A5003786960- Graphene research and applications
- Carbon Nanotubes in Composites
- 2D Materials and Applications
- Thermal properties of materials
- Advancements in Battery Materials
- Quantum and electron transport phenomena
- Molecular Junctions and Nanostructures
- Fullerene Chemistry and Applications
- Nanowire Synthesis and Applications
- Conducting polymers and applications
- Graphene and Nanomaterials Applications
- MXene and MAX Phase Materials
- Semiconductor materials and devices
- Diamond and Carbon-based Materials Research
- Perovskite Materials and Applications
- Nanopore and Nanochannel Transport Studies
- Nanotechnology research and applications
- Supercapacitor Materials and Fabrication
- Organic Electronics and Photovoltaics
- Surface and Thin Film Phenomena
- Boron and Carbon Nanomaterials Research
- Photonic and Optical Devices
- Advancements in Semiconductor Devices and Circuit Design
- Chemical and Physical Properties of Materials
- nanoparticles nucleation surface interactions
Kyushu University
2016-2025
ON Semiconductor (United States)
2025
Fukuoka University
2015-2020
National Institute of Advanced Industrial Science and Technology
2000-2018
Japan Science and Technology Agency
2004-2017
Graduate School USA
2016
Advanced Projects Research Incorporated (United States)
2016
Kasugai Municipal Hospital
2015-2016
Tsinghua University
2015
Hitachi (Japan)
2009
We have studied the work function and density of states (DOS) multiwall carbon nanotubes (MWNTs) using ultraviolet photoelectron spectroscopy (UPS). Raw MWNTs were purified by successive sonication, centrifugation, sedimentation, filtration processes with aid a nonionic surfactant. The showed slightly lower (4.3 eV) than that highly oriented pyrolytic graphite (4.4 eV). Effects three different oxidative treatments, air-, oxygen plasma-, acid-oxidation, also been studied. It was found...
Although the thermal properties of millimeter-sized carbon nanotube mats and packed nanofibers have been readily measured, measurements for a single are extremely difficult. Here, we report novel method that can reliably measure conductivity using suspended sample-attached $T$-type nanosensor. Our experimental results show at room temperature increases as its diameter decreases, exceeds $2000\text{ }\text{ }\mathrm{W}/\mathrm{mK}$ 9.8 nm. The dependence with 16.1 nm appears to an asymptote...
The advantages of combining carbon nanotubes with conjugated polymers for high-efficiency photovoltaic devices are explored in this article. preparation and optical properties a composite multiwalled (MWNTs) poly(p-phenylene vinylene) (PPV) reported the efficiency device fabricated from investigated. A quantum approximately twice that standard ITO is reported, believed to be due part complex interpenetrating network polymer chains MWNTs.
Anisotropic carbon nanotube–polyester composites have been realized by polymerization of the nanotube–monomer dispersion in a constant magnetic field (see Figure for method). Magnetic susceptibilities, electrical conductivities, and mechanical properties composite show clear anisotropy, indicating field-induced alignment nanotubes polymer matrix.
Epitaxial chemical vapor deposition (CVD) growth of uniform single-layer graphene is demonstrated over Co film crystallized on c-plane sapphire. The single crystalline realized the sapphire substrate by optimized high-temperature sputtering and successive H2 annealing. This enables formation graphene, while a polycrystalline deposited SiO2/Si gives number flakes with various thicknesses. Moreover, an epitaxial relationship between as-grown lattice observed when synthesis occurs at 1000 °C;...
This perspective discusses recent advances in using strain to engineer the properties of thin-layer materials such as graphene and transition metal dichalcogenides (TMDs).
Monolayers of transition metal dichalcogenides (TMDCs) have attracted a great interest for post-silicon electronics and photonics due to their high carrier mobility, tunable bandgap, atom-thick 2D structure. With the analogy conventional silicon electronics, establishing method convert TMDC p- n-type semiconductors is essential various device applications, such as complementary metal-oxide-semiconductor (CMOS) circuits photovoltaics. Here, successful control electrical polarity monolayer...
Abstract Multilayer hexagonal boron nitride (hBN) can be used to preserve the intrinsic physical properties of other two-dimensional materials in device structures. However, integrating material into large-scale heterostructures remains challenging due difficulties synthesizing high-quality large-area multilayer hBN and combining it with layers same scale. Here we show that centimetre-scale synthesized on iron–nickel alloy foil by chemical vapour deposition, then as a substrate...
Abstract Graphene and other two-dimensional (2D) materials can be used to create electronic optoelectronic devices. However, their development has been limited by the lack of effective large-area transfer processes. Here we report a method that uses functional tapes with adhesive forces controlled ultraviolet light. The adhesion tape is optimized for monolayer graphene, providing yield over 99%. Once detached from growth substrate, graphene/tape stack enables easy graphene desired target...
Abstract Alkali metal (AM) intercalation between graphene layers holds promise for electronic manipulation and energy storage, yet the underlying mechanism remains challenging to fully comprehend despite extensive research. In this study, we employ low-voltage scanning transmission electron microscopy (LV-STEM) visualize atomic structure of intercalated AMs (potassium, rubidium, cesium) in bilayer (BLG). Our findings reveal that adopt structures with hcp stacking, specifically a C 6 M 2...
Size, orientation, and boundary of graphene domains are the current focus chemical vapor deposition (CVD) growth because they closely related to graphene's physical properties. Here, we study domain structure single-layer grown by ambient pressure CVD over heteroepitaxial Cu(111) Cu(100) films. Low energy electron microscope measurements reveal that film gives uniform whose orientation is consistent with underlying Cu lattice for areas 1 mm2. On other hand, on exhibits clear multidomain two...
On single-crystal substrates, such as sapphire (alpha-Al 2O 3) and quartz (SiO 2), single-walled carbon nanotubes (SWNTs) align along specific crystallographic axes of the crystal, indicating that SWNT growth is influenced by crystal surface. Here, we show not only orientation, but also diameter chirality SWNTs are affected plane substrate. The aligned grown on A- R-planes have narrower distributions than randomly oriented tubes produced C-plane amorphous SiO 2. Photoluminescence...
Control over chemical reactivity is essential in the field of nanotechnology. Graphene a two-dimensional atomic sheet sp(2) hybridized carbon with exceptional properties that can be altered by functionalization. Here, we transferred single-layer graphene onto flexible substrate and investigated functionalization using different aryl diazonium molecules while applying mechanical strain. We found strain alter structure graphene, dramatically increase reaction rate, factor up to 10, as well...
For electronic applications, synthesis of large-area, single-layer graphene with high crystallinity is required. One the most promising and widely employed methods chemical vapor deposition (CVD) using Cu foil/film as catalyst. However, CVD generally polycrystalline contains a significant amount domain boundaries that limit intrinsic physical properties graphene. In this Perspective, we discuss growth mechanism on catalyst review recent development in observation control structure We...
Abstract The electrical contact is one of the main issues preventing semiconducting 2D materials to fulfill their potential in electronic and optoelectronic devices. To overcome this problem, a new approach developed here that uses chemical vapor deposition grown multilayer graphene (MLG) sheets as flexible electrodes for WS 2 field‐effect transistors. gate‐tunable Fermi level, van der Waals interaction with , high conductivity MLG significantly improve overall performance carrier mobility...
Multilayered heterostructures of two-dimensional materials have recently attracted increased interest because their unique electronic and optical properties. Here, we present chemical vapor deposition (CVD) growth triangular crystals monolayer MoS2 on single-crystalline hexagonal graphene domains which are also grown by CVD. We found that grows selectively the rather than bare supporting SiO2 surface. Reflecting heteroepitaxy process, two preferred equivalent orientations. The interaction...
Band gap opening in bilayer graphene (BLG) under a vertical electric field is important for the realization of high performance graphene-based semiconductor devices, and thus, synthesis uniform large-area BLG required. Here we demonstrate highly film by chemical vapor deposition (CVD) over epitaxial Cu−Ni (111) binary alloy catalysts. The relative concentration Ni Cu as well growth temperature cooling profile was found to strongly influence uniformity BLG. In particular, slow process after...
We report ambient pressure chemical vapor deposition (CVD) growth of single-crystalline NbS2 nanosheets with controlled orientation. On Si and SiO2 substrates, grow almost perpendicular to the substrate surface. However, when we apply transferred CVD graphene on as a substrate, sheets laterally lying graphene. The show triangular hexagonal shapes thickness about 20–200 nm several micrometres in lateral dimension. Analyses based X-ray diffraction Raman spectroscopy indicate that are single...
Multilayer hexagonal boron nitride (h-BN) is an ideal insulator for two-dimensional (2D) materials, such as graphene and transition metal dichalcogenides, because h-BN screens out influences from surroundings, allowing one to observe intrinsic physical properties of the 2D materials. However, synthesis large uniform multilayer still very challenging it difficult control segregation process B N atoms catalysts during chemical vapor deposition (CVD) growth. Here, we demonstrate CVD growth with...
Abstract High-speed light emitters integrated on silicon chips can enable novel architectures for silicon-based optoelectronics, such as on-chip optical interconnects, and photonics. However, conventional sources based compound semiconductors face major challenges their integration with a platform because of difficulty direct growth substrate. Here we report ultra-high-speed (100-ps response time), highly graphene-based on-silicon-chip blackbody in the near-infrared region including...
Transition metal dichalcogenides (TMDs) exhibit unique properties and potential applications when reduced to one-dimensional (1D) nanoribbons (NRs), owing quantum confinement high edge densities. However, effective growth methods for self-aligned TMD NRs are still lacking. We demonstrate a versatile approach lattice-guided of dense, aligned MoS 2 NR arrays via chemical vapor deposition (CVD) on anisotropic sapphire substrates, without tailored surface steps. This method enables the synthesis...