Terahertz and mid-infrared reflectance of epitaxial graphene.

Graphene has emerged as a promising material for infrared (IR) photodetectors and plasmonics. In this context, wafer scale epitaxial graphene on SiC is of great interest in a variety of applications in optics and nanoelectronics. Here we present IR reflectance spectroscopy of graphene grown epitaxially on the C-face of 6H-SiC over a broad optical range, from terahertz (THz) to mid-infrared (MIR).

Liquid-induced colour change in a beetle: the concept of a photonic cell.

The structural colour of male Hoplia coerulea beetles is notable for changing from blue to green upon contact with water. In fact, reversible changes in both colour and fluorescence are induced in this beetle by various liquids, although the mechanism has never been fully explained. Changes enacted by water are much faster than those by ethanol, in spite of ethanol's more rapid spread across the elytral surface.

High surface area zincosilicates as efficient catalysts for the synthesis of ethyl lactate: an in-depth structural investigation.

Novel Zn-MCM-41 mesoporous materials with particle diameters ranging from 20 to 120 nm were successfully prepared following a straightforward synthesis route. The structural and textural properties of the solids were characterized by N2-physisorption, X-ray diffraction, (29)Si MAS-NMR, TEM and EDX. These results allow evidencing the presence of an ordered mesoporous structure with a very high specific surface area.

Damage evaluation in graphene underlying atomic layer deposition dielectrics.

Based on micro-Raman spectroscopy (μRS) and X-ray photoelectron spectroscopy (XPS), we study the structural damage incurred in monolayer (1L) and few-layer (FL) graphene subjected to atomic-layer deposition of HfO2 and Al2O3 upon different oxygen plasma power levels. We evaluate the damage level and the influence of the HfO2 thickness on graphene. The results indicate that in the case of Al2O3/graphene, whether 1L or FL graphene is strongly damaged under our process conditions.

Single- and double-sided chemical functionalization of bilayer graphene.

An experimental study on the interaction between the top and bottom layer of a chemically functionalized graphene bilayer by mild oxygen plasma is reported. Structural, chemical, and electrical properties are monitored using Raman spectroscopy, transport measurements, conductive atomic force microscopy and X-ray photoelectron spectroscopy. Single- and double-sided chemical functionalization are found to give very different results: single-sided modified bilayers show relatively high mobility (200-600 cm(2) V(-1) s(-1) at room temperature) and a stable structure with a limited amount of defects, even after long plasma treatment (>60 s).