- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Electrochromic device with Magnetron sputtered Tungsten Oxide (WO<sub>3</sub>) and nafion membrane: performance with varying Tungsten Oxide thickness- A report
摘要： Electrochromics is the emerging technology for energy conservation and indoor climatic control through smart windows. In this study we are reporting four layer electrochromic device: ITO (400nm)/ commercially procured Nafion (183μm) / WO3 (44nm to 200nm)/ ITO (400nm). The active area (A) of the electrochromic devices are 3cm2. The tungsten oxide (WO3) and ITO thin films have been deposited at room temperature (300 K) by reactive DC Magnetron sputtering. The sheet resistance of ITO is 20 ?/□. The “as deposited” WO3 films are amorphous and have high optical transmission (75%- 85%) in the visible spectrum. The optical band gap decreases with increasing thickness of WO3 thin films. The coloration efficiency (CE) of the electrochromic device increases with increasing thickness of the WO3 layer. The CE for the device with WO3 thickness 200 nm is 184 cm2/C: the highest reported so far for a hybrid electrochromic device. The increase in the CE with thickness has been explained (for the first time) by replacing the surface charge density (Q/A) with the volume charge density (Q/A*t) in the coloration efficiency formula derived from the Beer Lambert’s law.
关键词： coloration efficiency,electrochromism,nafion and Magnetron sputtering.,Tungsten oxide
更新于2025-11-19 16:56:35
-
A novel bis(dihydroxypropyl) viologen-based all-in-one electrochromic device with high cycling stability and coloration efficiency
摘要： Electrochromism and related devices have been studied for a few decades from both fundamental and technological point of view. At the present stage, screening electrochromic materials with excellent properties is still an interesting job. In our previous work, we have demonstrated that hydroxyalkyl viologens could exhibit satisfying electrochromic behavior. Further, in this paper, the bis(dihydroxyalkyl) viologen, (1,1‘-bis(2,3-dihydroxypropyl) 4,4‘-bipyridine derivative dichloride, DHPV2t 2Cl-, was synthesized and incorporated as an electrochromic chromophore in the all-in-one electrochromic devices (ECDs) on the basis of poly (vinyl butyal) (PVB)-carbonate and po?y (vinyl alcohol) (PVA)-borax gel electrolytes, respectively. It was found that DHPV2t 2Cl- in PVB-based gel ECDs underwent reversible switching between transparent and deep blue hue, whereas the clear color changes from colorlessness to amaranth in PVA-borax-based ones upon the potential ranges from 0 V to (cid:2)1.0 V. For PVB-based gel ECD, spectroelectrochemical studies demonstrated that it only needs a low coloration voltage down to (cid:2)0.6 V, and exhibites high coloration ef?ciency (h) up to 301 cm2/C. The optical contrast of it only reduces by 1% after consecutive operation for 10000 cycles between (cid:2)1.0 V and 0 V, demonstrating an excellent cycling stability of this kind of device. The ECD based on PVA-borax gel modi?ed with glycerol shows burgundy, and good electrochromic performance. It is interesting to note that a relatively large-area PVB-based gel electrochromic devices up to 168 cm2 was realized, the driving voltage and response time being (cid:2)1.5 V and 12 s, respectively, for blue-violet coloration state. The advantages of electrochromic properties exhibited by 1,1‘-bis(2,3-dihydroxypropyl) viologen dichloride over those reported can be regarded as a pronounced improvement for organic electrochromic materials, and are expected to set the stage for novel electrochromic devices such as smart window and display applications and so forth.
关键词： Coloration ef?ciency,Electrochromic (EC) gel,Stability,Viologen,Electrochromic devices (ECD)
更新于2025-09-23 15:23:52
-
Double Twisted Photonic Honeycomb Frameworks with Mesoporous Structures
摘要： In nature, materials such as shell, bone, silk, and wood are assembled with hierarchical structures that span lengths from nanometers to centimeters. These biological materials are fascinating targets for replication and mimicry, often owing to their remarkable properties. The intricate and periodic structure of the snow crab (Chionoecetes opilio) exoskeleton that renders it iridescent is described here. It is discovered that the snow crab has a double twisted photonic honeycomb structure constructed by left-handed rotation of chitin nanofibrils around cavities throughout its shell. This new chiral framework provides a foundation for exploring chiral photonics and materials. With the goal of mimicking this intricate network, the iridescent mineralized chitin shell is successfully transferred to calcite, carbon, apatite, and fluorapatite/chitin materials with structural replication. It is shown that the sophisticated organization of the iridescent crab shell leads these new materials to have a distinctive macroscopic combination of multilevel chirality, honeycomb channels, and mesoporosity. These solid-state transformations of snow crab exoskeletons will open the path to making complex hierarchical frameworks of functional porous materials through bioinspired templating.
关键词： honeycomb,coloration,biomimicry,chirality,structural order
更新于2025-09-23 15:23:52
-
[Springer Series in Materials Science] Biomimetics Volume 279 (Bioinspired Hierarchical-Structured Surfaces for Green Science and Technology) || Structural Coloration
摘要： In living nature, flora and fauna produce color through pigments, bioluminescence, or structural coloration (Booth 1990). Biological pigments, or simply pigments, are substances produced by living organisms, which produce color resulting from selective light adsorption and reflection of a specific light wavelength. These include plant and flower pigments, such as green pigment chlorophyll used by plants for photosynthesis. Many biological structures contain pigments such as melanin in skin, eyes, fur, and hair. Bioluminescence is the production and emission of visible light by a living organism. It occurs widely in marine organisms, as well as in some fungi, bacteria, and terrestrial invertebrates, such as fireflies. Structural coloration is the production of color by selective light reflection by nanostructured surfaces with features of the same scale as incident visible light wavelengths (Fox 1976; Kinoshita 2008; Kinoshita et al. 2008; Sun et al. 2013; Yu et al. 2013). While pigments degrade and their colors fade over time, structural coloration can persist for long periods, even after the death of the organism.
关键词： iridescent,nanostructured surfaces,bioluminescence,pigments,structural coloration
更新于2025-09-23 15:21:21
-
Porosity-Controllable Magnetoplasmonic Nanoparticles and Their Assembled Arrays
摘要： Control of the chemical and physical properties of nanoscale colloids and their nanoassemblies remains a challenging issue for enhancing the performance and functionalities of nanodevices. In this study, we report a post-synthesis etching method to tailor the porosity of the Fe3O4 shells coating on Ag NPs, establishing a facile but effective approach to regulate the chemical and optical properties of the colloids and their assembled structures. As the shell porosity increases, the NPs are transformed, producing enhanced catalytic activity and the surface-enhanced Raman spectroscopy (SERS) effect, which results from enhanced chemical diffusion into the Ag core. Magnetoplasmonic (MagPlas) one- (1D) and two- (2D) dimensional arrays fabricated using these porosity-controllable NPs exhibit intriguing plasmon properties that are strongly affected by the porosity of the particle shell. Furthermore, the bright coloration of the 2D arrays is tuned by changing the shell porosity or introducing an additional metallic layer. Such 1D and 2D porous MagPlas metastructures possessing Fe3O4 shells with tunable porosities are a fulcrum for developing recyclable catalysts and tunable optical filters with optimized activity, selectivity, and sensitivity, as well as color displays and sensing platforms.
关键词： coloration,porosity,metamaterial,plasmon interaction,magnetoplasmonic
更新于2025-09-23 15:21:01
-
Optical Characterization of the Photonic Ball as a Structurally Colored Pigment
摘要： A photonic ball is a spherical colloidal crystal. Because it can exhibit vivid structural colors, many attempts have been made to apply it as a structurally colored pigment. However, the optical properties of the photonic ball are complicated because di?erent crystal planes can be involved in the coloration mechanism, depending on the size of the constituent colloidal particles. In this paper, we report a comparative study of photonic balls consisting of silica particles with sizes ranging from 220 to 500 nm. We ?rst analyze the re?ectance spectra acquired in a nearly backscattering geometry and con?rm that Bragg di?raction from di?erent crystal planes causes several spectral peaks. Second, the angular dependence of re?ection is experimentally characterized and theoretically analyzed with appropriate models. These analyses and a comparison with a planar colloidal crystal reveal that the spherical shape plays an essential role in the minor iridescence of photonic balls. We ?nally discuss a method to enhance color saturation by incorporating small light-absorbing particles. We also discuss the iridescence of the photonic ball under directional and ambient illumination conditions.
关键词： structural coloration,photonic ball,iridescence,colloidal crystal,Bragg diffraction
更新于2025-09-23 15:21:01
-
Lighta??Emitting Nanophotonic Designs Enabled by Ultrafast Laser Processing of Halide Perovskites
摘要： Nanophotonics based on resonant nanostructures and metasurfaces made of halide perovskites have become a prospective direction for efficient light manipulation at the subwavelength scale in advanced photonic designs. One of the main challenges in this field is the lack of large-scale low-cost technique for subwavelength perovskite structures fabrication preserving highly efficient luminescence. Here, unique properties of halide perovskites addressed to their extremely low thermal conductivity (lower than that of silica glass) and high defect tolerance to apply projection femtosecond laser lithography for nanofabrication with precise spatial control in all three dimensions preserving the material luminescence efficiency are employed. Namely, with CH3NH3PbI3 perovskite highly ordered nanoholes and nanostripes of width as small as 250 nm, metasurfaces with periods less than 400 nm, and nanowire lasers as thin as 500 nm, corresponding to the state-of-the-art in multistage expensive lithographical methods are created. Remarkable performance of the developed approach allows to demonstrate a number of advanced optical applications, including morphology-controlled photoluminescence yield, structural coloring, optical-information encryption, and lasing.
关键词： metasurfaces,structural coloration,lasing,halide perovskites,light emission,nanostructures
更新于2025-09-23 15:19:57
-
Structurally colored stainless steel processed by using femtosecond laser pulses
摘要： Structurally colored stainless steel (SS) surfaces were produced by using femtosecond laser at normal incidence at ambient conditions. The influence of laser polarization on the surface properties was investigated. The surface morphologies, roughness and color of the laser-treated surface were characterized by using environmental scanning electron microscope (ESEM), roughmeter and atomic force microscope (AFM). Results indicated that the circular polarization leads to more random structures than the horizontally linear polarization. Specimen with the highest surface roughness shows the brightest color. Different colors are cyclically exhibited by changing view angles due to different orders of diffraction. This investigation developed the technique of using femtosecond laser in situ preparation of periodic structures on 304 SS, and indicating that laser polarization is an important parameter to control surface structures to achieve different colors.
关键词： polarization,micro/nanostructure,coloration,Femtosecond laser,stainless steel
更新于2025-09-16 10:30:52
-
Effects of different pH regulators on the color properties of attapulgite/BiVO4 hybrid pigment
摘要： Four different pH regulators including NaOH, Na2CO3, NaHCO3 and NH3·H2O were employed to prepare attapulgite doped bismuth yellow hybrid pigments by aqueous precipitation followed by an annealing process. Different hybrid pigments derived from different pH regulators had different color properties, and it might be related to the generated products in the process of adjusting pH, which further affected the phase compositions of the end hybrid pigments after being annealed. By contrast, the bismuth yellow hybrid pigments prepared using Na2CO3 as pH regulator exhibited the optimal color properties (L? = 76.81, a? = 4.64, b? = 81.16, C ? = 81.29, and h° = 86.73). Interestingly, attapulgite provided the carrier for BiVO4 nanoparticles to inhibit the agglomeration, and the doping elements to improve its color properties as well. The as-prepared hybrid pigments are expected to be served as an eco-friendly and low-cost yellow colorant to replace the traditional and toxic ones.
关键词： Coloration mechanism,pH regulators,BiVO4,Attapulgite,Comparative studies
更新于2025-09-09 09:28:46
-
Soluble high coloration efficiency electrochromic polymers based on (N-phenyl)carbazole, triphenylamine and 9,9-dioctyl-9H-fluorene
摘要： Here, we synthesized four kinds of monomers of 3,6-dibromo-(N-phenyl)carbazole with different substituent group, DCB, DDC, DNC and DTC, respectively, and used 4-(3-bromo-9H-carbazol-9-yl)benzaldehyde to react with triphenylamine (TPA) unit and hydrazine hydrate unit, respectively, to obtain the other two monomers, BCB-TPA and BCB-HH. Six novel polymers coded as PDCB-DF, PDDC-DF, PDNC-DF, PDCB-DTC-DF, PBCB-TPA-DF and PBCB-HH-DF, were synthesized by Suzuki reactions of 2,2'-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(1,3,2-dioxaborinane) with the six kinds of monomers and their electrochemical and spectroelectrochemical properties were investigated. The polymers showed good solubility and film-forming ability. Flexible or robust films of them could be readily obtained via solution-casting. These polymers showed the onset temperatures in the range of 300–470 °C when the 10% weight loss of polymers. The polymer films showed high coloration efficiency (CE) (196-376 cm2·C?1) and electrochromic stability. These properties illustrate that the polymers have great application prospect as electrochromic materials.
关键词： Electrochromic stability,Coloration efficiency,Spectroelectrochemical,Polymers
更新于2025-09-04 15:30:14