(15)-triene-14,17,18-triol 14,17-diacetate (4), loba-8,10,13(15)-triene-14,17,18-triol 14-acetate (5), and lobatrienetriol (6), were isolated from a population of Okinawan soft coral Lobophytumsp. The structures of these compounds were elucidated by spectroscopy, including nuclear magnetic resonance and high-resolution mass spectrometry. The cytotoxicity and genotoxicity of these compounds were tested using human lymphoblastoid TK6 cells.

Graphical Abstract:

We investigated the electrical and optical properties of our two previously proposed Ge optical emitters, lateral-carrier-injected Ge waveguides and Ge-fins fabricated on the buried oxide layer of a silicon-on-insulator wafer. Intense photoluminescence spectra from both structures show that good crystallinity and sufficient carrier confinement can be achieved, and the obvious red-shifts of the peaks were observed due to the tensile strain in the Ge active region applied through the fabrication processes. The enhanced electroluminescence corresponding to the direct recombination at the G-valley was also observed by injecting forward currents into the Ge active regions. These results indicate that these device structures efficiently improve the performance of Ge optical emitters.

A light source made of group IV elements is the only missing device component to realize full monolithic integration on a Si chip to realize the convergence of photonics and electronics by Si photonics. It is well known that Si becomes an efficient light source in quantum confined structures like dots, wires and wells. These nanostructures were previously made by bottom up processes. These days, modern silicon fabrication technology is matured enough to make light-emitting silicon and germanium quantum wells by top down processes. We would like to review our several approaches to develop Si/Ge light sources fabricated in a standard Si process line.

Single crystal Ge layers were successfully fabricated on the buried oxide layer of a silicon-on-insulator wafer using a combined technique of two-step selective epitaxial growth and Ge condensation. X-ray diffraction measurements revealed that the single crystal Ge layer formed on the buried oxide layer had a tensile strain of 0.07% on the $\langle 110\rangle$ lattice plane in a large unpatterned area. Furthermore, a steep photoluminescence spectrum was obtained from Ge stripes fabricated on the buried oxide layer, and a red shift in the photoluminescence peak was observed due to tensile strain with a wavelength of 1620 nm. The peak intensity of a 10-mm-wide Ge stripe on the buried oxide layer was three times higher than that on a Ge stripe on an Si substrate, which was achieved by improving the crystallinity and carrier confinement within the Ge stripes. These results indicate that this combined technique efficiently improves the performance of Ge light-emitting devices.

•T1 mapping was performed using a PSIR sequence for focal liver lesions.•PSIR can measure focal liver lesions with a wide range of T1 values.•PSIR-based T1 measurements could be used to differentiate focal liver lesions.

A new cembranolide diterpene, sarcophytonolide V (1), along with 6 known compounds, isosarcophytonolide D (2), (4Z,8S*,9R*,12E,14E)-9-hydroxy-1-(prop-1-en-2-yl)-8,12-dimethyl-oxabicyclo[9.3.2]-hexadeca-4,12,14-trien-18-one (3), (7E,11E)-3,4-epoxy-7,11,15-cembratriene (4), (1S*,3S*,4S*,7E,11E)-3,4-epoxy-13-oxo-7,11,15-cembratriene (5), (-)-eunicenone (6), and 2-[(E,E,E)-7′,8′-epoxy-4′,8′,12′-trimethylcyclotetradeca-1′,3′,11′-trienyl]propan-2-ol (7) were isolated from the Bornean soft coral Sarcophytonsp. Their structures were elucidated based on spectroscopic data, such as nuclear magnetic resonance (NMR) and high resolution electron spray ionization mass spectroscopy (HRESIMS). These compounds were evaluated for their biological activity against marine pathogenic fungi.

Germanium (Ge) (111) fins of 320 nm in height were successfully fabricated using a combination of flattening sidewalls of a silicon (Si) fin structure by anisotropic wet etching with tetramethylammonium hydroxide, formation of thin Ge fins by selective Si oxidation in SiGe layers, and enlargement of Ge fins by Ge homogeneous epitaxial growth. The excellent electrical characteristics of Ge(111) fin light-emitting diodes, such as an ideality factor of 1.1 and low dark current density of 7.1 x 10[?]5 A cm[?]2 at reverse bias of [?]2 V, indicate their good crystalline quality. A tensile strain of 0.2% in the Ge fins, which originated from the mismatch of the thermal expansion coefficients between Ge and the covering SiO2 layers, was expected from the room-temperature photoluminescence spectra, and room-temperature electroluminescence corresponding to the direct band-gap transition was observed from the Ge fins.

We investigated the electrical and optical properties of our two previously proposed Ge optical emitters, lateral-carrier-injected Ge waveguides and Ge-fins fabricated on the buried oxide layer of a silicon-on-insulator wafer. Intense photoluminescence spectra from both structures show that good crystallinity and sufficient carrier confinement can be achieved, and the obvious red-shifts of the peaks were observed due to the tensile strain in the Ge active region applied through the fabrication processes. The enhanced electroluminescence corresponding to the direct recombination at the G-valley was also observed by injecting forward currents into the Ge active regions. These results indicate that these device structures efficiently improve the performance of Ge optical emitters.

Two types of Ge optical emitter, called Ge-on-insulator stripes and Ge-fins, were successfully fabricated on the buried oxide layer of a silicon-on-insulator wafer using a combined Ge condensation and selective epitaxial growth. Intense PL spectra from both structures show that the good crystallinity and the sufficient carrier confinement can be achieved, and the obvious red-shifts of the peaks were observed due to the tensile strain in the Ge active region applied through the fabrication processes. Moreover, the low dark current in I-V characteristics was obtained, and the electroluminescence corresponding to the direct recombination at the Γ valley was also observed by injecting forward currents into the Ge-fins. These results indicate that this combined technique efficiently improves the performance of Ge optical emitters.

A light source made of group IV elements is the only missing device component to realize full monolithic integration on a Si chip to realize the convergence of photonics and electronics by Si photonics. It is well known that Si becomes an efficient light source in quantum confined structures like dots, wires and wells. These nanostructures were previously made by bottom up processes. These days, modern silicon fabrication technology is matured enough to make light-emitting silicon and germanium quantum wells by top down processes. We would like to review our several approaches to develop Si/Ge light sources fabricated in a standard Si process line.

We fabricated a germanium-on-insulator (GeOI) lateral p--i--n diode by a standard silicon process and characterized it as a photodetector and a light emitter. For the photodetector, we observed photosensitivity by an excitation light with the wavelength of 1550 nm. The experimental radio frequency response has completely agreed with simulated results, and the observed 3-dB bandwidth of 2 GHz was limited by contact resistances. For the light emitter, the electroluminescence spectra have broad peaks located at 1460 nm, much shorter than that of photoluminescence spectra located at 1600 nm. The difference was presumably attributable to the poor interface properties by the surface passivation. From these results, GeOI p--i--n diodes can be promising device candidates for silicon photonics by improving process conditions.