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Article
Open AccessBlue-shifted and strongly-enhanced light emission in transition-metal dichalcogenide twisted heterobilayers
Moiré heterostructures produced by twisted heterojunction of transition-metal dichalcogenides are recognized as novel platforms for unique and tunable means of controlling the optical phenomena including photo...
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Article
Open AccessPossible permanent Dirac- to Weyl-semimetal phase transition by ion implantation
Three-dimensional (3D) topological semimetals (TSMs) are a new class of Dirac materials that can be viewed as 3D graphene and are referred to as Dirac semimetals (DSMs) or Weyl semimetals (WSMs) depending on w...
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Article
Open AccessGrowth of two-dimensional Janus MoSSe by a single in situ process without initial or follow-up treatments
Two-dimensional (2D) Janus transition metal dichalcogenides (TMDCs) are highly attractive as an emerging class of 2D materials, but only a few methods are available for fabricating them. These methods rely on ...
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Article
Open AccessPhysicochemical changes during 4 weeks ripening of Camembert cheeses salted with four types of salts
The objectives of this study were to compare physicochemical, rheological and sensory characteristics of Camembert cheeses salted with 4 types of salts (refined salt, baked refined salt, sun-dried salt, and Hi...
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Article
Open AccessInAs on GaAs Photodetectors Using Thin InAlAs Graded Buffers and Their Application to Exceeding Short-Wave Infrared Imaging at 300 K
Short-wave infrared (SWIR) detectors and emitters have a high potential value in several fields of applications, including the internet of things (IoT) and advanced driver assistance systems (ADAS), gas sensin...
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Article
High-performance Core/Shell InGaN/GaN Radial Multi-quantum-well Nanowire Solar Cells Non-catalytically Grown on Si Wafers
We report photovoltaic properties of solar cells made of core/shell InGaN/GaN multi quantum wells (MQWs)-nanowire (NW) arrays, vertically-grown through oxide-template hole patterns from n-GaN thin films on n-type...
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Article
Significantly-enhanced Stabilities in Flexible Hybrid Organic-Inorganic Perovskite Resistive Random Access Memories by Employing Multilayer Graphene Transparent Conductive Electrodes
Despite several reports on perovskite resistive random access memories (RRAMs), most of them are based on transparent conductive oxide electrodes, not suitable for high flexibility. We first employ multilayer-...
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Article
Use of Graphene for Solar Cells
In the last decade, graphene has been spotlighted as one of the novel materials for transparent conductive electrodes (TCEs) of solar cells. This paper provides an overview of recent progress for the applicati...
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Article
Graphene-based vertical-junction diodes and applications
In the last decade, graphene has received extreme attention as an intriguing building block for electronic and photonic device applications. This paper provides an overview of recent progress in the study of v...
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Article
Formation properties of an InGaN active layer for high-efficiency InGaN/GaN multi-quantum-well-nanowire light-emitting diodes
Nitride-based nanowires (NWs) have several advantages, such as flexibility in choosing a substrate, easy fabrication, large light-emitting area, no internal electric field, enhanced light extraction, and reduc...
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Article
Open AccessPrecise and selective sensing of DNA-DNA hybridization by graphene/Si-nanowires diode-type biosensors
Single-Si-nanowire (NW)-based DNA sensors have been recently developed, but their sensitivity is very limited because of high noise signals, originating from small source-drain current of the single Si NW. Her...
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Article
Non-catalytic direct synthesis of graphene on Si (111) wafers by using inductively-coupled plasma chemical vapor deposition
We employ inductively-coupled plasma chemical vapor deposition for non-catalytic growth of graphene on a Si (111) wafer or glass substrate, which is useful for practical device applications of graphene without...
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Article
Open AccessLight-induced negative differential resistance in graphene/Si-quantum-dot tunneling diodes
One of the interesing tunneling phenomena is negative differential resistance (NDR), the basic principle of resonant-tunneling diodes. NDR has been utilized in various semiconductor devices such as frequency m...
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Article
Open AccessEnergy transfer from an individual silica nanoparticle to graphene quantum dots and resulting enhancement of photodetector responsivity
Förster resonance energy transfer (FRET), referred to as the transfer of the photon energy absorbed in donor to acceptor, has received much attention as an important physical phenomenon for its potential appli...
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Article
Effect of defects in oxide templates on Non-catalytic growth of GaN nanowires for high-efficiency light-emitting diodes
Two kinds of oxide templates, one with and one without undercuts, are employed to study the effect of defects in oxide templates on non-catalytic growth of GaN nanowires (NWs). GaN NWs abnormally grown from th...
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Article
Open AccessCharacterization of airag collected in Ulaanbaatar, Mongolia with emphasis on isolated lactic acid bacteria
Airag, alcoholic sour-tasting beverage, has been traditionally prepared by Mongolian nomads who naturally ferment fresh mares’ milk. Biochemical and microbiological compositions of airag samples collected in U...
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Article
Open AccessAnisotropic Terahertz Emission from Bi2Se3 Thin Films with Inclined Crystal Planes
We investigate the surface states of topological insulator (TI) Bi2Se3 thin films grown on Si nanocrystals and Al2O3 substrates by using terahertz (THz) emission spectroscopy. Compared to bulk crystalline Bi2Te2S...
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Article
Effect of nitrogen do** on the structural and the optical variations of graphene quantum dots by using hydrazine treatment
Graphene quantum dots (GQDs) have been prepared by hydrothermal cutting of graphene sheets and subsequently doped with N atoms by using hydrazine treatment to study the effect of do** on the structural and t...
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Article
Sequential structural and optical evolution of MoS2 by chemical synthesis and exfoliation
Various types of MoS2 structures are successfully obtained by using economical and facile sequential synthesis and exfoliation methods. Spherically-shaped lumps of multilayer (ML) MoS2 are prepared by using a con...
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Article
Open AccessHigh-performance graphene-quantum-dot photodetectors
Graphene quantum dots (GQDs) have received much attention due to their novel phenomena of charge transport and light absorption/emission. The optical transitions are known to be available up to ~6 eV in GQDs, ...
