Thermally responsive dual-band electrochromic device

Abstract

It relates to a thermoresponsive dual-band electrochromic device capable of selectively controlling the amount of solar radiation emitted in the visible and near-infrared regions by operating in four different optical states, namely: fully transparent, visible light blocking, near-infrared blocking and total blocking. The device can be regulated by electrical stimulation, i.e. by controlling the sign and intensity of the applied bias voltage, or by thermal stimulation. In the latter, the attenuation of the incident thermal radiation increases with increasing temperature. The thermoresponsive dual-band electrochromic device comprises a first electrode consisting of a first transparent conductive substrate topped with a first electro-optically active layer and a second electrode consisting of a second transparent conductive substrate topped with a second electro-optically active layer, the second electro-optically active layer being separated by a temperature-dependent ion-conducting layer consisting of a thermoresponsive polymer gel, an ion conductor and a plasticizer.

Description

Technical Field

[0001] The present invention relates to an electro-optical device capable of modulating the intensity of incident optical radiation in at least two different spectral regions in response to an electrical or thermal stimulus. Background Art

[0002] Electrochromic windows provide reversible and rapid optical switching between light and dark states with large contrast. Compared to other types of smart window technologies, the electro-responsive system provides uniform optical properties in different states. A notable example is the automatic dimming smart window developed by Gentex, now installed on Boeing's 787 Dreamliner aircraft. [J. Jensen, M. [Al Dyer, F Krebs, Adv. Funct. Mater. 2015, 25, 2073. / www.gentex.com] It allows passengers to control the amount of sunlight passing through the window with a few simple touches at low voltage. Typical designs for window applications include five thin film layers on a single glass substrate or sandwiched between two glass substrates, where the absorption spectrum of one or more electrochromic materials changes through oxidation or reduction reactions. In other words, electrochromic materials do not emit light themselves, but instead exhibit color through light absorption. Electrochromic devices with these properties are widely used in applications such as vehicle mirrors and sunroofs, smart windows, and outdoor displays.

[0003] Due to the huge energy-saving potential offered by reducing cooling and heating loads, there is a growing demand for selectively modulating infrared waves without affecting (or with limited effect on) the transparency of visible light (VIS). In particular, approximately half of the solar energy incident on a window is in the near-infrared (NIR) spectral region, which does not contribute to daylighting.

[0004] Recent research achievements in the field of near-infrared selective plasmonic nanomaterials have paved the way for the realization of next-generation dual-band smart windows, which can achieve independent control of the near-infrared spectral region. Electrochromic devices based on plasmonic nanocrystals can indeed achieve NIR selective operation, inherently fast switching and greatly improved durability [Runnerstrom et al. Chem. Commun., 2014, 50, 10555]. For example: U.S. Patent No. 6193912, entitled "NEAR INFRARED-ABSORBING ELECTROCHROMIC COMPOUNDS AND DEVICES COMPRISING SAME (Near-infrared absorbing electrochromic compounds and devices containing the same)". U.S. Patent No. US2015 / 022980 “CONDUCTIVE TRANSITION METAL OXIDE ELECTROCHROMIC MATERIAL AND OPTICAL SWITCHING DEVICES CONSTRUCTED THEREOF”, U.S. Patent No. US9207513B2 “NANOCRYSTAL-POLYMER NANOCOMPOSITE ELECTROCHROMIC DEVICE”, U.S. Patent No. US2012 / 047935 “ELECTROCHROMIC NANOCOMPOSITE FILMS”.

[0005] Individual dynamic control of the NIR and VIS spectral regions is particularly advantageous for the development of energy-efficient glass facades, as it offers the intriguing prospect of implementing a system that allows ample daylight while conveniently regulating the thermal radiation entering the window. However, commercially available electrochromic dynamic windows to date have been unable to independently control the light transmittance T. LUM (measured according to ASTM D 1003-07) and Solar Heat Gain Coefficient (SHGC) (measured according to ASTM C 1199-14).

[0006] The market prospects for these technologies are expected to broaden based on improving the comfort of building occupants, especially as part of a package where smart windows are combined with smart lighting to provide optimal lighting and heating control.

[0007] While the aforementioned references disclose the use of various anode and cathode materials as active electrodes in electrochromic devices, to the applicant's knowledge, they are unable to simultaneously provide the following functions: 1. selectively modulate NIR radiation independently of VIS transmittance; and 2. responsively modulate thermal transmittance based on device temperature. This inability to operate in this manner has limited the use of prior art devices in many applications. SUMMARY OF THE INVENTION

[0009] The present invention is directed to a thermally responsive dual-band electrochromic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Schematic diagram of the dual-band tuning mechanism allowed by the dual-band electrochromic device disclosed here: NIR and T LUM The variation of is plotted as a function of the applied bias voltage.

[0011] Figure 2 A schematic cross-sectional view of a thermally responsive dual-band electrochromic device implemented according to a first preferred embodiment is disclosed.

[0012] Figure 3 A schematic cross-sectional view of a thermally responsive dual-band electrochromic device implemented according to a second preferred embodiment is disclosed.

[0013] Figure 4 A schematic cross-sectional view of a thermally responsive dual-band electrochromic device implemented according to a third preferred embodiment is disclosed.

[0014] Figure 5 A cross-sectional view of a nanocrystalline transparent conductive layer made of ITO nanoparticles achieved according to the preparation process described in Example 1 is disclosed.

[0015] Figure 6 The electrogeneration scheme of aromatic polyimide employed as the bipolar electrochromic polymer in Example 3 is disclosed. Detailed Description of the Invention

[0017] The present invention is directed to a thermally responsive dual-band electrochromic device comprising:

[0018] 1) a first transparent conductive substrate on which a first electro-optically active electrode is deposited, wherein the first electro-optically active electrode consists of at least one nanocrystalline transparent semiconductor layer and at least one electrochromic layer, wherein the first electro-optically active electrode is implemented as one of the following embodiments: 1a. a combination of a plurality of transparent conductive oxide nanocrystals that allow tuning of light transmittance in the NIR range, and at least one electrochromic polymer layer that allows tuning of light transmittance in the VIS range, or

[0019] 1b. A combination of a plurality of transparent metal oxide nanoparticles, which allows the light transmittance to be adjusted in the VIS range, and at least one electrochromic plasmonic layer, which allows the light transmittance to be adjusted in the NIR range, or

[0020] 1c. A combination of a plurality of transparent semiconductor nanoparticles that remain substantially transparent in both the visible and NIR ranges over the entire operating potential range, and a bipolar electrochromic polymer capable of reversibly tuning VIS transmittance in response to negative and positive applied potentials,

[0021] 2) a second transparent conductive substrate having deposited thereon a second electro-optically active electrode, wherein the second electro-optically active electrode is composed of a plurality of transparent semiconductor nanoparticles, which: 2a and 2b: remain substantially transparent within a potential range in which the first nanocrystalline transparent conductive layer can switch to a low transmittance state when the first electro-optically active electrode is selected from 1a or 1b, or 2c: modulate light transmittance in the NIR range in response to a negative potential within a range of potentials when the first electro-optically active electrode is 1c, wherein the bipolar electrochromic polymer is substantially transparent, and 3) a temperature-dependent ion-conducting layer embedded between the first electro-optically active electrode and the second electro-optically active electrode, wherein the temperature-dependent ion-conducting layer comprises a thermoresponsive polymer gel, an ion conductor, and an organic plasticizer.

[0022] The thermally responsive dual-band electrochromic devices disclosed herein are surprisingly able to selectively modulate VIS radiation independently of NIR transmittance; and to responsively modulate their thermal transmittance based on device temperature. This allows:

[0023] 1. Selectively and reversibly modulate the intensity of transmitted optical radiation in the visible and near-infrared spectral ranges in response to a specific applied bias potential;

[0024] 2. As the device temperature increases, the light transmittance in the near-infrared spectral range is responsively attenuated.

[0025] It can be used to realize dynamically switchable smart glass windows for a wide range of applications, from buildings and architecture to transportation and automobiles.

[0026] The device will be described more fully below with reference to the accompanying drawings, in which exemplary embodiments of the present invention are shown. However, the present invention can be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. On the contrary, these exemplary embodiments are provided to make this disclosure thorough and to fully convey the scope of the invention to those skilled in the art. In the accompanying drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. The same reference numerals in the figures represent the same elements.

[0027] In this specification and claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. The preposition "between" defines a range that also includes both ends.

[0028] Hereinafter, the expression "electro-optically active" refers to a physical system whose optical properties can be modified and / or adjusted by applying an electrical stimulus.

[0029] The expression "substantially transparent" in reference to a substrate, film, layer or material indicates a condition of high light transmittance of the substrate, film, layer or material. It must be associated with a total transmittance of more than 80%. Definitions and abbreviations:

[0030] where T(λ) is the light transmittance at a given wavelength λ, and E(λ) is the solar irradiance spectrum per ASTM G-173 for air mass 1.5.

[0031] where T(λ) is the light transmittance at a given wavelength λ, is the spectral sensitivity of the light-adapted human eye.

[0032] LSPR: Localized Surface Plasmon Resonance

[0033] LUMO: lowest unoccupied molecular orbital

[0034] V OC : Open circuit potential

[0035] V NIR-ON : corresponds to T NIR Adjust the starting anode potential V NIR-SAT : corresponds to T NIR Saturated anode potential V LUM1-ON : corresponds to T LUM Adjust the starting anode potential V LUM1-SAT : corresponds to T LUM Saturated anode potential V LUM2-ON : corresponds to T LUM Adjust the cathode potential V LUM2-SAT : corresponds to T LUM Saturated cathode potential

[0036] TCO: Transparent Conductive Oxide

[0037] ITO: Indium Tin Oxide

[0038] SEM: Scanning Electron Microscope

[0039] Schematic diagram of the electro-optical behavior of the dual-band thermal response electrochromic device disclosed herein (see Figure 1 ), when V NIR-ON and V NIR-SATWhen a negative (anode) potential between NIR always decreases from its initial value (above 75, preferably above 85%) to its saturation value (below 10%, preferably below 1%), while T LUM Keep it high (preferably above 85%). At higher negative potentials, i.e., ranging from V LUM1-ON to V LUM1-SAT , the electrochemical oxidation of one of the electrochromic materials constituting the first electro-photoactive electrode is also converted into T LUM The significant decrease until it reaches the corresponding V LUM1-SAT saturation value, where T is observed LUM The value is less than 15%, and preferably less than 5%.

[0040] When V OC To V LUM2-ON When a positive (cathode) potential between V and V is applied to the first transparent conductive substrate, the dual-band electrochromic device becomes substantially transparent in both the VIS and NIR ranges. At a higher positive potential, i.e., between V LUM2-ON Between VLUM2-SAT, the first electro-optically active electrode undergoes strong coloration, driving the dual-band electrochromic device in the VIS blocking state: T LUM The selectivity drops to values ​​below 15% and preferentially below 5%, while T NIR Maintain above 75% and preferably above 85%. OC To V NIR-ON When a negative potential between 1 and 2 is applied to the first transparent conductive substrate, the dual-band electrochromic device returns to its fully transparent state.

[0041] In addition to the aforementioned electro-optical responsiveness, the temperature-dependent ion-conducting layer also endows the device disclosed herein with a complementary special thermal responsiveness, which synergistically combines with the dual-band electrochromism to enable it to intelligently adjust T in response to a given temperature variation range. NIR In particular, when the NIR-ON To V NIR-SAT When a negative (anode) potential is applied to the first electro-optically active electrode, the electrochromic device responds to ambient temperature changes, such as those associated with daily and seasonal changes in sunlight intensity, by regulating T NIR That is, at higher sunlight intensities, the device switches to a lower T NIR It must be noted that this thermal responsiveness is not provided as a standalone operating mechanism, as it can only be achieved in the case of a voltage between V NIR-ON and V NIR-SATWhen the dual-band electrochromic device disclosed herein operates as a NIR dynamic filter, additional options for triggering and adjusting the dual-band electrochromic device disclosed herein are contemplated.

[0042] first and second transparent conductive substrates

[0043] The first transparent conductive substrate (100) and the second transparent conductive substrate (200) are both composed of transparent glass substrates (101) and (201) covered with transparent conductive layers (102) and (202) respectively. The composition and thickness of the transparent glass substrate and the transparent conductive layer can be selected from a variety of options. The transparent conductive layers (102) and (202) can be formed by transparent conductive films prepared using inorganic and / or organic materials. For example, the transparent conductive layers (102) and (202) can include inorganic films of transparent conductive oxides, such as indium tin oxide (ITO), aluminum zinc oxide (AZO), their doped variants, their derivatives or their combinations. Typically, the thickness is between 10 nm and 1000 nm, preferably between 80 nm and 400 nm. However, they must ensure that the transparent conductive substrates (100) and (200) provide a light transmittance of more than 80%, preferably more than 90%, in the spectral range between 380 nm and 2500 nm. The thin transparent conductive layers (102) and (202) have a sheet resistance between 0.1 Ω / sq and 200 Ω / sq, preferably between 10 Ω / sq and 50 Ω / sq. They are typically deposited or otherwise formed by a method selected from spray pyrolysis, solution-based coating, sputtering, evaporation, physical vapor deposition, or chemical vapor deposition.

[0044] first electro-optically active electrode

[0045] In any embodiment of the invention disclosed herein, the first electro-optically active electrode (103) consists of at least one nanocrystalline transparent semiconductor layer (104) and at least one electrochromic layer (106).

[0046] refer to Figure 1 In various embodiments, the nanocrystalline transparent semiconductor layer (104) is composed of at least one electro-optically active material that responds to the application of a voltage between V NIR-ON To V NIR-SAT negative (anode) potential between the NIR The electrochromic layer (106) is composed of an electro-optically active material that responds to the application of a voltage between V LUM1-ON To V LUM1-SAT negative (anode) potential between the LUM reversible modulation.

[0047] In a first preferred embodiment of the invention disclosed herein, the nanocrystalline transparent semiconductor layer (104) comprises a plurality of weakly doped metal oxide nanoparticles (105) that exhibit electrochemically tunable localized surface plasmon resonance (LSPR) scattering in the spectral region between 800 nm and 2500 nm.

[0048] The reliable exploitation of the extraordinary optical advantages of electron oscillations at the interface between weakly doped semiconductor nanoparticles (105) and dielectrics (often referred to as localized surface plasmons) actually provides a unique opportunity to selectively control the intensity of incident NIR (thermal) radiation without affecting the transparency of the window (see Runnerstrom et al. NANOSTRUCTUREDELECTROCHROMIC SMART WINDOWS: TRADITIONAL MATERIALS AND NIR-SELECTIVEPLASMONIC NANOCRYSTALS, Chem. Commun. 2014, 50, 10555-10572). This effect is associated with a purely capacitive charging mechanism: the amplitude of the offset modulated by the applied bias depends on the film thickness, nanoparticle size and doping level, since it is reasonably proportional to the free carrier concentration on the nanoparticle surface.

[0049] The weakly doped metal oxide nanoparticles (105) are formed from Nb-doped titanium oxide, Cs-doped tungsten oxide or Al-doped zinc oxide, preferably from substoichiometric tungsten oxide or Sn-doped indium oxide (or indium tin oxide, ITO). They can be synthesized using any well-known wet chemical colloidal route reported in the technical literature [e.g., see "NEW MATERIALS FOR TUNABLE PLASMONIC COLLOIDAL NANOCRYSTALS." Chem. Soc. Rev., 2014, 43, 3957-3975]. For example, solutions of ITO nanoparticles can be synthesized using well-known colloidal synthesis procedures, such as those mentioned in "SYNTHESISOF A NON-AGGLOMERATED INDIUM TIN OXIDE NANOPARTICLE DISPERSION", Adv. Mat. 2008, 20, 4163-4166" and "PREPARATION AND OPTICAL PROPERTIES OF COLLOIDAL MONODISPERSEAND HIGHLY CRYSTALLINE ITO NANOPARTICLES". Chem. Mater. 2008, 20, 2609-2611".

[0050] The nanocrystalline transparent semiconductor layer (104) can be formed by any well-known procedure for converting chemically tailored colloidal nanoparticles into a high-quality transparent mesoporous film. It can be achieved, for example, by screen printing, inkjet printing, or spraying when formulating a suitable ink or paste containing weakly doped metal oxide nanoparticles (105). After deposition, the film can be heat-treated in air to remove the organic compounds and form the nanocrystalline transparent semiconductor layer (104).

[0051] According to any implementation of the first embodiment, the nanocrystalline transparent semiconductor layer (104) is at V OC Shows high light transmittance (preferably T LUM >85% and T NIR >85%) and between 10 -7 S / cm to 10 -4 The electronic conductivity σ is between S / cm.

[0052] In a preferred implementation of the first embodiment, the electrochromic layer (106) is formed from a redox electrochromic polymer (113) deposited on top of the nanocrystalline transparent semiconductor layer (104). It can be formed from a conjugated polymer incorporating at least one of the following electro-optically active compounds: quinone, imide, carbazole, viologen, triphenylamine. In various implementations of the invention disclosed herein, the conjugated polymer is preferably polyaniline, polythiophene, or polypyrrole.

[0053] The electrochromic layer (106) is subjected to a voltage lower than V NIR-SAT At negative (anode) potentials, it remains essentially transparent, while at higher potentials (i.e., between V LUM1-ON To V LUM1-SAT The specific condition for achieving dual-band selective spectral control of light transmittance is the position of the conduction band edge of the weakly doped metal oxide nanoparticles (105) relative to the lowest starting redox potential value of the redox electrochromic polymer (113): the conduction band edge of the weakly doped metal oxide nanoparticles (105) must be lower than the starting redox potential of the electrochromic layer (106) by between 10 meV and 500 meV, preferably between 100 meV and 250 meV.

[0054] refer to Figure 1 The schematic "T vs V" diagram reported in the NIR-ON To V NIR-SAT When a negative (anode) potential between NIR As the optical density of the nanocrystalline transparent semiconductor layer (104) increases, the optical density continues to decrease, thereby making the dual-band electrochromic device have a T value higher than 75%, preferably higher than 85%. NIRSwitch to below 10%, preferably below 5% T NIR , and T LUM Keep above 75%, preferably above 85%. At higher negative potentials, i.e. from V LUM1-ON to V LUM1-SAT , due to the electrochemical reduction of the electrochromic polymer layer (106), T LUM When the range is V OC To -V LUM2-ON When a positive potential between 1 and 2 is applied to the transparent conductive substrate (100), the dual-band electrochromic device returns to its fully transparent state.

[0055] In a second embodiment of the thermally responsive dual-band electrochromic device disclosed herein, the first electro-optically active electrode (103) is made of a combination of a plurality of transparent metal oxide nanoparticles (107), which allows the adjustment of light transmittance in the VIS range, and at least an electrochromic plasma layer (108), which covers each of the plurality of transparent metal oxide nanoparticles (107) and allows the adjustment of light transmittance in the NIR range.

[0056] exist Figure 3 In a preferred implementation of the second embodiment schematically depicted in FIG, the first electro-optically active electrode (103) is formed from a plurality of core-shell building blocks, wherein the outer electrochromic plasma layer (108) is preferably made of a transparent semiconductor material. NIR-ON To V NIR-SAT When the negative (anode) potential is between NIR , while the inner electrochromic region (107) is caused by applying a voltage between V LUM1-ON To V LUM1-SAT The metal transition oxide selectively absorbs incident VIS radiation at a negative (anodic) potential between 0.

[0057] The conduction band edge of the electrochromic plasma layer (108) is at a lower electrochemical potential than the inner region. The potential gap ΔV between the conduction band edges of the inner and outer materials is between 10mV and 900mV, preferably between 100meV and 500meV.

[0058] In a preferred implementation of the second embodiment, the outer electrochromic plasma layer (108) is at V OCThe inner region (107) is composed of an electrochromic metal oxide preferably selected from the group consisting of tungsten oxide, molybdenum oxide, niobium oxide, titanium oxide, copper oxide, iridium oxide, chromium oxide, manganese oxide, vanadium oxide, nickel oxide, cobalt oxide, etc.

[0059] In any implementation of the second embodiment, only the outer electrochromic plasma layer (108) is in physical contact with the temperature-dependent ionically conductive medium (301).

[0060] When applying an anodic potential in the range of VNIR-ON to VNIR-SAT, electrons accumulated on the surface of the electrochromic plasma layer (108) cause a blue shift and enhancement of the LSPR, which is marked by a strong optical extinction in the NIR range as described above. At higher potentials, diffusion-driven ion insertion into the inner electrochromic region (107) also becomes a significant modulation of the VIS absorption.

[0061] In order to allow ions to be inserted into the inner region (107), the thickness of the outer electrochromic plasma layer (108) must be between 0.1 and 10 nm, preferably between 1 nm and 5 nm, while the radius of the inner electrochromic region (107) can be between 1 and 100 nm, preferably between 5 nm and 25 nm.

[0062] In a third embodiment of a thermally responsive dual-band electrochromic device disclosed herein, it is schematically depicted in Figure 4 In the invention, the first electro-optically active electrode (103) comprises: a first transparent nanocrystalline semiconductor layer (109), which remains substantially transparent in both the VIS and NIR ranges over the entire operating potential range of the thermally responsive dual-band electrochromic device, and a bipolar bipolar electrochromic layer (110), which is capable of reversibly adjusting the VIS transmittance in response to the potential applied by the anode (negative) and the cathode (positive).

[0063] According to a preferred implementation of the third embodiment, the first transparent nanocrystalline semiconductor layer (109) does not contribute to the modulation of light transmittance. It consists of a plurality of transparent metal oxide nanoparticles (109), preferably (undoped) titanium dioxide nanoparticles or (undoped) zinc oxide nanoparticles, which are deposited on top of a transparent conductive substrate (100) to form a thin mesoporous layer, which is then used as a template for depositing the electrochromic layer (105).

[0064] The transparent metal oxide nanoparticles (109) can be produced by various sol-gel chemical procedures well known to experts in the field (Niederberger, NONAQUEOUS SOL–GEL ROUTES TO METAL OXIDE NANOPARTICLES. Acc. Chem. Res., 2007 40, 9, 793-800). The average size of the electro-optically passive transparent semiconductor nanoparticles (109) is in the range of 1 nm to 30 nm, preferably in the range of 1 nm to 5 nm. They are deposited on top of the first transparent conductive substrate (100) by one of the well-known thin film deposition techniques (spin coating, screen printing, slot die, etc.). Depending on the specific synthesis route adopted to prepare the nanoparticle suspension, a post-deposition heat treatment may be required. The thickness of the transparent nanocrystalline semiconductor layer formed by the (electro-optically passive) metal oxide nanoparticles (109) is in the range of 1 nm to 500 nm, preferably in the range of 5 nm to 100 nm.

[0065] According to the same preferred implementation of the third embodiment, the electrochromic layer (104) is formed of a bipolar redox electrochromic polymer (115) capable of undergoing a reversible electrochemical process and a strong color change upon electrooxidation and electroreduction. It is indeed capable of reversibly modulating the visible light transmittance T in response to an anodic or cathodic bias voltage. LUM This allows the dual-band electrochromic device disclosed herein to be LUM2-ON To V LUM2-SAT When a positive (cathode) bias voltage between LUM Selective reversible modulation.

[0066] The bipolar redox polymer layer (110) is preferably composed of aromatic polyimide or polyanthraquinone as the main polymer chain, to which electroactive terminal triphenylamine or carbazole groups are grafted and serve as color centers. It can be prepared by the following procedures reported in the literature: the two-step polymerization procedure reported by Chang et al. in NOVEL RAPID SWITCHING AND BLEACHING ELECTROCHROMIC POLYIMIDES CONTAINING TRIARYLAMINE WITH 2-PHENYL-2-ISOPROPYL GROUPS (Polymer, 51, 2010, 4493-4502), or the electropolymerization reported by Koyuncu et al. in AN AMBIPOLAR ELECTROCHROMIC POLYMER BASED ON CARBAZOLE AND NAPHTHALENE BISIMIDE: SYNTHESIS AND ELECTRO-OPTICAL PROPERTIES (Electrochimica Acta, 68, 2012, 184-191), or by Hsiao et al. in A COMPARATIVE STUDY OF REDOX-ACTIVE, AMBIPOLAR ELECTROCHROMIC TRIPHENYLAMINE-BASED POLYIMIDES The electrochemical polymerization and conventional polycondensation methods disclosed in PREPARED BY ELECTROCHEMICALPOLYMERIZATION AND CONVENTIONAL POLYCONDENSATION METHODS (Pol.Chem., 2018, 9(2), 236-248) are described.

[0067] In any embodiment of the invention disclosed herein, the thickness of the first electro-optically active electrode (103) is between 50 nm and 2000 nm, and preferably between 150 nm and 500 nm.

[0068] The second electro-optical electrode

[0069] In the first and second preferred embodiments of the invention disclosed herein, the second electro-optical electrode (203) serves as an ion storage layer. It is made of a plurality of transparent semiconductor nanoparticles (204) and is substantially transparent in the spectral range between 380 nm and 2500 nm under any applied cathodic (positive) potential and transparent in the spectral range between V OC and V LUM2-ONIt is essentially transparent in the spectral range between 380nm and 700nm under the condition of an anodic (negative) potential between V OC To V LUM2-SAT At an anodic (negative) potential between 1.5 and 2.5 V, it is essentially transparent in the spectral range between 700 nm and 2500 nm.

[0070] The transparent electro-optically passive semiconductor nanoparticles (204) may be made of transparent metal oxides, such as indium oxide, tin oxide, manganese oxide, zinc oxide, gallium oxide, molybdenum oxide, iron oxide and mixtures thereof, preferably ceria and titanium dioxide.

[0071] In a third preferred embodiment of the invention disclosed herein, which corresponds to Figure 4 , the second electrode (203) is also an electro-optically active electrode and consists of a transparent nanocrystalline semiconductor layer (210) that exhibits electrochemically tunable localized surface plasmon resonance scattering in the spectral region between 800 nm and 2500 nm, while the first electro-optically active electrode (103) consists only of a bipolar electrochromic polymer (110) deposited on top of a first transparent conductive substrate.

[0072] The transparent nanocrystalline semiconductor layer (210) of the second nanostructured electrode (203) is implemented as described previously for the transparent semiconductor layer of the first electro-optically active electrode (103) used as a preferred implementation of the first embodiment. It is preferably formed of at least one of the following materials: substoichiometric tungsten oxide, Sn-doped indium oxide (or indium tin oxide, ITO), Nb-doped titanium oxide, Cs-doped tungsten oxide, Al-doped zinc oxide, and can be formed according to the same procedure as described above.

[0073] Its spectral response is essentially complementary to that of the bipolar electrochromic polymer (110) which responds only in the VIS range. Its optical density can be electrochemically tuned to NIR-ON To V NIR-SAT Adjust T at the negative (anode) potential between NIR , while maintaining high T LUM Value, preferably higher than 85%.

[0074] In any embodiment, the thickness of the second electro-optically active electrode (203) is between 100 nm and 4000 nm, preferably between 200 nm and 1000 nm.

[0075] Temperature-dependent ion-conducting layer

[0076] In any embodiment of the invention disclosed herein, the first electro-optically active electrode (103) and the second electro-optically active electrode (203) are interfaced with a temperature-dependent ion-conducting layer (301) that provides positive and negative ions to ensure charge neutrality under any applied bias.

[0077] In recent years, there has been increasing interest in the study of temperature-dependent ionic conductivity, and several assembly structures of different ionic liquid-based block copolymers with thermoresponsive segments have been proposed. For example, thermoreversible polymer gels using triblock copolymers based on poly(ethylene oxide) that self-assemble into different microcrystalline phases upon temperature changes have been developed as novel polymer gel electrolytes with microphase-dependent ionic conductivity (see, for example, “IONIC CONDUCTIVITY THROUGHTHERMO-RESPONSIVE POLYMER GEL: ORDERING MATTERS,” Langmuir 2012, 28, 751–756).

[0078] The temperature-dependent ion-conducting layer (301) disclosed in the thermoresponsive dual-band electrochromic device mentioned herein comprises at least one thermoresponsive polymer gel, at least one ionic compound and at least one organic plasticizer.

[0079] The thermoresponsive polymer gel can be formed from at least two polymer blocks, at least one of which is composed of an ionic liquid-based block and the other of which is composed of a polar polymer that is at least partially crystalline at room temperature.

[0080] Ionic liquid-based polymer blocks can be made from several classes of linear, quaternized copolymers that are stable over a wide temperature range. These blocks can be obtained by polymerizing an electrolyte precursor solution containing an ionic liquid and at least one monomer capable of forming a gel upon polymerization. The ionic liquids can contain positively charged cyclic amine groups, such as pyrazolium, pyrrolidinium, and pyrrolium, with imidazolium and pyridinium being preferred.

[0081] Another constituent element is a polar polymer block, which can be synthesized starting from conventional monomers known to those skilled in the art. There are no restrictions on the type of monomer as long as it can form a gel polymer by polymerization. Examples of copolymerizable monomers are styrene-containing monomers such as styrene itself, divinylbenzene, cyano-containing monomers such as methacrylonitrile, unsaturated carboxylic acids such as acrylic acid and its salts such as sodium acrylate, anhydrides such as maleic anhydride, esters such as methyl methacrylate, ethyl acrylate, propyl acrylate, tetra(ethylene glycol) diacrylate, hydroxyethyl methacrylate, vinyl halides such as vinyl chloride, vinyl fluoride, and vinyl bromide, vinyl halide monomers such as vinylidene chloride, vinylidene fluoride, and vinylidene bromide, vinyl esters such as vinyl formate, vinyl acetate, vinyl-containing acid compounds or their salts, anhydrides, or derivatives such as p-styrenesulfonic acid, methallylsulfonic acid, vinyl ethers such as methyl vinyl ether, and dienes such as butadiene, isoprene, and chloroprene. Good candidates are, for example, polymers containing alkyl methacrylate monomer units in combination with alkylpyridine and / or alkylimidazole monomer units; these units may be present in appropriate proportions. The electrolyte precursor solution may also contain conventional polymerization initiators known to those skilled in the art.

[0082] The ionic compound used in the present invention can be composed of organic cations and inorganic anions, and is compatible with the ionic liquid-based copolymer block. Compatibility depends primarily on the type of anion and has a significant impact on the transparency of the gel polymer electrolyte using ionic liquids and vinyl monomers. The type of anion in the ionic liquid determines whether the ionic liquid is hydrophilic or hydrophobic. Any lithium salt or acid known to those skilled in the art can be used. Suitable ionic conductors are lithium salts LiCIO4, LiCF3SO3, LiPF6, LiN(CF3SO)2, LiBF4 and LiAsF6, as well as other salts, including K-based salts, Na-based salts, Al-based salts and various organic salts, preferably tetraalkylammonium organic sulfonates and perchlorates.

[0083] In various embodiments, the temperature-dependent ion-conducting layer (301) further comprises at least one plasticizer or alternative cosolvent that is substantially miscible in the polymer backbone. Examples of suitable plasticizers or cosolvents are: methyl sulfolane, propylene carbonate, α-butyrolactone, polyethylene glycol, glycerol, sorbitol, diethylene glycol, dipropylene glycol, ethylene glycol and / or propylene glycol. Their total concentration is typically less than 20 wt%, preferably less than 10 wt%.

[0084] The temperature-dependent ion-conducting layer is preferably used in the form of a viscous gel that is suitable for curing by heat treatment or UV radiation exposure after being deposited on one of the two electro-optically active electrodes (103) or (203). In a preferred preparation method, the ionic compound is dissolved in a suitable solvent and then mixed with the thermoresponsive polymer gel and a plasticizer. A representative but non-exhaustive list of suitable solvents is: ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, dimethylformamide, tetrahydrofuran and mixtures thereof. The solvent is then partially removed after preparation in order to cure the electrolyte. It can also be used in the form of a laminated (or extruded) solid film (or membrane).

[0085] In general, the interface region between the temperature-dependent ion-conducting layer and the two electro-optically active electrodes typically (but not necessarily) has a heterostructure comprising at least two discrete components represented by different phases and / or compositions, the concentrations of which vary across the width of the interface region.

[0086] In any embodiment, the ionic conductivity of the temperature-dependent ion-conducting layer (301) varies with temperature. In the temperature range between -5°C and +80°C, it can vary from 10 -7 S / cm to 10 -3 S / cm oscillation.

[0087] The magnitude of the temperature-dependent NIR light transmittance variation can be adjusted by fine-tuning the composition of the temperature-dependent ion-conducting layer. The manner in which the invention disclosed herein can be implemented is not limited to some specific relationship between transmittance and temperature, nor to any exclusive formulation of the temperature-dependent ion-conducting medium. Rather, the present disclosure contemplates any formulation of the temperature-dependent ion-conducting layer (301) that conforms to the principle of thermally driven reduction in light transmittance of an electro-optically active electrode due to an increase in the available ion density in the electrolyte at a given applied voltage.

[0088] The thickness of the thermally responsive ion-conducting layer (301) is between 100 nm and 100,000 nm, preferably between 500 nm and 5,000 nm.

[0089] Overview of the Preferred Embodiments

[0090] In a first preferred embodiment, the dual-band electrochromic device of the present invention comprises:

[0091] a) A transparent conductive substrate (100) on which a first electro-optically active electrode (103) is deposited, wherein the first electro-optically active electrode consists of a nanocrystalline transparent semiconductor layer (104) and at least one electrochromic layer (106), wherein the nanocrystalline transparent semiconductor layer (104) consists of a plurality of transparent conductive oxide nanocrystals (105) which allow the light transmittance to be adjusted in the NIR range, and at least the electrochromic layer (106) is formed of a redox electrochromic forming polymer (113) which allows the light transmittance to be adjusted in the VIS range.

[0092] b) a second transparent conductive substrate (200) on which a second electro-optically active electrode (203) is deposited, wherein the second electro-optically active electrode comprises a plurality of transparent semiconductor nanoparticles (204) that remain substantially transparent over a potential range in which the first nanocrystalline transparent conductive layer (104) can switch to a low transmittance state.

[0093] c) A thermoresponsive ion-conducting layer (301) embedded between the first electro-optically active electrode (103) and the second electro-optically active electrode (203), comprising a thermoresponsive polymer gel, an ion conductor, and an organic plasticizer.

[0094] In a second preferred embodiment, the dual-band electrochromic device of the present invention comprises:

[0095] a) A transparent conductive substrate (100) on which a first electro-optically active electrode (103) is deposited, wherein the first electro-optically active electrode consists of a plurality of transparent semiconductor nanoparticles (107) that allow the light transmittance in the VIS range to be adjusted, and at least one electrochromic plasma layer (108) that allows the light transmittance in the NIR range to be adjusted.

[0096] b) a second transparent conductive substrate (200) on which a second electro-optically active electrode (203) is deposited, wherein the second electro-optically active electrode comprises a plurality of transparent semiconductor nanoparticles (204) that remain substantially transparent over a potential range in which the first nanocrystalline transparent conductive layer (104) can switch to a low transmittance state.

[0097] c) A temperature-dependent ion-conducting layer (301) embedded between the first electro-optically active electrode (103) and the second electro-optically active electrode (203), comprising a thermoresponsive polymer gel, an ion conductor, and an organic plasticizer.

[0098] In a third preferred embodiment, the thermally responsive dual-band electrochromic device of the present invention comprises: a) a first transparent conductive substrate (100) having deposited thereon a first electro-optically active electrode (103), wherein the first electro-optically active electrode is composed of: a nanocrystalline transparent semiconductor layer (104) which remains substantially transparent over the entire potential range covered by the operation of the thermally responsive dual-band electrochromic device, and a bipolar electrochromic polymer (115) which is capable of reversibly modulating VIS transmittance in response to negative (anode) and positive (cathode) applied potentials,

[0099] b) a second transparent conductive substrate (200) having a second electro-optically active electrode (203) deposited thereon, wherein the second electro-optically active electrode is composed of a plurality of weakly doped metal oxide nanoparticles (210) that modulate light transmittance in the NIR range in response to a negative potential within a potential range, wherein the bipolar electrochromic polymer results in substantial transparency,

[0100] c) A thermoresponsive ion-conducting layer (301) embedded between the first electro-optically active electrode (103) and the second electro-optically active electrode (203), comprising a thermoresponsive polymer gel, an ion conductor, and an organic plasticizer.

[0101] In the following examples, three specific thermally responsive dual-band electrochromic devices are described according to the above three preferred embodiments of the invention disclosed herein. Example

[0102] Example 1 : Thermally responsive dual-band electrochromic device implemented according to the first preferred embodiment According to a first preferred embodiment, the dual-band electrochromic device is composed of:

[0103] 1) The first electro-optically active electrode (103) is composed of a 1100 nm thick mesoporous indium tin oxide (ITO) film as a nanocrystalline transparent conductive layer (104), topped with a 150 nm thick polyaniline layer as a redox layer electrochromic polymer layer (113). To prepare the optically active electrode (103), 3 ml of a 20 nm sized ITO nanocrystal suspension (In2O3:SnO2 90:10, 10 wt% in ethanol, purchased from Avantama TM) was mixed with 5 ml of α-terpineol and 0.65 g of ethyl cellulose to prepare a suitably viscous slurry, which was subsequently deposited by screen printing onto a 1.1 mm thick ITO-coated glass substrate (100) (40 Ω / sq, purchased from Xinyan Technology Ltd). The film was heat-treated in air at 390°C for 30 minutes (after two intermediate 30-minute heating steps at 130°C and 250°C). The polyaniline layer was deposited on the mesoporous ITO electrode by potentiodynamic electrooxidation of aniline purchased from Sigma Aldrich in 0.5 M H2SO4 in the potential range between –0.2 V and +1.3 V (vs. AgCl / Ag), following a procedure such as that disclosed in Dalmolin et al., ELECTROPOLYMERIZATION OF POLYANILINE ON HIGH SURFACE AREA CARBON SUBSTRATES, Journal of Electroanalytical Chemistry, 2005 578, 1, 9-15.

[0104] 2) A second electro-optical electrode (203) is made of a 600 nm thick mesoporous layer comprising 80% cerium dioxide nanoparticles and 20% titanium dioxide nanoparticles. It is obtained by mixing a CeOx-based sol-gel paste with a TiOx-based sol-gel, both prepared by the procedure reported by Munro et al. in ALL SOL-GEL ELECTROCHROMIC SYSTEM FOR PLATE GLASS Journal of Non-Crystalline Solids, 1997, 218, 185-188. The sol-gel paste is deposited on a 2 mm thick ITO-coated glass substrate (200) (40 Ω / sq, purchased from Xinyan Technology Ltd) and then heat-treated in air at 450°C for 30 minutes (after two intermediate 30 minute heating steps at 130°C and 250°C).

[0105] 3) A temperature-dependent ion-conducting layer (301) laminated between the first and second electro-optically active electrodes. It consists of 39% wt of polymethyl methacrylate (MW 120 kDa), 45% wt of vinyl imidazole-grafted polymethyl methacrylate (prepared according to the method described in EP2571904), 10% wt of LiClO4, 5% wt of diethylene glycol and 1% wt of propylene carbonate. It is prepared by dissolving a measured volume of dry LiClO4 in a dry, sealed container filled with propylene carbonate. Then a measured weight of polymethyl methacrylate (MW 120 kDa) is added and the container is heated to 85°C under mechanical stirring until the polymer is completely dissolved. Finally, a measured weight of vinyl-imidazolium-grafted polymethyl methacrylate (MW 11 kDa) is added to the solution and dissolved under continuous stirring at the same temperature.

[0106] After depositing the temperature-dependent ion-conducting layer (301) onto the second electro-optically active electrode (203), the device is assembled to form Figure 2 The sandwich architecture depicted in . According to the manufacturing method described in EP1227362, the first electro-optically active layer (103) is then pushed on top of the gel and the two glasses are subjected to a lamination process in an autoclave at 130°C and 0.2 bar.

[0107] Example 2 : Thermally responsive dual-band electrochromic device implemented according to the second preferred embodiment

[0108] According to a second preferred embodiment, the dual-band electrochromic device is composed of:

[0109] 1) The first electro-optically active layer (103) consists of a 600 nm thick mesoporous (undoped) TiO2 (anatase) layer, which serves as the inner electrochromic region (107), topped with 5 nm Nb-doped titanium oxide, which serves as the electrochromic plasma layer (108). This is achieved by using a TiO2 anatase nanoparticle (Dyesol) containing 18 nm sized TiO2 nanoparticles. TMThe electrochromic plasmonic layer of Nb-doped TiO2 was achieved by immersing the mesoporous TiO2 film in a sol-gel solution consisting of tetraethyl orthotitanate [Ti(OCH2CH3)4], niobium ethanolate [Nb(OCH2CH3)5] and ethanol as solvents, with 2,4-pentanedione as a chelating agent. The molar ratio between TiO2 and Nb2O5 was set to 90:10, which corresponds to a Nb concentration of about 7 wt%. The film was heat treated again at 450°C (in air). This process was repeated several times until the desired thickness (5 nm) was obtained.

[0110] 2) A second electro-optically active electrode (203) was made of an 800 nm thick mesoporous layer containing 80% cerium oxide and 20% titanium dioxide, deposited on 2 mm thick ITO-coated glass (200) (40 Ω / sq, purchased from Xinyan Technology Ltd), following the procedure described in Example 1.

[0111] 3) A temperature-dependent ion-conducting layer (301) laminated between the first electro-optically active electrode (103) and the second electro-optically active electrode (203). It is composed of 75% wt of a thermoresponsive ion-conducting polymer, 24% wt of polymethyl methacrylate (MW 20k Da, purchased from Sigma Aldrich), and 1% of propylene carbonate (purchased from Sigma Aldrich). The thermoresponsive ion-conducting polymer was prepared by free radical copolymerization of lithium N-methylsulfonyl-vinylsulfonimide and poly(ethylene glycol) methyl ether acrylate according to the procedure reported by Matsumura et al. in COMMUNICATION—SYNTHESIS OF FLUORINE-FREE HIGHLY IONCONDUCTIVE POLYMER ELECTROLYTE HAVING LITHIUM BISSULFONIMIDE UNIT, J. Electrochem. Soc. 2018, 165, 8, B3119-B3121.

[0112] After depositing the temperature-dependent ion-conducting layer (301) onto the second electro-optically active electrode (203), the device is assembled to form Figure 3The sandwich structure shown is shown. According to the manufacturing method described in EP1227362, the first electro-optically active layer (103) is then pushed on top of the gel and the two glasses are subjected to a lamination process in an autoclave at 130°C and 0.2 bar.

[0113] Example 3 : Thermally responsive dual-band electrochromic device implemented according to the third preferred embodiment

[0114] According to a third preferred embodiment, the dual-band electrochromic device is composed of:

[0115] 1) A first electro-optically active electrode (103) consisting of a first plurality of ZnO nanoparticles with an average size of 3 nm deposited on a 1.1 mm thick ITO-coated glass substrate (100) (20 Ω / sq, purchased from Xinyan Technology Co., Ltd.) to form a 50 nm thick nanocrystalline transparent semiconductor layer (104), which is topped with a 300 nm thick bipolar electrochromic layer (110) formed of an electrically generated aromatic polyimide as a bipolar electrochromic polymer (115).

[0116] 2) The second electro-optically active electrode (203) consists of a 1100 nm thick nanocrystalline film made of 20 nm sized ITO nanocrystals deposited on a 1.1 mm thick ITO-coated glass substrate (200) (20 Ω / sq, purchased from Xinyan Technology Ltd).

[0117] 3) A temperature-dependent ion-conducting layer (301) laminated between the first electro-optically active electrode (103) and the second electro-optically active electrode (203), comprising 39% wt polymethyl methacrylate, 49% wt poly(1-vinylimidazole-co-methyl methacrylate, 18 kDa purchased from Iolitek), 8% wt tetrabutylammonium perchlorate (TBAClO4, purchased from Sigma Aldrich), 3% wt diethylene glycol (purchased from Sigma Aldrich), and 1% wt propylene carbonate (purchased from Sigma Aldrich).

[0118] The AZO nanoparticles used to prepare the nanocrystalline transparent semiconductor layer (104) were synthesized according to the following procedure: 0.225 g of aluminum isopropoxide Al[(CH3)2CHO]3 and 10.98 g of zinc acetate dihydrate Zn(CH3COO) 22 H2O was dissolved in 500 mL of ethanol. The resulting solution was refluxed at 85°C until 200 mL of ethanol evaporated. KOH was used instead of LiOH to avoid possible reaction with Li +Co-doping. 4.21 g of KOH was added to the solution and dissolved using an ultrasonic bath to obtain a transparent solution. 3 mL of water was added dropwise to the boiling solution under continuous stirring using a magnetic stirrer. After adding water, the solution was sealed and stirred at room temperature for 16 hours. The obtained AZO nanoparticles were separated from the supernatant solution by centrifugation, washed three times with ethanol and re-placed in ethanol. In order to stabilize the obtained AZO colloid, diethanolamine (DEA) was added to ensure that the molar ratio of Zn / DEA was equal to 1.0. The obtained colloidal solution with AZO nanoparticles was deposited onto a 1.1 mm thick ITO-coated glass substrate (100) by spin coating. After heating at 400°C, the film showed excellent uniformity and transparency (T>90%) in the visible spectrum.

[0119] The electrogenerated aromatic polyimide (115) is prepared by Figure 6 The schematic reaction reported in

[15] was repeatedly cycled (between 0 and 1.4 V) at a scan rate of 20 mVs-1 for 10 cycles in dichloromethane using 1 × 10 -3 N,N'-bis(4-diphenylaminophenyl)pyromellitimide was obtained by electropolymerization in M ​​solution. N,N'-bis(4-diphenylaminophenyl)pyromellitimide was obtained by condensing pyromellitic dianhydride (purchased from Sigma Aldrich) with two equivalents of 4-aminotriphenylamine (purchased from Sigma Aldrich) according to the synthesis procedure described by Jeon et al. in SYNTHESIS AND CHARACTERIZATION OF STAR-SHAPED IMIDE COMPOUNDS, Rapid Communication in Photoscience, 2012, 1, 19-20.

[0120] The ITO nanocrystalline thin film used as the second electro-optically active electrode was prepared by the same procedure used to prepare the first nanocrystalline transparent conductive layer (104) described in Example 1.

[0121] The temperature-dependent ion-conducting layer was prepared by dissolving 1.5 g of TBAClO4 and 0.75 g of ethylene glycol in a container with 20 ml of propylene carbonate. 7.5 g of polymethyl methacrylate (20 kDa, purchased from Sigma Aldrich) was then added and the container was heated to 75°C under mechanical stirring until the polymer was completely dissolved. Finally, 9.0 g of poly(1-vinylimidazole-co-methyl methacrylate) (18 kDa from Iolitek) was added to the solution and dissolved under continuous stirring at the same temperature. The container was then cooled to room temperature and laminated between the first and second electro-optically active electrodes. The thickness of the temperature-dependent ion-conducting layer during the lamination process was approximately 1800 nm.

Claims

1. Dual-band electrochromic device, including: - a first transparent conductive substrate on which a first electro-optically active electrode is deposited, wherein the first electro-optically active electrode is composed of a first nanocrystalline transparent semiconductor layer and at least one electrochromic layer, - a second transparent conductive substrate having a second electro-optically active electrode deposited thereon, wherein the second electro-optically active electrode is composed of a second nanocrystalline transparent semiconductor layer, - a temperature-dependent ion-conducting layer embedded between the first electro-photoactive electrode and the second electro-photoactive electrode, comprising a thermoresponsive polymer gel, an ion conductor, and an organic plasticizer, wherein - the first electro-optically active electrode is capable of selectively adjusting light transmittance in the near-infrared spectral range when an electrical bias is applied within a first potential range, and selectively adjusting light transmittance in the visible light range when an electrical bias is applied within a second potential range, - the second electro-optically active electrode is capable of adjusting the light transmittance in the near infrared range upon application of an electrical bias comprised in a third potential range that overlaps neither the first potential range nor the second potential range of the first electro-optically active electrode, and The temperature-dependent ion-conducting layer is capable of adjusting the density of charges flowing between the first electro-optically active electrode and the second electro-optically active electrode according to temperature changes.

2. The dual-band electrochromic device according to claim 1, wherein: The first nanocrystalline transparent semiconductor layer includes a plurality of weakly doped metal oxide nanoparticles and Sn-doped indium oxide, Nb-doped titanium oxide, and Al-doped zinc oxide nanoparticles.

3. The dual-band electrochromic device according to claim 1, wherein: The first nanocrystalline transparent semiconductor layer includes a plurality of weakly doped metal oxide nanoparticles, Cs-doped tungsten oxide and substoichiometric tungsten oxide nanoparticles.

4. The dual-band electrochromic device according to claim 2, wherein: The first nanocrystalline transparent semiconductor layer exhibits reversibly tunable localized surface plasmon resonance in a spectral region between 800 nm and 2500 nm.

5. The dual-band electrochromic device according to claim 1, wherein: The at least one electrochromic layer of the first electro-optically active electrode is composed of an electrochromic redox polymer.

6. The dual-band electrochromic device according to claim 5, wherein: The electrochromic redox polymer is composed of a conjugated polymer selected from polyaniline, polythiophene or polypyrrole, and is combined with at least one of the following electro-optically active compounds: quinone, imide, carbazole, viologen, triphenylamine.

7. The dual-band electrochromic device according to claim 6, wherein: The conduction band edge of the first nanocrystalline transparent semiconductor layer is between 10 meV and 500 meV lower than the onset redox potential of the electrochromic redox polymer.

8. The dual-band electrochromic device according to claim 7, wherein: The conduction band edge of the first nanocrystalline transparent semiconductor layer is between 100 meV and 250 meV.

9. The dual-band electrochromic device according to claim 1, wherein: The first electro-optically active electrode is composed of a plurality of transparent semiconductor nanoparticles formed from at least two different electro-optically active materials.

10. The dual-band electrochromic device according to claim 9, wherein: At least one of the two different electro-optically active materials allows adjusting the light transmission in the near infrared range, while the other allows adjusting the light transmission in the visible range.

11. The dual-band electrochromic device according to claim 9, wherein: The first electro-optically active electrode is composed of a plurality of core-shell nanoparticles.

12. The dual-band electrochromic device according to claim 11, wherein: The shell of the core-shell nanoparticles allows adjustment of light transmittance in the near-infrared range, and the core allows adjustment of light transmittance in the visible range.

13. The dual-band electrochromic device according to claim 1, wherein: The second electro-optically active electrode remains transparent within a potential range in which the first nanocrystalline transparent conductive layer can switch to a low transmittance state, and the total light transmittance is above 80%.

14. The dual-band electrochromic device according to claim 13, wherein: The second electro-optically active electrode comprises a plurality of transparent semiconductor nanoparticles, wherein the nanoparticles are made of indium oxide, tin oxide, manganese oxide, zinc oxide, gallium oxide, molybdenum oxide, iron oxide, and a mixture thereof.

15. The dual-band electrochromic device according to claim 13, wherein: The second electro-optically active electrode comprises a plurality of transparent semiconductor nanoparticles, wherein the nanoparticles are made of indium oxide, cerium dioxide and titanium dioxide.

16. The dual-band electrochromic device according to claim 1, wherein: The first electro-optically active electrode comprises: a first transparent nanocrystalline semiconductor layer that remains transparent in the visible and near-infrared ranges over the entire operating potential range, with a total light transmittance of more than 80%, and at least one bipolar electrochromic polymer that can reversibly adjust visible light transmittance in response to potentials applied by the anode (negative) and the cathode (positive).

17. The dual-band electrochromic device according to claim 16, wherein: The bipolar electrochromic polymer consists of aromatic polyimide or polyanthraquinone as the polymer backbone, into which electroactive terminal triphenylamine or carbazole groups are grafted.

18. The dual-band electrochromic device according to claim 1, wherein: The second nanocrystalline transparent semiconductor layer of the second electro-optically active electrode comprises a plurality of transparent semiconductor nanoparticles exhibiting electrochemically tunable localized surface plasmon resonance scattering in a spectral region between 800 nm and 2500 nm.

19. The dual-band electrochromic device according to claim 1, wherein: The thermoresponsive polymer gel of the temperature-dependent ion-conducting layer is formed of at least two polymer blocks, at least one of which is composed of an ionic liquid-based polymer block and the other is composed of a polar polymer that is at least partially crystalline at room temperature.

20. The dual-band electrochromic device according to claim 19, wherein: The ionic liquid-based polymer blocks are made of linear quaternized copolymers.

21. The dual-band electrochromic device according to claim 20, wherein: The quaternized copolymer is a copolymer containing at least one alkylpyridine or at least one alkylimidazole monomer, and the polar polymer block is composed of poly(methyl methacrylate), poly(ethyl acrylate), or poly(ethylene oxide).

22. The dual-band electrochromic device according to claim 1, wherein: The temperature-dependent ion-conducting layer is used in the form of a viscous gel suitable for curing by heat treatment or UV radiation after being laminated between the first electro-optically active electrode and the second electro-optically active electrode.

Images