Polyaniline-based electrochromic devices exhibit excellent adaptive camouflage potential in both visible and infrared spectral regions, but they currently still suffer from a slow response issue. Here, a fast visible-to-infrared electrochromic device based on electrochemically fabricated [BSO3]Py·HSO4-doped polyaniline is demonstrated. The electrochromic device achieves an ultrafast electrical response time of 0.5 s for coloration and 0.9 s for bleaching as well as maximum emissivity modulation of 0.35 in 3-5 μm and 0.51 in 8-14 μm bands. The device is fabricated by direct electrochemical polymerization of aniline monomers on Au-plated nylon porous electrodes with mixed ionic liquids of [BSO3]Py·HSO4/[BMIM]BF4 simultaneously as acidic precursor solution and gel electrolyte, termed as a one-step device fabrication method. Importantly, the one-step device fabrication combines the high ion diffusion rate of [BSO3]Py·HSO4-doped polyaniline film, the high ionic conductivity of an ionic liquid electrolyte, and improved electrolyte wettability, providing an advanced device fabrication strategy for adaptive camouflage applications.

Vanadium pentoxide (V2O5) films were fabricated on indium tin oxide substrates via a simple electrophoretic deposition method, with precise control over applied voltage and deposition duration. Both the electrophoretic deposition time and applied voltage are identified as key parameters in the electrophoretic deposition process. A systematic investigation was conducted to determine the optimal voltage and time for deposition of V2O5 films. The uniform V2O5 films with excellent multicolor electrochromic properties, such as yellow, yellow-green, green and orange-red, could be obtained when the electrophoretic deposition time was 5 min and the voltage was -2 V. An electrochromic device based on the as-prepared V2O5 film was assembled and its switching performance was evaluated. At 730nm, the coloration efficiency (CE) value of the V2O5 device was 22.6cm2C-1 (from green to orange-red), and the coloring and fading times of the V2O5 device were 6s and 4s, respectively. The V2O5 films maintained 81.79% charge transfer after 200 cyclic voltammetry (CV) measurements in the voltage range of -1 V to 2V. This work presents a facile and green strategy for the controllable preparation of V2O5 films and their devices with multicolor electrochromic behaviors.

A stable and efficient composite electrochromic material, Vanadium Pentoxide combined with polyethylene oxide (V2O5-PEO), was exhibited using an Electrophoretic Deposition (EPD) technique. The interlayer spacing of V2O5 was adjusted by the PEO component during electrophoretic adsorption, allowing for rapid ion exchange, with overall conductivity being enhanced and electrolyte penetration being accelerated. The elemental composition of the films was analyzed via X-ray Photoelectron Spectroscopy (XPS). A higher relative content of V4+ was observed in the green and blue states, while V5+ was predominant in the orange state. An electrochromic device (ECD) was assembled using V2O5-PEO as the active electrochromic layer. Multicolor performance was demonstrated by the device, with transitions observed between yellow, yellow-green, green, blue-green, orange, and various intermediate shades. Due to the moderate increase in the interlayer spacing of the film, the ionic migration ability was enhanced, with a balance achieved between the conductivity and ion exchange capability of PEO. Outstanding electrochromic performance was exhibited by the V2O5-0.5PEO device, including a rapid response time (3 s for coloration and 1.5 s for bleaching at 796 nm), high optical contrast (Delta T = 40 % at 796 nm), and a significant coloration efficiency (CE = 38.3 cm2/C).

Recently, various types of resonant cavities are widely fused with inorganic electrochromic material WO3 to compensate for its monotonous color modulation range. However, combining stabilized flexibility and vivid color performance in electrochromic devices is limited by the inherent brittleness and constrained transparency of commonly used top transparent electrodes, such as indium tin oxide (ITO). Herein, a novel top electrode-free structure of Cr/WO3/Au metal-dielectric-metal (MDM) resonant cavity type flexible multicolor electrochromic device based on inner-layer porous Nylon 66 substrate is reported. By implementing a UV-cured gel electrolyte and PET thermoplastic sealing process, the electrochromic device exhibits ultra-flexibility, retaining 92.9% of its initial performance after 900 bending cycles at a radius of 4 mm, a wide color gamut spanning hues from violet to red, 40.59% maximum reflectance, and fast response times (tcolored/tbleached = 4.5 s/4.8 s). The porous MDM cavity generates a sharper scattered multi-beam interference resonance and provides a multi-path transport channel for ions, while the bottom porous Au reflection layer serves as the conductive electrode thus replacing the top transparent electrodes in traditional sandwich-like electrochromic device structure. Moreover, a large-area multipixel electrochromic array is further proposed to display different patterns, which demonstrates potential applications in future wearable electronic labels and smart camouflage.

In this study, we develop a simple method for efficiently preparing poly(2,2 '-bithiophene) flexible electrochromic devices. The poly(2,2 '-bithiophene) films are fabricated in the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate. The poly(2,2 '-bithiophene) films are characterized by Fourier transform infrared spectroscopy, scanning electron microscope, and ultraviolet-visible absorbance spectroscopy. The poly(2,2 '-bithiophene) films exhibit electrochromic behavior, transitioning from an orange-red color in its reduced state to a dark green upon oxidation, particularly pronounced in the near-infrared region. Further studies demonstrate that poly(2,2 '-bithiophene) films exhibits flexibility, allowing it to be bent and folded. This method for fabricating poly(2,2 '-bithiophene) films shows promising potential for future applications.

Er3+-doped germanate-tellurite glasses were prepared by high-temperature melting method, in which structure, luminescent and, temperature-sensing properties were studied. The Raman spectrum indicates that the maximum phonon energy is low, which is 860 cm-1. The transmission spectrum indicates that the infrared transmissive range of glass is wide, visible, and infrared transmittance is high. Parameters of spectral line intensity Ox and radiation parameters were calculated based on Judd-Ofelt theory, which showed that the glass has large values of O2 and O6, and values of O2 and O6 decrease with increasing concentration of Er3+ ions. Strong up-conversion luminescence was obtained at 808, 980 and 1550 nmLD with wavelengths at 534, 553 and 668 nm, respectively, and strong down-conversion luminescence of 1.53 and 2.7 mu m also were obtained. The up-conversion emission intensity under three-wavelength simultaneous excitation is significantly enhanced compared to monochromatic excitation. The emission intensity corresponding to the 2H11/2 - 4I15/2 and 4S3/2 - 4I15/2 transition of Er3+ ions varied with temperature, and the fluorescence intensity ratio FIR of 556 nm and 524 nm increased with increasing temperature. In the temperature range from 330 to 610 K, the maximum sensitivity of glasses was 15.63 x 10-3 K-1 and 19.74 x 10-3 K-1 at T = 570 K, respectively under 808 and 980 nm LD excitation.

The red V 2 O 5 sol was prepared by facile alternating stirring and ultrasonic dispersion route. A V 2 O 5 film fabricated on ITO-PET by electrophoresis method was used to demonstrate a flexible electrochromic device. The effects of applied voltage and electrophoresis time for V 2 O 5 films were investigated in detail. When the electrophoresis time was kept 30 s, the applied voltage was above 3 V to deposit uniform V 2 O 5 -PET film. The electrophoresis time could more significantly regulate the deposition of V 2 O 5 on ITO-PET film. A flexible electrochromic device with “sandwich” structure was fabricated using V 2 O 5 film, and its electrochromic performance of the device was evaluated. The flexible V 2 O 5 electrochromic devices show the multicolor electrochromic performance of yellow, yellow-green, green and orange-red. The coloration efficiency values of V 2 O 5 devices were 21.6 cm 2 C[Formula: see text] (from initial yellow to green) and 26.9 cm 2 C[Formula: see text] (from green to orange-red), respectively, and the highest transmittance modulation range was 51% at 741 nm. The work provided a facile and green method for fabrication of flexible V 2 O 5 electrochromic device.

A vanadium oxide (VO) film was prepared on indium tin oxide (ITO) glass using a simple electrophoretic method and the VO film and its device demonstrated multicolor electrochromic properties of yellow, green, orange-red, and their intermediate colors. The X-ray diffraction (XRD) and X-ray photoelectron spectra (XPS) were employed to characterize the composition of the as-prepared films. The ratio of V5+/V4+ in the XPS is significantly different in the yellow, green, and orange-red states and this ratio can be adjusted by applied voltages. The detailed effect of calcination temperature as a post-treatment method on the electrochromic performance of VO film was explored. With the increase of calcination temperature, the optical modulation ability of the films was enhanced, and the color change contrast of the films was most obvious at 200 degrees C. Meanwhile, the cyclic stability of the VO films was also enhanced. The cyclic voltammetry (CV) curves show that the prepared V2O5 films have high cyclic stability at a calcination temperature of 300 degrees C. The color efficiency (CE) values of the VO devices were 3.4 cm2C-1 (from initial yellow to green) and 21.6 cm2C-1 (from green to orange-red) at 700 nm, and the coloring time (Tc) and bleaching time (Tb) of the VO devices were 6 s and 10 s, respectively. This work develops a simple and environmentally friendly method to prepare VO films and their devices with multicolor electrochromic properties. (c) 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Only utilizing hydrochloric acid and potassium ferricyanide as reaction reagents, Prussian Green (PG) films were facilely fabricated on fluorine doped tin dioxide glasses by a hydrothermal method. The amount of hydrochloric acid and the temperatures of hydrothermal treatment significantly affect the component and color of as-prepared films. The optimal preparation conditions are 0.5-1 mL of hydrochloric acid and hydrothermal temperature of 100-120 degree celsius. The hydrochloric acid plays the role of both as a reducing agent and providing acidic conditions. The PG devices based on as-prepared PG films firstly exhibited typical four-colors electrochromic properties: yellow, green, blue and colorless states, respectively, under different power supplies, which exhibit its potential application in nonemission display field.

Prussian Blue (PB) films were directly grown on FTO glass by a hydrothermal method only using potassium ferricyanide and hydrobromic acid as raw reagents. Hydrobromic acid plays the role of both providing acidic conditions and as a reducing agent which improves the atomic utilization of the raw materials. The as-prepared PB devices exhibited multicolor electrochromic properties: Blue, green and transparent states, reversibly. The maximum optical modulations of PB device could reach the range of 47.7%. The PB films also have a fast coloration/bleaching time of 1.9/1.3[Formula: see text]s, respectively. This study provided a novel method for preparing PB films by a facile hydrothermal method.

V2O5 films were facilely fabricated on indium tin oxide glasses by spin coating vanadyl oxalate precursor sols and subsequent calcination. The as-prepared V2O5 films and devices exhibit multicolor electrochromic performances: yellow, green and blue. Calcination temperature, precursor concentration and applied power were found to largely affect the electrochromic properties of the V2O5 films. The calcination temperature is key factor for the successful preparation of vanadium oxide films with electrochromic properties. V2O5 film could be synthesized by calcining above 300 & DEG;C for 1 h. With the increase of temperature, the morphology of the film changes from flat plane to wrinkle and crack to rice-like nanoparticles and to nanoplate. The transmittance modulation in the nearinfrared region is relatively high, and the maximum light modulation can reach to 48.3%. Cyclic voltammetry tests indicate that the as-prepared V2O5 films have high cycling stability. After 1000 cycles, the V2O5 films prepared at 400 & DEG;C still have excellent electrochromic properties. The coloration efficiency value is ca. 29.6 cm2/ C at a wavelength of 890 nm and the exact coloring/bleaching times of the V2O5 device are 12 s/18 s, respectively. The study provided a simple and low-cost method to fabricate V2O5 films and their devices.

二氧化钒(M/R相)作为一种典型的热致相变材料,在诸多领域都有着广阔的应用.仅在 68℃左右便可发生高温金属相-低温半导体相的完全可逆相变,且相变前后材料的光学、电学等特性均会发生明显变化.基于该特性,二氧化钒可应用于设计各种近红外和中红外调制器件,如"智能窗"、光学器件、军事防护器件等,并具有极高的实用价值.二氧化钒热致变色性能的优劣在很大程度上取决于薄膜的合成方法和制备过程中的参数调控,首先总结了关于二氧化钒相变机理的探索研究,其次重点概述了近几年二氧化钒薄膜制备方法的研究进展,包括磁控溅射法、脉冲激光沉积法、溶胶-凝胶法、分子束外延法和溶剂热/水热法等,并讨论了各种制备技术的优缺点.另外,在改善薄膜的热致变色性能方面,总结概述了掺杂和复合工艺对薄膜性能的影响.最后,对二氧化钒薄膜存在的问题及其未来的研究及应用方向进行了讨论与展望.

Electrochromic polyaniline (PANI) films with high electrochemical performance have been intensively pursued for their potential applications in various fields. Here, the growth process of the PANI films synthesized by the pre-nucleation electrodeposition method is analyzed and the optimal parameters with highest electrochemical activity are obtained. The PANI film fabricated under high current density of 10 mA cm-2 and impact time of 0.2 s shows the best electrochemical performance. It has a maximum active charge of 22.3 mC cm-2. The optimum electrochemical performance is attributed to the loose and porous structure. The PANI films fabricated under the optimal parameters also show the flattest structure and the smooth surface. It concludes a universal evaluation basis of the optimal conditions for the pre-nucleation method. That is, in the nucleation stage, the potential curve shall peak rapidly and then fall slowly to the valley without any upward growth; when entering into the low current density growth stage, the potential shall fall rapidly to a certain value and grow at that potential smoothly. This work evokes a deeper understanding and controlling of the growth process of polymers. In this work, the growth process of the polyaniline (PANI) films synthesized by pre-nucleation electrodeposition method is analyzed, and the optimum parameters of the PANI films with the highest electrochemical activity are obtained. A universal evaluation basis of the optimal conditions for pre-nucleation method is concluded. This work evokes a deeper understanding and controlling the growth process of polymers.image

In recent years, Fabry-Perot (F-P) cavity-type electrochromic devices composed of more stable inorganic materials have been extensively investigated for achieving colorful reflective displays and military camouflage functions. However, the majority of reported substrates for colorful F-P cavity electrochromic devices are rigid conductive glasses, which hinders their practical application in flexible reflective displays and camouflage. Herein, we construct a WO3/W/Au bilayer F-P cavity multicolor tunable electrochromic device based on a flexible porous filter membrane, in which WO3, an inorganic electrochromic material, is used as the electrochromic layer, metallic W as the partial reflective layer, and metallic Au as the total reflective and conductive layer. Highly flexible bilayer F-P cavity multicolor electrochromic devices have been prepared by combining UVcurable electrolytes and thermoplastic sealing procedures. By adjusting the thickness of the WO3 layer, a wide spectrum of colors including yellow, purplish red, violet, blue, green, olivine, peach, etc. can be obtained. In addition, by adjusting the driving voltage of the electrochromic device, more precise color adjustment can be achieved. The electrochromic device has a fast coloring (2.06 s) and bleaching (2.70 s) response time, providing a new solution for future flexible colorful reflective display devices.

Prussian blue films were fabricated on fluorine doped tin dioxide glass by a hydrothermal technique through modulation of reactants, reaction temperature and reaction duration. Reagents and hydrothermal temperature were found to largely affect the color, structure, and property of PB films. When the dosage of hydrobromic acid was above 0.9 mL and the hydrothermal temperature was above 120 degrees C, the reagents could react completely. A plausible formation mechanism of PB was proposed based on experimental results. Hydrobromic acid acts as both a reducing agent and a strong acid in the hydrothermal process. The PB film obtained in presence of 0.9 mL HBr by a hydrothermal treatment at 180 degrees C for 1h shows a good cycle stability. The PB devices with "sandwich" structure were assembled and exhibited multicolor electrochromic behaviors, and could change the color from initial blue to transparent and green, reversibly, under different power supplies. The coloration efficiency values of PB device were ca. 50.1 and 27.6 cm2/C, corresponding to the process from PB to PW and PG, respectively.

Currently, the difficulty of electrochromic use for full-color reflective display includes the color rendering range expansion and reflectance enhancement. The Fabry–Perot resonant cavity structure consisting of a broadband absorption layer allows high reflectivity spectral selection. It can actively modulate the optical response to a certain extent by implementing electrochemical control of the resonant cavity nanostructure. WO3 electrochromic layer was used as the dielectric layer of the broadband absorbing Fabry–Perot cavity, the transition metal Cr as the broadband absorbing layer material, and the inactive metal Al as the metal reflecting layer. The feasibility of the Al/WO3/Cr structure was analyzed theoretically, and the reflection spectrum of the designed electrochromic reflection display film was further investigated. The spectral colors of red, orange, yellow, green, blue, and violet can be obtained by adjusting the thickness of tungsten oxide. Moreover, the dynamic color control of the electrochromic device is achieved by electrically modulating the optical constants (n, k) of the WO3 film layer. The electrochromic device has the advantages of high brightness, high saturation, low cost, and low power consumption, providing a new option for designing full-color reflective displays in the future.

Random lasers (RLs) are a kind of coherent light source with optical feedback based on disorder-induced multiple scattering effects instead of a specific cavity. The unique feedback mechanism makes RLs different from conventional lasers. They have the advantages of small volume, flexible shape, omnidirectional emission, etc., and have broad application prospects in the fields of laser illumination, speckle-free imaging, display, and sensing. Colloidal metal-halide perovskite nanomaterials are a hot research field in light sources. They have been considered as desired gain media owing to their superior properties, such as high photoluminescence, tunable emission wavelengths, and easy fabrication processes. In this review, we summarize the research progress of RLs based on perovskite nanomaterials. We first present the evolution of the RLs based on the perovskite quantum dots (QDs) and perovskite films. The fabrication process of perovskite nano-/microstructures and lasers is discussed in detail. After that, the frontier applications of perovskite RLs are discussed. Finally, the challenges are discussed, and the prospects for further development are proposed.

Tungsten oxide films with electrochromic properties were prepared by spin coating WCl6 ethanol solution on indium tin oxide (ITO) glass and polyethylene terephthalate (PET) substrate, and followed heat treatment at 60-400 degrees C in air for 1 h. The films were characterized by X-ray powder diffraction, scanning electron microscopy, energy spectrum analysis, electrochemistry and ultraviolet-visible-near-infrared (UV-Vis-NIR) spectrophotometer. Tungsten oxide films with different components can be obtained at different heat treatment temperatures. With the increase of heat treatment temperature, the products gradually lose the crystal water from WO3 center dot 2H(2)O to WO3 center dot H2O and finally to WO3. The as-prepared film has many tiny cracks, which is beneficial for effective electrolyte penetration. The tungsten oxide PET films also show good electrochromic properties, and the coloring and bleaching processes are consistent with that of tungsten oxide device. The treatment at low temperature is no damage to the substrate and maintains the flexibility of the films. The method provides a simple, low-cost and large-scale practical scheme for the flexible electrochromic films.

A long-term stable aqueous colloidal dispersed ATO solution was obtained through the addition of aqueous ammonia. ATO nanoparticles could be dispersed evenly, forming stable ATO water-dispersed sol solution, and no agglomeration or sedimentation occurred at least 9 months. X-ray diffraction, transmission electron microscopy and energy-dispersive spectroscopy were employed to characterize the obtained ATO. Dynamic light scattering and UV–Vis–NIR spectrophotometer were used to record the particle sizes and transmission spectra of as-prepared ATO inks, respectively. The highest transmittance at low ATO concentration is 89.6% at 760 nm. In the near-infrared region, the transmittance has an obvious decrease, which is 51.5% at 1300 nm. The transmittance of as-prepared ATO solution in visible and near-infrared wavelengths (300–1300 nm) decreased significantly with the increase in the ATO concentration, especially in the near-infrared wavelengths, which proved that the as-prepared ATO had a shielding performance in the near-infrared region.

氧化锑锡因其固有的高可见光透过率、良好的红外屏蔽性能和导电性, 可应用于节能建筑、光电器件以及军事隐身等领域, 得到了广泛的研究.主要概述了氧化锑锡纳米材料及其薄膜制备技术的研究现状, 介绍了沉淀法、溶胶-凝胶法、水热法/溶剂热法等纳米材料制备技术, 以及喷雾热解法、脉冲激光沉积法、磁控溅射法和涂覆法等薄膜制备技术, 分析了锑掺杂浓度、干燥方式、煅烧温度、氧气流量、薄膜厚度等工艺参数对氧化锑锡纳米材料及其薄膜的结构特征、光电性能的影响.介绍了氧化锑锡薄膜在光电、建筑、军事等领域的应用现状, 总结了各种制备技术的优缺点, 并就该领域存在的问题及未来的研究和应用方向进行了讨论和展望.