Unequal {110} Facets: The Potential Role of Intraparticle Heterogeneity and Facet Termination in Photoelectrochemical Activity of Single BiVO Particles.

BiVO photoanodes are promising for solar water splitting, with photogenerated electrons and holes preferentially reacting at top {010} and lateral {110} facets, respectively. However, the mechanisms driving this facet-dependent reactivity remain unclear. Here, we investigate facet-dependent photocurrent and material heterogeneity using correlative scanning photoelectrochemical microscopy (SPCM), electron beam induced current (EBIC) mapping, and mid-IR scattering scanning near-field optical microscopy (s-SNOM).

Patterned Adhesion Layer Enables Rugged Pd-MIS Hydrogen Sensors.

Rugged Pd-metal-insulator-semiconductor (Pd-MIS) hydrogen sensors for detecting charge-exchange particles in fusion reactors have been constructed by utilizing a novel patterned adhesion layer. Poor adhesion at the interface between Pd and SiO is a common failure mode for Pd-MIS devices, severely limiting the Pd thickness and their usefulness as hydrogen sensors. The mechanical integrity of the Pd coatings is of particular importance in magnetic fusion energy research where the Pd-MIS diodes are used to measure hydrogen charge-exchange neutral fluence at the wall in tokamaks.

Single-Particle Measurements Reveal the Origin of Low Solar-to-Hydrogen Efficiency of Rh-Doped SrTiO Photocatalysts.

Solar-powered photochemical water splitting using suspensions of photocatalyst nanoparticles is an attractive route for economical production of green hydrogen. SrTiO-based photocatalysts have been intensely investigated due to their stability and recently demonstrated near-100% external quantum yield (EQY) for water splitting using wavelengths below 360 nm. To extend the optical absorption into the visible, SrTiO nanoparticles have been doped with various transition metals.

Visualizing the Electron Wind Force in the Elastic Regime.

With continued scaling toward higher component densities, integrated circuits (ICs) contain ever greater lengths of nanowire that are vulnerable to failure via electromigration. Previously, plastic electromigration driven by the "electron wind" has been observed, but not the elastic response to the wind force itself. Here we describe mapping, via electron energy-loss spectroscopy, the density of a lithographically defined aluminum nanowire with sufficient precision to determine both its temperature and its internal pressure.

Differential electron yield imaging with STXM.

Total electron yield (TEY) imaging is an established scanning transmission X-ray microscopy (STXM) technique that gives varying contrast based on a sample's geometry, elemental composition, and electrical conductivity. However, the TEY-STXM signal is determined solely by the electrons that the beam ejects from the sample. A related technique, X-ray beam-induced current (XBIC) imaging, is sensitive to electrons and holes independently, but requires electric fields in the sample.

Electron-Transparent Thermoelectric Coolers Demonstrated with Nanoparticle and Condensation Thermometry.

More efficient thermoelectric devices would revolutionize refrigeration and energy production, and low-dimensional thermoelectric materials are predicted to be more efficient than their bulk counterparts. But nanoscale thermoelectric devices generate thermal gradients on length scales that are too small to resolve with traditional thermometry methods. Here we fabricate, using single-crystal bismuth telluride (BiTe) and antimony/bismuth telluride (SbBiTe) flakes exfoliated from commercially available bulk materials, functional thermoelectric coolers (TECs) that are only 100 nm thick.