In nature, self-healing can be induced by sunlight for damage and wound repair, and this phenomenon is very important to living species for prolonging their lives. This self-repairing feature is obviously highly desirable for non-biological materials and manmade systems. In this paper, we demonstrate, for the first time, that battery electrodes can be self-repaired when exposed to sunlight. Here, we show that the optical, and photoelectrochemical (PEC) properties can be controlled by varying structural and compositional parameters of copper selenide nanocrystals (NCs). Cation to anion ratio in copper selenide (Cu2±xSe) NCs can be controlled over a wide range of 1.3–2.7 by simply changing the reaction temperature and impurity. Light-induced self-repairable behavior is demonstrated with electrochemical (EC) and PEC performances of electrodes made with stoichiometric copper selenide NCs. This nature-inspired, self-repairing behavior can be applied to batteries, supercapacitors, and photo-electrochemical fuel generators.
Triple‐cation mixed metal halide perovskites are important optoelectronic materials due to their high photon to electron conversion efficiency, low exciton binding energy, and good thermal stability. However, the perovskites have low photon to electron conversion efficiency in near‐infrared (NIR) due to their weak intrinsic absorption at longer wavelength, especially near the band edge and over the bandgap wavelength. A plasmonic functionalized perovskite photodetector (PD) is designed and fabricated in this study, in which the perovskite ((Cs0.06FA0.79MA0.15)Pb(I0.85Br0.15)3) active materials are spin‐coated on the surface of Au bowtie nanoantenna (BNA) arrays substrate. Under 785 nm laser illumination, near the bandedge of perovskite, the fabricated BNA‐based plasmonic PD exhibits ≈2962% enhancement in the photoresponse over the Si/SiO2‐based normal PD. Moreover, the detectivity of the plasmonic PD has a value of 1.5 × 1012 with external quantum efficiency as high as 188.8%, more than 30 times over the normal PD. The strong boosting in the plasmonic PD performance is attributed to the enhanced electric field around BNA arrays through the coupling of localized surface plasmon resonance. The demonstrated BNA‐perovskite design can also be used to enhance performance of other optoelectronic devices, and the concept can be extended to other spectral regions with different active materials.
Nanostructure and nanoantenna-based all-optical (AO) devices have attracted significant research interests in recent years due to their small size, high information capacity, ultrafast processing, low power consumption, and overall practicality. Here, in this Letter, we propose a novel metasurface having quasi-rhombus-shaped antennas to modulate optical modes in a dielectric-loaded waveguide for the realization of a complete family of logic gates including NOT, AND, OR, XOR, NAND, NOR, and XNOR. These logic operations are realized using destructive and constructive interferences between the input optical signals. The high contrast ratios of about 33.39, 27.69, and 33.11 dB are achieved for the NAND, NOR, and XNOR logic gates, respectively, with the speed as high as 108 Gb/s.
Efficient and reliable mode converters with broadband operation and small footprint will enable high‐density silicon photonic integrated circuits to build high bitrate optical networks and handheld optical devices. Here, all‐dielectric nanoaperture metasurfaces in the silicon layer of a silicon‐on‐insulator platform are reported for mode‐order conversion with an ultrasmall footprint. Utilizing the advantages of an abrupt width change and metasurface, the mode conversion between TE00 and TE10 modes is realized with a conversion efficiency as high as ≈90% in simulations and 83.1% in experiments at λ = 1.55 µm within an ultrashort conversion length of about 2.42 µm, the shortest ever achieved. The incident TE00 mode is converted to TE10 mode with purity of more than 90% in a broadband (Δλ ≈ 230 nm) wavelength range from 1.42 to 1.65 µm. Moreover, optimizing the number, position, and dimension of nanoapertures, it is further demonstrated that the nanoaperture metasurface design can enable mode conversion between silicon waveguides of different thicknesses and different relative positions, and between TM modes.
The zinc finger homeodomain (ZF-HD) genes belong to the homeobox gene family, playing critical roles in flower development and stress response. Despite their importance, however, to date there has been no genome-wide identification and characterization of the ZF-HD genes that are probably involved in stress responses in maize. In this study, 24 ZF-HD genes were identified, and their chromosomal locations, protein properties, duplication patterns, structures, conserved motifs and expression patterns were investigated. The results revealed that the ZF-HD genes are unevenly distributed on nine chromosomes and that most of these genes lack introns. Six and two ZF-HD genes have undergone segmental and tandem duplication, respectively, during genome expansion. These 24 ZF-HD transcription factors were classified into six major groups on the basis of protein molecular evolutionary relationship. The expression profiles of these genes in different tissues were evaluated, resulting in producing two distinct clusters. ZF-HD genes are preferentially expressed in reproductive tissues. Furthermore, expression profiles of the 24 ZF-HD genes in response to different kinds of stresses revealed that ten genes were simultaneously up-regulated under ABA, salt and PEG treatments; meanwhile four genes were simultaneously down-regulated. These findings will pave the way for deciphering the function and mechanism of ZF-HD genes on how to implicate in abiotic stress.
Due to the rise of 5G, IoT, AI, and high-performance computing applications, datacenter traffic has grown at a compound annual growth rate of nearly 30%. Furthermore, nearly three-fourths of the datacenter traffic resides within datacenters. The conventional pluggable optics increases at a much slower rate than that of datacenter traffic. The gap between application requirements and the capability of conventional pluggable optics keeps increasing, a trend that is unsustainable. Co-packaged optics (CPO) is a disruptive approach to increasing the interconnecting bandwidth density and energy efficiency by dramatically shortening the electrical link length through advanced packaging and co-optimization of electronics and photonics. CPO is widely regarded as a promising solution for future datacenter interconnections, and silicon platform is the most promising platform for large-scale integration. Leading international companies (e.g., Intel, Broadcom and IBM) have heavily investigated in CPO technology, an inter-disciplinary research field that involves photonic devices, integrated circuits design, packaging, photonic device modeling, electronic-photonic co-simulation, applications, and standardization. This review aims to provide the readers a comprehensive overview of the state-of-the-art progress of CPO in silicon platform, identify the key challenges, and point out the potential solutions, hoping to encourage collaboration between different research fields to accelerate the development of CPO technology.
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