Attenuation, dispersion and nonlinearity effects in graphene-based waveguides

• Almir Wirth Lima Jr.,
• João Cesar Moura Mota and
• Antonio Sergio Bezerra Sombra

Beilstein J. Nanotechnol. 2015, 6, 1221–1228, doi:10.3762/bjnano.6.125

• (t) of the graphene nanoribbon, given as [15][16]: In a graphene nanoribbon embedded in a substrate with relative permittivity εr, the TM modes are dominant. Considering the nonretarded regime (q >> ω/c, where c is the speed of light in air), the equation for the dispersion relation for graphene

Graphene quantum interference photodetector

• Mahbub Alam and
• Paul L. Voss

Beilstein J. Nanotechnol. 2015, 6, 726–735, doi:10.3762/bjnano.6.74

• volume of V, c is the speed of light, εr is the relative permittivity, μr is the relative permeability and ε is the absolute permittivity. The photon scattering functions, and , are calculated assuming monochromatic light and two energy levels for excitation. Both the acoustic phonon and optical phonon

Kelvin probe force microscopy of nanocrystalline TiO₂ photoelectrodes

• Alex Henning,
• Gino Günzburger,
• Res Jöhr,
• Yossi Rosenwaks,
• Biljana Bozic-Weber,
• Catherine E. Housecroft,
• Edwin C. Constable,
• Ernst Meyer and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2013, 4, 418–428, doi:10.3762/bjnano.4.49

• surface and bulk defect states. TiO2 is regarded as an insulator with a relative permittivity of εr = 36 and consequently acts as a charge storage capacitor between a metallic tip and a highly conductive SnO2:F contact. Upon photoelectric charge injection, the redistribution of charge carriers (by

Influence of diffusion on space-charge-limited current measurements in organic semiconductors

• Thomas Kirchartz

Beilstein J. Nanotechnol. 2013, 4, 180–188, doi:10.3762/bjnano.4.18

• Mott–Gurney law [18][19] Here ε0 is the vacuum permittivity and εr is the relative permittivity. The Mott–Gurney law is frequently used to determine the mobility of organic semiconductors used for light emitting diodes and solar cells. However, its derivation uses three assumptions that are often not

• simulations except for the one with Vbi = 1 V in Figure 2, where the contact barrier at the cathode (x = d) is 0.1 eV and the contact barrier at the anode (x = 0) is 1.1 eV. The relative permittivity used in all simulations is εr = 3.8 and the capture coefficient for the Gaussian defect is 10−10 cm3·s−1 for

Schottky junction/ohmic contact behavior of a nanoporous TiO₂ thin film photoanode in contact with redox electrolyte solutions

• Masao Kaneko,
• Hirohito Ueno and
• Junichi Nemoto

Beilstein J. Nanotechnol. 2011, 2, 127–134, doi:10.3762/bjnano.2.15

• Equation 2, the flat band potential Efb, carrier density N, and the thickness of space charge layer dsc were calculated and are shown in Table 1. For the calculation, since the relative permittivity ε of TiO2 is anisotropic (85.8 and 170), we used both the values in the calculation, and thereafter took

• photoelectrochemistry, the nanostructured TiO2 also forms a Schottky junction in the redox electrolyte solution generating photocurrents. For a Schottky junction semiconductor, the Mott–Schottky relation (Equation 1) is obtained [4], where Csc is the capacitance of the space charge layer [F·m−2], ε the relative

• permittivity (ε of TiO2 = 85.8 and 170, anisotropic), ε0 the vacuum permittivity (8.854 × 10−12 F·m−1), q the elementary electric charge (1.602 × 10−19 C), N the carrier density [m−3], E the applied potential [V], Efb the flat band potential [V], kB the Boltzman constant (1.380 × 10−23 J·K−1), and T the

Defects in oxide surfaces studied by atomic force and scanning tunneling microscopy

• Thomas König,
• Georg H. Simon,
• Lars Heinke,
• Leonid Lichtenstein and
• Markus Heyde

Beilstein J. Nanotechnol. 2011, 2, 1–14, doi:10.3762/bjnano.2.1

• relative permittivity or dielectric constant of the medium and z the distance between the charges. The Coulomb force FCoulomb is given by It is well known [12] that for very small amplitudes, the shift of the resonance frequency Δf corresponds to the derivative of the tip-sample forces with respect to z