Vibrational properties of metastable orthorhombic BiSe.

Chalcogenide materials are being considered as some of the most promising systems for energy harvesting and energy conversion. Among them, the orthorhombic family of compounds XY (with X = Bi, Sb and Y = S, Se) has attracted special attention due to its interesting atomic structure and thermoelectric and optical properties. While BiS and SbSe have already been applied to solar cells, practical application of the new metastable BiSe is still a challenge due to the lack of data and knowledge on its properties.

On-chip microfluidic buffer swap of biological samples in-line with downstream dielectrophoresis.

Microfluidic cell enrichment by dielectrophoresis, based on biophysical and electrophysiology phenotypes, requires that cells be resuspended from their physiological media into a lower conductivity buffer for enhancing force fields and enabling the dielectric contrast needed for separation. To ensure that sensitive cells are not subject to centrifugation for resuspension and spend minimal time outside of their culture media, we present an on-chip microfluidic strategy for swapping cells into media tailored for dielectrophoresis. This strategy transfers cells from physiological media into a 100-fold lower conductivity media by using tangential flows of low media conductivity at 200-fold higher flow rate versus sample flow to promote ion diffusion over the length of a straight channel architecture that maintains laminarity of the flow-focused sample and minimizes cell dispersion across streamlines.

Self-aligned sequential lateral field non-uniformities over channel depth for high throughput dielectrophoretic cell deflection.

Dielectrophoresis (DEP) enables the separation of cells based on subtle subcellular phenotypic differences by controlling the frequency of the applied field. However, current electrode-based geometries extend over a limited depth of the sample channel, thereby reducing the throughput of the manipulated sample (sub-μL min-1 flow rates and <105 cells per mL). We present a flow through device with self-aligned sequential field non-uniformities extending laterally across the sample channel width (100 μm) that are created by metal patterned over the entire depth (50 μm) of the sample channel sidewall using a single lithography step.

Photoelectrochemistry of Self-Limiting Electrodeposition of Ni Film onto GaAs.

Gallium arsenide (GaAs) provides a suitable bandgap (1.43 eV) for solar spectrum absorption and allows a larger photovoltage compared to silicon, suggesting great potential as a photoanode toward water splitting. Photocorrosion under water oxidation condition, however, leads to decomposition or the formation of an insulating oxide layer, which limits the photoelectrochemical performance and stability of GaAs.

Bias-dependent effects in planar perovskite solar cells based on CH3NH3PbI(3-x)Clx films.

A unique bias-dependent phenomenon in CH3NH3PbI(3-x)Cl(x) based planar perovskite solar cells has been demonstrated, in which the photovoltaic parameters derived from the current-voltage (I-V) curves are highly dependent on the initial positive bias of the I-V measurement. In FTO/CH3NH3PbI(3-x)Cl(x)/Au devices, the open-circuit voltage and short-circuit current increased by ca. 337.