Physical vapor deposition equipment, electrochromic device and preparation method of electrochromic device

Abstract

The invention discloses physical vapor deposition equipment, an electrochromic device and a preparation method of the electrochromic device, and relates to the technical field of electrochromic devices. The preparation method comprises the following steps: sputtering and depositing the WO3 electrochromic layer on the surface of the first ITO layer, wherein the oxygen content is any one of 42.5-52.5%; sputtering and depositing a tungsten oxide ion conducting layer with a preset thickness on the electrochromic layer, wherein the oxygen content of the corresponding chamber is any one of 35%-45%; sputtering and depositing an ion storage layer containing lithium ions on the ion conduction layer; a second ITO layer is deposited on the ion storage layer, and the electrochromic device is prepared after vacuum annealing treatment and cooling treatment; wherein the deposition temperature of the second ITO layer is any one value from 350 DEG C to 400 DEG C, and the annealing temperature of the vacuum annealing treatment is any one value from 450 DEG C to 500 DEG C. The electrochromic device prepared by the invention has the characteristics of high transmittance and low sheet resistance.

Description

Technical Field

[0001] This invention relates to the field of electrochromic device technology, specifically to a physical vapor deposition apparatus, an electrochromic device, and a method for preparing the same. Background Technology

[0002] Electrochromic devices can change color under the influence of an applied voltage and are widely used in electrochromic lenses, smart windows, and displays. In practical applications, these devices not only need to have good electrochromic response performance, but also high light transmittance and low haze to meet optical performance requirements.

[0003] Currently, electrochromic devices typically employ physical vapor deposition (PVD) to fabricate multilayer functional structures, including an electrochromic layer, an ion-conducting layer, and an ion-storage layer. Tungsten oxide, a typical electrochromic material, exhibits electrochromic performance dependent on the insertion and extraction of lithium ions. Simultaneously, the ion-conducting and ion-storage layers significantly influence lithium-ion transport efficiency and storage capacity. However, in existing technologies, the deposition process of these functional layers often lacks precise control over oxygen content. This can easily lead to deviations in the ideal stoichiometry of the electrochromic layer, insufficient or excessive defective structures in the ion-conducting layer, and instability in the ion-storage layer structure. Consequently, these issues affect lithium-ion migration efficiency and storage stability, ultimately reducing the response speed and cycle performance of the electrochromic device.

[0004] Furthermore, in the electrode layer preparation and post-processing, existing technologies typically employ low-temperature deposition of the ITO layer followed by annealing to improve its conductivity. However, the ITO thin film formed by low-temperature deposition is prone to structural changes under high-temperature vacuum annealing conditions, leading to a significant increase in sheet resistance. To avoid this problem, some technical solutions employ atmospheric annealing, but this method suffers from long annealing times and the potential introduction of oxygen and moisture, which affects the activity of lithium ions, resulting in decreased optical performance of electrochromic devices and poor product consistency.

[0005] Therefore, existing technologies cannot simultaneously achieve synergistic optimization of electrochromic layer performance, ion transport performance, and electrode conductivity performance during multilayer structure deposition, especially in terms of oxygen content control and matching of ITO deposition with vacuum annealing processes. An improved method for fabricating electrochromic devices is urgently needed to enhance the overall performance and stability of the devices. Summary of the Invention

[0006] One objective of the first aspect of this invention is to provide a method for fabricating electrochromic devices based on physical vapor deposition, which solves the technical problems in the prior art where insufficient oxygen content control of each functional layer during the fabrication of electrochromic devices leads to unstable ion transport and storage performance, and where the sheet resistance of the low-temperature deposited ITO layer increases under vacuum high-temperature annealing conditions and atmospheric annealing easily affects lithium-ion activity.

[0007] Another objective of the first aspect of the present invention is to maintain the high crystallinity and low sheet resistance of the second ITO layer.

[0008] A second aspect of the present invention is to provide a physical vapor deposition apparatus for carrying out the above-described preparation method.

[0009] The third aspect of this invention aims to provide an electrochromic device prepared according to the above-described preparation method.

[0010] According to a first aspect of the present invention, the present invention provides a method for fabricating an electrochromic device based on a physical vapor deposition process, comprising the following steps: An electrochromic layer is sputtered onto the surface of the first ITO layer located above the substrate. The electrochromic layer is made of WO3 and the oxygen content of the corresponding chamber is any value between 42.5% and 52.5%. An ion-conducting layer with a preset thickness of 200 nm to 500 nm is sputtered and deposited on the electrochromic layer. The ion-conducting layer is a non-stoichiometric tungsten oxide layer with an oxygen vacancy structure, and the oxygen content of the corresponding chamber is any value of 35% to 45%. An ion storage layer and a lithium-ion-containing layer are sequentially sputtered and deposited on the ion conduction layer. The ion storage layer is a nickel oxide layer with an amorphous structure, so that lithium ions in the lithium-ion-containing layer diffuse and are stored in the ion storage layer. The deposition temperature of the ion storage layer is any value between 350°C and 400°C, and the oxygen content of the corresponding chamber is any value between 80% and 87%. The electrochromic device is prepared by depositing a second ITO layer on the ion storage layer and then sequentially undergoing vacuum annealing and cooling treatments; wherein, The deposition temperature of the second ITO layer is any value between 350℃ and 400℃, the annealing temperature of the vacuum annealing treatment is any value between 450℃ and 500℃, the annealing time is any value between 480s and 900s, and the vacuum degree is less than 6.0×10⁻⁶. -4 Pa.

[0011] Optionally, during the vacuum annealing process, a first constant temperature chamber and a second constant temperature chamber are respectively provided between the chamber where the vacuum annealing process is performed and the chamber where the second ITO layer is deposited, and between the chamber where the vacuum annealing process is performed and the chamber where the cooling process is performed. The temperature of the first constant temperature chamber and the second constant temperature chamber is any value between 380°C and 400°C.

[0012] Optionally, before depositing the lithium-ion-containing layer, the substrate is passed through a first isolation chamber disposed between the chamber for depositing the ion storage layer and the chamber for depositing the lithium-ion-containing layer, so as to perform temperature transition on the substrate and block gas flow.

[0013] Optionally, after depositing the lithium-ion-containing layer, the substrate is passed through a second isolation chamber disposed between the chamber for depositing the lithium-ion-containing layer and the chamber for depositing the second ITO layer, so as to perform temperature transition on the substrate and block gas flow.

[0014] Optionally, a vacuuming process is performed in an isolation chamber between the chamber where the ion storage layer is deposited and the chamber where the lithium-ion layer is deposited, to reduce the moisture content carried by the substrate before it enters the lithium-ion layer deposition chamber.

[0015] Optionally, the step of sputtering and depositing an electrochromic layer on the surface of the first ITO layer located above the substrate further includes: The first ITO layer disposed on the substrate is subjected to cleaning and preheating treatment in sequence.

[0016] Optionally, the deposition temperature of the electrochromic layer is any value between 200℃ and 300℃.

[0017] Optionally, the deposition temperature of the ion-conducting layer is any value between 200℃ and 300℃, and the deposition temperature of the lithium-ion-containing layer is any value between 90℃ and 110℃.

[0018] According to a second aspect of the present invention, the present invention also provides a physical vapor deposition apparatus for implementing the above-described method for fabricating an electrochromic device based on physical vapor deposition, comprising a first tungsten deposition chamber, a second tungsten deposition chamber, a nickel deposition chamber, a lithium deposition chamber, an ITO deposition chamber, a vacuum annealing chamber, and a cooling chamber arranged sequentially along the production process direction.

[0019] According to a third aspect of the present invention, the present invention also provides an electrochromic device prepared according to the electrochromic device preparation method based on physical vapor deposition process described in any one of the preceding claims, comprising a substrate, a first ITO layer, an electrochromic layer, an ion-conducting layer, an ion-storage layer, and a second ITO layer arranged sequentially from bottom to top, wherein the thickness of the ion-conducting layer is any value between 200 nm and 500 nm, and the ion-storage layer is a nickel oxide layer in which lithium ions are distributed.

[0020] This invention establishes a multi-step coupled and optimized fabrication system by synergistically designing the structure and process parameters of the electrochromic layer, ion-conducting layer, ion-storage layer, and second ITO layer in an electrochromic device. First, by forming an ion-conducting layer with a preset thickness of 200nm-500nm and an oxygen vacancy structure under conditions of 35%-45% oxygen content, the ion migration efficiency within the electrochromic device is improved, while the electronic conductivity of the ion-conducting layer is suppressed. Second, by forming an amorphous nickel oxide ion-storage layer under deposition conditions of 350℃-400℃ and 80%-87% oxygen content and introducing lithium ions, stable and efficient ion storage and release are achieved. Furthermore, by depositing a second ITO layer under high-temperature conditions and combining it with high-temperature vacuum annealing, the sheet resistance of the low-temperature second ITO layer can be increased during high-temperature annealing, while the electrode conductivity can be improved and lithium-ion activity can be maintained. This prevents the light transmittance of the electrochromic device from decreasing, thereby improving the product yield of the electrochromic device. The device can simultaneously possess fast ion transport capability, stable ion storage capability, and excellent electrical performance, thus improving the overall response speed, optical modulation performance, and cycle stability of the electrochromic device.

[0021] Furthermore, during the vacuum annealing process, the present invention provides a first constant-temperature chamber between the vacuum annealing chamber and the ITO deposition chamber, and a second constant-temperature chamber between the vacuum annealing chamber and the cooling chamber. The temperatures of the first and second constant-temperature chambers are both any values ​​between 380°C and 400°C. This ensures that the substrate is in a thermal environment matching the annealing temperature before entering and after leaving the vacuum annealing chamber, and that the temperature distribution is uniform throughout the vacuum annealing chamber. This achieves a gradual temperature transition, effectively avoiding temperature abrupt changes during the transfer of the substrate between different chambers, reducing film cracking, interface peeling, and structural instability caused by thermal stress. At the same time, it ensures that the second ITO layer is in a high-temperature stable state before entering the vacuum annealing stage and is slowly cooled after annealing, thereby maintaining the high crystallinity and low sheet resistance of the second ITO layer.

[0022] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0023] The following sections will describe some specific embodiments of the invention in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings: Figure 1 This is a schematic flowchart of a method for preparing an electrochromic device according to an embodiment of the present invention; Figure 2 This is a schematic structural diagram of an electrochromic device according to an embodiment of the present invention; Figure 3 This is a schematic structural diagram of a physical vapor deposition apparatus according to an embodiment of the present invention.

[0024] Figure label: 100 - Electrochromic device; 10 - Substrate; 11 - Glass substrate; 12 - Silicon oxide substrate; 20 - First ITO layer; 30 - Electrochromic layer; 40 - Ion conduction layer; 50 - Ion storage layer; 60 - Second ITO layer; 200 - Physical vapor deposition equipment; 210 - First tungsten deposition chamber; 220 - Second tungsten deposition chamber; 230 - Nickel deposition chamber; 240 - Lithium deposition chamber; 250 - ITO deposition chamber; 260 - Vacuum annealing chamber; 270 - Cooling chamber; 261 - First isothermal chamber; 262 - Second isothermal chamber; 241 - First isolation chamber; 242 - Second isolation chamber; 243 - Cold pump; 280 - Clean chamber; 290 - Preheating chamber. Detailed Implementation

[0025] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0026] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0027] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0028] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] Figure 1 This is a schematic flowchart illustrating a method for fabricating an electrochromic device according to an embodiment of the present invention. Figure 2 This is a schematic structural diagram of an electrochromic device according to an embodiment of the present invention. Figure 3 This is a schematic structural diagram of a physical vapor deposition apparatus according to an embodiment of the present invention.

[0030] like Figure 1 As shown, this invention provides a method for fabricating an electrochromic device 100 based on a physical vapor deposition process. The electrochromic device 100 can be used in lenses. The fabrication method includes the following steps: Step S100: An electrochromic layer 30 is sputtered and deposited on the surface of the first ITO layer 20 located above the substrate 10. The material of the electrochromic layer 30 is WO3, and the oxygen content of the corresponding chamber is any value between 42.5% and 52.5%. That is, when the electrochromic layer 30 is deposited on the first ITO layer 20, the oxygen content of the corresponding chamber can be 42.5%, 43%, 45%, 47%, 49%, 50%, or 52.5%. Step S200: Sputter deposit an ion-conducting layer 40 with a preset thickness of any value between 200nm and 500nm on the electrochromic layer 30. The ion-conducting layer 40 is a non-stoichiometric tungsten oxide layer with an oxygen vacancy structure, and the oxygen content of the corresponding chamber is any value between 35% and 45%. That is, the oxygen content of the chamber where the ion-conducting layer 40 is deposited on the electrochromic layer 30 can be 35%, 37%, 39%, 40%, 42%, 44%, or 45%, or any other value between 35% and 45%. The thickness of the ion-conducting layer 40 can be 200nm, 250nm, 300nm, 350nm, 400nm, 450nm, or 500nm, or any other value between 200nm and 500nm. Step S300: An ion storage layer 50 and a lithium-ion-containing layer are sequentially sputtered and deposited on the ion conduction layer 40. The ion storage layer 50 is a nickel oxide layer with an amorphous structure, so that lithium ions in the lithium-ion-containing layer diffuse and are stored in the ion storage layer 50. The deposition temperature of the ion storage layer 50 is any value between 350℃ and 400℃, and the oxygen content of the corresponding chamber is any value between 80% and 87%. That is, the deposition temperature of the ion storage layer 50 can be 350℃, 360℃, 370℃, 380℃, 390℃ or 400℃, or any other value between 350℃ and 400℃. The oxygen content of the corresponding chamber of the deposited ion storage layer 50 can be 80%, 81%, 82%, 83%, 84%, 85%, 86% or 87%, or any other value between 80% and 87%. Step S400: A second ITO layer 60 is deposited on the ion storage layer 50, and then subjected to vacuum annealing and cooling treatments to obtain an electrochromic device 100; wherein the deposition temperature of the second ITO layer 60 is any value between 350℃ and 400℃, the annealing temperature of the vacuum annealing treatment is any value between 450℃ and 500℃, the annealing time is any value between 480s and 900s, and the vacuum degree is less than 6.0×10⁻⁶. -4 The deposition temperature of the second ITO layer 60 (Pa) can be 350℃, 360℃, 370℃, 380℃, 390℃, or 400℃, or any other value between 350℃ and 400℃. The annealing temperature for vacuum annealing can be 450℃, 460℃, 470℃, 480℃, 490℃, or 500℃, or any other value between 450℃ and 500℃. The annealing time can be 480s, 500s, 600s, 700s, 800s, or 900s, or any other value between 480s and 900s. The vacuum degree can be 5.0 × 10⁻⁶. -4 Pa, 4.0 × 10 -4 Pa, 3.0 × 10 -4 Pa, 2.0×10 -4 Pa or 1.0 × 10 -4 Pa can also be less than 6.0 × 10 -4 Other vacuum levels of Pa. Here, the oxygen content in the chamber where the sputtered deposited ion-conducting layer 40 is located is less than the oxygen content in the chamber where the sputtered deposited electrochromic layer 30 is located.

[0031] In this embodiment, an electrochromic device 100 is fabricated using a physical vapor deposition (PVD) process. First, a substrate 10 with a first ITO layer 20 deposited on it is provided. Then, an electrochromic layer 30, an ion-conducting layer 40, and a lithium-ion-containing ion storage layer 50 are sequentially sputtered and deposited on the surface of the first ITO layer 20. Next, a second ITO layer 60 is deposited on the surface of the ion storage layer 50. After vacuum annealing and cooling, the electrochromic device 100 is obtained. Here, the substrate 10 is placed on a fixture, allowing the fixture to carry the substrate 10 and the first ITO layer 20 sequentially into each chamber along the production line direction for the fabrication of the corresponding structural layers. The substrate 10 includes a glass substrate 11 and a silicon oxide substrate 12, with the first ITO layer 20 disposed on the silicon oxide substrate 12.

[0032] In this embodiment, a multi-step coupled and optimized fabrication system is formed by synergistically designing the structure and process parameters of the electrochromic layer 30, ion-conducting layer 40, ion storage layer 50, and second ITO layer 60 in the electrochromic device 100. First, by forming an ion-conducting layer 40 with a predetermined thickness and an oxygen vacancy structure under conditions of 35%-45% oxygen content, the ion migration efficiency inside the electrochromic device 100 is improved, while the electronic conductivity of the ion-conducting layer 40 is suppressed. Second, by forming an amorphous nickel oxide ion storage layer 50 and introducing lithium ions under deposition conditions of 350℃-400℃ and 80%-87% oxygen content, stable and efficient ion storage and release are achieved. Furthermore, by depositing a second ITO layer 60 under high-temperature conditions and combining it with high-temperature vacuum annealing, the sheet resistance of the low-temperature second ITO layer 60 can be prevented from increasing during high-temperature annealing, while simultaneously improving electrode conductivity and maintaining lithium-ion activity, preventing a decrease in the transmittance of the electrochromic device 100, thereby improving the product yield of the electrochromic device 100. The synergistic effect of the above-mentioned multiple steps in terms of process parameters and functional effects enables the device to simultaneously possess rapid ion transport capability, stable ion storage capability, and excellent electrical performance, thereby comprehensively improving the response speed, optical modulation performance, and cycle stability of the electrochromic device 100.

[0033] In step S400, by depositing the second ITO layer 60 at a relatively high temperature of 350℃-400℃ and further performing vacuum annealing at 450℃-500℃, the second ITO layer 60 has a high degree of crystallinity during the deposition stage, thereby effectively reducing its sheet resistance and improving its conductivity. At the same time, it avoids the problem of structural degradation and increased resistance caused by low-temperature deposited ITO during subsequent high-temperature annealing. While ensuring the high conductivity of the electrode, it maintains lithium-ion activity, thereby improving the yield and performance consistency of the electrochromic device 100.

[0034] Furthermore, high-temperature deposition of the second ITO layer 60 promotes grain growth and reduces carrier scattering, while high-temperature vacuum annealing facilitates the repair of internal defects in the thin film and the diffusion and rearrangement of interface atoms, resulting in a stable interface structure between the functional layers. Simultaneously, the vacuum environment effectively isolates oxygen and moisture, inhibiting lithium-ion oxidation or deactivation. Therefore, through the synergistic effect of high-temperature deposition and vacuum annealing, the electrode conductivity, interface stability, and ion activity are simultaneously optimized, thereby improving the overall performance of the electrochromic device 100.

[0035] In step S300, an amorphous nickel oxide layer is deposited at a temperature of 350℃-400℃ and a high oxygen content of 80%-87%, and a lithium-ion-containing layer is formed on it. This allows lithium ions to diffuse and embed into the nickel oxide layer, providing high-density and stable lithium-ion storage sites. This enables reversible lithium-ion insertion and extraction, improving the cycle stability and lifespan of the electrochromic device 100. Specifically, NiO formed under high temperature and high oxygen conditions... x The ion storage layer 50 has an amorphous structure with numerous disordered sites and defects, which can serve as embedding sites for lithium ions. After the lithium-ion-containing layer is deposited, lithium ions are driven by heat and a concentration gradient to enter NiO. x The layer diffuses and embeds itself to form a stable lithium storage state. Under the action of an external electric field, lithium ions can reversibly migrate between this layer and the electrochromic layer 30, thereby supporting the continuous progress of the electrochromic reaction.

[0036] In step S200, by controlling the oxygen content in the deposition chamber to be 35%-45% and combining this with the preset thickness of the ion-conducting layer 40, a non-stoichiometric tungsten oxide ion-conducting layer 40 is formed on the electrochromic layer 30. This layer has a rich oxygen vacancy structure and its thickness is controlled, thereby ensuring continuous film formation while constructing a stable ion transport path. This not only forms a continuous and low-barrier lithium-ion migration channel, improving the transport efficiency of lithium ions between the electrochromic layer 30 and the ion storage layer 50, but also prevents the formation of electron-through conductive paths through thickness control, thereby suppressing electronic conductivity and improving ion selective conduction, thus improving the response speed and color uniformity of the electrochromic process.

[0037] Furthermore, the tungsten oxide deposited under low oxygen conditions exhibits a non-stoichiometric state, i.e., a non-stoichiometric tungsten oxide ion-conducting layer (WO). xIn the case of x < 3, a large number of oxygen vacancy defects are formed in the crystal lattice. Oxygen vacancies serve as effective jumping sites for ion migration, enabling lithium ions to diffuse rapidly in the thin film through the vacancy migration mechanism. At the same time, this layer is usually amorphous or low-ordered, further reducing the resistance to ion migration. By reasonably controlling the film thickness, the formation of continuous conduction paths for electron carriers can be effectively restricted, thereby achieving transport characteristics dominated by ion conduction and suppressed electronic conductivity.

[0038] In step S100, by controlling the oxygen content in the deposition chamber to be 42.5%-52.5%, a tungsten oxide electrochromic layer 30 with a stoichiometric ratio close to the ideal state is formed on the surface of the first ITO layer 20. This ensures that the layer has good electrochromic activity and structural stability, thereby improving the lithium ion insertion and extraction capability of the electrochromic layer 30, enhancing the color change amplitude, and improving the optical modulation performance and cycle stability of the electrochromic device 100. Specifically, the WO3 film deposited under the condition of 42.5%-52.5% oxygen content is closer to the stoichiometric ratio, with a relatively complete lattice structure and moderate defects, which is conducive to reversible ion insertion / extraction reactions under the action of an external electric field, thereby realizing a stable and repeatable electrochromic process. At the same time, it can avoid the enhanced electronic conductivity caused by excessive oxygen vacancies, thereby suppressing leakage current and improving color change uniformity and device reliability.

[0039] In this embodiment, the working principle of the electrochromic device 100 is as follows: In the coloring process of the electrochromic device 100, when a voltage is applied between the two ITO electrodes, lithium ions in the lithium-ion-containing layer migrate through the ion-conducting layer 40 with an oxygen vacancy structure to the electrochromic layer 30 under the drive of the electric field and are embedded in the WO3 lattice. At the same time, electrons are injected into the electrochromic layer 30 through the external circuit, causing the WO3 to undergo a reduction reaction to form Li. x WO3, which causes a change in the band structure of the material and leads to enhanced absorption of visible light, resulting in a colored state for the electrochromic device 100. Here, the chemical formula (1) of the reduction reaction corresponding to the coloring process is as follows: WO3+xLi + +xe - →Li x WO3 chemical formula (1); In the process of restoring transparency of the electrochromic device 100, the amorphous nickel oxide structure in the ion storage layer 50 provides stable ion storage sites. Under the action of no applied voltage or reverse voltage, lithium ions embedded in the electrochromic layer 30 are driven by an electric field to return to the ion storage layer 50 through the ion conduction layer 40 and be stored again, so that WO3 is restored to its initial state, thereby realizing the fading process and restoring the electrochromic device 100 to the transparent state. Here, the chemical formula (2) corresponding to the fading process is as follows: Lix WO3→WO3+xLi + +xe - Chemical formula (2).

[0040] like Figure 2 As shown, the electrochromic device 100 in this embodiment is implemented in multiple chambers of a physical vapor deposition (PVD) apparatus 200, that is, the PVD apparatus 200 is used to implement the above-described method for fabricating the electrochromic device 100 based on the PVD process. Specifically, the PVD apparatus 200 includes a first tungsten deposition chamber 210, a second tungsten deposition chamber 220, a nickel deposition chamber 230, a lithium deposition chamber 240, an ITO deposition chamber 250, a vacuum annealing chamber 260, and a cooling chamber 270 arranged sequentially along the production process direction. Furthermore, after the electrochromic device 100 is fabricated, the fixture after removing the electrochromic device 100 can again carry a new substrate 10 for the fabrication of the next electrochromic device 100. The first tungsten deposition chamber 210 is used to deposit the electrochromic layer 30, the second tungsten deposition chamber 220 is used to deposit the ion conduction layer 40, the nickel deposition chamber 230 is used to deposit the ion storage layer 50, the lithium deposition chamber 240 is used to deposit the lithium ion-containing layer and diffuse the lithium ions to the ion storage layer 50, the ITO deposition chamber 250 is used to deposit the second ITO layer 60, the vacuum annealing chamber 260 is used to perform vacuum annealing treatment, and the cooling chamber 270 is used to cool the prepared electrochromic device 100.

[0041] In a preferred embodiment, there are two ITO deposition chambers 250. The two ITO deposition chambers 250 have the same function and structure. When depositing the second ITO layer 60, one ITO deposition chamber 250 is selected and the other ITO deposition chamber is used as a backup to facilitate production line change or replacement when one ITO deposition chamber needs maintenance.

[0042] In a further embodiment, during vacuum annealing, a first constant-temperature chamber 261 is provided between the vacuum annealing chamber 260 and the ITO deposition chamber 250, and a second constant-temperature chamber 262 is provided between the vacuum annealing chamber 260 and the cooling chamber 270. The temperature of both the first constant-temperature chamber 261 and the second constant-temperature chamber 262 is any value between 380°C and 400°C, meaning the temperature of the first constant-temperature chamber 261 and the second constant-temperature chamber 262 is always the same. Furthermore, the temperature of the first constant-temperature chamber 261 and the second constant-temperature chamber 262 can be 380°C, 385°C, 390°C, 395°C, or 400°C, or it can be between 380°C and 400°C. Any other value within 00℃ ensures that the substrate 10 is in a thermal environment matching the annealing temperature before entering and after leaving the vacuum annealing chamber 260, and that the temperature distribution throughout the vacuum annealing chamber 260 is uniform, thereby achieving a gradual temperature transition. This effectively avoids temperature abrupt changes during the transfer of the substrate 10 between different chambers, reduces film cracking, interface peeling, and structural instability caused by thermal stress, and ensures that the second ITO layer 60 is in a high-temperature stable state before entering the vacuum annealing stage and is slowly cooled after annealing, thereby maintaining the high crystallinity and low sheet resistance characteristics of the second ITO layer 60.

[0043] Furthermore, the aforementioned isothermal transition process, together with the aforementioned high-temperature deposition of the second ITO layer 60 and high-temperature vacuum annealing, works synergistically. Firstly, it ensures that the ITO crystal structure formed by high-temperature deposition does not undergo abrupt degradation when entering the annealing stage, thereby avoiding an increase in sheet resistance. Secondly, the high-temperature buffer transition after annealing suppresses the regeneration of defects and the concentration of interface stress caused by rapid cooling, while reducing the risk of adsorption of ambient gases driven by temperature difference. This helps maintain lithium-ion activity and interface stability, thereby achieving a synergistic improvement in temperature field uniformity, electrode conductivity, and device reliability, further enhancing the performance consistency and product yield of the electrochromic device 100.

[0044] In a further embodiment, before depositing the lithium-ion layer, the substrate 10 passes through a first isolation chamber 241 disposed between the nickel deposition chamber 230 and the lithium deposition chamber 240 to allow for a temperature transition of the substrate 10 and to block gas flow. This effectively reduces the temperature abrupt change from the high-temperature environment of the ion storage layer 50 deposition to the lithium-ion layer deposition environment, preventing structural defects or interface stress concentration in the substrate 10 and the formed film due to thermal shock. At the same time, it prevents oxygen and water vapor in adjacent chambers from entering the lithium-ion layer deposition area, thereby reducing the risk of lithium material oxidation or reaction with water vapor during the deposition process and ensuring the activity of lithium ions and the deposition quality.

[0045] Furthermore, the first isolation chamber 241 works synergistically with the aforementioned high-temperature and high-oxygen deposition process of the ion storage layer 50, enabling the substrate 10 to achieve both a gradual decrease in temperature and effective atmosphere isolation when transitioning from a high-temperature and high-oxygen environment to a lithium-ion layer deposition environment. This provides suitable process conditions for the stable deposition of the lithium-ion layer, thereby improving the diffusion efficiency and embedding stability of subsequent lithium ions into the ion storage layer 50.

[0046] In a further embodiment, after depositing the lithium-ion layer, the substrate 10 passes through a second isolation chamber 242 disposed between the lithium deposition chamber 240 and the ITO deposition chamber 250 to allow for temperature transition of the substrate 10 and block gas flow. This effectively prevents the substrate 10 from directly entering the high-temperature deposition environment from the low-temperature environment of lithium-ion layer deposition, reducing film structure damage and interface stress concentration caused by thermal shock. At the same time, it prevents the lithium-ion layer from contacting oxygen or water vapor in adjacent chambers during the transfer process, thereby reducing the risk of lithium ion oxidation or deactivation and ensuring the stability and effectiveness of the lithium-ion layer.

[0047] Furthermore, the second isolation chamber 242 works synergistically with the subsequent high-temperature deposition process of the second ITO layer 60, allowing the substrate 10 to gradually heat up and remain in a relatively stable thermal environment before entering the high-temperature ITO deposition stage. This facilitates the formation of a good crystalline structure and interface bonding state in the second ITO layer 60 during the initial deposition stage. Simultaneously, atmospheric isolation prevents interference from impurity gases on the lithium-ion-containing layer, helping to maintain lithium-ion activity and reduce the formation of interface defects. This, in turn, improves electrode conductivity and interlayer bonding stability, ultimately enhancing the overall performance and product consistency of the electrochromic device 100.

[0048] In a further embodiment, evacuation is performed in a first isolation chamber 241 between the nickel deposition chamber 230 and the lithium deposition chamber 240 to reduce the moisture content carried by the substrate 10 before entering the lithium deposition chamber 240. This significantly reduces the introduction of moisture during the subsequent lithium-ion layer deposition process, preventing lithium from reacting with moisture during deposition or diffusion, thereby reducing the risk of lithium ion consumption or deactivation and ensuring the compositional stability and deposition quality of the lithium-ion layer. Here, the device for evacuating the first isolation chamber 241 is a cold pump 243, rather than being directly installed in the nickel deposition chamber 230. This effectively avoids thermal damage to the cold pump 243 caused by the high-temperature environment during nickel oxide deposition, which would occur if it were directly installed in the nickel deposition chamber 230. It also avoids the problem of reduced evacuation efficiency caused by enhanced moisture desorption and re-release under high-temperature conditions, thus ensuring that the evacuation process is carried out efficiently under relatively suitable temperature conditions. This arrangement simultaneously improves moisture removal efficiency and equipment operational stability.

[0049] Furthermore, the cold pump 243 works synergistically with the temperature transition and gas barrier functions of the isolation chamber, enabling the substrate 10 to simultaneously achieve stable temperature changes and atmosphere purification control during the transition from a high-temperature, high-oxygen environment to a lithium-ion layer deposition environment. This provides a low-moisture, low-impurity process environment for lithium-ion layer deposition, which is beneficial to improving the diffusion efficiency and embedding stability of lithium ions into the ion storage layer 50, reducing interfacial side reactions, and thus improving the response performance, cycle stability, and product yield of the electrochromic device 100.

[0050] In a further embodiment, step S100 includes the following prior to: The first ITO layer 20 disposed on the substrate 10 is sequentially cleaned and preheated.

[0051] In this embodiment, by sequentially cleaning and preheating the first ITO layer 20 disposed on the substrate 10 before step S100, particulate impurities, organic residues, and adsorbed moisture on the surface of the first ITO layer 20 can be effectively removed, thereby improving its surface cleanliness and activity, and enhancing the interfacial adhesion between the subsequent electrochromic layer 30 and the first ITO layer 20. Simultaneously, the preheating treatment brings the substrate 10 and the first ITO layer 20 to a temperature state matching the subsequent deposition process, reducing temperature fluctuations in the early stages of deposition and avoiding film stress and structural defects caused by temperature differences. Here, the cleaning treatment is performed in the cleanroom 280, and the preheating treatment is performed in the preheating chamber 290.

[0052] In a further embodiment, the deposition temperature of the electrochromic layer 30 is any value between 200°C and 300°C. That is, the deposition temperature of the electrochromic layer 30 can be 200°C, 220°C, 240°C, 260°C, 280°C, or 300°C, or any other value between 200°C and 300°C. This ensures that the film has an appropriate crystalline structure, which is conducive to the reversible insertion and extraction reactions of lithium ions, improving the electrochromic activity and optical modulation capability. At the same time, it avoids the problems of loose film, porosity, and poor interface bonding caused by too low a deposition temperature, as well as the problems of excessive grain growth, stress accumulation, or interface deterioration caused by too high a temperature. At the same time, this temperature range is conducive to the formation of a WO3 layer with a uniform structure and moderate defects. While ensuring the synergistic operation of electron conduction and ion diffusion, it reduces the occurrence of non-ideal side reactions, thereby improving the response speed, color uniformity, and cycle stability of the electrochromic device 100.

[0053] In a further embodiment, the deposition temperature of the ion-conducting layer 40 is any value between 200°C and 300°C. That is, the deposition temperature of the ion-conducting layer 40 can be 200°C, 220°C, 240°C, 260°C, 280°C, or 300°C, or any other value between 200°C and 300°C. This not only facilitates the formation of a stable and continuous oxygen vacancy structure in the thin film, providing a low-barrier migration channel for lithium ions and thus improving ion conductivity, but also avoids the problems of excessively low deposition temperature leading to a loose film layer and discontinuous structure, affecting ion transport stability, and excessively high temperature causing crystallization enhancement, reduced oxygen vacancies, or even increased electronic conductivity. At the same time, this temperature range helps to form a functional layer structure with ion conduction as the main feature and suppressed electronic conductivity, and ensures good interfacial bonding between the film layer and the adjacent electrochromic layer 30 and ion storage layer 50, thereby improving the ion transport efficiency, response speed, and overall device stability during the electrochromic process.

[0054] In a further embodiment, the deposition temperature of the lithium-ion layer is any value between 90°C and 110°C. The deposition temperature can be 90°C, 95°C, 100°C, 105°C, or 110°C, or any other value within the 90°C-110°C range. This allows lithium to possess both appropriate migration activity and structural stability during deposition, providing a certain diffusion driving force for lithium ions during the deposition stage. This enables lithium ions to effectively diffuse and intercalate into the lower ion storage layer 50, thereby improving lithium storage efficiency. It also avoids the problems of excessively high deposition temperatures leading to excessive lithium activity, oxidation, volatilization, or side reactions with residual gases. Simultaneously, this temperature range helps to reduce interfacial reactions and structural disturbances while ensuring uniform lithium-ion layer formation, thus maintaining the effective lithium ion content and activity.

[0055] The present invention also provides an electrochromic device 100 prepared by the above-mentioned physical vapor deposition process, comprising a substrate 10, a first ITO layer 20, an electrochromic layer 30, an ion-conducting layer 40, an ion-storage layer 50, and a second ITO layer 60 arranged sequentially from bottom to top. The thickness of the ion-conducting layer 40 is any value between 200 nm and 500 nm, and the ion-storage layer 50 is a nickel oxide layer in which lithium ions are distributed.

[0056] In this embodiment, the electrochromic layer 30 is used to achieve optical modulation, the ion-conducting layer 40 is used to provide a high-efficiency ion migration channel, the ion storage layer 50 is used to provide stable lithium-ion storage and release sites, and the first ITO layer 20 and the second ITO layer 60 serve as transparent conductive electrodes to achieve rapid electron transport. By controlling the thickness of the ion-conducting layer 40 within a preset range, the continuity of ion transport can be ensured while the electrons can be prevented from passing through the conductive path, thereby improving the ion selective conduction capability. At the same time, the nickel oxide structure with lithium ions distributed in the ion storage layer 50 can achieve stable insertion and reversible release of lithium ions, thereby improving the cycle stability and lifetime of the electrochromic device 100. Thus, the device achieves synergistic optimization among ion transport, charge conduction, and optical response, thereby improving the response speed, color uniformity, optical modulation range, and overall reliability of the electrochromic device 100.

[0057] The technical solution of this application will be further described below with reference to specific embodiments.

[0058] Example 1 The method for fabricating an electrochromic device 100 based on physical vapor deposition includes the following steps: Step S100: An electrochromic layer 30 is sputtered and deposited on the surface of the first ITO layer 20 located above the substrate 10. The material of the electrochromic layer 30 is WO3, and the oxygen content of the corresponding chamber is 45%. Step S200: Sputter and deposit an ion-conducting layer 40 with a thickness of 300 nm on the electrochromic layer 30. The ion-conducting layer 40 is a non-stoichiometric tungsten oxide layer with an oxygen vacancy structure, and the oxygen content of the corresponding chamber is 40%. Step S300: An ion storage layer 50 and a lithium-ion-containing layer are sequentially sputtered and deposited on the ion conduction layer 40. The ion storage layer 50 is a nickel oxide layer with an amorphous structure, so that lithium ions in the lithium-ion-containing layer diffuse and are stored in the ion storage layer 50. The deposition temperature of the ion storage layer 50 is 380°C, and the corresponding oxygen content in the chamber is 82%. Step S400: A second ITO layer 60 is deposited on the ion storage layer 50, and then subjected to vacuum annealing and cooling treatments to obtain an electrochromic device 100. The deposition temperature of the second ITO layer 60 is 380℃, the annealing temperature for the vacuum annealing treatment is 475℃, the annealing time is 600s, and the vacuum degree is 5.0 × 10⁻⁶. -4 Pa; The first isolation chamber 241, which is equipped with a cold pump 243, is provided between the nickel deposition chamber 230 and the lithium deposition chamber 240. The first isolation chamber 241 is provided between the ITO deposition chamber 250 and the lithium deposition chamber 241. The first constant temperature chamber 261 is provided between the vacuum annealing chamber 260 and the ITO deposition chamber 250. The second constant temperature chamber 262 is provided between the vacuum annealing chamber 260 and the cooling chamber 270. The temperature of the first constant temperature chamber 261 and the second constant temperature chamber 262 is 400℃.

[0059] Comparative Example 1 The only difference between Comparative Example 1 and Example 1 is that the deposition temperature of the second ITO layer 60 is 250°C and the annealing temperature is 500°C.

[0060] Comparative Example 2 The only difference between Comparative Example 2 and Example 1 is that the vacuum annealing treatment is carried out at room temperature and pressure.

[0061] Comparative Example 3 The only difference between Comparative Example 3 and Example 1 is that the oxygen content in the second tungsten deposition chamber 220 is 50%.

[0062] Comparative Example 4 The only difference between Comparative Example 4 and Example 1 is that the oxygen content in the second tungsten deposition chamber 220 is 30%.

[0063] Comparative Example 5 The only difference between Comparative Example 5 and Example 1 is that the first isolation chamber 241 is not provided on both sides of the lithium deposition chamber 240.

[0064] Comparative Example 6 The only difference between Comparative Example 6 and Example 1 is that no second isolation chamber 242 is provided on both sides of the lithium deposition chamber 240.

[0065] Comparative Example 7 The only difference between Comparative Example 7 and Example 1 is that no heat preservation chambers are provided on both sides of the vacuum annealing chamber 260.

[0066] Sheet resistance and transmittance tests were performed on the electrochromic devices 100 prepared in Example 1 and Comparative Examples 1-6, respectively, and the test results are shown in Table 1.

[0067] Table 1. Test results of electrochromic device 100 in Example 1 and Comparative Examples 1-6

[0068] As shown in Table 1, the electrochromic device 100 prepared in Example 1 exhibits the best performance in terms of sheet resistance and transmittance, with a sheet resistance of 7Ω / sq ​​and a transmittance of 85%. In contrast, the performance of each comparative example decreased to varying degrees after the corresponding process conditions were removed or changed.

[0069] First, in Comparative Example 1, a second ITO layer 60 was deposited at low temperature and then subjected to high-temperature annealing. Its sheet resistance increased from 7 Ω / sq to 10 Ω / sq, while its transmittance decreased from 85% to 81%. This indicates that the low-temperature deposited second ITO layer 60 underwent structural degradation during high-temperature annealing, leading to a decrease in conductivity. This verifies that the synergistic process of high-temperature deposition of the second ITO layer 60 and high-temperature vacuum annealing in this invention can effectively reduce sheet resistance and improve optical performance.

[0070] Secondly, Comparative Example 2 was annealed under normal temperature and pressure conditions, and its sheet resistance increased significantly to 25Ω / sq and its transmittance decreased to 78%. This indicates that annealing in a non-vacuum environment will introduce oxygen and water vapor, leading to a decrease in lithium-ion activity and interface degradation, which will significantly affect the electrochromic performance. This verifies the key role of vacuum annealing in maintaining device performance.

[0071] For Comparative Examples 3 and 4, corresponding to cases where the oxygen content was too high (above 42.5%) and too low (below 35%) during the deposition of the ion-conducting layer 40, respectively, the sheet resistance increased to 20 Ω / sq and 15 Ω / sq, and the transmittance decreased to 78% and 80%. This indicates that when the oxygen content deviates from the range defined in this invention, the structure of the ion-conducting layer 40 cannot simultaneously balance oxygen vacancy concentration and structural stability, leading to a decrease in ion transport efficiency and thus affecting the overall performance of the device. This verifies the rationality of the oxygen content range control in this invention.

[0072] Furthermore, in Comparative Examples 5 and 6, the first isolation chamber 241 and the second isolation chamber 242 were not provided on both sides of the lithium deposition chamber 240. Their sheet resistance increased to 10 Ω / sq, and their transmittance decreased to 80% and 82%, respectively. This demonstrates that without the first isolation chamber 241 and the second isolation chamber 242, sudden temperature changes and gas cross-contamination (especially water vapor and oxygen) affect the lithium-ion deposition quality and activity, thereby reducing device performance. This verifies the important role of the isolation chambers in temperature transition and atmosphere control.

[0073] In summary, Example 1, through the synergistic optimization of the oxygen content of the ion-conducting layer 40, the deposition temperature of the second ITO layer 60, and the vacuum annealing process, combined with the setting of the first isolation chamber 241 and the second isolation chamber 242, achieved a significant improvement in the conductivity and optical performance of the electrochromic device 100, demonstrating that the technical solution described in this invention has good comprehensive performance advantages.

[0074] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for fabricating an electrochromic device based on physical vapor deposition, characterized in that, Includes the following steps: An electrochromic layer is sputtered onto the surface of the first ITO layer located above the substrate. The electrochromic layer is made of WO3 and the oxygen content of the corresponding chamber is any value between 42.5% and 52.5%. An ion-conducting layer with a preset thickness of 200 nm to 500 nm is sputtered and deposited on the electrochromic layer. The ion-conducting layer is a non-stoichiometric tungsten oxide layer with an oxygen vacancy structure, and the oxygen content of the corresponding chamber is any value of 35% to 45%. An ion storage layer and a lithium-ion-containing layer are sequentially sputtered and deposited on the ion conduction layer. The ion storage layer is a nickel oxide layer with an amorphous structure, so that lithium ions in the lithium-ion-containing layer diffuse and are stored in the ion storage layer. The deposition temperature of the ion storage layer is any value between 350°C and 400°C, and the oxygen content of the corresponding chamber is any value between 80% and 87%. The electrochromic device is prepared by depositing a second ITO layer on the ion storage layer and then sequentially undergoing vacuum annealing and cooling treatments; wherein, The deposition temperature of the second ITO layer is any value between 350℃ and 400℃, the annealing temperature of the vacuum annealing treatment is any value between 450℃ and 500℃, the annealing time is any value between 480s and 900s, and the vacuum degree is less than 6.0×10⁻⁶. -4 Pa.

2. The method for fabricating an electrochromic device based on physical vapor deposition according to claim 1, characterized in that, During the vacuum annealing process, a first constant temperature chamber and a second constant temperature chamber are respectively provided between the vacuum annealing chamber and the chamber where the second ITO layer is deposited, and between the vacuum annealing chamber and the cooling chamber. The temperature of the first constant temperature chamber and the second constant temperature chamber is any value between 380°C and 400°C.

3. The method for fabricating an electrochromic device based on physical vapor deposition according to claim 1, characterized in that, Before depositing the lithium-ion-containing layer, the substrate is passed through a first isolation chamber disposed between the chamber for depositing the ion storage layer and the chamber for depositing the lithium-ion-containing layer, so as to perform temperature transition on the substrate and block gas flow.

4. The method for fabricating an electrochromic device based on physical vapor deposition according to claim 1, characterized in that, After depositing the lithium-ion-containing layer, the substrate is passed through a second isolation chamber disposed between the chamber for depositing the lithium-ion-containing layer and the chamber for depositing the second ITO layer, so as to perform temperature transition on the substrate and block gas flow.

5. The method for fabricating an electrochromic device based on physical vapor deposition according to claim 1, characterized in that, Before depositing the lithium-ion layer, a vacuum process is performed in an isolation chamber between the chamber for depositing the ion storage layer and the chamber for depositing the lithium-ion layer to reduce the moisture content carried by the substrate before entering the lithium-ion layer deposition chamber.

6. The method for fabricating an electrochromic device based on physical vapor deposition according to any one of claims 1-5, characterized in that, Prior to the step of sputtering and depositing the electrochromic layer on the surface of the first ITO layer located above the substrate, the method further includes: The first ITO layer disposed on the substrate is subjected to cleaning and preheating treatment in sequence.

7. The method for fabricating an electrochromic device based on physical vapor deposition according to claim 6, characterized in that, The deposition temperature of the electrochromic layer is any value between 200℃ and 300℃.

8. The method for fabricating an electrochromic device based on physical vapor deposition according to claim 7, characterized in that, The deposition temperature of the ion-conducting layer is any value between 200℃ and 300℃; The deposition temperature of the lithium-ion layer is any value between 90℃ and 110℃.

9. A physical vapor deposition apparatus for implementing the method for fabricating an electrochromic device based on physical vapor deposition according to any one of claims 1-8, characterized in that, It includes a first tungsten deposition chamber, a second tungsten deposition chamber, a nickel deposition chamber, a lithium deposition chamber, an ITO deposition chamber, a vacuum annealing chamber, and a cooling chamber arranged sequentially along the production process direction.

10. An electrochromic device prepared by the method for fabricating an electrochromic device based on physical vapor deposition according to any one of claims 1-8, characterized in that, It includes a substrate, a first ITO layer, an electrochromic layer, an ion-conducting layer, an ion-storage layer, and a second ITO layer arranged in sequence from bottom to top. The thickness of the ion-conducting layer is any value between 200nm and 500nm, and the ion-storage layer is a nickel oxide layer in which lithium ions are distributed.

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