Interfacial complexation driven three-dimensional assembly of cationic phosphorus dendrimers and graphene oxide sheets.

High content nitrogen, sulfur and phosphorus heteroatoms assembled in tree-like dendrimers (DG ) are confined within the galleries of two-dimensional graphene oxide (GO). The presence of the ternary diethyl--ethyl-ammonium groups on the dendrimer peripheries ensures the exfoliation of graphene sheets thereby affording interfacially bridged, three-dimensional heteroatom-enriched graphene-based hybrid nanostructures (DG -GO). Dendrimer generation (from 1 to 4) that reflects the bulkiness of these conceived nano-trees impacts increasingly the degree of dispersion-exfoliation and sheet desordering.

A novel 2-step ALD route to ultra-thin MoS films on SiO through a surface organometallic intermediate.

The lack of scalable-methods for the growth of 2D MoS crystals, an identified emerging material with applications ranging from electronics to energy storage, is a current bottleneck against its large-scale deployment. We report here a two-step ALD route with new organometallic precursors, Mo(NMe) and 1,2-ethanedithiol (HS(CH)SH) which consists in the layer-by-layer deposition of an amorphous surface Mo(iv) thiolate at 50 °C, followed by a subsequent annealing at higher temperature leading to ultra-thin MoS nanocrystals (∼20 nm-large) in the 1-2 monolayer range. In contrast to the usual high-temperature growth of 2D dichalcogenides, where nucleation is the key parameter to control both thickness and uniformity, our novel two-step ALD approach enables chemical control over these two parameters, the growth of 2D MoS crystals upon annealing being ensured by spatial confinement and facilitated by the formation of a buffer oxysulfide interlayer.

Evidence for Charge Transfer at the Interface between Hybrid Phosphomolybdate and Epitaxial Graphene.

The interfacing of polyoxometalates and graphene can be considered to be an innovative way to generate hybrid structures that take advantage of the properties of both components. Polyoxometalates are redox-sensitive and photosensitive compounds with high temperature stability (up to 400 °C for some), showing tunable properties depending on the metal incorporated inside the complex. Graphene has a unique electronic band structure combined with good material properties for electrical and optical applications.

Doping characteristics of iodine on as-grown chemical vapor deposited graphene on Pt.

Using laboratory X-ray photoelectron emission microscopy (XPEEM), we investigated the doping efficiency and thermal stability of iodine on as-grown graphene on Pt. After iodine adsorption of graphene in saturated vapor of I2, monolayer and bilayer graphene exhibited work function of 4.93 eV and 4.

Catalyst preparation for CMOS-compatible silicon nanowire synthesis.

Metallic contamination was key to the discovery of semiconductor nanowires, but today it stands in the way of their adoption by the semiconductor industry. This is because many of the metallic catalysts required for nanowire growth are not compatible with standard CMOS (complementary metal oxide semiconductor) fabrication processes. Nanowire synthesis with those metals that are CMOS compatible, such as aluminium and copper, necessitate temperatures higher than 450 degrees C, which is the maximum temperature allowed in CMOS processing.