A transparent, conductive, and flexible electrode is demonstrated. It is based on an inexpensive and easily manufacturable metallic network formed by depositing metals onto a template film. This electrode shows excellent electro-optical properties, with the figure of merit ranging from 300 to 700, and transmittance from 82% (~4.3 Ω sq(-1) ) to 45% (~0.5 Ω sq(-1) ).

The microwave absorption (MA) performance of carbon materials is severely hindered by their drawbacks of lacking magnetic loss ability and mismatched electromagnetic impedance. In this work, utilizing sustainable biomass kapok as a template, the hierarchically tubular C/Co nanoparticle composite is rationally constructed to acquire the enhanced MA performance for the first time. The fruit‐tree‐like hierarchical structure is composed from a “trunk” of kapok‐derived carbon microtubes, a “branch” of entangled carbon nanotubes, and “fruit” of Co nanoparticles embedded in the nanotubes. Such a hierarchically tubular structure offers the composite: i) a submillimeter‐scale 3D magnetic coupling network and reinforced magnetic loss ability, ii) a hierarchical dielectric carbon network, iii) better matched impedance, confirmed by the off‐axis electron holography and micromagnetic simulation. Accordingly, the as‐prepared hierarchically tubular carbon composite demonstrates impressive MA performance, with a maximum reflection loss of as much as −52.3 dB and a broad absorption bandwidth of 5.1 GHz. These encouraging achievements light the way to the development of the hierarchical microstructure of magnetic absorbents.

An organic flexible temperature-sensor array exhibits great potential in health monitoring and other biomedical applications. The actively addressed 16 × 16 temperature sensor array reaches 100% yield rate and provides 2D temperature information of the objects placed in contact, even if the object has an irregular shape. The current device allows defect predictions of electronic devices, remote sensing of harsh environments, and e-skin applications.

Herein, the advances in low-dimensional core-shell EM wave absorption materials are outlined and a selection of the most remarkable examples is discussed. The derived key information regarding dimensional design, structural engineering, performance, and structure-function relationship are comprehensively summarized. Moreover, the investigation of the cuttingedge mechanisms is given particular attention. Additional applications, such as oxidation resistance and self-cleaning functions, are also introduced. Finally, insight into what may be expected from this rapidly expanding field and future challenges are presented.

Low-cost solution-shearing methods are highly desirable for deposition of organic semiconductor crystals over a large area. To enhance the rate of evaporation and deposition, elevated substrate temperature is commonly employed during shearing processes. However, the Marangoni flow induced by a temperature-dependent surface-tension gradient near the meniscus line shows negative effects on the deposited crystals and its electrical properties. In the current study, the Marangoni effect to improve the shearing process of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene for organic field-effect transistor (OFET) applications is utilized and regulated. By modifying the gradient of surface tension with different combinations of solvents, the mass transport of molecules is much more favorable, which largely enhances the deposition rate, reduces organic crystal thickness, enlarges grain sizes, and improves coverage. The average and highest mobility of OFETs can be increased up to 13.7 and 16 cm 2 V −1 s −1 . This method provides a simple deposition approach on a large scale, which allows to further fabricate large-area circuits, flexible displays, or bioimplantable sensors.

Modern optoelectronics needs development of new materials characterized not only by high optical transparency and electrical conductivity, but also by mechanical strength, and flexibility. Recent advances employ grids of metallic micro-and nanowires, but the overall performance of the resulting material composites remains unsatisfactory. In this work, we propose a new strategy: application of natural scaffoldings perfected by evolution. In this context, we study two bio-inspired networks for two specific optoelectronic applications. The first network, intended for solar cells, light sources and similar devices, has a quasi-fractal structure and is derived directly from a chemically extracted leaf venation system. The second network is intended for touch screens and flexible displays, and is obtained by metalizing a spider's silk web. We demonstrate that each of these networks attain an exceptional optoelectonic and mechanical performance for its intended purpose, providing a promising direction in the development of more efficient optoelectronic devices.

applications in the fields of gas storage, electron conducting materials, catalysis, and sensors. [2] Nevertheless, the conductive and dielectric properties of pure MOF are too low to meet the requirement of electromagnetic (EM) impedance match. To improve the conductively and EM response capability, the thermal annealing of MOF precursors is the preferred strategy to gain the porous metal-carbonbased nanostructured materials. [3] More importantly, the final constituent of MOF derivatives can be effectively regulated by selecting the different metals sources and organic ligand. The MOF-derived hybrids can be consisted of magnetic metal oxide/ alloy, semiconductive carbon, or their composites via a facile subsequent treatment. Benefitting from the diversified composition and good chemical homogeneity, a number of efforts have been made to prove that MOFs are ideal templates or precursors for fabricating the versatile inorganic functional materials, such as graphitic carbon-encapsulated Ni nanoparticles, core-shell Fe/C nanocubes and CoSe@carbon nanoboxes. [2c,4] Based on these premises, it can be envisioned that MOF derivatives are promising and meaningful to fabricate the novel functional materials, especially in the microwave absorption (MA) field. Using a transformed strategy, MOF-derived magnetic-carbon composites can inherit the well-dispersed nanoparticles and the pristine microstructure with desirable properties.Nowadays, EM pollution issues have become increasingly serious due to the wide utilization in telecommunication, navigation, radar detector, and increasing number of electronic devices, which is an omnipresent problem that threatens our daily lives. [5] Therefore, EM absorption materials are crucial to the human protection and sophisticated equipment operation, having attracted the most extensive attention in past decades. To address these problems, searching for high-efficiency MA materials with a broadband absorption frequency and high loss capacity has stimulated huge interest in civil and military fields, especially in the gigahertz (GHz) band range. [6] It is known that the MA performance of absorbers is mainly determined by two Metal-organic framework (MOF) is highly desirable as a functional material owing to its low density, tunable pore size, and diversity of coordination formation, but limited by the poor dielectric properties. Herein, by controlling the solvent and mole ratio of cobalt/linker, multidimension-controllable MOF-derived nitrogen-doped carbon materials exhibit tunable morphology from sheet-, flower-, cube-, dodecahedron-to octahedron-like. Tunable electromagnetic parameters of Co@N-doped carbon composites (Co@NC)can be obtained and the initial MOF precursor determines the distribution of carbon framework and magnetic cobalt nanoparticles. Carbonized Co@NC compo sites possess the following advantages: i) controllable dimension and morphology to balance the electromagnetic properties with evenly charged density distribution; ii) magnetic-carbon composites offer plenty of inte...

No abstract