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Highly luminescent indium phosphide zinc sulfide (InPZnS) quantum dots (QDs), with zinc selenide/zinc sulfide (ZnSe/ZnS) shells, were synthesized. The QDs were modified via a post-synthetic ligand exchange reaction with 3-mercaptopropionic acid (MPA) and 11-mercaptoundecanoic acid (MUA) in different MPA:MUA ratios, making this study the first investigation into the effects of mixed ligand shells on InPZnS QDs. Moreover, this article also describes an optimized method for the correlation of the QD size vs. optical absorption of the QDs. Upon ligand exchange, the QDs can be dispersed in water. Longer ligands (MUA) provide more stable dispersions than short-chain ligands. Thicker ZnSe/ZnS shells provide a better photoluminescence quantum yield (PLQY) and higher emission stability upon ligand exchange. Both the ligand exchange and the optical properties are highly reproducible between different QD batches. Before dialysis, QDs with a ZnS shell thickness of ~4.9 monolayers (ML), stabilized with a mixed MPA:MUA (mixing ratio of 1:10), showed the highest PLQY, at ~45%. After dialysis, QDs with a ZnS shell thickness of ~4.9 ML, stabilized with a mixed MPA:MUA and a ratio of 1:10 and 1:100, showed the highest PLQYs, of ~41%. The dispersions were stable up to 44 days at ambient conditions and in the dark. After 44 days, QDs with a ZnS shell thickness of ~4.9 ML, stabilized with only MUA, showed the highest PLQY, of ~34%.

Covellite phase CuS and carrollite phase CuCo2S4 nano-and microstructures were synthesized from tetrachloridometallate-based ionic liquid precursors using a novel, facile, and highly controllable hot -injection synthesis strategy. The synthesis parameters including reaction time and temperature were fir st optimized to produce CuS with a well-controlled and unique morphology providing the best electrocatalytic activity towards the oxygen evolution reaction (OER). In an extension to this approach, the electrocatalytic activity was further improved by incorporating Co in the CuS synthesis method to yield CuCo2S4 microflowers synthesized via the same approach. Both routes provide high microflower yields of >80 wt.%. The CuCo 2S4 microflowers exhibit a superior performance for the OER in alkaline medium compared to CuS. This is demonstrated by a lower onset potential (~1.45 V vs. RHE @10 mA/cm 2 ), better durability, and higher turnover frequencies compared to bare CuS flowers or commercial Pt/C and IrO2 electrodes. Likely, this effect is a associated with the presence of Co 3+ sites on which a better adsorption of reactive species formed during OER (e.g., OH, O, OOH, etc.) can be achieved, thus reducing the OER charge transfer resistance, as indicated from XPS and EIS measurements.

Hexagonal p-type semiconductor CuS nanoplates were synthesized via a hot injection method from bis(trimethylsilyl)sulfide and the ionic liquid precursor bis(N-dodecylpyridinium) tetrachloridocuprate(ii). The particles have a broad size distribution with diameters between 30 and 680 nm and well-developed crystal habits. The nanoplates were successfully incorporated into organic photovoltaic (OPV) cells as hole conduction materials. The power conversion efficiency of OPV cells fabricated with the nanoplates is 16% higher than that of a control device fabricated without the nanoplates.

Abstract. In this paper a computationally efficient and high-quality preserving DCT architecture is presented. It is obtained by optimizing the Loeffler DCT based on the Cordic algorithm. The computational complexity is reduced from 11 multiply and 29 add operations (Loeffler DCT) to 38 add and 16 shift operations (which is similar to the complexity of the binDCT). The experimental results show that the proposed DCT algorithm not only reduces the computational complexity significantly, but also retains the good transformation quality of the Loeffler DCT. Therefore, the proposed Cordic based Loeffler DCT is especially suited for low-power and high-quality CODECs in battery-based systems.

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We have previously shown (Nanomaterials, 2020, 10 (9), 1858) that InPZnS/ZnSe/ZnS multishell quantum dots (QDs) with a variety of shell thicknesses can be dispersed in water using a ligand exchange reaction with mercaptocarboxylic acids. Here, we demonstrate that the concept can further be extended to a larger variety of QD core sizes while keeping the shell thickness constant. The photoluminescence quantum yield of the QDs in the aqueous phase depends on the QD size and the QDs only show a slight red‐shift upon dispersion in water. This provides access to a larger group of particles with different emission colors, which is interesting for application in e. g. biological or medical diagnostics.

Future terminals for CDMA will have to employ multiuser detection to implement high data rate modes such as HSDPA in the UTRA/3GPP standard. Therefore efficient and flexible detection algorithms are needed. In [1] we have already shown an approach of such an equalizer for single user detection. The principle algorithm of this equalizer has now been extended to a multiuser detector, which can make use of the same Cordic based platform as the original equalizer.The paper shows that our approach has got a significant performance increase in comparison to a standard Rake based equalizer, whereas the computational complexity remains roughly the same.