CN108761949A - A kind of solid ionic conducting shell and the solid-state electrochromic device containing the solid ionic conducting shell - Google Patents

Abstract

The invention provides a solid-state ion-conducting layer and a solid-state electrochromic device containing the solid-state ion-conducting layer. The solid-state ion-conducting layer is a multilayer film formed by alternately laminating lithium aluminum oxide films and tantalum oxide films. The chemical formula of lithium aluminum oxide film is LiAl _x O _y , wherein 0.4≤x≤1.2, preferably 0.44≤x≤1, more preferably 0.45≤x≤0.67; 0.5≤y≤3, preferably 0.5≤y≤2.5, more preferably 0.5≤y≤2.

Description

A kind of solid-state ion conduction layer and solid-state electrochromism containing the solid-state ion conduction layer device

technical field

The invention relates to the field of material technology, in particular to a solid-state ion conduction layer with a special multilayer film structure and a solid-state electrochromic device containing the solid-state ion conduction layer, which can be used in technical fields such as electrochromic glass and displays.

Background technique

Electrochromic devices can reversibly change their optical properties such as transmittance and reflectance under the action of an external electric field, and can be widely used in architectural glass and windows of vehicles, trains, ships, airplanes and other vehicles to achieve the purpose of comfort and energy saving. At the same time, it can also be used in semiconductor product industries such as various displays. Among various forms of electrochromic devices, all-solid-state electrochromic devices in which each film layer in the structure is made of solid inorganic materials have the most extensive application prospects due to their high regulation efficiency and good stability.

A typical solid-state electrochromic device generally consists of a transparent substrate and a first transparent conductive layer sequentially formed on the transparent substrate, a first electrochromic layer, an ion-conducting layer (or electrolyte layer), a second electrochromic layer , a second transparent conductive layer, and a protective layer. Among them, the ion-conducting layer is responsible for the fast channel for the coloring particles to move under the action of the electric field, and its structure and preparation process are one of the most important technologies to ensure the performance of the device. Of course, the ion-conducting layer in the all-solid-state electrochromic device must also be an inorganic solid material.

Tantalum oxide (Ta ₂ O ₅ ) is the most widely used inorganic ion-conducting membrane in electrochromic devices so far due to its low leakage current, high dielectric constant, fast ion transport, and high thermodynamic and chemical stability. Since the preparation of Ta ₂ O ₅ thin films can be realized by reactive DC magnetron sputtering using metal tantalum targets, it has the advantages of easy target preparation, high deposition efficiency, and is suitable for large-scale continuous coating production. However, the Ta ₂ O ₅ ion-conducting layer also has some disadvantages, such as: 1) low visible light transmittance; 2) additional lithium ions need to be introduced by additional processes such as lithiation; 3) if the introduction of lithium tantalate by direct sputtering Lithium-ion technology requires the use of lithium tantalate ceramic targets for radio frequency magnetron sputtering. The targets are complex and the deposition efficiency is low, etc., which have a negative impact on the large-scale electrochromic device preparation process.

In view of the above existing problems, Patent Document 1 (Chinese Patent Application No.: 201710333624.9) provides a solid electrolyte containing lithium-aluminum double ions ( ion-conducting layer. However, it is obvious that what is formed by co-sputtering is a mixture whose composition and structure are difficult to control; secondly, a lithium alumina ceramic target is used in co-sputtering, so a radio frequency power supply has to be used for magnetron sputtering , the deposition rate is extremely low; and the co-sputtering method cannot be applied to the large-scale device coating process.

Similarly, Patent Document 2 (Chinese Patent Application No.: 201710240528.X) provides an ion-conducting layer and its preparation method, including preparing an inorganic solid-state medium layer, and preparing a separate lithium alloy layer, and doping lithium into the inorganic In the solid-state dielectric layer (electrical lithiation) to form a lithium-containing ion-conducting layer. However, this method requires follow-up lithiation engineering, which increases the complexity of the process. Secondly, lithiation is accompanied by the disappearance of the lithium alloy layer, which makes the overall structure of the ion-conducting layer containing lithium lack of consistency and uniformity; and, due to The finally formed ion conducting layer can only be a single film layer of a compound or mixture, and its optical properties, such as visible light transmittance, cannot achieve the best performance effect.

Contents of the invention

In view of the above problems, the object of the present invention is to provide an ion-conducting multilayer film structure alternately formed by high and low refractive index materials, the best optical effect can be obtained through structural optimization design, and lithium ions are directly introduced in the film forming process without Subsequent lithiation process and multi-layer film formation process are all realized by DC or intermediate frequency magnetron sputtering using metal targets. The deposition rate is fast and the efficiency is high, meeting the needs of large-scale rapid coating.

Specifically, the present invention provides a multilayer film in which the solid-state ion-conducting layer is alternately laminated with lithium aluminum oxide thin films and tantalum oxide thin films. The chemical formula of the lithium aluminum oxide thin films is LiAl _x O _y , Wherein 0.4≤x≤1.2, preferably 0.44≤x≤1, more preferably 0.45≤x≤0.67; 0.5≤y≤3, preferably 0.5≤y≤2.5, more preferably 0.5≤y≤2.

Lithium aluminum oxide is used as the solid-state ion-conducting layer (such as lithium aluminum _oxide LiAlO2, etc.), because it is a lithium-containing transparent ion conductor, and the device can be fully satisfied by controlling the composition ratio of lithium in the multilayer film. Electrochromic performance requirements. At the same time, due to the relatively low refractive index of lithium aluminum oxide (such as LiAlO ₂ , n≈1.62), in addition to having high visible light transmittance, it can be compared with oxides with higher refractive index according to the principle of antireflection of multilayer films. Tantalum (Ta ₂ O ₅ , n≈2.15) forms a multi-layer film structure with alternating high and low refractive index materials, and obtains a higher visible light transmittance than any single film. Wherein, the chemical formula of the lithium aluminum oxide thin film is selected as LiAl _x O _y , wherein 0.4≤x≤1.2, preferably 0.44≤x≤1, more preferably 0.45≤x≤0.67; 0.5≤y≤3, preferably 0.5≤y ≤2.5, more preferably 0.5≤y≤2. The tantalum oxide film is Ta ₂ O ₅ . It should be noted that if more lithium ions need to be introduced, the value of x in LiAl _x O _y should be as small as possible. However, due to the low melting point and strong chemical activity of metal lithium, its metal target is difficult to prepare; and if the x value is too high, although the alloy target has high stability and is easy to prepare, it cannot provide enough lithium ions for the structure. . The value range of y depends on the range of x, and the main consideration is to achieve the best optical performance such as the visible light transmittance of the film layer.

Preferably, in order to simultaneously realize the supply of lithium ions and produce the anti-reflection effect of visible light, the solid ion conduction layer includes at least one lithium aluminum oxide film and one tantalum oxide film (the positions of the two can be interchanged).

Also, preferably, the multilayer film comprises at least one lithium aluminum oxide film sandwiched between two tantalum oxide films, or one tantalum oxide film is sandwiched between two lithium aluminum oxide films, according to the multilayer Based on the principle of film interference, multi-layer film can obtain better anti-reflection effect.

Preferably, the total number of layers of the multilayer film formed by alternately stacking the lithium aluminum oxide thin film and the tantalum oxide thin film is 2-20, preferably 3-15, more preferably 3-5. Certainly, adopting a multilayer film structure of more than 3 layers can further improve the visible light anti-reflection effect of the multilayer film and make the diffusion of lithium ions more uniform. However, in consideration of the technological feasibility of realizing large-scale production, the total number of layers of the multilayer film formed by alternately stacking the lithium aluminum oxide thin film and the tantalum oxide thin film is limited to 2-20, preferably 3-15, more preferably 3-5 . Because, too much film layer will increase the complexity of equipment and process, and too few film layers will have no obvious anti-reflection effect.

Preferably, the total thickness of the solid ion conducting layer is designed to be 100nm-1000nm, preferably 200nm-600nm. Because if the total thickness is too large, the deposition time will be long and the efficiency will be low; if the total thickness is too small, sufficient ion storage and conduction effects cannot be achieved. When designing the structure of the film thickness of each layer, the requirements of providing sufficient lithium ions and achieving the maximum optical effect should be met at the same time.

Preferably, the thickness of the lithium aluminum oxide film is 10-500 nm, preferably 50-400 nm; the thickness of the tantalum oxide film is 50-500 nm, preferably 50-200 nm.

According to the anti-reflection principle of multi-layer film, the visible light transmittance of the solid-state ion-conducting layer with multi-layer film structure is higher than that of lithium aluminum oxide single-layer film or tantalum oxide single-layer film with the same film thickness; at the same time, the structure is sufficient Utilize the excellent ion conductivity and stability of tantalum oxide; at the same time, the structure provides enough lithium ions to meet the discoloration requirements of the device; finally, multilayer films can be prepared with high efficiency using metal targets.

Preferably, the lithium aluminum oxide thin film in the solid-state ion-conducting layer (multilayer film solid-state ion-conducting layer) is prepared by reactive magnetron sputtering using an aluminum-lithium alloy target, and the aluminum-lithium alloy target is At least one of a solid solution composed of _AlLix , an Al ₂ Li ₃ crystal phase, and an Al ₄ Li ₉ crystal phase. That is to say, the aluminum-lithium alloy target can be a solid solution alloy composed of AlLi _x (for example, x can be ≈1), or any one of the alloys composed of Al ₂ Li ₃ or Al ₄ Li ₉ , or both of them. Mixed alloys of more than one species.

Preferably, the preparation parameters of the lithium aluminum oxide thin film are: the background vacuum is 1×10 ^-5 to 5×10 ^-3 Pa, the substrate temperature is 20°C to 200°C, the coating time is 1 to 60min, and the working atmosphere is The atmosphere contains oxygen and argon, the working pressure is 0.5-5Pa, and the sputtering power density is 1-10W/cm ² .

Preferably, the tantalum oxide film is prepared by reactive magnetron sputtering using a metal tantalum target; preferably, the preparation parameters of the tantalum oxide film are: background vacuum 1×10 ^-5 ~ 5×10 ^-3 Pa, the substrate temperature is 20°C-200°C, the coating time is 1-60min, the working atmosphere is an atmosphere containing oxygen and argon, the working pressure is 0.5-5Pa, and the sputtering power density is 1-10W/cm ² . It should be noted that tantalum oxide is a well-known electrochromic solid-state ion-conducting layer, and all known preparation methods can be used, and the specific preparation conditions will not be repeated here.

On the other hand, the present invention also provides an all-solid-state electrochromic device, the structure of which includes a substrate, and a first transparent conductive layer, a first electrochromic layer, and the solid-state ions described in the present invention are sequentially arranged on the substrate. Conductive layer, second electrochromic layer, second transparent conductive layer and protective layer.

Preferably, the first electrochromic layer is nickel oxide with a thickness of 100-500 nm; the second electrochromic layer is tungsten oxide with a thickness of 200-600 nm; the transparent conductive layer is ITO with a thickness of 50-500 nm; the protective layer is silicon aluminum oxynitride with a thickness of 50-500 nm.

Preferably, if the first transparent conductive layer or the second transparent conductive layer in the all-solid-state electrochromic device is replaced with a reflective metal conductive film, the device has variable reflectivity and can be used for automotive anti-glare and other purposes.

The present invention has the following advantages: 1) The solid ion conduction layer of the multilayer film is formed alternately by high and low refractive index materials. According to the principle of multilayer film anti-reflection, the visible light transmittance of the optimized structure is higher than that of lithium aluminum oxide with the same film thickness. single-layer film or tantalum oxide single-layer film; 2) using tantalum oxide as a high refractive index component to maximize its excellent ion conductivity and stability; 3) increasing the lithium content in lithium aluminum oxide to solid state The ion-conducting layer provides enough lithium ions to meet the discoloration requirements of the device; 4) Each film layer in the solid-state ion-conducting layer can use metal targets and DC (or intermediate frequency) magnetron sputtering process, which has high efficiency and low cost. Therefore, the present invention solves the problems of high material cost, complex process, low film forming rate and insufficient optical performance existing in the current structure and preparation process of the ion conducting layer, and lays a solid foundation for realizing large-scale device production.

Description of drawings

Fig. 1 is a schematic structural view of a solid-state electrochromic device in the present invention;

Fig. 2 is the relationship between the thickness of each film layer and the visible light transmittance in the solid ion conducting layer with three-layer film structure;

Fig. 3 is a visible light transmittance reflectance curve and visible light transmittance integral value of a solid ion conduction layer optimized structure with a three-layer film structure;

Description of figure number:

100 transparent substrates;

110 the first transparent conductive film;

120 electrochromic layer;

130 ion conducting layer;

140 electrochromic layer;

150 second transparent conductive layer;

160 layers of protection;

131 LiAl _x O _y ;

132 Ta ₂ O ₅ ;

13n LiAl _x O _y (repeat the structure of 131 and 132 to the 13n layer).

Detailed ways

The present invention will be further described below through the following embodiments. It should be understood that the following embodiments are only used to illustrate the present invention, not to limit the present invention.

In one embodiment of the present invention, the solid-state ion-conducting layer is a multilayer film formed by alternately stacking lithium aluminum oxide thin films and tantalum oxide thin films. The chemical formula of the lithium aluminum oxide thin films is LiAl _x O _y , where 0.4≤x ≤1.2, preferably 0.44≤x≤1, more preferably 0.45≤x≤0.67; 0.5≤y≤3, preferably 0.5≤y≤2.5, more preferably 0.5≤y≤2; the tantalum oxide film is tantalum pentoxide ( Ta ₂ O ₅ ).

In an optional embodiment, the solid-state ion-conducting layer includes at least one lithium aluminum oxide film and one tantalum oxide film, and the positions of the two can be interchanged. More preferably, the solid ion conducting layer comprises at least one lithium aluminum oxide film sandwiched between two tantalum oxide films, or one tantalum oxide film sandwiched between two lithium aluminum oxide films. The total number of layers of the multilayer film formed by alternately stacking the lithium aluminum oxide thin film and the tantalum oxide thin film is 2-20, preferably 3-15, more preferably 3-5. The total thickness of the solid ion conducting layer is 100nm-1000nm, preferably 200nm-600nm.

In an optional embodiment, the lithium-aluminum oxide film in the solid-state ion-conducting layer (multilayer film solid-state ion-conducting layer) is prepared by reactive magnetron sputtering using an aluminum-lithium alloy target, and the aluminum-lithium alloy target is A solid solution with a composition of AlLi _x (0.4≤x≤1.2, for example, x can be ≈1), or an Al ₂ Li ₃ crystal phase, or any one or a mixture of two or more of the Al ₄ Li ₉ crystal phases. The preparation parameters of the lithium aluminum oxide thin film are: the background vacuum is 1×10 ^-5 to 5×10 ^-3 Pa, the substrate temperature is 20°C to 200°C, the coating time is 1 to 60min, and the working atmosphere is oxygen and argon. gas atmosphere, the working pressure is 0.5-5Pa, and the sputtering power density is 1-10W/cm ² . It should be noted that as long as a lithium aluminum oxide thin film with a given thickness and a given quality can be obtained, the deposition method should not be limited.

In an optional embodiment, the tantalum oxide thin film is prepared by reactive magnetron sputtering using a metal tantalum target, and its preparation parameters are: background vacuum 1×10 ^-5 ~5×10 ^-3 Pa, substrate The temperature is 20°C-200°C, the coating time is 1-60min, the working atmosphere is an atmosphere containing oxygen and argon, the working pressure is 0.5-5Pa, and the sputtering power density is 1-10W/cm ² . It should be noted that as long as a tantalum oxide thin film with a given thickness and a given quality can be obtained, its deposition method should not be limited.

In this disclosure, due to the anti-reflection principle of the multilayer film, the visible light transmittance of the solid ion conduction layer of the lithium aluminum oxide/tantalum oxide multilayer film is higher than that of the lithium aluminum oxide single layer film or the tantalum oxide single layer film of the same thickness. solid-state ion-conducting layer. For example, the optical performance of an ion-conducting multilayer film formed by sandwiching only one layer of tantalum oxide film between two layers of lithium aluminum oxide film (such as lithium aluminum oxide) has exceeded the respective single-layer films of the same thickness. Moreover, since the tantalum oxide film with excellent performance is also used at the same time, the structure has good stability and durability. Furthermore, both of them can be formed by sputtering a metal target, which has high efficiency and low cost.

In the present disclosure, the beneficial effects of the ion conducting layer: 1) the optical performance is the best; 2) the metal target can be used to realize the magnetron sputtering of DC or intermediate frequency power supply, the target is easy to prepare, and the production efficiency is high; 3) it has sufficient The concentration of ion ions is high, without additional complex processes such as electrified lithiation; 4) The composition and structure are evenly distributed.

In one embodiment of the present invention, a solid-state electrochromic device is formed by using a solid-state ion-conducting layer, and its structure is shown in FIG. 1 . The manufacturing feature of the solid-state electrochromic device is: select a transparent substrate (for example, glass, plexiglass, etc.), and sequentially form a certain thickness of the first transparent conductive layer (ITO, AZO, FTO, ATO, etc.), the first electrochromic layer (for example, nickel oxide film), solid ion conduction layer (lithium aluminum oxide/tantalum oxide multilayer film), second electrochromic layer (for example, tungsten oxide film), second transparent conductive layer (ITO conductive film, AZO, FTO, ATO, etc.), and protective layers (for example, silicon nitride, silicon oxide, silicon oxynitride, silicon aluminum oxynitride, etc.), the above film layers constitute a complete solid-state electrochromic device. In an optional embodiment, the thickness of the first electrochromic layer may be 100-500 nm, the thickness of the second electrochromic layer may be 200-600 nm, and the thickness of the first and second transparent conductive layers may be 50-50 nm. 500nm, the thickness of the protective layer is 50-500nm.

The above structure is an example of a solid-state electrochromic device in the present invention. Of course, part of the film layer sequence can be changed according to needs, such as changing the positions of the tungsten oxide film and the nickel oxide film. Part of the dielectric film can also be added as needed, and so on. As long as the ion-conducting layer of the multilayer film structure specified in the present invention is included in the solid-state electrochromic device, other combinations should not be limited in any way. In addition, one layer of the transparent conductive layer in the structure of the solid-state electrochromic device can also be replaced with a reflective conductive metal, such as silver, chromium or their alloys, so that the device becomes an electrochromic device with reflectivity change. It should be noted that the thickness of each film layer in a solid-state electrochromic device can be adjusted as needed, and as long as each film layer of a given thickness and a given quality can be obtained, its deposition method can be prepared with reference to a lithium aluminum oxide thin film, or for other preparations The method should not be limited.

In the present disclosure, the solid-state ion-conducting layer with a special multilayer film structure has excellent optical properties, low material cost, simple coating process and fast rate, and the formed solid-state electrochromic device has good performance and is suitable for large-scale industrial production . The product of the invention can be widely used in fields such as automobiles, trains, ships, aircrafts and energy-saving glass and display screens in construction industries.

Examples are given below to describe the present invention in detail. It should also be understood that the following examples are only used to further illustrate the present invention, and should not be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art according to the above contents of the present invention all belong to the present invention scope of protection. The specific process parameters and the like in the following examples are only examples of suitable ranges, that is, those skilled in the art can make a selection within a suitable range through the description herein, and are not limited to the specific values exemplified below.

Example 1

In this embodiment 1, at first the optical properties of the multilayer film ion conducting layer are verified both theoretically and practically, and the main work includes the following steps:

1) Lithium aluminum oxide and tantalum oxide with ion-conducting properties are selected as the main research objects. Tantalum oxide monolayer film (Ta ₂ O ₅ , thickness 100-200nm) and lithium aluminum oxide monolayer film ( LiAl _x O _y , with a thickness of 100-200 nm). Among them, the tantalum oxide single-layer film uses a metal tantalum target, and the lithium-aluminum oxide single-layer film uses an aluminum-lithium alloy target, and is prepared by reactive DC magnetron sputtering. The process parameters of the DC magnetron sputtering include: a background vacuum of 1×10 ^-4 Pa, a substrate temperature of room temperature, a working atmosphere containing oxygen and argon, a working pressure of 2 Pa, and a sputtering power density of 1 to 1.25W /cm ² , the coating time is 10~30min;

2) The optical constant (refractive index) of the above thin film in the visible light region was measured by using an ellipsometer. The measurement results show that the refractive index of lithium aluminum oxide and tantalum oxide has a large difference, which are n=1.615 and n=2.126 respectively. According to the multilayer film interference theory, it fully meets the anti-reflection conditions of alternating high and low refractive index multilayer films;

3) Use optical software to analyze the structure of "lithium aluminum oxide/tantalum oxide/lithium aluminum oxide/glass substrate" with a multilayer (three-layer) film, aiming at the visible light transmittance, by changing each film in the multilayer film The thickness of the layer is optimized for the structure, and the best film structure is selected;

4) The optimized structure was prepared by magnetron sputtering, and its optical properties were evaluated and verified.

Firstly, the optical constants were used to optimize the design of the structure using optical software. Figure 2 shows one example of the visible light transmittance vs. The relationship between the thickness of each film layer. When t1=t2=0, that is, only a single layer of tantalum oxide, the visible light transmittance is very low (shown by the horizontal arrow in Figure 2); and when the upper and lower layers of lithium aluminum oxide films are introduced, the visible light transmittance is wavy rises and reaches the maximum value under certain conditions (as shown by the vertical arrow in the figure). Theoretical calculation fully demonstrates the superiority and feasibility of the present invention.

Considering the actual thickness range of the ion-conducting layer in the device, the structure design and optimization calculation were further carried out. Figure 3 shows the optimized multilayer with "lithium aluminum oxide (LAO: 80 ~ 120nm) / tantalum oxide (TO: 160 ~ 200nm) / lithium aluminum oxide (LAO: 80 ~ 120nm) / glass substrate (G)" The visible light transmission spectrum of one of the film structures was compared with the transmittance curves of the lithium aluminum oxide thin film alone and the tantalum oxide thin film alone with the same total thickness. It can be seen from the figure that the visible light transmittance curve of the alternating multilayer film is higher than that of the other two types of films, and its integrated value of visible light transmittance (98.4%) is much higher than that of lithium aluminum oxide (94.3%) and tantalum oxide ( 90.2%) monolayer film.

The above calculations show that the visible light transmittance of tantalum oxide/lithium aluminum oxide alternating multi-layer film structure with high and low refractive index values is much higher than that of a film with the same thickness when only a simple three-layer film structure is used. Thin films of tantalum oxide or lithium aluminum oxide alone. In this way, the present invention demonstrates the great superiority of the multi-layer ion conducting layer in terms of visible light transmittance performance from the theory and structure optimization experiments. Obviously, the use of an ion-conducting layer with a higher visible light transmittance directly leads to a higher visible light transmittance of the electrochromic device, and the applicability as a building energy-saving window is improved. Moreover, since tantalum oxide or lithium aluminum oxide can be prepared by using a metal target (metal tantalum or aluminum-lithium alloy target) by DC or intermediate frequency magnetron sputtering, it has high efficiency and is easy to scale up, and is suitable for large-scale device production processes. In addition, by adjusting the composition ratio of aluminum-lithium alloy and increasing the number of film layers, a uniform ion-conducting layer structure containing a predetermined concentration of lithium ions can be directly obtained.

The experimental verification of the optimized design results will be carried out in the following. Referring to the preparation parameters of the above-mentioned tantalum oxide and lithium aluminum oxide thin films, a solid-state ion-conducting layer of a multilayer film ("lithium aluminum oxide (LiAl _x O _y : 80-120nm)/tantalum oxide (Ta ₂ O ₅ :160~200nm)/lithium aluminum oxide (LiAl _x O _y :80~120nm)/glass substrate (G)"), the integral value of visible light transmittance was measured, and compared with the oxide with the same total thickness Tantalum and lithium aluminum oxide monolayer films were compared and the results are shown in Table 1:

Table 1:

The actual coating experiment results prove that the multilayer film structure of the present invention has a higher visible light transmittance than the single layer film, and one of the structures in this experiment reached the maximum value of 94.1%. Of course, due to the influence of film thickness control accuracy, there is still a certain gap between the experimental results and the theoretical optimization calculation, but it also shows the room for further improvement in performance.

Example 2

Embodiment 2 explains in detail the preparation process of the all-solid-state electrochromic device with the ion-conducting layer structure of the present invention:

Device preparation is carried out on a small magnetron sputtering apparatus (4 target positions, φ4 inch target material, rotating substrate);

Select the glass substrate, put it into the magnetron sputtering equipment after cleaning;

Magnetron sputtering ITO conductive target material in an inert atmosphere to prepare the first transparent conductive layer (thickness is 120nm), the preparation parameters include: background vacuum 1×10 ^-4 Pa, substrate temperature 200°C, working atmosphere is argon Gas, the working pressure is 1Pa, the sputtering power density is 1.25W/cm ² , and the coating time is 10-30min;

The first electrochromic layer (with a thickness of 100 nm) was prepared by reactive magnetron sputtering in an oxygen-containing atmosphere using a nickel metal target. The preparation parameters included: background vacuum 1×10 ^-4 Pa, substrate temperature of At room temperature, the working atmosphere is oxygen and argon, the working pressure is 3Pa, the sputtering power density is 2W/cm ² , and the coating time is 10-30min;

Using a LiAl _x alloy target, the first layer of lithium aluminum oxide film (thickness is 100nm, LiAl _x O _y , x=0.5～0.8, y =1.8～2.2), the preparation parameters include: the background vacuum is 1×10 ^-4 Pa, the substrate temperature is room temperature, the working atmosphere is oxygen and argon, the working pressure is 3Pa, and the sputtering power density is 2W/cm ² , coating time is 10~30min;

Using a metal tantalum target, a tantalum oxide film (160nm in thickness) was prepared by reactive magnetron sputtering in an oxygen-containing atmosphere. The preparation parameters include: background vacuum 1×10 ^-4 Pa, substrate temperature at room temperature, working The atmosphere is oxygen and argon, the working pressure is 3Pa, the sputtering power density is 2W/cm ² , and the coating time is 10-30min;

When preparing an electrochromic device with a single ion-conducting layer structure of tantalum oxide, in order to introduce lithium ions, a lithium tantalate (LiTaO ₃ ) target was used and prepared by radio frequency magnetron sputtering, and other parameters were the same as above.

Prepare a second layer of lithium aluminum oxide film (LiAl _x O _y , x=0.5-0.8, y=1.8-2.2) with a thickness of 100nm, under the same conditions as the preparation of the first layer of lithium aluminum oxide film;

Using a W metal target, the second electrochromic layer (with a thickness of 450 nm) was prepared by reactive magnetron sputtering in an oxygen-containing atmosphere. The preparation parameters include: background vacuum 1×10 ^-4 Pa, substrate temperature of At room temperature, the working atmosphere is oxygen and argon, the working pressure is 3Pa, the sputtering power density is 2W/cm ² , and the coating time is 10-30min;

The above samples were taken out and put into another magnetron sputtering apparatus, and a SiAlN _m O _n protective layer (with a thickness of 50-200 nm) was prepared by reactive magnetron sputtering in an atmosphere containing oxygen and nitrogen using a SiAl _m alloy target. The above preparation parameters include: the background vacuum is 1×10 ^-4 Pa, the substrate temperature is room temperature, the working atmosphere is oxygen, nitrogen and argon, the working pressure is 1Pa, the sputtering power density is 2W/cm ² , and the coating time is 10 ~30min;

The multilayer film structure of the all-solid electrochromic device is obtained through the above steps.

Use electrodes to connect the first transparent conductive layer and the second transparent conductive layer in the all-solid-state electrochromic device) and apply voltage, test the coloring-achromatic transmittance spectrum of the device after the forward and reverse voltages are applied, and integrally calculate the light transmittance and adjustment rate. Compared with single-layer Ta ₂ O ₅ (using lithium tantalate target) and single-layer LiAl _x O _y ion-conducting layer, the results are shown in Table 2:

Table 2:

Experimental results show that the electrochromic device using the special multilayer film solid ion conduction layer structure of the present invention, compared with the electrochromic device using the single layer film solid ion conduction layer structure, has higher visible light transmittance and lower dimming rate. There are great advantages in terms of enlargement.

Claims (12)

1. a kind of solid ionic conducting shell, which is characterized in that the solid ionic conducting shell is lithium aluminum oxide film and oxidation The chemical formula of multilayer film made of tantalum films are alternately laminated, the lithium aluminum oxide film is LiAl_xO_y, wherein 0.4≤x≤ 1.2, preferably 0.44≤x≤1, more preferable 0.45≤x≤0.67；0.5≤y≤3, preferably 0.5≤y≤2.5, more preferable 0.5≤y ≤2。

2. solid ionic conducting shell according to claim 1, which is characterized in that the multilayer film includes at least a lithium aluminium Sull and a tantalum oxide films.

3. solid ionic conducting shell according to claim 2, which is characterized in that the multilayer film includes at least a lithium aluminium Sull and be clipped between two tantalum oxide films or a tantalum oxide films and be clipped in two lithium aluminum oxide films it Between.

4. solid ionic conducting shell according to any one of claim 1-3, which is characterized in that the lithium aluminum oxide is thin The total number of plies of multilayer film made of film and tantalum oxide films are alternately laminated is 2~20, preferably 3~15, more preferable 3~5.

5. the solid ionic conducting shell according to any one of claim 1-4, which is characterized in that the solid ionic conduction Layer overall thickness is 100nm~1000nm, preferably 200nm~600nm.

6. solid ionic conducting shell according to any one of claims 1-5, which is characterized in that the lithium aluminum oxide is thin The thickness of film is 10~500 nm, preferably 50~400 nm；The thickness of the tantalum oxide films is 50~500 nm, preferably 50~200 nm.

7. the solid ionic conducting shell according to any one of claim 1-6, which is characterized in that the solid ionic conduction Lithium aluminum oxide film in layer is prepared using aluminium lithium alloy target by reactive magnetron sputtering mode, the aluminium lithium alloy target Material is AlLi_xSolid solution, the Al of composition₂Li₃Crystalline phase and Al₄Li₉At least one of crystalline phase.

8. solid ionic conducting shell according to claim 7, which is characterized in that the lithium aluminum oxide film preparation parameter For：Base vacuum 1 × 10^-5~5 × 10^-3Pa, base reservoir temperature are 20 DEG C~200 DEG C, and plated film time is 1~60 min, work gas Atmosphere is oxygenous and argon gas atmosphere, and operating air pressure is 0.5~5Pa, and Sputtering power density is 1~10W/cm²。

9. the solid ionic conducting shell according to any one of claim 1-8, which is characterized in that the tantalum oxide films make It is prepared by reactive magnetron sputtering mode with metal tantalum target；Preferably, the tantalum oxide films preparation parameter is：Background is true Sky 1 × 10^-5~5 × 10^-3Pa, base reservoir temperature are 20 DEG C~200 DEG C, and plated film time is 1~60 min, and work atmosphere is oxygen-containing Gas and argon gas atmosphere, operating air pressure are 0.5~5Pa, and Sputtering power density is 1~10W/cm²。

10. a kind of full-solid electrochromic device, which is characterized in that structure includes substrate, and is set in turn in the substrate On the first transparency conducting layer, the first electrochromic layer, the solid ionic conducting shell described in any one of claim 1-9, Two electrochromic layers, the second transparency conducting layer and protective layer.

11. full-solid electrochromic device according to claim 10, which is characterized in that first electrochromic layer is Nickel oxide, thickness are 100~500nm；Second electrochromic layer is tungsten oxide, and thickness is 200~600nm；It is described transparent Conductive layer is ITO, and thickness is 50~500nm；The protective layer is silicon-aluminium-nitride-oxide, and thickness is 50~500nm.

12. the full-solid electrochromic device according to claim 10 or 11, which is characterized in that will be described all solid state electroluminescent The first transparency conducting layer or the second transparency conducting layer replace with reflection-type metal conductive film in Electrochromic device.