Confined Banach spaces

We discuss smoothness of theWeyl functional calculus and use it to prove that every C*-algebra is a confined Banach space. Received: 17 August 2005     

Invertibility in Fréchet Algebras

Using tensor products and a generalised spectrum, we extend to infinite dimensional domains classical results on the ideals generated by a finite or countable set of elements in a Fréchet algebra.     

Observation of zinc phthalocyanine aggregates on a water surface using grazing incidence X-ray scattering

Reported here are the structural properties of a zinc 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine Langmuir monolayer on a water surface under progressive lateral compression investigated by grazing incidence X-ray scattering. Grazing incidence diffuse X-ray scattering out of the specular plane (GIXOS) is exploited to determine specular reflectivity-like information where the phase change of flat-lying molecules on the surface to edge-standing molecules perpendicular to the surface is directly observed. Furthermore, grazing incident X-ray diffraction (GIXD) is used to investigate the in-plane ordering of the system where it has been found that in the high-density state (approximately 0.35 nm2 per molecule) the system can be considered to be a monolayer consisting of arrays of side-by-side lying cofacially aggregated cylindrical rodlike entities.     

Enhanced electrical percolation due to interconnection of three-dimensional pentacene islands in thin films on low surface energy polyimide gate dielectrics

The role of lateral interconnections between three-dimensional pentacene islands on low surface energy polyimide gate dielectrics was investigated by the measurement of the surface coverage dependence of the charge mobility and the use of conducting-probe atomic force microscopy (CP-AFM). From the correlation between the electrical characteristics and the morphological evolution of the three-dimensionally grown pentacene films-based field-effect transistors, we found that during film growth, the formation of interconnections between the three-dimensional pentacene islands that are isolated at the early stage contributes significantly to the enhancement process of charge mobility. The CP-AFM current mapping images of the pentacene films also indicate that the lateral interconnections play an important role in the formation of good electrical percolation pathways between the three-dimensional pentacene islands.     

High performance Zn–Sn–O thin film transistors with Cu source/drain electrode

Zn–Sn–O (ZTO) thin film transistors (TFTs) were fabricated with a Cu source/drain electrode. Although a reasonably high mobility (μ_FE) of 13.2 cm²/Vs was obtained for the ZTO TFTs, the subthreshold gate swing (SS) and threshold voltage (V_th) of 1.1 V/decade and 9.1 V, respectively, were inferior. However, ZTO TFTs with Ta film inserted as a diffusion barrier, exhibited improved SS and V_th values of 0.48 V/decade and 3.0 V, respectively as well as a high μ_FE value of 18.7 cm²/Vs. The improvement in the Ta‐inserted device was attributed to the suppression of Cu lateral diffusion into the ZTO channel region. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)