A visible-light and infrared video database for performance evaluation of video/image fusion methods

Multidimensional Systems and Signal Processing - In general, the fusion of visible-light and infrared images produces a composite representation where both data are pictured in a single image. The...     

Inverted Organic Solar Cells with Sol–Gel Processed High Work‐Function Vanadium Oxide Hole‐Extraction Layers

For large‐scale and high‐throughput production of organic solar cells (OSCs), liquid processing of the functional layers is desired. We demonstrate inverted bulk‐heterojunction organic solar cells (OSCs) with a sol–gel derived V₂O₅ hole‐extraction‐layer on top of the active organic layer. The V₂O₅ layers are prepared in ambient air using Vanadium(V)‐oxitriisopropoxide as precursor. Without any post‐annealing or plasma treatment, a high work function of the V₂O₅ layers is confirmed by both Kelvin probe analysis and ultraviolet photoelectron spectroscopy (UPS). Using UPS and inverse photoelectron spectroscopy (IPES), we show that the electronic structure of the solution processed V₂O₅ layers is similar to that of thermally evaporated V₂O₅ layers which have been exposed to ambient air. Optimization of the sol gel process leads to inverted OSCs with solution based V₂O₅ layers that show power conversion efficiencies similar to that of control devices with V₂O₅ layers prepared in high‐vacuum.     

Parlay‐based service provision in circuit‐ and packet‐switched telecommunications networks

The spectrum of potential value added services over Internet telephony is wide, but the current service provision solutions are inadequate or proprietary. The nature of Internet differs significantly from that of circuit switched network, however, VoIP architectures can capitalize service control architectures in the PSTN world. We describe such an architecture based on the intelligent network and the Parlay, employing distributed objects and mobile agents as enabling technologies. This architecture has been implemented in the PSTN and the Internet and it has provided a framework for service provisioning, augmenting the space of supported services. Copyright © 2004 John Wiley & Sons, Ltd.     

Dual-Color InAs/GaSb Superlattice Focal-Plane Array Technology

Within a very few years, InAs/GaSb superlattice technology has proven its suitability for high-performance infrared imaging detector arrays. At the Fraunhofer Institute for Applied Solid State Physics (IAF) and AIM Infrarot-Module GmbH, efforts have been focused on developing mature fabrication technology for dual-color InAs/GaSb superlattice focal-plane arrays for simultaneous, colocated detection at 3 μm to 4 μm and 4 μm to 5 μm in the mid-wavelength infrared atmospheric transmission window. Integrated into a wide-field-of-view missile approach warning system for an airborne platform, a very low number of pixel outages and cluster defects is mandatory for bispectral detector arrays. Process refinements, intense root-cause analysis, and specific test methodologies employed at various stages during the process have proven to be the key for yield enhancements.     

Nanoimprint Lithography Facilitated Plasmonic-Photonic Coupling for Enhanced Photoconductivity and Photocatalysis

Imprint lithography has emerged as a reliable, reproducible, and rapid method for patterning colloidal nanostructures. As a promising alternative to top-down lithographic approaches, the fabrication of nanodevices has thus become effective and straightforward. In this study, a fusion of interference lithography (IL) and nanosphere imprint lithography on various target substrates ranging from carbon film on transmission electron microscope grid to inorganic and dopable polymer semiconductor is reported. 1D plasmonic photonic crystals are printed with 75% yield on the centimeter scale using colloidal ink and an IL-produced polydimethylsiloxane stamp. Atomically smooth facet, single-crystalline, and monodisperse colloidal building blocks of gold (Au) nanoparticles are used to print 1D plasmonic grating on top of a titanium dioxide (TiO₂) slab waveguide, producing waveguide-plasmon polariton modes with superior 10 nm spectral line-width. Plasmon-induced hot electrons are confirmed via two-terminal current measurements with increased photoresponsivity under guiding conditions. The fabricated hybrid structure with Au/TiO₂ heterojunction enhances photocatalytic processes like degradation of methyl orange (MO) dye molecules using the generated hot electrons. This simple colloidal printing technique demonstrated on silicon, glass, Au film, and naphthalenediimide polymer thus marks an important milestone for large-scale implementation in optoelectronic devices.     

Interfacial reactions between a Pb-Free solder and die backside metallizations

The interfacial reactions between Sn-3.0 Ag-0.7 Cu solder and backside metallizations on two semiconductor devices, field-effect transistors (FET) and diode, are studied. The metallizations on both devices were vacuum evaporated Ti/Ni/Ag. The intermetallic compounds (IMC) formed near the diode/solder and FET/solder joints during reflow, and the interdiffusion processes during solid state aging are characterized by the quantitative energy dispersive x-ray analysis and the x-ray mapping technique in a scanning electron microscope. Two different intermetallic compounds are found near the diode/solder interface. Both are in the form of particles, not a continuous layer, and are referred to as IMC-I and IMC-II. IMC-I corresponds to Ni₃Sn₄, with Cu atoms residing on the Ni sublattice. It is uncertain whether IMC-II is Cu₆Sn₅ or a Cu-Ni-Sn ternary phase. Near the as-reflowed FET/solder interface, both isolated scallops and a skeleton-like layer of Ni₃Sn₄ are observed. The primary microstructural dynamics during solid-state aging are the coarsening of IMCs and the reactions involving the Ni-and Ti-layer with Sn and Au. While the reaction with the Ni-layer yields only Ni₃Sn₄ intermetallic, the reaction involving the Ti-layer suggests the formation of Ti-Sn and Au-Sn-Ti intermetallics. The latter is due to the diffusion of Au from the substrate side to the die side. It is postulated that the kinetics of the Au-Sn-Ti layer is primarily governed by the diffusion of Au through the Ni₃Sn₄ layer by a grain boundary mechanism.     

SIVA: A System for Coverage-Directed State Space Search

We introduce SImulation Verification with Augmentation (SIVA), a tool for coverage-directed state space search on digital hardware designs. SIVA tightly integrates simulation with symbolic techniques for efficient state space search. Specifically, the core algorithm uses a combination of ATPG and BDDs to generate directed input vectors, i.e., inputs which cover behavior not excited by simulation. We also present approaches to automatically generate lighthouses that guide the search towards hard-to-reach coverage goals. Experiments demonstrate that our approach is capable of achieving significantly greater coverage than either simulation or symbolic techniques in isolation.     

Optical Interconnects on and in Printed Circuit Boards

Two types of short distance optical interconnects for on-board applications are presented: Small diameter plastic optical fibre (POF) links and multimode polymer waveguide layers integrated in multilayer printed circuit boards (PCB). POF links with fibre numbers up to 128 and link lengths up to 50 cm are realized with total transmission loss values below 2 dB at 660 nm. First tests of 10 cm long temperature stable multimode polymer waveguides laminated into standard multilayer PCBs demonstrate the capabilities of combined electrical-optical circuit boards.