WO2019034952A1

WO2019034952A1 - All-solid- state electrochromic devices

Info

Publication number: WO2019034952A1
Application number: PCT/IB2018/055658
Authority: WO
Inventors: Marivone GUSATTI; Daniel ARAGAO RIBEIRO DE SOUZA
Original assignee: Gusatti Marivone
Priority date: 2017-08-16
Filing date: 2018-07-29
Publication date: 2019-02-21
Also published as: BR112020003249A2

Abstract

The current invention disclosures the formation of all-solid-state electrochromic devices (ECDs) completely free of indium-doped tin oxide, lithium, and tungsten trioxide materials. These ECDs do not have any kind of liquid or gel electrolyte material in its structure, have great application versatility and can be manufactured on flexible or rigid substrates by using a simple and economical spray coating technique. These ECDs comprise an aluminum substrate or a substrate coated with an aluminum layer, on which are deposited at least one layer of at least one semiconductor material and at least one layer of an electrochromic material or one hybrid layer with combinations of such materials.

Description

ALL-SOLID-STATE ELECTROCHROMIC DEVICES

******

The present invention relates to all-solid-state electrochromic devices.

In particular, the invention in object is advantageously suitable in different technical fields, such as for example, in optical for producing lenses for eyeglasses or similar optical articles, or in construction industry as material for realization of windows or the like to be used in buildings or equivalent, to which the following description makes explicit reference without thereby losing its generality.

Background

Electrochromism is a known physical phenomenon related to the reversible optical changes displayed by some materials when a voltage is applied to them.

Various materials can be used to manufacture electrochromic devices (ECD), such as transition metal oxides, liquid crystals, photonic crystals, and polymers.

There are many possible electrochromic device construction available in the prior art literature and commercially.

Typically, the conventional configuration is composed of multiple layers deposited directly on top of one another.

This configuration includes at least a substrate, two conductive layers, an electrochromic layer, an ion conductor layer (electrolyte), and a counter electrode layer (ion storage layer).

In this conventional EC devices, the transparent conductor layer is generally made up of indium tin oxide (ITO) and the electrochromic layer is typically formed from tungsten oxide (W0₃).

The electrolyte is a layer that should have a high conductivity for ions and zero conductivity for electrons. In turn, the counter electrode is the layer able of donating and receiving electrons and ions to and from the electrochromic layer.

The counter electrode could be another electrochromic material or the same as that of electrochromic layer.

Briefly, the function of these conventional EC devices results of the transport of ions

(typically protons (H⁺) or lithium ions (Li⁺)) from an ion storage layer and through an ion conducting layer when a voltage is applied. These ions are extracted from or injected into the electrochromic layer, which changes its optical properties.

One of the most significant issues for all electrochromic systems is the cost of the devices and the trade-off between cost, benefit, and lifetime.

The transparent conductors are a significant cost for all electrochromic device types.

ITO is a main transparent conductor material used in the conventional ECDs.

Moreover, ITO also has a huge global demand in several technological fields. As a result, the consumption of this material is increasing annually and unfortunately its global reserves are becoming scarce. The high ITO consumption will also contribute to increase its final price leading, consequently, to a higher production cost of the

EC devices.

Tungsten is another important raw material that is vastly used in the production of various kinds of electronic goods.

However, there have been increasing concerns regarding the reliability of supply of this material.

A main contributor to these concerns is the fact that some of the largest deposits of this material are in areas of difficult access, or have a low-grade ore, making the long-term view of tungsten cost a key factor in determining their economic viability. Besides, W0₃ is pH-dependent, moisture dependent, and sensitive to exposure to the atmosphere, which can affect the performance and reliability of the EC devices. Additionally, because of their high dissolution rate in acidic electrolyte solutions, the W0₃ films should be preferably used in lithium-based electrolytes, which may lead to a reduction in the durability and slower switching time of the EC device.

Another problem of conventional ECDs is that, in general, the W0₃ and ITO layers are deposited by expensive and complex methods, such as sputtering, thermal evaporation, electron beam evaporation, chemical vapour deposition, and laser deposition. Thus, the high cost of ITO and W0₃ materials associated with the high cost and complexity of the deposition techniques, make conventional electrochromic devices not practical to large-scale applications.

In the case of eletrolyte layer, even the selection of a electrolyte requires attention. It must be durable and easily spread on the electrochromic layer, as well as it should be temperature-resistant and must keep its properties within a wide range of temperature.

One of the conventional versions of EC devices use a liquid electrolyte layer, where the electrolyte is dissolved in a solvent.

However, the use of liquid electrolyte requires a reliable seal. Otherwise, there is leakage or evaporation of the electrolyte solution leading to degradation of the EC devices. To solve this problem, the solid electrolytes, that include a matrix polymer and an inorganic salt (most frequently it is a lithium salt), were proposed in the literature. These electrolytes showed good electrochemical stability and mechanical properties, but have a low values of ion conductivity. Moreover, the problem of dissolution of W0₃ films degrading the EC devices could not be overcome fully even in Li-based solid electrolytes. In addition, the presence of lithium ions in the electrochromic system can lead to failures in complete erasure of the device after several months of cycling. Some improvements in the electrolyte layer have already been proposed, but they are still not a viable and attractive solution for practical use in EC devices.

After conducting extensive research, the present inventors provide an electrochromic device completely free of indium-doped tin oxide, lithium, and tungsten trioxide materials. In addition, this electrochromic device can be produced by a cost-effective spray coating technique and is reliable, since it has no liquid or gel layer in its structure.

The current invention presents a new all-solid-state electrochromic devices that require only a few different materials, such as aluminum (electrode), Tris-(8- hydroxyquinoline)aluminum(lll) (Alq₃) and/or zinc oxide (ZnO), and Poly(3,4- ethylenedioxythiophene):Poly(styrenesulfonate) (PEDOT:PSS), to form the ECD layers. The use of a few different materials also avoids potential material incompatibilities and considerably simplifies the fabrication process while reducing manufacturing costs and risks of ECD decomposition.

In the ECDs disclosed herein, the electrochromic material (PEDOT:PSS) changes its color when a voltage was applied through the electrochromic device (ECD). In general, for electrochromic devices the coloration and bleaching can be reversible obtained by an electrochemical process. However, by analyzing the room temperature current-voltage (l-V) curve of electrochromic devices of the invention (Figure 1 1), we can see a diode behavior. This result indicates that the electrochemical process can not explain the color change mechanism of our electrochromic devices.

One of the possible reasons to explain this phenomenon will be presented following. PEDOT:PSS in the bleached state is a p-type conductor material ([1] H. J. Ahonen, J. Lukkari, and J. Kankare, Macromolecules, 33, (2000) 6787) with a low bandgap of 1 .6 eV ([2] L. B. Groenendaal, F. Jonas, D. Freitag, H. Pielartzik, and J. R. Reynolds, Adv. Mater., 12,(2000) 481), which is more easily excited than ZnO and Alq₃ (n-type semiconductors) with a bandgap value of around 3.0 eV ([3] M. Duvenhage, M. Ntwaeaborw, H. G. Visser, P. J. Swarts, J. C. Swarts, H. C. Swart, Optical Materials 42 (2015) 193-198). Although PEDOT:PSS is conductive, it is assumed that PEDOT:PSS possesses semiconductor-like characteristics. In addition, it is assumed that the potential of the aluminum (Al) electrode is the Fermi level which will remain constant in any circumstances.

Thus, in our electrochromic devices, the p/n/AI junction reaches thermal equilibrium when it is not stimulated by an external voltage (V_ex). When a V_ex is applied through the electrochromic device, the p-type PEDOT:PSS is stimulated first at the p/n interface because of its lower bandgap. In this process, the V_ex generates both the hole and the electron in the PEDOT:PSS layer. Then these electrons flow downward along the conduction band of the p/n interface to the Alq₃ or ZnO (n-type), and the Fermi level of PEDOT:PSS moves toward the positive direction (downward) owing to the lack of electron density. At the same time, the Fermi Level Difference (FLD) between PEDOT:PSS and Alq₃ or between PEDOT:PSS and ZnO rises because of the accumulation of holes in PEDOT:PSS layer.

Following p-type stimulation, the n-type begins to generate holes and electrons at the n/AI interface. Therefore, the Fermi level of the n-type begins to rise. As electrons accumulate with time, the Fermi level and conduction band of the n-type begin to override those of the p-type greatly. Thus, the electrons are injected backwards to the p-type, causing a rise in the Fermi level, thus decreasing the FLD value. The injection of electrons transforms PEDOT:PSS into an n-conducting polymer and because of this a darkening electrochromic reaction in the EC device is generated.

This color change reaction occurred when the p/n/AI interface was simultaneously stimulated, which created a competition between the two directions of the electron flow as long as PEDOT:PSS remains as the p-type. Thus, when first stimulated, the electron flow to the n-type (ZnO or/and Alq₃) is dominant. For a long time, due to n/AI interface, the injection of electrons into PEDOT:PSS will dominate. Once the p- type PEDOT:PSS becomes the n-type PEDOT:PSS the color of our EC devices changes from a light blue to a dark blue.

This new EC device exhibits fast coloration response, good "memory effect", low- current consumption, low oxidation potentials, and great stability at ambient and moderate temperatures and conditions. Moreover, our EC structure has great application versatility and can be used on flexible or rigid substrates.

Scope of the Invention

The aim of the present invention is therefore to realize all-solid-state electrochromic devices be able to overcome the drawbacks of the prior art devices described above.

Another aim of the present invention is to provide an improved method for producing all-solid-state electrochromic devices.

The structural and functional characteristics of the present invention and their advantages over the known art will be clearer and more evident from the claims below, and in particular from an examination of the description that follows, referring to the attached drawings, showing the schemes of some preferred but non-limiting embodiments of the all-solid-state electrochromic devices in object, in which:

- Fig. 1 shows an all-solid-state electrochromic devices according to at least one embodiment;

Fig. 2 shows an all-solid-state electrochromic devices according to at least one embodiment;

Fig. 3 shows an all-solid-state electrochromic devices according to at least one embodiment;

Fig. 4 shows an all-solid-state electrochromic devices according to at least one embodiment;

Fig. 5 shows an all-solid-state electrochromic devices according to at least one embodiment;

- Fig. 6 shows an all-solid-state electrochromic devices according to at least one embodiment;

Fig.7 shows an all-solid-state electrochromic devices according to at least one embodiment;

Fig.8 shows an all-solid-state electrochromic devices according to at least one embodiment;

Fig. 9 shows an all-solid-state electrochromic devices according to at least one embodiment;

Fig. 10 shows an all-solid-state electrochromic devices according to at least one embodiment; and

- Fig. 1 1 shows a room temperature current-voltage (l-V) curve of a all-solid- state electrochromic device according the present invention.

Detailed description.

According to the attached figures, from 1 to 10, below it's described different embodiments of an all-solid-state electrochromic device of the present invention. In details, Fig. 1 shows an all-solid-state electrochromic device with a substrate onto which is disposed, in order, an aluminum (Al) layer, a Tris-(8- hydroxyquinoline)aluminum(lll) (Alq₃) layer, and a Poly-(3,4- ethylenedioxythiophene):Poly(styrenesulfonate) (PEDOT:PSS) layer;

Fig. 2 shows an all-solid-state electrochromic device with a substrate onto which is disposed, in order, an Al layer and a hybrid layer formed with a mixture of Alq₃ and PEDOT:PSS materials;

Fig. 3 shows an all-solid-state electrochromic device with a substrate onto which is disposed, in order, an Al layer, a nanostructured zinc oxide (nanoZnO) layer and a PEDOT:PSS layer;

Fig. 4 shows an all-solid-state electrochromic device with a substrate onto which is disposed, in order, an Al layer and a hybrid layer formed with a mixture of nanoZnO and PEDOT:PSS materials;

Fig. 5 shows an all-solid-state electrochromic device with a substrate onto which is disposed, in order, an Al layer and a hybrid layer formed with a mixture of nanoZnO, Alq₃, and PEDOT:PSS materials;

Fig. 6 shows an all-solid-state electrochromic device with an Al substrate onto which is disposed, in order, a Alq₃ layer and a PEDOT:PSS layer;

Fig. 7 shows an all-solid-state electrochromic device with an Al substrate onto which is disposed a hybrid layer formed with a mixture of Alq₃ and PEDOT:PSS materials; Fig. 8 shows an all-solid-state electrochromic device with an Al substrate onto which is disposed in order a nanoZnO layer and a PEDOT:PSS layer;

Fig. 9 shows an all-solid-state electrochromic device with an Al substrate onto which is disposed a hybrid layer formed with a mixture of nanoZnO and PEDOT:PSS materials; and Fig. 10 shows an all-solid-state electrochromic device with an Al substrate onto which is disposed a hybrid layer formed with a mixture of Alq₃, nanoZnO, and PEDOT:PSS materials.

Therefore summarizing, in the present invention:

Some embodiments include an electrochromic system, comprising: a substrate, wherein the electrochromic structures comprises at least three layers disposed successively on each other.

Some embodiments include an electrochromic system, comprising: a substrate, wherein the electrochromic structures comprises at least two layers disposed successively on each other.

Some embodiments include an electrochromic system, comprising: an Al substrate, wherein the electrochromic structures comprises at least two layers disposed successively on each other.

Some embodiments include an electrochromic system, comprising: an Al substrate, wherein the electrochromic structures comprises at least one hybrid layer disposed directly on metal (Al) substrate.

Some embodiments include an electrochromic system, comprising a electrochromic material combined with a inorganic semiconductor nanostructured material or organic semiconductor material, wherein the nanostructured inorganic materials comprises a zinc oxide (ZnO) and/or zinc hydroxide (Zn(OH)₂) materials, with any molecular stoichiometry and wherein the organic material is Alq₃.

Moreover:

In all embodiments, the electrochromic material is a conductive polymer.

In all embodiments, the electrochromic material is one of the electrodes of the electrochromic system. In all embodiments, the aluminum material is the other electrode of the electrochromic system.

In some embodiments, the electrochromic system includes at least one type of nanostructured inorganic material.

In some embodiments, the nanostructured material comprises at least one of these morphologies: nanoflowers, nanorods, nanoparticles, rounded nanoparticles, agglomerate of nanoparticles.

In some embodiments, the electrochromic layer is in contact with at least one layer comprising a nanostructured material.

In some embodiments, an electrochromic material is mixed with at least one type of nanostructured material.

In some embodiments, the electrochromic system was encapsulated using any type of glass, or polymers, or polymer resins.

In some embodiments the electric contact of electrochromic system was made using a silver paste, or carbon paste, or PEDOT:PSS.

In some embodiments, the electrochromic system also includes one inorganic layer that is deposited over the Al layer or Al substrate.

In some embodiments, the electrochromic system also includes one organic layer that is deposited over the Al layer or Al substrate.

In some embodiments, the electrochromic system also includes one organic material that is mixed with the electrochromic material. This blend is deposited over the Al layer or Al substrate.

In some embodiments, the electrochromic system also includes one inorganic material that is mixed with the electrochromic material. This blend is deposited over the Al layer or Al substrate. In some embodiments, the electrochromic system also includes a mixture containing the inorganic, organic and electrochromic materials. This blend is deposited over the Al layer or Al substrate.

In some embodiments, the electrochromic material is in contact with the Al material. In some embodiments, the electrochromic material penetrates into the organic layer. In some embodiments, the electrochromic material penetrates into the inorganic layer.

In some embodiments, the Al layer has a thickness from 1 to 1000 nm. In some embodiments, the organic layer has a thickness from 1 to 1000 nm. In some embodiments, the inorganic layer has a thickness from 1 to 1000 nm. In some embodiments, the electrochromic layer has a thickness from 1 to 1000 nm. In some embodiments, the electrochromic system has a thickness of 2 to 1500 nm.

Some embodiments include a method of manufacturing an electrochromic system, the method including depositing one Al layer over the substrate, depositing one inorganic nanostructured layer over the Al layer, the inorganic nanostructured layer including a nanostructured material, and depositing an electrochromic layer over the nanostructured layer. In some embodiments, this device was finished with an electric contact and encapsulated.

Some embodiments include a method of manufacturing an electrochromic system, the method including depositing one Al layer over the substrate, depositing one organic layer over Al metal layer, and depositing an electrochromic material layer over the organic layer. In some embodiments, this device was finished with an electric contact and encapsulated.

Some embodiments include a method of manufacturing an electrochromic system, the method including depositing one Al layer over the substrate and depositing one inorganic-electrochromic hybrid layer over the Al layer. In some embodiments, this device was finished with an electric contact and encapsulated.

Some embodiments include a method of manufacturing an electrochromic system, the method including depositing one Al layer over the substrate and depositing one organic-electrochromic hybrid layer over the Al layer. In some embodiments, this device was finished with an electric contact and encapsulated.

Some embodiments include a method of manufacturing an electrochromic system, the method including depositing one Al layer over the substrate, depositing one electrochromic-inorganic-organic hybrid layer over the Al layer. In some embodiments, this device was finished with an electric contact and encapsulated. Some embodiments include a method of manufacturing an electrochromic system, the method including depositing one inorganic nanostructured layer over the Al substrate, the inorganic nanostructured layer including a nanostructured material, and depositing an electrochromic layer over the nanostructured layer. In some embodiments, this device was finished with an electric contact and encapsulated. Some embodiments include a method of manufacturing an electrochromic system, the method including depositing one organic layer over Al substrate, and depositing an electrochromic material layer over the organic layer. In some embodiments, this device was finished with an electric contact and encapsulated.

Some embodiments include a method of manufacturing an electrochromic system, the method including depositing one inorganic-electrochromic hybrid layer over the Al substrate. In some embodiments, this device was finished with an electric contact and encapsulated.

Some embodiments include a method of manufacturing an electrochromic system, the method including depositing one organic-electrochromic hybrid layer over the Al substrate. In some embodiments, this device was finished with an electric contact and encapsulated.

Some embodiments include a method of manufacturing an electrochromic system, the method including depositing one electrochromic-inorganic-organic hybrid layer over the Al substrate. In some embodiments, this device was finished with an electric contact and encapsulated.

In some embodiments, the metallic layer is deposited using at least one process selected from the group including vacuum-deposition process, electrochemical deposition process, magnetron- or RF-sputtering, e-beam or thermal evaporation. In some embodiments, the organic, inorganic and electrochromic layers are deposited using at least one process selected from the group including vacuum- deposition process, electrochemical deposition process, dip-coating process, spin- coating process, drop-dry process, magnetron- or RF-sputtering, e-beam or thermal evaporation, layer-by-layer assembly, electrospray coating process, ultrasound spray process, and spray coating process.

In some embodiments, at least one of the layers in the electrochromic system comprises a nanostructured material. In some embodiments, the term nanostructured material may be a material with a characteristic length scale in the order of a few nanometers (typically 1 - 100 nm). Nanosized characteristics include, but are not limited to, nanometer-sized crystallites, nanorods, nanoparticles, and rounded particles with different crystallographic orientations. A nanosized dimension includes at least one characteristic length scale between 9 nm to 300 nm or more in size. Preferably, a nanosized characteristic includes at least one dimension between 10 and 100 nm in size. The nanostructured material can be produced by any suitable method. In some embodiments, the nanostructure material is formed by any chemical method such as solochemical processing or sol-gel method. In some embodiments, the nanostructured material is an oxide or/and hydroxide of zinc or titanium.

In some embodiments, the nanostructured material can be simultaneously formed and deposited on the Al substrate or substrate/AI-layer during the solochemical processing by several methods such as dip-coating, spin-coating, drop-dry, layer-by- layer assembly, ultrasound spray coating, electrospray coating, spray coating, resulting in a nanostructured metal oxide layer on the Al substrate or substrate/Allayer. In some embodiments, the nanostructured material, in nanopowder form, can be dispersed in a liquid medium and then deposited on the substrate/AI-layer or Al substrate.

In some embodiments, additional layers and materials can be included for produce some changes such as alter the color of the electrochromic system, improve the stability of the device and improve the switching speed.

Moreover, in details:

Substrates :

When the denotation Al Layer is used, it means that there is a layer of aluminum deposited on any type of substrate. The substrate is not limited to any particular material, so long as the material is suitable for use in a specific application. The substrates include, but are not limited to, polymeric materials (such as poly(ethylene terephthalate) - PET), glass, silicon wafer, quartz, paper, synthetic fabric, cotton fabric, rubber, wood, any metallic material. The substrate may be opaque or transparent. The substrate can be rigid or flexible. Unless indicated otherwise, the substrate in each embodiment described herein may include a material selected from the above exemplary substrate material. Thus, when the substrate is coated with Al layer, the denotation used is substrate/AI-layer.

When the denotation Al Substrate is used, it means that only the aluminum material is used without the presence of any other substrate. It can be a flexible aluminum foil, or an aluminum plat, or any three-dimensional geometry made of aluminum. Materials.

The electrochromic devices (ECDs) were based on Aluminum (Al) as a metallic electrode, Tris-(8-hydroxyquinoline)aluminum(lll) (Alq₃) as an organic semiconductor material, ZnO nanostructures as an inorganic semiconductor material, Poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonate) (PEDOT:PSS) as an electrochromic and conductive organic material.

The Alq₃ and PEDOT:PSS materials were purchased commercially and are of analytical grade: Alq₃ (99.995%), and PEDOT:PSS (1 .3 weight % dispersion in H₂0, or 3.0 - 4.0% in H₂0, or 2.8 wt% dispersion in H₂0, or 0.8% in H₂0, or conductive inkjet ink, or any other solution containing PEDOT and PSS).

ZnO nanostructures (called as nanoZnO) was synthesized using the solochemical method by the present inventors as described in some references ([4] M. Gusatti , D.A.R. Souza, N.C. Kuhnen, H.G. Riella, J. Mater. Sci. Technol. 31 (2015) 10-15; [5] M. Gusatti, C.E.M. Campos, D.A.R. Souza, N.C. Kuhnen, H. G. Riella, P. S. Pizani, J. Nanosci. Nanotechnol. 12 (2012) 7986-7992; [6] M. Gusatti, D.A.R. Souza, V.M. Moser, N.C. Kuhnen, H.G. Riella, J. Nanoeng. Nanomanuf. 3 (2013) 15-18; [7] M. Gusatti, C.E.M. Campos, J.A. Rosario, D.A.R. Souza, N.C. Kuhnen, H.G. Riella, J. Nanosci. Nanotechnol. 1 1 (201 1 ) 5187-5192).

Structure of the devices.

The ECDs are formed on Al substrate or substrate/AI-layer, on which are deposited one layer of organic material and one layer of electrochromic material; Or one layer of inorganic material and one layer of electrochromic material; Or a single layer formed by one organic-electrochromic hybrid layer; Or a single layer formed by one inorganic-electrochromic hybrid layer; Or a single layer formed by one electrochromic-inorganic-organic hybrid layer.

When the denotation organic layer is used, it means that it is a layer consisting of Alq₃.

When the denotation inorganic layer is used, it means that it is a layer consisting of nanostructured ZnO.

When the denotation electrochromic layer is used, it means that it is a layer consisting of PEDOT:PSS.

When the denotations organic-electrochromic hybrid layer or Alq₃+PEDOT:PSS hybrid layer are used, it means that it is a layer consisting of a blend of Alq₃ and PEDOT SS.

When the denotations inorganic-electrochromic hybrid layer or nanoZnO+PEDOT:PSS hybrid layer are used, it means that it is a layer consisting of a blend of nanoZnO and PEDOT:PSS.

When the denotations electrochromic-inorganic-organic hybrid layer or PEDOT:PSS+nanoZnO+Alq₃ hybrid layer are used, it means that it is a layer consisting of a blend of PEDOT:PSS, nanoZnO, and Alq₃.

Device manufacturing.

Prior to deposition, the electrochromic, inorganic, and organic materials are dissolved to form the following solutions (A - F):

Solution A: Solution of Alq₃ with methanol at a concentration ranging from 0.01 g/L to 10 g/L or more. This solution was mechanically or ultrasonically stirred for several minutes.

Solution B: Solution of nanoZnO with isopropyl alcohol (I PA) at a concentration ranging from 0.01 g/L to 10 g/L or more. This solution was mechanically or ultrasonically stirred for several minutes.

Solution C: Solution of PEDOT:PSS with isopropyl alcohol (I PA) at a concentration ranging from 100 g/L to 980 g/L or more. This solution was mechanically or ultrasonically stirred for several minutes.

Solution D: It is an organic-electrochromic hybrid solution. This solution is a mixture between solution A and solution C. Here, the solution C is present in a range of composition from 50% to 88% of the total solution D.

- Solution E: It is an inorganic-electrochromic hybrid solution. This solution is a mixture between solution B and solution C. Here, the solution C is present in a range of composition from 50% to 88% of the total solution E.

- Solution F: It is an electrochromic-inorganic-organic hybrid solution. This solution is a mixture between solution A, solution B, and solution C. Here, the solutions A and

B are present in a range of compositions from 6% to 25% and from 5% to 25 %, respectively, relative to the total solution F.

These solutions are used to form the different embodiments of the device (from Fig. 1 to Fig. 10) as follows:

The device shown in Fig. 1 is formed with a substrate/AI-layer coated with the solution A followed by the solution C.

The device shown in Fig. 2 is formed with a substrate/AI-layer coated with the solution D.

The device shown in Fig. 3 is formed with a substrate/AI-layer coated with the solution B followed by the solution C. The device shown in Fig. 4 is formed with a substrate/AI-layer coated with the solution E.

The device shown in Fig. 5 is formed with a substrate/AI-layer coated with the solution F.

The device shown in Fig. 6 is formed with an Al substrate coated with the solution A followed by the solution C.

The device shown in Fig. 7 is formed with an Al substrate coated with the solution D. The device shown in Fig. 8 is formed with an Al substrate coated with the solution B followed by the solution C.

The device shown in Fig. 9 is formed with an Al substrate coated with the solution E. The device shown in Fig. 10 is formed with an Al substrate coated with the solution F.

All solutions A, B, C, D, E, and F are singly deposited by spray-coating technique on a heated substrate at a temperature range of 20 °C to 120 °C or more. The solution A, or B, or C, or D, or E, or F is injected on the substrate through a nozzle at a feed rate of 5μΙ/η"ΐίη to 3000μΙ/η"ΐίη or more. The distance between the nozzle and the substrate is maintained of 0.1 cm to 60 cm or more. The experiments are carried out at a air pressure of 0.5 ^χ 10^"5 Pa to 10.0 ^χ 10^"5 Pa or more, with a speed of the nozzle ranging from 0.5 cm/s to 500 cm/s or more. To ensure full solvent vapor removing, after each spraying the samples were dried at a temperature ranging from 50 °C to 120 °C or more for a time interval of 5 min to 60 min or more.

Claims

1. All-solid-state electrochromic device comprising an aluminum substrate (Al substrate) or a substrate coated with an aluminum (Al) layer, at least a layer of at least one semiconductor material, and at least a layer of one electrochromic conductive material.

2. All-solid-state electrochromic device according to claim 1 , wherein it further comprises said electrochromic conductive material mixed with said semiconductor material for forming a hybrid layer; said semiconductor material comprising an inorganic semiconductor material, said inorganic material comprising a nanostructured material.

3. All-solid-state electrochromic device according to claim 1 , wherein it further comprises said electrochromic conductive material mixed with said semiconductor material for forming a hybrid layer; said semiconductor material comprising an organic semiconductor material.

4. All-solid-state electrochromic device according to claim 1 , wherein it further comprises said electrochromic conductive material mixed with two semiconductor materials for forming a hybrid layer; said semiconductor materials comprising at least one organic and one inorganic semiconductor materials; said inorganic material comprising a nanostructured material.

5. All-solid-state electrochromic device according to any claims from 1 to 4, wherein said electrochromic conductive material is Poly(3,4- ethylenedioxythiophene):Poly(styrenesulfonate)(PEDOT:PSS).

6. All-solid-state electrochromic device according to claims 1 , 3 and 4, wherein said organic semiconductor material is Tris-(8- hydroxyquinoline)aluminum(lll) (Alq₃).

7. All-solid-state electrochromic device according to claims 1 , 2 and 4, wherein said inorganic semiconductor nanostructured material comprises a nanostructured zinc oxide (nanoZnO) or zinc hydroxide (Zn(OH)₂); wherein the nanoZnO comprises at least one of: nanometer sized-crystallites, nanorods, nanoparticles, and rounded particles with a size range from 9 nm to 300 nm.

8. All-solid-state electrochromic device according to claim 1 , wherein said layer of semiconductor material comprising one organic semiconductor material is formed by depositing a solution A consisting of a mixture of Alq₃ and methanol at a concentration ranging from 0.01 g/L to 10 g/L or more by spray coating technique.

9. All-solid-state electrochromic device according to claim 1 , wherein said layer of semiconductor material comprising one inorganic semiconductor material is formed by depositing a solution B consisting of a mixture of nanoZnO and isopropyl alcohol at a concentration ranging from 0.01 g/L to 10 g/L or more by spray coating technique.

10. All-solid-state electrochromic device according to claim 1 , wherein said layer of electrochromic conductive material is formed by depositing a solution C consisting of a mixture of PEDOT:PSS and isopropyl alcohol at a concentration ranging from 100 g/L to 980 g/L or more by spray coating technique.

11. All-solid-state electrochromic device according to claim 3, wherein said hybrid layer is formed by depositing a solution D consisting of a mixture between said solution A and said solution C by spray coating technique; wherein said solution C is present in a range of composition from 50% to 88% of the solution D.

12. All-solid-state electrochromic device according to claim 2, wherein said hybrid layer is formed by depositing a solution E consisting of a mixture between said solution B and said solution C by spray coating technique; wherein said solution C is present in a range of composition from 50% to 88% of the solution E.

13. All-solid-state electrochromic device according to claim 4, wherein said hybrid layer is formed by depositing a solution F consisting of a mixture between said solution A, said solution B, and said solution C by spray coating technique; wherein said solutions A and B are present in a range of composition from 6 % to 25 % of the solution F.

14. All-solid-state electrochromic device according to any claim from 8 to 13, wherein said spray coating technique for depositing the electrochromic, organic, inorganic, and hybrid layers comprising the following parameters: a heated substrate at a temperature range of 20 °C to 120 °C or more; a feed rate of the solution through the nozzle ranging from δμΙΛηίη to 3000 μΙ/min or more; a distance between the nozzle and the substrate at a range of 0.1 cm to 60 cm or more; a air pressure of 0.5 ^χ 10-5 Pa to 10.0 ^χ 10-5 Pa or more; a speed of the nozzle ranging from 0.5 cm/s to 500 cm/s or more; drying of organic, inorganic, electrochromic and hybrid layers was performed after each individual spraying at a temperature ranging from 50 °C to 120 °C or more for a time interval of 5 min to 60 min or more.