The Valuation of Callable Russian Options for Double Exponential Jump Diffusion Processes (Financial Modeling and Analysis)

There is a strong interest to attach nanoparticles noncovalently to one-dimensional systems like boron nitride nanotubes to form composites. The combination of those materials might be used for catalysis, in solar cells, or for water splitting. Additionally, the fundamental aspect of charge transfer between the components can be studied in such systems. We report on the synthesis and characterization of nanocomposites based on semiconductor nanoparticles attached directly and noncovalently to boron nitride nanotubes. Boron nitride nanotubes were simply integrated into the colloidal synthesis of the corresponding nanoparticles. With PbSe, CdSe, and ZnO nanoparticles, a wide range of semiconductor band gaps from the near-infrared to the ultraviolet range was covered. A high surface coverage of the boron nitride nanotubes with these semiconducting nanoparticles was achieved, while it was found that a similar <i>in situ</i> approach with metallic nanoparticles does not lead to proper attachment. In addition, possible models for the underlying attachment mechanisms of all investigated nanoparticles are presented. To emphasize the new possibilities that boron nitride nanotubes offer as a support material for semiconductor nanoparticles, we investigated the fluorescence of BN-CdSe composites. In contrast to CdSe nanoparticles attached to carbon nanotubes, where the fluorescence is quenched, particles attached to boron nitride nanotubes remain fluorescent. With our versatile approaches, we expand the library of BN-nanoparticle composites that present an interesting, electronically noninteracting complement to the widely applied carbon nanotube-nanoparticle composite materials

Synthesis and Characterization of Monodisperse Metallodielectric SiO₂@Pt@SiO₂ Core–Shell–Shell Particles

Metallodielectric nanostructured core–shell–shell particles are particularly desirable for enabling novel types of optical components, including narrow-band absorbers, narrow-band photodetectors, and thermal emitters, as well as new types of sensors and catalysts. Here, we present a facile approach for the preparation of submicron SiO₂@Pt@SiO₂ core–shell–shell particles. As shown by transmission and scanning electron microscopy, the first steps of this approach allow for the deposition of closed and almost perfectly smooth platinum shells onto silica cores via a seeded growth mechanism. By choosing appropriate conditions, the shell thickness could be adjusted precisely, ranging from ∼3 to ∼32 nm. As determined by X-ray diffraction, the crystalline domain sizes of the polycrystalline metal shells were ∼4 nm, regardless of the shell thickness. The platinum content of the particles was determined by atomic absorption spectroscopy and for thin shells consistent with a dense metal layer of the TEM-measured thickness. In addition, we show that the roughness of the platinum shell strongly depends on the storage time of the gold seeds used to initiate reductive platinum deposition. Further, using polyvinylpyrrolidone as adhesion layer, it was possible to coat the metallic shells with very homogeneous and smooth insulating silica shells of well-controlled thicknesses between ∼2 and ∼43 nm. After depositing the particles onto silicon substrates equipped with interdigitated electrode structures, the metallic character of the SiO₂@Pt particles and the insulating character of the SiO₂ shells of the SiO₂@Pt@SiO₂ particles were successfully demonstrated by charge transport measurements at variable temperatures