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One-dimensional (1D) nanostructures of the wide band gap semiconductors are promising building blocks for photoelectric nanodevices. However, some problems like strong 1D confinement largely hamper their applications. To avoid these problems, here, we provide another 1D configuration, in which an inner-wire coaxial Schottky junction exists, thus effectively avoiding the recombination of the photoexcited carriers. As an example, we produce ZnS/carbon nanotube nanocables with uniform morphologies by a two-step vapor deposition method and find that they have good conductance, obvious light response, and ohmic contacts with electrodes, avoiding the limitations of both the pristine nanomaterials. We believe that this configuration would be valuable for applying the 1D nanomaterials in photoelectronics. [ABSTRACT FROM AUTHOR]

Controllable and scalable production is of great importance for the application of graphene; however, to date, it is still a great challenge and a major obstacle which hampers its practical applications. Here, we develop a template chemical vapor deposition method for scalable synthesis of few-layer graphene ribbons (FLGRs) with controlled morphologies. The FLGRs have a good conductivity and are ideal for use in nanoelectromechanics (NEM). As an application, we fabricate a reversible NEM switch and a logic gate by using the FLGRs. This work realizes both controllable and scalable synthesis of graphene, provides an application of graphene in NEM switches, and would be valuable for both the scientific studies and the practical applications of graphene. [ABSTRACT FROM AUTHOR]

Molecular electronics is often limited by the lack of a simple method to fabricate nanoelectrodes with controlled gap size. This is partly attributed to the lack of a real time characterization in the fabrication. Here, we report a new method based on an electron induced deposition process operated in scanning electron microscopy that realizes in situ and real time characterization in the nanoelectrode fabrication; thus the gap size can be controlled easily and precisely. It is a clean and nondestructive process for carbon nanotube (CNT) electrodes. The mechanism is detailed. The nanoelectrodes have a π-conjugated surface due to the deposition of sp 2-rich amorphous carbon. As an application, DNA molecules are assembled between the CNT electrodes by π-stacking interaction for current−voltage measurement. Our result provides a feasible route to prepare nanoelectrodes with controlled gap size, and it will be valuable for current efforts in molecular electronics and nanoelectronics. [ABSTRACT FROM AUTHOR]

A magnetism-assisted chemical vapor deposition method was developed to synthesize branched or iron-encapsulated carbon nanotubes. In the process, the external magnetic field can promote the coalescence or division of the catalyst particles, causing the formation of branched or encapsulated nanostructures. This finding will extend the understanding of the chemical vapor deposition method in a magnetic field and promote the applications of branched or encapsulated nanostructures. [ABSTRACT FROM AUTHOR]

Here we develop a simple method by using flow fluctuation to synthesize arrays of multibranched carbon nanotubes (CNTs) that are far more complex than those previously reported. The architectures and compositions can be well controlled, thus avoiding any template or additive. A branching mechanism of fluctuation-promoted coalescence of catalyst particles is proposed. This finding will provide a hopeful approach to the goal of CNT-based integrated circuits and be valuable for applying branched junctions in nanoelectronics and producing branched junctions of other materials. [ABSTRACT FROM AUTHOR]

The article focuses on the development of a closed-loop catalytic nanoreactor system, which enables precise control and monitoring of chemical reactions at the molecular level. Topics include the use of Deoxyribonucleic Acid (DNA) frameworks and enzymes for precise reaction control, the application of this technology in sensitive molecular diagnostics, and the intelligent nano-systems for precision chemistry.

The article discusses emergent topological Dirac semimetals afford fresh pathways for optoelectronics, device implementation has elusive to date. Topics include palladium ditelluride combining the capabilities provided by peculiar band structure, with topologically protected electronic states; and a responsivity of 10 A/W and a noise-equivalent power lower than 2 pW/Hz0.5 are achieved at room temperature.

Perovskite single crystals exhibit extraordinary optoelectronic performances due to their advantages such as low trap-state densities, long carrier diffusion, and large absorption coefficient, and thus, photodetectors based on perovskite single crystals have attracted much research interest. Unlike the reported one-component single-crystal perovskite photodetectors, here, we have developed a facile two-step approach to fabricate a core-shell heterojunction based on the CH3NH3PbBr3 single crystal. A photodetector made of the as-prepared perovskite heterojunction renders the feature of self-power attributed to a built-in electric field in the junction and exhibits a wavelength-dependent responsivity with a peak responsivity up to 11.5mAW-1 under 450nm irradiation at zero bias, which is one order of magnitude higher than the CH3NH3PbBr3 single crystal and shows a maximum external quantum efficiency of 3.17%, also higher than the reported 0.2% of the CH3NH3PbBr3 single crystal. Our work may lead to more efficient self-powered heterojunction systems based on perovskite single crystals. [ABSTRACT FROM AUTHOR]

We report significant changes of optical conductivity (σ1) in single-layer graphene induced by mild oxygen plasma exposure and explore the interplay between carrier doping, disorder, and many-body interactions from their signatures in the absorption spectrum. The first distinctive effect is the reduction of the excitonic binding energy that can be extracted from the renormalized saddle point resonance at 4.64 eV. Secondly, σ1 is nearly completely suppressed (σ1⪡σ0) below an exposure-dependent threshold in the near-infrared range. The clear steplike suppression follows the Pauli blocking behavior expected for doped monolayer graphene. The nearly zero residual conductivity below ω ~ 2EF can be interpreted as arising from the weakening of the electronic self-energy. Our data shows that mild oxygen exposure can be used to controllably dope graphene without introducing the strong physical and chemical changes that are common in other approaches to oxidized graphene, allowing a controllable manipulation of the optical properties of graphene. [ABSTRACT FROM AUTHOR]

Metal-catalyzed chemical vapor deposition (CVD) has been broadly employed for large-scale production of high-quality graphene. However, a following transfer process to targeted substrates is needed, which is incompatible with current silicon technology. We here report a new CVD approach to form nanographene and nanographite films with accurate thickness control directly on non-catalytic substrates such as silicon dioxide and quartz at 800 °C. The growth time is as short as a few seconds. The approach includes using 9-bis(diethylamino)silylanthracene as the carbon source and an atomic layer deposition (ALD) controlling system. The structure of the formed nanographene and nanographite films were characterized using atomic force microscopy, high resolution transmission electron microscopy, Raman scattering, and x-ray photoemission spectroscopy. The nanographite film exhibits a transmittance higher than 80% at 550 nm and a sheet electrical resistance of 2000 ohms per square at room temperature. A negative temperature-dependence of the resistance of the nanographite film is also observed. Moreover, the thickness of the films can be precisely controlled via the deposition cycles using an ALD system, which promotes great application potential for optoelectronic and thermoelectronic-devices. [ABSTRACT FROM AUTHOR]

Graphene has attracted tremendous research interest owing to its widespread potential applications. However, these applications are partially hampered by the lack of a general method to produce high-quality graphene at low cost. Here, to the best of our knowledge, we use low-cost solid carbon allotropes as the precursor in plasma-enhanced chemical vapor deposition (PECVD) for the first time, and find that the hydrogen plasma and reaction temperature play a crucial role in the process. Hydrogen plasma etches carbon black, and produces graphene crystals in a high-temperature zone. Based on this finding, a modified PECVD technology is developed, which produces transparent conductive nanographene films directly on various substrates at a temperature as low as 600 °C. For application, the closely packed structure of the nanographene film enables a remarkable temperature-dependent behavior of the resistance with a ratio higher than that previously reported, indicating its great potential for usage in highly sensitive temperature detectors. [ABSTRACT FROM AUTHOR]

The article discusses the research on the excellent electrical properties of low-cost organic transistors and inverters with chemical modified bottom electrodes. Study reveals, compatibility on energy of electrodes and organic semiconductors were important on forming a ohmic contact for efficient charge injection. However, semiconductors and gate dielectrics must be stable to prevent chemical reactions which could interfere.