"One-Pot" CuCl2-Mediated Condensation/C-S Bond Coupling Reactions to Synthesize Dibenzothiazepines by Bi-Functional-Reagent N, N'-Dimethylethane-1,2-Diamine.

The efficient "One-pot" CuCl2-catalyzed C-S bond coupling reactions were developed for the synthesis of dibenzo[b,f][1,4]thiazepines and 11-methy-ldibenzo[b,f][1,4]thiazepines via 2-iodobenzaldehydes/2-iodoacetophenones with 2-aminobenzenethiols/2,2'-disulfanediyldianilines by using bifunctional-reagent N, N'-dimethylethane-1,2-diamine (DMEDA), which worked as ligand and reductant. The reactions were compatible with a range of substrates to give the corresponding products in moderate to excellent yields.

Mimicking synaptic functionality with an InAs nanowire phototransistor.

We demonstrate a nanowire (NW) phototransistor with synaptic behavior based on inherent persistent photoconductivity. The device is comprised of a single crystalline InAs NW, covered by a native indium oxide layer acting as the photogating layer (PGL). In the negative photoresponse range, the device mimics synaptic neuromorphic behaviors of short-term plasticity, long-term plasticity (LTP), and paired-pulse facilitation. Moreover, the transition from short-term to LTP is observed as the stimulus intensity increases, behaving in accord with the feature of cooperativity. The synaptic behaviors of the device are attributed to the photo-generated electrons trapped/detrapped in the PGL. This NW-based photonic synaptic device would find promising applications in neuromorphic systems and networks.

Investigation on the performance of photonics-aided W-band millimeter-wave wireless transmission.

W-band (75-110 GHz) is a potential radio frequency band to provide long-distance wireless links for mobile data transmission. This paper proposes and experimentally demonstrates high-speed wireless transmission at W-band using photonics-aided method, including optical heterodyne, photonics-aided down-conversion without RF oscillator and coherent detection. A comparison between the photonics-aided method and the conventional electronic method employing solid-state electronic devices is conducted for the first time. The photonics-aided method is shown to offer advantages such as lower harmonic components, spur, reduced nonlinearity, and no local oscillator leakage, results in a 2.5 dB better performance of the photonic-aided W-band mm-wave transmitter compared to the electronic one. In the terms of receiver, the photonics-aided method can surpass the electronic method, with the help of larger electro-optical modulator bandwidth and lower drive voltage in the photonic down-conversion stage. Ultimately, using the photonics-aided method, a recorded equivalent transmission distance of 29 km@84 GHz and 45km@75.6GHz is achieved respectively for 1Gbaud QPSK signal.

Surface Oxygen Species in Metal Oxide Photoanodes for Solar Energy Conversion.

Converting and storing solar energy directly as chemical energy through photoelectrochemical devices are promising strategies to replace fossil fuels. Metal oxides are commonly used as photoanode materials, but they still encounter challenges such as limited light absorption, inefficient charge separation, sluggish surface reactions, and insufficient stability. The regulation of surface oxygen species on metal oxide photoanodes has emerged as a critical strategy to modulate molecular and charge dynamics at the reaction interface. However, the precise role of surface oxygen species in metal oxide photoanodes remains ambiguous. The review focuses on elucidating the formation and regulation mechanisms of various surface oxygen species in metal oxides, their advantages and disadvantages in photoelectrochemical reactions, and the characterization methods employed to investigate them. Additionally, the article discusses emerging opportunities and potential hurdles in the regulation of surface oxygen species. By shedding light on the significance of surface oxygen species, this review aims to advance our understanding of their impact on metal oxide photoanodes, paving the way for the design of more efficient and stable photoelectrochemical devices.

A graphene/single GaAs nanowire Schottky junction photovoltaic device.

A graphene/nanowire Schottky junction is a promising structure for low-cost high-performance optoelectronic devices. Here we demonstrate a graphene/single GaAs nanowire Schottky junction photovoltaic device. The Schottky junction is fabricated by covering a single layer graphene onto an n-doped GaAs nanowire. Under 532 nm laser excitation, the device exhibits a high responsivity of 231 mA W-1 and a short response/recover time of 85/118 µs at zero bias. Under AM 1.5 G solar illumination, the device has an open-circuit voltage of 75.0 mV and a short-circuit current density of 425 mA cm-2, yielding a remarkable conversion efficiency of 8.8%. The excellent photovoltaic performance of the device is attributed to the strong built-in electric field in the Schottky junction as well as the transparent property of graphene. The device is promising for self-powered high-speed photodetectors and low-cost high-efficiency solar cells.