Effect of fluorination on the molecule–substrate interactions of pentacene/Cu(1 0 0) interfaces

4 páginas, 3 figuras.-- et al.-- El pdf es la versión post-print del artículo.By means of scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS) and nearedge X-ray absorption fine structure (NEXAFS), we study and compare the crystalline and electronic structure of fluorinated and non-fluorinated pentacene fims on Cu(1 0 0). Pentacene perfluorination strongly affects its electronic structure both in the bulk and at the metal–organic interface. While the azimuthal anisotropy of the molecule–substrate interactions on Cu(1 0 0) remains unaffected by the fluorination, the interaction mechanisms, as concluded from their effect on the core-levels and on the conduction band of the respective molecules, show a completely disparate behaviour.Peer reviewe

Mn5Ge3C0.6/Ge(111) Schottky contacts tuned by a n-type ultra-shallow doping layer

International audienceMn 5 Ge 3 Cxcompound is of great interest for spintronics applications. 10 The various parameters of Au/Mn 5 Ge 3 C 0.6 /Ge(111) and Au/Mn 5 Ge 3 C 0.6 /δ-doped Ge(111) Schottky diodes were measured in the temperature range of 30-300 K by using current-voltage and capacitance-voltage techniques. The Schottky barrier heights and ideality factors were found to be temperature dependent. These anomaly behaviours were explained by Schottky barriers inhomogeneities 15 and interpreted by means of Gaussian distributions model of the Schottky barrier heights. Following this approach we show that the Mn 5 Ge 3 C 0.6 /Ge contact is described with a single Gaussian distribution and a conduction mechanism mainly based on the thermoionic emission. On the other hand the Mn 5 Ge 3 C 0.6 /δ-doped Ge contact is depicted with two Gaussian distributions according to the 20 temperature and a thermionic-field emission process. The differences between the two types of contacts are discussed according to the distinctive features of the growth of heavily doped germanium thin films

Individually separated supramolecular polymer chains toward solution-processable supramolecular polymeric materials

Herein, we present a simple design concept for a monomer that affords individually separated supramolecular polymer chains. Random introduction of alkyl chains with different lengths onto a monomer prevented its supramolecular polymers from bundling, permitting the preparation of concentrated solutions of the supramolecular polymer without gelation, precipitation, or crystallization. With such a solution in hand, we succeeded in fabricating self-standing films and threads consisting of supramolecular polymers

Arbitrary cross-section SEM-cathodoluminescence imaging of growth sectors and local carrier concentrations within micro-sampled semiconductor nanorods

Future one-dimensional electronics require single-crystalline semiconductor free-standing nanorods grown with uniform electrical properties. However, this is currently unrealistic as each crystallographic plane of a nanorod grows at unique incorporation rates of environmental dopants, which forms axial and lateral growth sectors with different carrier concentrations. Here we propose a series of techniques that micro-sample a free-standing nanorod of interest, fabricate its arbitrary cross-sections by controlling focused ion beam incidence orientation, and visualize its internal carrier concentration map. ZnO nanorods are grown by selective area homoepitaxy in precursor aqueous solution, each of which has a (0001):+c top-plane and six {1–100}:m side-planes. Near-band-edge cathodoluminescence nanospectroscopy evaluates carrier concentration map within a nanorod at high spatial resolution (60 nm) and high sensitivity. It also visualizes +c and m growth sectors at arbitrary nanorod cross-section and history of local transient growth events within each growth sector. Our technique paves the way for well-defined bottom-up nanoelectronics