Transparent Patternable Large-Area Graphene p-n Junctions by Photoinduced Electron Doping.

We present a novel approach to achieve n-type doping in graphene and create graphene p-n junctions through a photoinduced electron doping method using photobase generators (PBGs). The unique properties of PBGs allow us to spatially and temporally control the doping process via light activation. The selective irradiation of specific regions on the graphene film enables switching their doping from p- to n-type, as confirmed by changes in the electromotive force and Seebeck and Hall coefficients.

Impedance Characteristics of Monolayer and Bilayer Graphene Films with Biofilm Formation and Growth.

Biofilms are the result of bacterial activity. When the number of bacteria (attached to materials' surfaces) reaches a certain threshold value, then the bacteria simultaneously excrete organic polymers (EPS: extracellular polymeric substances). These sticky polymers encase and protect the bacteria.

Microscopic Mechanism of Van der Waals Heteroepitaxy in the Formation of MoS/hBN Vertical Heterostructures.

Recent studies have revealed that van der Waals (vdW) heteroepitaxial growth of 2D materials on crystalline substrates, such as hexagonal boron nitride (hBN), leads to the formation of self-aligned grains, which results in defect-free stitching between the grains. However, how the weak vdW interaction causes a strong limitation on the crystal orientation of grains is still not understood yet. In this work, we have focused on investigating the microscopic mechanism of the self-alignment of MoS grains in vdW epitaxial growth on hBN.

Electrical properties of bilayer graphene synthesized using surface wave microwave plasma techniques at low temperature.

Bilayer graphene was synthesized at low temperature using surface wave microwave plasma techniques where poly(methyl metacrylate) (PMMA) and methane (CH) were used as carbon sources. Temperature-dependent Hall effect measurements were carried out in a helium atmosphere. Sheet resistance, sheet carrier density and mobility showed weak temperature dependence for graphene from PMMA, and the highest carrier mobility is 740 cm V s.

The preparation of Ag nanoparticle-modified single-walled carbon nanotubes and their antibacterial activity.

The sidewall modified single-walled carbon nanotubes (SWNTs) with amino-containing substituents were prepared using the radicals generated by the photolysis of acetonitrile. A subsequent treatment of modified SWNTs with the Ag colloid gave an attachment of Ag nanoparticles on the surface of SWNTs through the functionalized linkages. The Ag nanoparticle-modified SWNTs evaluated by antibacterial tests showed strong activities against Escherichia coli and Staphylococcus aureus.

Characterization of amorphous hydrogenated carbon formed by low-pressure inductively coupled plasma enhanced chemical vapor deposition using multiple low-inductance antenna units.

Three-dimensional plasma enhanced chemical vapor deposition (CVD) of hydrogenated amorphous carbon (a-C:H) has been demonstrated using a new type high-density volumetric plasma source with multiple low-inductance antenna system. The plasma density in the volume of phi 200 mm x 100 mm is 5.1 x 10(10) cm(-3) within +/-5% in the lateral directions and 5.

Photochemical modification of diamond films: introduction of perfluorooctyl functional groups on their surface.

Photolysis of perfluoroazooctane with diamond films led the chemical modification of the surface to introduce perfluorooctyl functional groups, confirmed by means of Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and time-of-flight secondary ion mass spectrometry measurements. Diamond films modified with fluorine moieties showed improved frictional property and reduction of surface energy, as evaluated by contact angle to water, compared with a pristine diamond film. The contact angle and friction coefficient of chemically modified diamond film are 118 degrees and 0.

Chemical modification of diamond powder using photolysis of perfluoroazooctane.

Photolysis of perfluoroazooctane with diamond powders led to chemical modification of the surface with the introduction of perfluorooctyl ester and ether functional groups, the presence of which was confirmed by means of FT-IR, XPS and 19F NMR measurements.