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 共查询到20条相似文献，搜索用时 15 毫秒
1.
采用循环扫描伏安法在Au/Cr/PET复合基底上聚合出聚苯胺(PAN)膜,设计并制备了基于PAN的反射型柔性电致变色器件(ECD)。研究了该ECD反射光谱的电压响应特性。结果显示,所得PAN具有晶体结构,微观上呈直径约60nm的纤维网形态,与Au/Cr/PET基底结合良好;该ECD的反射光谱曲线的波长选择性,在-0.4～+1.8V电压范围内随电压增加而逐渐明显,反射率峰值出现的位置由476nm移至584nm,表现出良好的电致变色响应特性。  相似文献   

2.
Two new multichromophoric electrochromic polymers featuring a conjugated EDOT/ProDOT copolymer backbone (PXDOT) and a reversible Weitz‐type redox active small molecule electrochrome (WTE) tethered to the conjugated chain are reported here. The careful design of the WTEs provides a highly reversible redox behavior with a colorless red switching that complements the colorless blue switching of the conjugated backbone. Subtractive color mixing successfully provides high performing solution processable polymeric layers with colorless neutral tint switchable limiting states for application in see‐through electrochromic devices. Design, synthesis, comprehensive chemical and spectroelectrochemical characterization as well as the preparation of a proof‐of‐concept device are discussed.  相似文献   

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4.
    
An electroactive polyazomethine is prepared from a solution processable 2,5‐diaminothiophene derivative and 4,4′‐triphenylamine dialdehyde by spray‐coating the monomers on substrates, including indium tin oxide (ITO) coated glass and native glass slides. The conjugated polymer was rapidly formed in situ by heating the substrates at 120 °C for 30 min in an acid saturated atmosphere. The resulting immobilized polymer is easily purified by rinsing the substrate with dichloromethane. The on‐substrate polymerization is tolerant towards large stoichiometry imbalances of the comonomers, unlike solution step‐growth polymerization. The resulting polyazomethine is electroactive and it can be switched reversibly between its neutral and oxidized states both electrochemically and chemically without degradation. A transmissive electrochromic device is fabricated from the immobilized polyazomethine on an ITO electrode. The resulting device is successfully cycled between its oxidized (dark blue) and neutral (cyan/light green) states with applied biases of +3.2 and ‐1.5 V under ambient conditions without significant color fatigue or polymer degradation. The coloration efficiency of the oxidized state at 690 nm is 102 cm2 C?1.  相似文献   

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6.
    
Conjugated electrochromic (EC) polymers for flexible EC devices (ECDs) generally lack a fully colorless bleached state. A strategy to overcome this drawback is the implementation of a new sidechain‐modified poly(3,4‐ethylene dioxythiophene) derivative that can be deposited in thin‐film form in a customized high‐throughput and large‐area roll‐to‐roll polymerization process. The sidechain modification provides enhanced EC properties in terms of visible light transmittance change, Δτv = 59% (ΔL* = 54.1), contrast ratio (CR = 15.8), coloration efficiency (η = 530 cm² C?1), and color neutrality (L* = 83.8, a* = ?4.3, b* = ?4.1) in the bleached state. The intense blue‐colored polymer thin films exhibit high cycle stability (10 000 cycles) and fast response times. The design, synthesis, and polymerization of the modified 3,4‐ethylene dioxythiophene derivative are discussed along with a detailed optical, electrochemical, and spectroelectrochemical characterization of the resulting EC thin films. Finally, a flexible see‐through ECD with a visible light transmittance change of Δτv = 47% (ΔL* = 51.9) and a neutral‐colored bleached state is developed.  相似文献   

7.
    
MXenes, a large family of 2D transition metal carbides and nitrides, have shown potential in energy storage and optoelectronic applications. Here, the optoelectronic and pseudocapacitive properties of titanium carbide (Ti3C2Tx) are combined to create a MXene electrochromic device, with a visible absorption peak shift from 770 to 670 nm and a 12% reversible change in transmittance with a switching rate of <1 s when cycled in an acidic electrolyte under applied potentials of less than 1 V. By probing the electrochromic effect in different electrolytes, it is shown that acidic electrolytes (H3PO4 and H2SO4) lead to larger absorption peak shifts and a higher change of transmittance than the neutral electrolyte (MgSO4) (Δλ is 100 nm vs 35 nm and ΔT770 nm is ≈12% vs ≈3%, respectively), hinting at the surface redox mechanism involved. Further investigation of the mechanism by in situ X‐ray diffraction and Raman spectroscopy reveals that the reversible shift of the absorption peak is attributed to protonation/deprotonation of oxide‐like surface functionalities. As a proof of concept, it is shown that Ti3C2Tx MXene, dip‐coated on a glass substrate, functions as both transparent conductive coating and active material in an electrochromic device, opening avenues for further research into optoelectronic and photonic applications of MXenes.  相似文献   

8.
    
Highly conductive poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films as stand‐alone electrodes for organic solar cells have been optimized using a solvent post‐treatment method. The treated PEDOT:PSS films show enhanced conductivities up to 1418 S cm?1, accompanied by structural and chemical changes. The effect of the solvent treatment on PEDOT:PSS has been investigated in detail and is shown to cause a reduction of insulating PSS in the conductive polymer layer. Using these optimized electrodes, ITO‐free, small molecule organic solar cells with a zinc phthalocyanine (ZnPc):fullerene C60 bulk heterojunction have been produced on glass and PET substrates. The system was further improved by pre‐heating the PEDOT:PSS electrodes, which enhanced the power conversion efficiency to the values obtained for solar cells on ITO electrodes. The results show that optimized PEDOT:PSS with solvent and thermal post‐treatment can be a very promising electrode material for highly efficient flexible ITO‐free organic solar cells.  相似文献   

9.
    
Mechanically robust, highly ionic conductive gels based on a random copolymer of poly[styrene‐ran‐1‐(4‐vinylbenzyl)‐3‐methylimidazolium hexafluorophosphate] (P[S‐r‐VBMI][PF6]) and the ionic liquid 1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMI][TFSI]) are successfully prepared. The gels with either homo P[VBMI][PF6] or conventional PS‐block‐poly(methyl methacrylate)‐block‐PS (SMS) show significant trade‐off between ionic conductivity and mechanical resilience. In contrast, the P[S‐r‐VBMI][PF6]‐based gels exhibit both large elastic modulus (≈0.105 MPa) and ionic conductivity (≈1.15 mS cm−1) at room temperature. To demonstrate that these materials can be used as solid‐state electrolytes, the ion gels are functionalized by incorporating electrochromic (EC) chromophores (ethyl viologen, EV2+) and are applied to EC devices (ECDs). The devices show low‐voltage operation, large optical transmittance variation, and good cyclic coloration/bleaching stability. In addition, flexible ECDs are fabricated to take advantage of the mechanical properties of the gels. The ECDs have excellent bending durability under both compressive and tensile strains. The versatile P[S‐r‐VBMI][PF6]‐based gel is anticipated to be of advantage in flexible electrochemical applications, such as batteries and electrochemical displays.  相似文献   

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11.
    
Efficient transparent organic light‐emitting diodes (OLEDs) with improved stability based on conductive, transparent poly(3,4‐ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) electrodes are reported. Based on optical simulations, the device structures are carefully optimized by tuning the thickness of doped transport layers and electrodes. As a result, the performance of PEDOT:PSS‐based OLEDs reaches that of indium tin oxide (ITO)‐based reference devices. The efficiency and the long‐term stability of PEDOT:PSS‐based OLEDs are significantly improved. The structure engineering demonstrated in this study greatly enhances the overall performances of ITO‐free transparent OLEDs in terms of efficiency, lifetime, and transmittance. These results indicate that PEDOT:PSS‐based OLEDs have a promising future for practical applications in low‐cost and flexible device manufacturing.  相似文献   

12.
    
Highly conductive poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films as stand‐alone electrodes for organic solar cells have been optimized using a solvent post‐treatment method. The treated PEDOT:PSS films show enhanced conductivities up to 1418 S cm?1, accompanied by structural and chemical changes. The effect of the solvent treatment on PEDOT:PSS has been investigated in detail and is shown to cause a reduction of insulating PSS in the conductive polymer layer. Using these optimized electrodes, ITO‐free, small molecule organic solar cells with a zinc phthalocyanine (ZnPc):fullerene C60 bulk heterojunction have been produced on glass and PET substrates. The system was further improved by pre‐heating the PEDOT:PSS electrodes, which enhanced the power conversion efficiency to the values obtained for solar cells on ITO electrodes. The results show that optimized PEDOT:PSS with solvent and thermal post‐treatment can be a very promising electrode material for highly efficient flexible ITO‐free organic solar cells.  相似文献   

13.
Solid and flexible electrochromic (EC) devices require a delicate design of every component to meet the stringent requirements for transparency, flexibility, and deformation stability. However, the electrode technology in flexible EC devices stagnates, wherein brittle indium tin oxide (ITO) is the primary material. Meanwhile, the inflexibility of metal oxide usually used in an active layer and the leakage issue of liquid electrolyte further negatively affect EC device performance and lifetime. Herein, a novel and fully ITO-free flexible organic EC device is developed by using Ag–Au core–shell nanowire (Ag–Au NW) networks, EC polymer and LiBF4/propylene carbonate/poly(methyl methacrylate) as electrodes, active layer, and solid electrolyte, respectively. The Ag–Au NW electrode integrated with a conjugated EC polymer together display excellent stability in harsh environments due to the tight encapsulation by the Au shell, and high area capacitance of 3.0 mF cm−2 and specific capacitance of 23.2 F g−1 at current density of 0.5 mA cm−2. The device shows high EC performance with reversible transmittance modulation in the visible region (40.2% at 550 nm) and near-infrared region ( − 68.2% at 1600 nm). Moreover, the device presents excellent flexibility ( > 1000 bending cycles at the bending radius of 5 mm) and fast switching time (5.9 s).  相似文献   

14.
Chemical and electrochemical stability of thermally evaporated amorphous films of WO3 on conductive glass substrates have been studied in various electrolytes in order to determine the intrinsic lifetime or WO3-based dis-play devices. The thickness loss of the WO3 films measured under storage conditions in the glycerin-H2SO4 (10 : 1) mixture was a linear function of time for devices held at 50? C with a dissolution rate of 20 –25 å/day. Under cycling at room temperature an average dissolution rate of about 18 å/day was observed during the first 30 days at 0.5 Hz and 40 % con-trast [defined as 100 (Bcolored - Bbleached / Bbleached) where B = brightness]. After that time the dissolution rate increased and the WO3 film began to crumble. The dissolution rate of WO3 has also been meas-ured in various non-aqueous solvents. The electrochemical response of WO3 in the various electrolytes has been investigated.  相似文献   

15.
    
Undoped zinc oxide thin films were grown at room temperature using two techniques: plasma deposition (PD) and electron beam evaporation in an argon atmosphere. PD offers some advantages, such as low ion damage and low deposition temperature. The optical transmittance of the films deposited by both methods was higher than 80% in the near UV–VIS range; the energy band gap and index of refraction agree with values reported in the literature. The resistivity of films grown by PD was 3.1 × 10−2 Ω cm, lower than the value of 1.2 × 10−1 Ω cm found for plasma assisted e‐beam evaporated films. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

16.
    
A switch‐like structure that can be turned on/off with photons is considered necessary for most optoelectronic devices, such as phototransistors and photodetectors. However, developing a single device whose photoresponse can be modulated without changing the measuring voltage or illuminating light is challenging, and yet to be achieved. In this work, a conceptually new 2D perovskite‐based fully transparent two‐terminal optoelectronic device that can be turned on/off with a short electric pulse without any further change in the measuring conditions, such as the illuminating photon or applied voltage is proposed and demonstrated. The device exhibits loop opening in the current–voltage characteristics, which is utilized to design the novel electrically triggered optoelectronic device. The photocurrent of the device can be modulated from zero to 2.2 mA using a simple voltage pulse. Further, a responsivity of 550 mA W−1 and detectivity of 2.16 × 1010 Jones are measured in the on‐state. Potentially, the approach opens a new avenue for the design of two‐terminal advanced highly transparent optoelectronic devices, such as smart windows and transparent image sensors.  相似文献   

17.
    
Metallic mesh materials are promising candidates to replace traditional transparent conductive oxides such as indium tin oxide (ITO) that is restricted by the limited indium resource and its brittle nature. The challenge of metal based transparent conductive networks is to achieve high transmittance, low sheet resistance, and small perforation size simultaneously, all of which significantly relate to device performances in optoelectronics. In this work, trilayer dielectric/metal/dielectric (D/M/D) nanomesh electrodes are reported with precisely controlled perforation size, wire width, and uniform hole distribution employing the nanosphere lithography technique. TiO2/Au/TiO2 nanomesh films with small hole diameter (≤700 nm) and low thickness (≤50 nm) are shown to yield high transmittance (>90%), low sheet resistance (≤70 Ω sq?1), as well as outstanding flexural endurance and feasibility for large area patterning. Further, by tuning the surface wettability, these films are applied as easily recyclable flexible electrodes for electrochromic devices. The simple and cost‐effective fabrication of diverse D/M/D nanomesh transparent conductive films with tunable optoelectronic properties paves a way for the design and realization of specialized transparent electrodes in optoelectronics.  相似文献   

18.
    
Transparent p‐type CuI layers with high hole mobility can be fabricated on flexible plastic sheets, a system which has been unattainable with p‐type transparent oxide semiconductors. Mildly heat‐treated CuI layers have mobilities of ≈20 cm2 V−1 s−1, which are comparable to those of p‐type GaN epilayers. Highly transparent p–n diodes with sufficient rectification ratio (106) can be manufactured by employing a heterojunction of p‐type CuI and amorphous n‐type In‐Ga‐Zn‐O layers on plastic sheets. Thus, CuI can be regarded as an excellent transparent p‐type semiconductor for flexible transparent electronics.  相似文献   

19.
    
As environmental considerations for both the processing and disposal of electronic devices become increasingly important, the ability to replace plastic and glass substrates with bioderived and biodegradable materials remains a major technological goal. Here, the use of cellulose nanofiber‐coated paper is explored as an environmentally benign substrate for preparing low‐resistance (460 Ω sq?1), colorless (a* = ?2.3, b* = ?2.7) printed poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) electrodes. The PEDOT:PSS/paper electrodes support the reversible oxidation of three electrochromic polymers (ECPs) (cyan, magenta, and yellow), affording the possibility for fully printed, color displays on paper. Lateral electrochromic devices (ECDs) incorporating an ion gel electrolyte are demonstrated where a magenta‐to‐colorless device achieves a color contrast (ΔE*) of 56 owing to a highly color‐neutral bleached state of the ECP (a* = ?0.5, b* = 2.9). Black‐to‐colorless devices achieve ΔE* = 29 and are able to retain 86% of their color contrast after 9000 switches. The switching times of these lateral devices are quantified through colorimetric image analysis which shows comparable performance for devices constructed on paper as devices using ITO/glass electrodes (10 Ω sq?1). The paper ECDs are then combusted in air leaving 3% of the initial mass at 600 °C, highlighting this approach as a promising route toward disposable displays.  相似文献   

20.
    
Graphene has been highlighted as a platform material in transparent electronics and optoelectronics, including flexible and stretchable ones, due to its unique properties such as optical transparency, mechanical softness, ultrathin thickness, and high carrier mobility. Despite huge research efforts for graphene‐based electronic/optoelectronic devices, there are remaining challenges in terms of their seamless integration, such as the high‐quality contact formation, precise alignment of micrometer‐scale patterns, and control of interfacial‐adhesion/local‐resistance. Here, a thermally controlled transfer printing technique that allows multiple patterned‐graphene transfers at desired locations is presented. Using the thermal‐expansion mismatch between the viscoelastic sacrificial layer and the elastic stamp, a “heating and cooling” process precisely positions patterned graphene layers on various substrates, including graphene prepatterns, hydrophilic surfaces, and superhydrophobic surfaces, with high transfer yields. A detailed theoretical analysis of underlying physics/mechanics of this approach is also described. The proposed transfer printing successfully integrates graphene‐based stretchable sensors, actuators, light‐emitting diodes, and other electronics in one platform, paving the way toward transparent and wearable multifunctional electronic systems.  相似文献   

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