Al2O3 doped Ba0.5Sr0.5TiO3 ~BST! thin films, with different Al2O3 contents, were deposited on ~100! LaAlO3 substrates by the pulsed laser deposition technique to develop agile thin films for tunable microwave device applications. The dielectric properties of Al2O3 doped BST films were determined with a nondestructive dual resonator near 7.7 GHz. We demonstrated that the Al2O3 doping plays a sig...

We investigated the dielectric relaxation process in high-dielectric constant polymer composite films filled with barium titanate particles. In order to extend the dielectric measurements to the microwave range, we employed a new broadband measurement technique where a thin film capacitance terminating a coaxial waveguide is treated as a transmission line. The complex permittivity, measured at ...

We report on the electrical in-situ characterisation of organic thin film transistors under high vacuum conditions. Model devices in a bottom-gate/bottom-contact (coplanar) configuration are electrically characterised in-situ, monolayer by monolayer (ML), while the organic semiconductor (OSC) is evaporated by organic molecular beam epitaxy (OMBE). Thermal SiO2 with an optional polymer interface...

Superhydrophobic polymethylene (PM) films provide remarkable protection against the transport of aqueous redox probes as a result of entrapped air at the water/polymer interface. The wetting properties and the topography for a set of superhydrophobic (SH) and nonsuperhydrophobic (NSH) PM films were established to compare their interfacial behavior using electrochemical impedance spectroscopy (E...

Thin film transistor circuits using organic semiconductors (oTFT) have received intense interest for applications requiring structural flexibility, large area coverage, low temperature processing, and low-cost [1]. Pentacene TFTs have demonstrated the highest performance among TFTs with an organic semiconductor channel. A major limitation, however, has been unusually high operating voltages (20...

The definition for dielectric constant relates to the permittivity of the material (symbol use here ε). The permittivity expresses the ability of a material to polarise in response to an applied field. It is the ratio of the permittivity of the dielectric to the permittivity of a vacuum. Physically it means the greater the polarisation developed by a material in an applied field of given streng...

The nonlinear one-dimensional model of controllable photonic crystals is considered. A photonic crystal is formed in a dielectric film on which the electromagnetic pump and signal waves fall. It is shown that the shape of the superlattice is controlled by the variation of the external electrostatic field imposed on the film. Thus it leads to changing boundaries of the allowed and forbidden zone...

We study the effective third-order nonlinear susceptibility of a graded metal–dielectric composite film of anisotropic particles with weak nonlinearity by invoking the local field effects within the Maxwell–Garnett theory. We further numerically demonstrate that the film can serve as a novel optical material to produce a broad structure in both the linear and the nonlinear response and an enhan...

We demonstrate a controllable viewing angle liquid crystal display (LCD) using an inserted blue-phase liquid crystal (BPLC) cell. The BPLC layer functions as a tunable positive C-film or a negative C-film, depending on whether the employed LC has a positive or negative dielectric anisotropy. Therefore, the viewing angle of the LCD panel can be controlled continuously by the applied voltage of t...

The propagation of laser-excited surface plasmons along a gold film with surface roughness is directly observed via scattered light. The attenuation length of surface plasmons in a broad wavelength interval is calculated for smooth gold and silver films. The surface roughness, which was characterized with an AFM, introduces corrections to the attenuation length, angular dependence of the surfac...