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Discrete dipole approximation (DDA) calculations, each of a distinctive morphology, are performed to demonstrate the specific ways in which shape affects the absorption and scattering of light. The control of nanostructure shape has allowed the optimization of plasmon resonance for molecular detection and spectroscopy.

Appropriate redox-active inks and linear sweep voltametry is used to control the assembly of charged nanostructures with sub-100 nm dimensions. The orthogonal assembly of oligonucleotide functionalized nanoparticles was affected using patterned substrate as a working electrode in an electrochemical cell.

Sb2S3-sensitized mesoporous-TiO2solar cells using several conjugated polymers as hole-transporting materials (HTMs) are fabricated. We found that the cell performance was strongly correlated with the chemical interaction at the interface of Sb2S3as sensitizer and the HTMs through the thiophene moieties, which led to a higher fill factor (FF), open-circuit voltage (Voc), and short-circuit current density (Jsc). With the application of PCPDTBT (poly(2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b′]dithiophene)-alt-4,7(2,1,3-benzothiadiazole)) as a HTM in a Sb2S3-sensitized solar cell, overall power conversion efficiencies of 6.18, 6.57, and 6.53% at 100, 50, and 10% solar irradiation, respectively, were achieved with a metal mask. [ABSTRACT FROM AUTHOR]

We were able to attach CdSe quantum dots (QDs) having a ZnS inorganic glue layer directly to a mesoporous TiO2(mp-TiO2) surface by spray coating and thermal annealing. Quantum-dot-sensitized solar cells based on CdSe QDs having ZnS as the inorganic glue layer could easily transport generated charge carriers because of the intimate bonding between CdSe and mp-TiO2. The application of spray pyrolysis deposition (SPD) to obtain additional CdSe layers improved the performance characteristics to Voc= 0.45 V, Jsc= 10.7 mA/cm2, fill factor = 35.8%, and power conversion efficiency = 1.7%. Furthermore, ZnS post-treatment improved the device performance to Voc= 0.57 V, Jsc= 11.2 mA/cm2, fill factor = 35.4%, and power conversion efficiency = 2.2%. [ABSTRACT FROM AUTHOR]

Microscale fish bowls, hollow particles with engineered holes in their surfaces, were prepared using two different methods. In the first method, commercial latex beads suspended in water were swollen with a good solvent of the polymer, followed by freezing with liquid nitrogen and evaporation of the solvent below 0 °C. While one big hole was generated when the amount of solvent used for the swelling was relatively low, small holes could be produced in the outer surface of each bowl by increasing the degree of swelling. The porosity and pore structure show a similar dependence on the degree of swelling for both amorphous and semicrystalline polymers even though they are supposed to exhibit different phase behaviors during the freezing and solvent evaporation processes. In the second method, a polymer emulsion in water was prepared and then frozen with liquid nitrogen, followed by solvent evaporation below 0 °C. The porosity and pore structure could be controlled by adjusting the concentration of the polymer solution used to prepare the emulsion. As for encapsulation, the bowl-shaped particles could be transformed back into solid beads via thermal annealing at a temperature near the glass transition temperature of the polymer or by adding a good solvent of the polymer to the colloidal suspension. In a proof-of-concept experiment, microscale fish bowls were fabricated from poly(caprolactone), quickly loaded with a fluorescent dye, and sealed through thermal annealing. The encapsulated dye could then be slowly released in a phosphate buffered saline, suggesting their potential use as a new class of microscale capsules for drug delivery. [ABSTRACT FROM AUTHOR]

Silver nanostructures are containers for surface plasmons − the collective oscillation of conduction electrons in phase with incident light. By controlling the shape of the container, one can control the ways in which electrons oscillate, and in turn how the nanostructure scatters light, absorbs light, and enhances local electric fields. With a series of discrete dipole approximation (DDA) calculations, each of a distinctive morphology, we illustrate how shape control can tune the optical properties of silver nanostructures. Calculated predictions are validated by experimental measurements performed on nanocubes with controllable corner truncation, right bipyramids, and pentagonal nanowires. Control of nanostructure shape allows optimization of plasmon resonance for molecular detection and spectroscopy. [ABSTRACT FROM AUTHOR]