Identification of the paint process for steel sheet applications

Surface waviness of steel sheet is one of the key characteristics determining the final appearance after painting. To support a proper definition of the filters to be applied when defining a waviness parameter, the calculation of the transfer function of the paint process itself represents a crucial aspect. In this study an appropriate methodology is proposed in order to identify the filter characteristics of this paint process. Firstly, the approach is applied to a series of known filters and a number of explicit case studies have been explored to better understand the various mechanisms. Subsequently, the method is used for different painted samples yielding a number of interesting features. It is anticipated that these results can suggest significant improvements for a uniform methodology for the waviness assessment of steel sheet based on 2D surface profiling.     

Xetal-II: A 107 GOPS, 600 mW Massively Parallel Processor for Video Scene Analysis

Xetal-II is a single-instruction multiple-data (SIMD) processor with 320 processing elements. It delivers a peak performance of 107 GOPS on 16-bit data while dissipating 600 mW. A 10 Mbit on-chip memory is provided which can store up to four VGA frames, allowing efficient implementation of frame-iterative algorithms. A massively parallel interconnect provides an internal bandwidth of more than 1.3 Tbit/s to sustain the peak performance. The IC is realized in 90 nm CMOS and takes up 74 mm².     

Tuning the Properties of CZTS Films by Controlling the Process Parameters in Cost-Effective Non-vacuum Technique

Highly dispersive Cu₂ZnSnS₄ (CZTS) nanoparticles were successfully synthesized by a simple solvothermal route. A low cost, non-vacuum method was used to deposit CZTS nanoparticle ink on glass substrates by a doctor blade process followed by selenization in a tube furnace to form Cu₂ZnSn (S,Se)₄ (CZTSSe) layers. Different selenization conditions and particle concentrations were considered in order to improve the crystallinity and surface morphology; the annealing temperature was varied between 400°C and 550°C and the annealing time was varied between 5 min and 20 min in a selenium-nitrogen atmosphere. The influence of annealing conditions on structural, compositional, optical and electrical properties of CZTSSe thin films was studied. An improvement in the structural and surface morphology was observed with increasing of annealing temperature (up to 500°C). An enhancement in the crystallinity and surface morphology were observed for thin films annealed for 10–15 min. Absorption study revealed that the band gap energy of as-deposited CZTS thin film was approximately 1.43 eV, while for CZTSSe thin films it ranged from 1.15 eV to 1.34 eV at different annealing temperatures, and from 1.33 eV to 1.38 eV for different annealing times.     

Stokes-Anti-Stokes Iterative Resonator Method for Modeling Raman Lasers

We present a novel modeling method to describe the steady-state and transient regimes of a continuous-wave pumped Raman laser emitting both Stokes and anti-Stokes photons. Our so-called "Stokes-anti-Stokes iterative resonator method" evaluates for every half round-trip time the longitudinal distribution of the intracavity pump, Stokes and anti-Stokes fields propagating in forward and backward directions. Although this Stokes-anti-Stokes iterative resonator method is widely applicable, its most important asset resides in its ability to accurately model Raman lasers that feature cavity enhancement of the pump power and that emit both Stokes and anti-Stokes photons. Important here is that our modeling method correctly incorporates the longitudinal intracavity field distributions, the generation of anti-Stokes photons, and the interference effects between incident and intracavity pump fields, and that it describes not only the lasers' steady-state operation but also their transient characteristics. We demonstrate for both a hydrogen-based and a silicon-based Raman laser with pump cavity enhancement that the Stokes-anti-Stokes iterative resonator method performs better than the modeling methods presently used for these categories of Raman lasers. Finally, to demonstrate the potentialities of our modeling method, we numerically simulate, for the first time according to our knowledge, the anti-Stokes emission generated by a silicon-based Raman laser     

Progress on large area n‐type silicon solar cells with front laser doping and a rear emitter

We report on the progress of imec's n‐type passivated emitter, rear totally diffused rear junction silicon solar cells. Selective laser doping has been introduced in the flow, allowing the implementation of a shallow diffused front surface field and a reduction of the recombination current in the contact area. Simplifications have been implemented towards a more industrial annealing sequence, by replacing expensive forming gas annealing steps with a belt furnace annealing. By applying these improvements, together with an advanced texturing process and emitter passivation by atomic layer deposition of Al₂O₃, 22.5% efficient cells (three busbars) have been realized on commercial 156 · 156 mm² Czochralski‐Si. This result has been independently confirmed by ISE CalLab. Copyright © 2016 John Wiley & Sons, Ltd.     

Shallow and Undoped Germanium Quantum Wells: A Playground for Spin and Hybrid Quantum Technology

Buried‐channel semiconductor heterostructures are an archetype material platform for the fabrication of gated semiconductor quantum devices. Sharp confinement potential is obtained by positioning the channel near the surface; however, nearby surface states degrade the electrical properties of the starting material. Here, a 2D hole gas of high mobility (5 × 10⁵ cm² V^?1 s^?1) is demonstrated in a very shallow strained germanium (Ge) channel, which is located only 22 nm below the surface. The top‐gate of a dopant‐less field effect transistor controls the channel carrier density confined in an undoped Ge/SiGe heterostructure with reduced background contamination, sharp interfaces, and high uniformity. The high mobility leads to mean free paths ≈ 6 µm, setting new benchmarks for holes in shallow field effect transistors. The high mobility, along with a percolation density of 1.2 × 10¹¹cm^?2, light effective mass (0.09m_e), and high effective g‐factor (up to 9.2) highlight the potential of undoped Ge/SiGe as a low‐disorder material platform for hybrid quantum technologies.     

Formalized three-layer system-level model and reuse methodology forembedded data-dominated applications

In embedded data-dominated applications, a global system-level data transfer and storage exploration phase is crucial in obtaining a cost- and performance-efficient solution. We have developed a novel formalism to describe reusable blocks such that the essential part of the design exploration freedom is retained. This formalism is the basis for a system-level reuse methodology which allows reusing large parts of the design as heavily optimized structural VHDL or assembly code and describes the costly data access-related constructs at higher levels in the code hierarchy. Compared to a reuse approach based on fixed blocks, considerable power and area savings can be obtained, as demonstrated on real-life video and modem applications     

Moisture Sensitive Smart Yarns and Textiles from Self‐Balanced Silk Fiber Muscles

Smart textiles that sense, interact, and adapt to environmental stimuli have provided exciting new opportunities for a variety of applications. However, current advances have largely remained at the research stage due to the high cost, complexity of manufacturing, and uncomfortableness of environment‐sensitive materials. In contrast, natural textile materials are more attractive for smart textiles due to their merits in terms of low cost and comfortability. Here, water fog and humidity‐driven torsional and tensile actuation of thermally set twisted, coiled, plied silk fibers, and weave textiles from these silk fibers are reported. When exposed to water fog, the torsional silk fiber provides a fully reversible torsional stroke of 547° mm^?1. Coiled‐and‐thermoset silk yarns provide a 70% contraction when the relative humidity is changed from 20% to 80%. Such an excellent actuation behavior originates from water absorption‐induced loss of hydrogen bonds within the silk proteins and the associated structural transformation, which are corroborated by atomistic and macroscopic characterization of silk and molecular dynamics simulations. With its large abundance, cost‐effectiveness, and comfortability for wearing, the silk muscles will open up additional possibilities in industrial applications, such as smart textiles and soft robotics.     

Zr‐Doped Indium Oxide (IZRO) Transparent Electrodes for Perovskite‐Based Tandem Solar Cells

Parasitic absorption in transparent electrodes is one of the main roadblocks to enabling power conversion efficiencies (PCEs) for perovskite‐based tandem solar cells beyond 30%. To reduce such losses and maximize light coupling, the broadband transparency of such electrodes should be improved, especially at the front of the device. Here, the excellent properties of Zr‐doped indium oxide (IZRO) transparent electrodes for such applications, with improved near‐infrared (NIR) response, compared to conventional tin‐doped indium oxide (ITO) electrodes, are shown. Optimized IZRO films feature a very high electron mobility (up to ≈77 cm² V^?1 s^?1), enabling highly infrared transparent films with a very low sheet resistance (≈18 Ω □^?1 for annealed 100 nm films). For devices, this translates in a parasitic absorption of only ≈5% for IZRO within the solar spectrum (250–2500 nm range), to be compared with ≈10% for commercial ITO. Fundamentally, it is found that the high conductivity of annealed IZRO films is directly linked to promoted crystallinity of the indium oxide (In₂O₃) films due to Zr‐doping. Overall, on a four‐terminal perovskite/silicon tandem device level, an absolute 3.5 mA cm^?2 short‐circuit current improvement in silicon bottom cells is obtained by replacing commercial ITO electrodes with IZRO, resulting in improving the PCE from 23.3% to 26.2%.