UV-assisted modification and removal mechanism of a fluorocarbon polymer film on low-k dielectric trench structure.

In this study, we report the first chemical characterization of a plasma-deposited model fluoropolymer on low-k dielectric nanostructure and its decomposition in UV/O2 conditions. Carbonyl incorporation and progressive removal of fluorocarbon fragments from the polymer were observed with increasing UV (≥230 nm) irradiation under atmospheric conditions. A significant material loss was achieved after 300 s of UV treatment and a subsequent wet clean completely removed the initially insoluble fluoropolymer from the patterned nanostructures.

Templated electrodeposition and photocatalytic activity of cuprous oxide nanorod arrays.

Cuprous oxide (Cu2O) nanorod arrays have been prepared via a novel templated electrodeposition process and were characterized for their photocatalytic behavior in nonaqueous photoelectrochemical cells. Zinc oxide (ZnO) nanorod films serve as sacrificial templates for the in situ formation of polymer nanopore membranes on transparent conductive oxide substrates. Nitrocellulose and poly(lactic acid) are effective membrane-forming polymers that exhibit different modes of template formation, with nitrocellulose forming conformal coatings on the ZnO surface while poly(lactic acid) acts as an amorphous pore-filling material.

Solid-state photogalvanic dye-sensitized solar cells.

Photogalvanic cells are photoelectrochemical systems wherein the semiconductor electrode is not a participant in primary photoinduced charge formation. The discovery of photoelectrochemical systems that successfully exploit secondary (thermal) electron injection at dye-semiconductor interfaces may enable studies of electron transfer at minimal driving force for electron injection into the semiconductor. In this study, we have examined thermal electron transfer from molecular sensitizers to nanostructured semiconductor electrodes composed of titanium dioxide nanorods by means of transient spectroscopy and the assembly and testing of photoelectrochemical cells.

Optoelectronic tuning of organoborylazadipyrromethenes via effective electronegativity at the metalloid center.

Organoborylazadipyrromethenes were synthesized from free base and fluoroborylazadipyrromethenes and characterized with regard to their structural and electronic properties. B-N bond lengths, along with photophysical and redox behavior, appear dependent on the effective electronegativity at the boron atom as tuned by its substituents, with stronger electronegativity correlating to a shorter B-N bond length, red-shifted absorbance, enhanced fluorescence lifetime and yield, and positively shifted redox potentials.

Influence of seeding and bath conditions in hydrothermal growth of very thin (∼20 nm) single-crystalline rutile TiO₂ nanorod films.

New seeding conditions have been examined for the hydrothermal growth of single-crystalline rutile TiO₂ nanorods. Rutile nanorods of ∼20 nm diameter are grown from seed layers consisting of either (A) TiO₂ or MnOOH nanocrystals deposited from suspension, or (B) a continuous sheet of TiO₂. These seed layers are more effective for seeding the growth of rutile nanorods compared to the use of bare F-SnO₂ substrates.