Large-Scale Synthesis of Semiconducting Cu(In,Ga)Se Nanoparticles for Screen Printing Application.

During the last few decades, the interest over chalcopyrite and related photovoltaics has been growing due the outstanding structural and electrical properties of the thin-film Cu(In,Ga)Se photoabsorber. More recently, thin film deposition through solution processing has gained increasing attention from the industry, due to the potential low-cost and high-throughput production. To this end, the elimination of the selenization procedure in the synthesis of Cu(In,Ga)Se nanoparticles with following dispersion into ink formulations for printing/coating deposition processes are of high relevance.

Scalable colloidal synthesis of BiTeSe plate-like particles give access to a high-performing n-type thermoelectric material for low temperature application.

Colloidal synthesis is harnessed for the gram-scale preparation of hexagonal-shaped plate-like BiTeSe particles, yielding nearly 5 g of the product in one experiment. The resultant textured particles are highly crystalline, phase-pure, chemically uniform, and can serve as a starting material for the preparation of bulk thermoelectrics for room temperature applications. The consolidation occurs spark plasma sintering, which affords nanostructured n-type BiTeSe material exhibiting a high figure of merit ≈ 1 at 373 K with an average ≈ 0.

Self-assembly of bis-salphen compounds: from semiflexible chains to webs of nanorings.

The recently-observed self-assembly of certain salphen-based compounds into neuron-like networks of microrings interconnected with nano-thin strings may suggest a new highly-potent tool for nanoscale patterning. However, the mechanism behind such phenomena needs to be clarified before they can be applied in materials design. Here we show that, in contrast with what was initially presumed, the emergence of a "rings-and-rods" pattern is unlikely to be explained by merging, collapse and piercing of vesicles as in previously reported cases of nanorings self-assembly via non-bonding interactions.

Nanorings and rods interconnected by self-assembly mimicking an artificial network of neurons.

Molecular electronics based on structures ordered as neural networks emerges as the next evolutionary milestone in the construction of nanodevices with unprecedented applications. However, the straightforward formation of geometrically defined and interconnected nanostructures is crucial for the production of electronic circuitry nanoequivalents. Here we report on the molecularly fine-tuned self-assembly of tetrakis-Schiff base compounds into nanosized rings interconnected by unusually large nanorods providing a set of connections that mimic a biological network of neurons.

Modelling the effect of contact formation on electron transfer in single-molecule device.

The electric properties of single-molecule devices are very sensitive to details of contact formation between the molecule and the metallic electrodes. However the factors that control the electron transfer through the molecule in these devices, corresponding to slightly different molecule-metal attachments, are not well understood. In this work, we used a self-consistent molecular dynamics method to study the effect of symmetric and asymmetric contact realizations on electron transfer between two metallic electrodes through a spatially symmetric conjugated molecule.

Modelling the effects of molecular arrangements in polymer light-emitting diodes.

In order to understand how to enhance the performance of polymer light-emitting diodes (PLEDs), we used a mesoscopic hopping model, taking into account molecular properties and polymer morphology, to investigate the impact of a number of conjugated polymers and molecular arrangements on the functioning of single-layer devices. The model is applied to devices with the active polymer consisting of poly(p-phenylene vinylene) (PPV) and PPV derivatives with stiff conjugated segments having their long axis oriented parallel and perpendicular to the electrode surfaces as well as randomly oriented, which are three of the molecular arrangements that can be obtained experimentally at microscopic scale in solution-processed conjugated polymer thin films. The model provides insight into current efficiency, charge distribution, internal electric field and consequently recombination throughout the polymer layer.