We report the first experimental demonstration of an electrostatic electron orbital angular momentum (OAM) sorter, which can be used to analyze the OAM states of electrons in a transmission electron microscope. We verify the sorter functionality for several electron beams possessing different superpositions of OAM states, and use it to record the electron beams OAM spectra. Our current electrostatic OAM sorter has an OAM resolution of 2 in the units of ℏ -the reduced Planck constant. It is expected to increase the OAM resolution of the sorter to the optimal resolution of 1 in the future via fine control of the sorting phase elements.

The growth of 3C-SiC on (001) silicon substrates by means of vapor phase epitaxy is described. The growth mechanisms are discussed with the aid of structural and morphological characterizations performed by X-ray diffraction, transmission electron microscopy, and atomic force microscopy. Raman spectroscopy was used to study the residual stress. A large shift of Raman peaks with respect to the expected values for the bulk is observed and explained by the relaxation of Raman selection rules due to lattice defects. The stress and stress gradients through the film thickness are observed and studied on micrometer-sized structures such as membranes and cantilevers. Local Raman peak fluctuations are observed on millimeter-sized membranes, while cantilevers show different degrees of curling depending on film thickness.

In previous publications it was shown that the precipitation of silicon boride around grain boundaries may lead to an increase of the power factor in nanocrystalline silicon. Such an effect was further explained by computational analyses showing that the formation of an interphase at the grain boundaries along with high boron densities can actually lead to a concurrent increase of the electrical conductivity σ and of the Seebeck coefficient S. In this communication we report recent evidence of the key elements ruling such an unexpected effect. Nanocrystalline silicon films deposited onto a variety of substrates were doped to nominal boron densities in excess of 1020cm-3 and were annealed up to 1000°C to promote boride precipitation. Thermoelectric properties were measured and compared with their microstructure. A concurrent increase of σ and S with the carrier density was found only upon formation of an interphase. Its dependency on the film microstructure and on the deposition and processing conditions will be discussed

Micro and nanotechnologies are called to play a key role in the fabrication of small and low cost sensors with excellent performance enabling new continuous monitoring scenarios and distributed intelligence paradigms (Internet of Things, Trillion Sensors). Harvesting devices providing energy autonomy to those large numbers of microsensors will be essential. In those scenarios where waste heat sources are present, thermoelectricity will be the obvious choice. However, miniaturization of state of the art thermoelectric modules is not easy with the current technologies used for their fabrication. Micro and nanotechnologies offer an interesting alternative considering that silicon in nanowire form is a material with a promising thermoelectric figure of merit. This paper presents two approaches for the integration of large numbers of silicon nanowires in a cost-effective and practical way using only micromachining and thin-film processes compatible with silicon technologies. Both approaches lead to automated physical and electrical integration of medium-high density stacked arrays of crystalline or polycrystalline silicon nanowires with arbitrary length (tens to hundreds microns) and diameters below 100 nm.

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