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Distributed acoustic sensing (DAS) using optical fiber cables, widely deployed for communications, can capture various information on the surrounding environment. Phase-sensitive optical time-domain reflectometry (Φ-OTDR) DAS is suitable for sensing deployed cables because Φ-OTDR has long measurement distances. However, a simple Φ-OTDR setup suffers from interference fading, in which sensitivity degradation occurs at many points. Multi-frequency Φ-OTDR is a practical solution that can remove the sensitivity degradation points effectively by averaging the signals of multi-frequency pulses. The method used to average multi-frequency signals affects the total measurement performance, including the sensitivity and the measurable vibration amplitude range. While vector-based averaging on the IQ plane is a powerful method in terms of sensitivity, calculating accurate vibration waveforms becomes difficult when vibrations become strong (> sub-μϵ). Consequently, large-scale vibration patterns are not accurately visualized, limiting potential applications. In this work, we develop a vector-based averaging method that can resolve this issue. We clarify that the known problem of the difference in phase response to strain change between multiplexed frequencies is the key matter causing the issue. To address this discrepancy, we propose a dynamically updated vector-based averaging method, enabling us to monitor strong vibrations. In the proposed method, parameters used in vector-based averaging—rotation angles and reference frequencies—that are fixed in the conventional method are updated over time in accordance with the fiber state. We demonstrate the effectiveness of the proposed method in both laboratory and field environments. We successfully visualize patterns of large-scale vibrations experienced by field-deployed communication cables, such as those caused by vehicle movements and wind blowing.

Process development of E7130 Drug Substance, which is a novel anticancer drug candidate, is described. To accomplish rapid delivery of such a large and structurally complex drug substance for first-in-human (FIH) clinical trial, close collaboration among medicinal chemistry, process chemistry, and academia teams was required. The successful establishment of a suitable synthetic route in a concise time frame while negotiating challenging chemical reactions (e.g., asymmetric catalytic Nozaki–Hiyama–Kishi (NHK) reaction and Zr/Ni-mediated ketone coupling reaction) is described herein. Experience with the development of eribulin mesylate was helpful in anticipating and overcoming the chemical and logistical challenges encountered in the E7130 project. Based on this background, more than 10 g of E7130 Drug Substance has been successfully manufactured under Good Manufacturing Practice (GMP) controls within 1.5 years after the medicinal chemistry team succeeded in the first total synthesis.

The serial changes in intraventricular pressure gradient in the left ventricle and NYHA functional classification in each case. Both the left intraventricular pressure gradient and symptoms improved after right ventricular pacing. In one case, the left intraventricular pressure gradient disappeared immediately after right ventricular pacing, while in the others it disappeared during the chronic phase, more than a year later.

Distributed acoustic sensing (DAS) measures local strains along a sensing fiber using as an array of dense virtual strain sensors. One related application of DAS is a seismic wave sensing. Due to the densely deployed virtual sensors, DAS can detect seismic wave propagation along the sensing fiber, which is useful for underground structure imaging. Thus, DAS has been used as an alternative to the conventional sparsely deployed seismometers for investigating geophysical phenomena. DAS for seismic wave sensing uses optical time domain reflectometry (OTDR), which measures a differential phase caused by elongation between two locations. The bandwidth of a probe pulse light defines the gauge length and allowable differential phase or strain rate. Although OTDR has shown to be effective, the nature of the log-scale amplitude of earthquakes may require a broad amplitude dynamic range for DAS. To broaden the bandwidth, we utilize optical frequency domain reflectometry (OFDR), which launches a frequency-swept probe light and measures optical frequency shift proportional to the strain. Using an existing optical fiber in a telecommunication network as a sensing fiber, we demonstrate sensing for two seismic waves with amplitude scales of 0 and 3. Because the spatial resolution is higher than that of OTDR, we can finely visualize underground facilities along the existing telecommunication optical fiber. We also discuss an inherent limitation of OFDR that becomes evident when measuring a long wavelength vibration such as a seismic wave.

We report the growth of a GaN layer on a (101¯0)m-plane ScAlMgO4(SAM) substrate. The GaN layer demonstrated (101¯3)preference growth orientation. The anisotropy of the crystalline quality was distinctly observed through an X-ray rocking curve (XRC) taken across the sample surface over various azimuths across the orthogonal directions [0001] and [12¯10]of the SAM substrate. Notably, the crystalline quality exhibited gradual degradation as the substrate was rotated around its surface normal away from the c-direction [0001]of the SAM substrate toward the a-direction [112¯0].This degradation of the GaN layer was quantified by an increase in the XRC full width at half maxima for the 101¯3XRC: starting from 1210 arcsec at 0° azimuth, deteriorating to its lowest crystallinity at 1512 arcsec at 60° azimuth, before a slight improvement to 1481 arcsec at 90° azimuth, followed by a symmetrical repetition of this pattern. Additionally, basal stacking faults in the 101¯3-oriented GaN were observed along the [0001] direction using scanning transmission electron microscopy. Moreover, the selected area electron diffraction analysis was utilized to confirm the 101¯3growth orientation that was found to be consistent with the X-ray diffraction result. The c-direction of the 101¯3-oriented GaN layer was determined and it exhibited a metal face through integrated differential phase contrast imaging.

Here, we proposed fabricating ultra-small InGaN-based micro-light-emitting diodes (µLEDs). The selective p-GaN areas were intentionally passivated using a H_2 plasma treatment and served as the electrical isolation regions to prevent the current from injecting into the InGaN quantum wells below. Three kinds of green µLEDs, two squircle shapes with widths of 5 and 4 µm and one circular shape with a diameter of 2.7 µm, were successfully realized. The current-voltage characteristics indicate that the series resistance and the turn-on voltage increase as the dimension of the µLED decreases. This originates from the diffusion of the hydrogen atoms into the unexpected conductive p-GaN area. The light output power density and the calculated external quantum efficiency of the µLEDs from a 5-µm-squircle to a 2.7-µm-circle were enhanced by 10−20% when compared to 98×98µm^2 µLEDs that were fabricated using mesa etching.

We investigated the performance of InGaN-based red/green micro-light-emitting diodes (µLEDs) ranging from 98×98µm^2 to 17×17µm^2. The average forward voltage at 10A/cm^2 was independent of the dimension of µLEDs. Red µLEDs exhibited a larger blueshift of the peak wavelength (∼35nm) and broader full-width at half maximum (≥50nm) at 2−50A/cm^2 compared to green µLEDs. We demonstrated that 47×47µm^2 red µLEDs had an on-wafer external quantum efficiency of 0.36% at the peak wavelength of 626 nm, close to the red primary color defined in the recommendation 2020 standard.

We have improved the InGaN/GaN heterointerface to achieve higher energy conversion efficiency by replacing a uniform InGaN layer with a graded In-content InGaN layer. Even In0.08Ga0.92N/GaN heterostructure has a large conduction band offset, which is large enough to suppress the photocurrent in the photocatalytic system. The graded In-content InGaN structures were grown by metalorganic vapor-phase epitaxy by changing the TMIn flow rate gradually. X-ray reciprocal space mapping confirmed the graded structures. The graded InGaN/GaN structure significantly increased photocurrent and H2generation by 50% and more compared with the conventional uniform InGaN/GaN structures.

E7130 is a novel drug candidate with an exceedingly complex chemical structure of the halichondrin class, discovered by a total synthesis approach through joint research between the Kishi group at Harvard University and Eisai. Only 18 months after completion of the initial milligram-scale synthesis, ten-gram-scale synthesis of E7130 was achieved, providing the first good manufacturing practice (GMP) batch to supply clinical trials. This paper highlights the challenges in developing ten-gram-scale synthesis from the milligram-scale synthesis.

We report a 330 ppi monolithic RGB micro light-emitting diodes (μLED) array of blue, green and red GaInN-based LEDs stacked on the same wafer. Considering it is challenging to form ohmic electrodes on the plasma-etched p-type GaN surface, GaInN-based tunnel junctions were used to connect each LED, and anode electrodes for the blue and green LEDs were formed on n-type AlGaN. The fabricated stacked monolithic μLED arrays were tested at room temperature (approximately 26 °C) and DC. Each μLED emitted blue, green and red with peak wavelengths of 486, 514 and 604 nm at a current density of 50 A cm−2.

We have investigated the use of nanopillar structures on high indium content InGaN amber multiple quantum well (MQW) samples to enhance the emission efficiency. A significant emission enhancement was observed which can be attributed to the enhancement of internal quantum efficiency and light extraction efficiency. The size-dependent strain relaxation effect was characterized by photoluminescence, Raman spectroscopy and time-resolved photoluminescence measurements. In addition, the light extraction efficiency of different MQW samples was studied by finite-different time-domain simulations. Compared to the as-grown sample, the nanopillar amber MQW sample with a diameter of 300 nm has demonstrated an emission enhancement by a factor of 23.8.

The PR approach combines the advantages of the second window of the ilioinguinal approach and the medial view of the modified Stoppa approach. However, it is unclear whether the PR approach is more effective or safer than the other approaches, as few clinical studies have compared the PR approach with the other approaches. The aim of this study was to provide a systematic review and meta-analysis comparing the PR approach with the other approaches for the treatment of acetabular fractures and to answer the following question: are the results of the PR approach superior to those of the other approaches in terms of reduction quality, operative time, operative blood loss, complications, and clinical outcomes for treatment of acetabular fractures?

We investigated the effect of the sidewall passivation by hydrogen plasma on the InGaN green micro-LED performance. Hydrogen passivation deactivates the surface region of p-GaN around the perimeter of the device mesa. Thus, hole injection is suppressed in this region, where etching-caused material degradation results in leakage current, decreasing device efficiency. We have confirmed the hydrogen passivation effect on LED square pixels with sizes of 20 and 100 μm. For smaller LEDs, the reverse leakage current has reduced more than tenfold, and the external quantum efficiency of LEDs was enhanced 1.4-times due to the suppression of the non-radiative recombination.

We report the characterization of a N-polar InGaN layer deposited by metalorganic vapor-phase epitaxy on a ScAlMgO4(0001) (SAM) substrate without a low-temperature buffer layer. The InGaN layer was tensile-strained, and its stoichiometry corresponded to In0.13Ga0.87N. We also present the microstructural observation of the InGaN/SAM interface via integrated differential phase contrast-scanning transmission electron microscopy. The results show that the interface between N-polar InGaN and SAM occurs between the O atoms of the O–Sc SAM surface and the (Ga,In) atoms of InGaN.

Molecular chaperones selectively trap heat-denatured proteins or their intermediates, primarily by hydrophobic interactions, to prevent irreversible aggregation resulting from macromolecular host (molecular chaperone)-guest (protein) interactions. The molecular chaperone function is an important concept that is expected to lead to breakthroughs in drug delivery systems, especially for protein or peptide delivery in regenerative medicine, such as bone regeneration. We have reported that polysaccharide nanogels act as artificial molecular chaperones. To further clarify the molecular chaperone function of nanogels as protein carriers, the elucidation of nanogel-protein interactions are especially important. Here, we investigated the interaction of a protein with a polysaccharide nanogel using fluorescence correlation spectroscopy at variable temperatures, using fluorescence-labeled bovine serum albumin (BSA) as a model protein. In particular, thermodynamic parameters of the heat-induced complexation of protein with CHP nanogels were evaluated using the vant Hoff plot. The plot shows that the CHP nanogels strongly complexed with heat-denatured BSA. The increased hydrophobicity of the denatured, unfolded protein may prefer complexation with amphiphilic hydrogel nanoparticles over complexation with the completely folded native protein. Thermodynamic parameters suggest that the complexation is entropically driven, rather than enthalpically, under the conditions studied.

We fabricated and characterized AlGaN/GaN heterostructure growth by MOVPE on vicinal m‐plane free‐standing GaN substrates prepared by the Na flux method. The miscut angle in the LPE‐GaN substrate has a great influence on the surface morphology and crystalline quality of epitaxial GaN and AlGaN films. In particular, AlGaN/GaN on a 4° miscut‐angle LPE‐GaN substrate shows large step bunching, small‐miscut‐angle LPE GaN substrate is essential for fabricating on FET structure with a flat surface.

We have investigated the pharmacology of sodium (R)-2-[4-(2,2-dimethyl-1,3-dioxan-5-yl) methoxy-3,5-dimethylpyridin-2-yl]methylsulfinyl-1H-benzimidazol (E3710), a new proton pump inhibitor (PPI), and its effect on gastric acid secretion. E3710 irreversibly inhibited H+,K+-ATPase activity in pig gastric vesicles with an acidic internal environment with an IC50of 0.28 μM. Administration of E3710 (0.1, 0.2, 0.4, and 0.8 mg/kg; n= 6) intraduodenally in a gastric fistula model in dogs inhibited histamine-stimulated gastric acid secretion at 0 to 2 and 24 to 26 h after administration with ED50values of 0.18 and 0.22 mg/kg, respectively. The inhibition by E3710 was 2.3 times more potent than that of another representative PPI, esomeprazole (0.2, 0.4, 0.8, and 1.6 mg/kg; n= 6) at 0 to 2 h after administration (ED50= 0.40 mg/kg) and 2.8 times more potent at 24 to 26 h (ED50= 0.71 mg/kg). In the gastric fistula dogs, the intragastric pH was ≥4 for 17% (n= 27) of a 24-h period with vehicle alone, but when E3710 was administered, at 0.2 (n= 4), 0.4 (n= 8), and 0.8 mg/kg (n= 5), the pH was ≥4 for 40, 79, and 88% of a day, respectively. The corresponding values for esomeprazole at 0.8 (n= 4) and 1.6 mg/kg (n= 8) were 55 and 59%, respectively. In a crossover study with vehicle, E3710 at 0.4 mg/kg and esomeprazole at 1.6 mg/kg (n= 6), E3710 increased the intragastric pH to >4 for 82% of a day compared with 61% of a day with esomeprazole. These results show that E3710 is a long-acting inhibitor of gastric acid secretion and a promising novel therapy for acid-related diseases, such as gastroesophageal reflux disease.

We have investigated the pharmacology of sodium (R)-2-[4-(2,2-dimethyl-1,3-dioxan-5-yl) methoxy-3,5-dimethylpyridin-2-yl]methylsulfinyl-1H-benzimidazol (E3710), a new proton pump inhibitor (PPI), and its effect on gastric acid secretion. E3710 irreversibly inhibited H(+),K(+)-ATPase activity in pig gastric vesicles with an acidic internal environment with an IC(50) of 0.28 microM. Administration of E3710 (0.1, 0.2, 0.4, and 0.8 mg/kg; n = 6) intraduodenally in a gastric fistula model in dogs inhibited histamine-stimulated gastric acid secretion at 0 to 2 and 24 to 26 h after administration with ED(50) values of 0.18 and 0.22 mg/kg, respectively. The inhibition by E3710 was 2.3 times more potent than that of another representative PPI, esomeprazole (0.2, 0.4, 0.8, and 1.6 mg/kg; n = 6) at 0 to 2 h after administration (ED(50) = 0.40 mg/kg) and 2.8 times more potent at 24 to 26 h (ED(50) = 0.71 mg/kg). In the gastric fistula dogs, the intragastric pH was >or=4 for 17% (n = 27) of a 24-h period with vehicle alone, but when E3710 was administered, at 0.2 (n = 4), 0.4 (n = 8), and 0.8 mg/kg (n = 5), the pH was >or=4 for 40, 79, and 88% of a day, respectively. The corresponding values for esomeprazole at 0.8 (n = 4) and 1.6 mg/kg (n = 8) were 55 and 59%, respectively. In a crossover study with vehicle, E3710 at 0.4 mg/kg and esomeprazole at 1.6 mg/kg (n = 6), E3710 increased the intragastric pH to >4 for 82% of a day compared with 61% of a day with esomeprazole. These results show that E3710 is a long-acting inhibitor of gastric acid secretion and a promising novel therapy for acid-related diseases, such as gastroesophageal reflux disease.

We propose a simple and cost-effective technique that can reduce the electrical bandwidth for Brillouin frequency-shift sensors with heterodyne detection without the need for expensive instruments or a complicated system. With this technique we use only a reference fiber. The reference Brillouin scattering light in the reference fiber is used as a local light for heterodyne detection. We confirm that this method can be used for measuring the Brillouin scattering spectrum distribution with a much lower frequency bandwidth (0.2 GHz) than that employed for conventional heterodyne detection (11 GHz). The method operates in a way similar to conventional Brillouin optical time domain reflectometry with comparable accuracy. Moreover, we successfully demonstrate temperature distribution sensing and show that we can compensate for temperature variation in the reference fiber.

The electron-donating polymer containing vinylogous TTF unit in the main chain was successfully obtained by oxidative polymerization of bisdithiafulvene (bisDTF) (1). The polymer was soluble in common organic solvents such as chloroform and toluene. Structural characterization of the polymer was provided by 1H and 13C NMR spectroscopies. The number-average molecular weight of the polymer was estimated as 5,400 by gel permeation chromatographic analysis (chloroform, polystyrene standards). Optical and electrochemical properties of the polymer were studied by UV-vis analysis and cyclic voltammetry. Charge transfer complex of the polymer with tetracyanoquinodimethane (TCNQ) was obtained in a DMSO solution.

Various primary and secondary alcohols were smoothly oxidized to the corresponding aldehydes and ketones by using a new oxidizing agent, N-t-butylbenzenesulfinimidoyl chloride (4a), in the coexistence of DBU or zinc oxide. The present oxidation proceeded under mild conditions via five-membered intramolecular proton-transfer of an alkyl arenesulfinimidate intermediate.

InGaN-based LEDs are efficient light sources in the blue–green light range and have been successfully commercialized in the last decades. Extending their spectral range to the red region causes a significant reduction in LED efficiency. This challenge hinders the integration of red, green, and blue LEDs based on III-nitride materials, especially for full-color micro-LED displays. We review our recent progress on InGaN-based red LEDs with different chip sizes from hundreds to tens of micrometers, including the epitaxial structures, device fabrication, and optical performance (peak wavelength, full-width at half-maximum, light output power, efficiency, temperature stability, and color coordinates).

The reaction of silane with atomic oxygen (3P) was investigated by the shock‐tube–laser‐photolysis method over the temperature range of 900–1170 K. Oxygen atoms were produced by the ArF laser photolysis of SO2behind reflected shock waves and monitored with atomic resonance absorption spectroscopy. The rate constant for the SiH4+ O reaction was evaluated by taking the possible contribution of the consecutive reaction into consideration. The Arrhenius temperature coefficient was determined to be Ea= 26.6 kJ mol−1, which is much higher than the experimental activation energies obtained at lower temperatures. Rate constants calculated by a transition state theory with the reaction barrier height of E0= 10.2 kJ mol−1agreed well with both the present and the previous experimental results for a wide temperature range.

We report on the electrical properties of AlGaN/GaInN heterostructures fabricated with various InN molar fractions from 0 to 0.60 in GaInN on a GaN template. The sheet carrier density of the AlGaN/GaInN heterostructure monotonically increased with increasing InN molar fraction in GaInN, reaching 5.0 × 1013cm−2at an InN molar fraction of 0.60. The Al0.30Ga0.70N/Ga0.40In0.60N heterostructure exhibited static field‐effect transistor (FET) characteristics.

Here we report InGaN-based red light-emitting diodes (LEDs) grown on () ?-Ga2O3substrates. AlN/AlGaN strain-compensating layers and hybrid multiple-quantum-well structures were employed to improve the crystalline-quality of the InGaN active region. A bare LED showed that peak wavelength, light output power, and external quantum efficiency were 665 nm, 0.07 mW, and 0.19% at 20 mA, respectively. As its forward voltage was 2.45 V at 20 mA, the wall-plug efficiency was 0.14%. The characteristic temperature of the LEDs was 222 K at 100 mA evaluated from the temperature dependence of electroluminescence.

We investigated photoelectrochemical hydrogen generation using InGaN-based photoelectrodes with different p-GaN layer thicknesses. It was confirmed that the photocurrent density and hydrogen generation can be enhanced at zero bias between the photoelectrode and counterelectrode. We found that the maximum energy conversion efficiency was 2.0% when using an InGaN-based photoelectrode with a 20-nm-thick p-GaN layer; this was one order larger than for a photoelectrode without a p-GaN layer. The p-GaN layer can pull the potential of the InGaN layer upward, leading to efficient electron-hole separation in the photoabsorption layer and improving carrier transfer from the InGaN layer. By measuring incident photon to current efficiency, it was confirmed that the InGaN layer worked as a photoelectrode since the absorption edge wavelength was around 400 nm.

We demonstrate the effectiveness of a hybrid multiple-quantum-wells (MQWs) structure in InGaN-based orange light-emitting diodes (LEDs) grown by metalorganic vapor phase epitaxy. The hybrid MQWs-LED is composed of orange InGaN double QWs and a blue-green InGaN single QW. Using the hybrid MQWs structure, the orange LEDs exhibited electroluminescence spectra with narrow full widths at half maximum of 51 nm at 20 mA. The light output power and external quantum efficiency of the InGaN-based orange LEDs were 0.23 mW and 0.6%, respectively, at 20 mA.

We investigated InGaN-based amber light-emitting diodes (LEDs) with AlN/(Al)GaN barrier layers grown by metalorganic vapor-phase epitaxy. Tensilely strained AlN/Al0.03Ga0.97N barriers improved the crystalline quality of compressively strained InGaN quantum wells. We found that strain compensation among wells and barriers improves the external quantum efficiency of high-In-content InGaN-based amber LEDs. The amber LEDs with AlN/Al0.03Ga0.97N barriers have shown an electroluminescence (EL) intensity approximately 2.5-fold that of LEDs with the AlN/GaN barriers at 20 mA.

Various primary and secondary alcohols were smoothly oxidized to the corresponding carbonyl compounds with N-chlorosuccinimide by using a catalytic amount of N-tert-butylbenzenesulfenamide (1) in the co-existence of potassium carbonate and molecular sieves 4A.

Various alkoxy(N-tert-butylamino)(methyl)sulfonium triflates are prepared by selective O-alkylation of N-tert-butylmethanesulfinamide (4c) with primary alkyl trifluoromethanesulfonates (triflates). Successive treatment of thus formed alkoxyaminosulfonium salts with DBU smoothly affords the corresponding aldehydes in good yields. The sequential combination of the two reactions provides a new method for oxidation of primary alkyl triflates to aldehydes, and the present study suggests the existence of alkoxysulfilimines as intermediates of the previously-reported direct oxidation of alcohols by using N-tert-butylphenylsulfinimidoyl chloride (1a) and DBU.

Various primary and secondary alcohols bearing β-aryl, alkenyl, or alkoxy moiety were efficiently oxidized to the corresponding labile aldehydes and ketones under mild conditions with N-tert-butylphenylsulfinimidoyl chloride (1) in the coexistence of zinc oxide.

The aldol reaction of several aldehydes with silyl enol ethers proceeded smoothly to give the corresponding aldols in good to high yields at −78 °C by using 1.0 mol% of a novel cationic species with tetrakis(pentafluorophenyl)borate anion.

We discovered that Si-doped Al0.05Ga0.95N can be used to realize an extremely low-resistivity n-type layer at room temperature. In Si-doped GaN, a resistivity of 2.7×10-3? cm with a carrier concentration of 4.0×1019cm-3was almost saturated. In contrast, Si-doped Al0.05Ga0.95N with a minimum resistivity of 5.9×10-4? cm was produced with an electron concentration and electron mobility of 1.4×1020cm-3and 70 cm2/V s, respectively. We confirmed a reduction in the differential resistance of a violet light-emitting diode with a high external quantum efficiency by using this Si-doped Al0.05Ga0.95N.

We fabricated and characterized a nonpolar a-plane nitride-based solar cell on an r-plane sapphire substrate. The maximum external quantum efficiency of the solar cell reached 62% at a wavelength of approximately 400 nm. The open-circuit voltage, the short-circuit current density, and the fill factor of the solar cell were 0.9 V, 4.8 mA/cm2, and 57%, respectively. A conversion efficiency of 1.6% was obtained from the solar cell under a solar simulator of air mass 1.5 G and an irradiation intensity of 155 mW/cm2at room temperature.

We fabricated and characterized a nonpolar a-plane nitride-based solar cell on an r-plane sapphire substrate. The maximum external quantum efficiency of the solar cell reached 62% at a wavelength of approximately 400 nm. The open-circuit voltage, the short-circuit current density, and the fill factor of the solar cell were 0.9 V, 4.8 mA/cm2, and 57%, respectively. A conversion efficiency of 1.6% was obtained from the solar cell under a solar simulator of air mass 1.5 G and an irradiation intensity of 155 mW/cm2 at room temperature.

High-performance GaInN-based solar cells with high open-circuit voltage, high short-circuit current density, and good fill factor have been obtained using a combination of two different GaInN superlattice structures. The GaInN barrier thicknesses (3 and 0.6 nm) in both superlattice structures were optimized, resulting in a thick GaInN-based active layer with a low pit density in the device. The conversion efficiency is approximately 2.5% under a solar simulator of air mass 1.5G and an irradiation intensity of 155 mW/cm2.

We demonstrated the high-temperature operation of normally off-mode heterostructure field-effect transistors (HFETs) with a p-GaN gate. The HFETs with a p-GaN gate were operated in the normally off mode at 350 °C. The temperature dependence of their performance was compared with the results of simulation.

GaInN films with different In compositions were grown using a raised-pressure metalorganic vapor phase epitaxy (MOVPE) system operated from 100 to 200 kPa. A precise X-ray diffraction study showed that the In composition increases with an increasing pressure during growth, which is consistent with the result of a thermodynamic analysis.

We fabricated GaInN/GaN multiple quantum wells (MQWs) on a high-crystalline-quality thick m-plane GaInN underlying layer, and the integral photoluminescence (PL) intensity was compared with that of the same GaInN/GaN MQWs on a high-crystalline-quality m-plane GaN underlying layer. The light emission wavelengths from the MQWs were violet (?396 nm), blue (?450 nm), and green (?535 nm). The integral PL intensities obtained from the GaInN/GaN violet, blue, and green MQWs on the high-crystalline-quality thick GaInN underlying layer were 1.1, 1.5, and 2.1 times higher than these of the MQWs on the m-plane GaN underlying layer, respectively.