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Considering the increasing demand for Li-ion batteries, there is a need for sophisticated recycling strategies with both high recovery rates and low costs. Applying optical sensors for automating component detection is a very promising approach because of the non-contact, real-time process monitoring and the potential for complete digitization of mechanical sorting processes. In this work, mm-scale particles from shredded end-of-life Li-ion batteries are investigated by five different reflectance sensors, and a range from the visible to long-wave infrared is covered to determine the ideal detection window for major component identification as relevant input signals to sorting technologies. Based on the characterization, a spectral library including Al, Cu, separator foil, inlay foil, and plastic splinters was created, and the visible to near-infrared range (400–1000 nm) was identified as the most suitable spectral range to reliably discriminate between Al, Cu, and other battery components in the recycling material stream of interest. The evaluation of the different sensor types outlines that only imaging sensors meet the requirements of recycling stream monitoring and can deliver sufficient signal quality for subsequent mechanical sorting controls. Requirements for the setup parameters were discussed leading to the setup recommendation of a fast snapshot camera with a sufficiently high spectral resolution and signal-to-noise ratio. [ABSTRACT FROM AUTHOR]

We report on the electrical and microstructural characterization of an Au-free V/Al/Ti/TiN ohmic contact for AlGaN/GaN heterostructures. Ultra-low contact resistance and specific contact resistivity of Rc < 0.1 Ω mm and ρc < 2.4 × 10−7 Ω cm2 have been achieved with very low RMS surface roughness. This was accomplished at a comparably low annealing temperature of 800 °C and without applying any contact recess, regrowth, or implantation process. High electron mobility transistors were fabricated and a comparison of the electrical performance with state-of-the-art Ti/Al/Ti/TiN and Ti/Al/Ni/Au contacts was made. The contact formation mechanism is discussed on the basis of microstructural features. [ABSTRACT FROM AUTHOR]

The controlled growth of surface‐modifying polymer films by electrodeposition often fails because of the lack of redox activity of these compounds. Here, electroactive complexants help to electrodeposit non‐electroactive polymers. Hence, we investigate the counterion‐induced electrodeposition of polyelectrolytes: three quaternized poly(N,N‐dialkylaminoethyl methacrylate)s (qPDAAEMA), in particular their methyl, ethyl, and isopropyl derivatives (i. e. qPDMAEMA, qPDEAEMA, and qPDPAEMA), provide transparent solutions in the presence of hexacyanoferrate(II) (ferrocyanide) at specific concentration windows of the KCl supporting electrolyte. Below a certain KCl concentration, insolubility dominates irrespective of the hexacyanoferrate valency, whilst above an upper threshold, full solubility is observed. Between these limits, oxidation reversibly electrodeposits polymer/hexacyanoferrate(III) (ferricyanide) complexes. Hydrodynamic voltammetry (and data analysis using in‐house software) provides access to the deposition efficiency (DE). qPDEAEMA with ethyl substituents shows highest DEs; larger or smaller substituents fall short because of a balance between "hydrophobicity" and charge separation, shifting the window toward smaller salt concentrations with increasing alkyl size. We always observe a DE maximum close to the minimum salt concentration, whilst electrochemical quartz crystal microbalance (EQCM) measurements indicate a change in film water content close to the maximum. These effects, being also discussed in terms of polymer conformation, can direct the future engineering of electroassisted coatings. [ABSTRACT FROM AUTHOR]

Embedded three-dimensional (3-D) metal-insulator-metal (MIM) decoupling capacitors with high-κ dielectric films of high capacitance and long-life time are increasingly needed on integrated chips. Towards achieving better electrical performance, there is a need for investigation into the influence of the variation in atomic layer deposition (ALD) parameters used for thin high-κ dielectric films (10 nm) made of Al2O3-doped ZrO2. This variation should always be related to the structural uniformity, the electrical characteristics, and the electrical reliability of the capacitors. This paper discusses the influence of different Zr precursor pulse times per ALD cycle and deposition temperatures (283 °C/556 K and 303 °C/576 K) with respect to the capacitance density (C-V), voltage linearity and leakage current density (I-V). Moreover, the dielectric breakdown and TDDB characteristics are evaluated under a wide range of temperatures (223–423 K). [ABSTRACT FROM AUTHOR]

The impact of an Au‐free Ti/Al/Ti/TiN (20/100/20/80 nm) ohmic contact metallization on an Al0.21Ga0.79N/GaN heterostructure is investigated. Using the transfer length method and Hall measurements, the sheet resistance and the carrier concentration below the contact are analyzed, depending on the post‐deposition annealing temperature. It is shown that with increasing annealing temperature, the carrier density below the contact is enhanced. This is caused by the contact formation mechanism, leading to an extremely low contact end resistance to the sub‐contact region of 0.04 Ω mm. However, while the sub‐contact semiconductor resistance is low, the contact (front) resistance to the device channel is 0.74 Ω mm after annealing at 900 °C, indicating a depletion of the sub‐contact 2D electron gas because of alloy formation. [ABSTRACT FROM AUTHOR]