Cationic auxiliary enhanced electrochromic variable emissivity device

Abstract

The invention discloses a cation-assisted enhanced electrochromic variable emissivity device, and belongs to the technical field of new materials and electrochromic variable infrared emissivity. The invention aims to solve the problems of high driving voltage, low response speed and poor cycling stability of an all-solid-state device caused by an existing pure electronic regulation and control mechanism. According to the cation-assisted enhanced electrochromic variable emissivity device, a cation source layer is constructed on an F-P cavity type electrochromic variable emissivity device, then the F-P cavity type electrochromic variable emissivity device has the memristive-capacitance double-control characteristic, and specifically, a bottom electrode layer, a dielectric layer and a composite functional layer are prepared on a substrate in sequence, and then heat treatment is carried out. The invention is used for the cation-assisted enhanced electrochromic variable emissivity device.

Description

Technical Field

[0001] This invention belongs to the field of new materials and electrovariable infrared emissivity technology. Background Technology

[0002] Dynamic control of infrared emissivity has significant application value in the field of intelligent thermal management, such as thermal control of space targets, adaptive thermal camouflage, and building energy conservation. Among various control mechanisms, electrovariable emissivity devices based on the Fabry-Perot (FP) resonant cavity principle have attracted much attention due to their simple structure, fast control speed, and low power consumption. Their typical structure is a sandwich configuration of "electrode layer / dielectric layer / electrode layer." By changing the carrier concentration at the dielectric layer / electrode layer interface or the optical constant of the dielectric layer through an electric field, the resonant state of the FP cavity is modulated, thereby achieving dynamic changes in infrared emissivity.

[0003] However, such all-solid-state devices face a fundamental technical bottleneck: the lack of an effective, freely movable ion source within the device. Their operating mechanism heavily relies on injecting electrons into inherent defects in the dielectric layer through extremely high electric fields, or on achieving limited charge storage through quantum tunneling. This purely electronic control mechanism leads to a series of inherent defects, including high driving voltage but poor withstand voltage; slow response speeds lasting tens of seconds; and poor cycle stability, with a device lifetime of only a few hundred cycles.

[0004] Therefore, in order to address the above shortcomings, there is an urgent need in the field for a new method that is compatible with existing thin film processes and can construct efficient ion migration channels in situ within all-solid-state devices, in order to develop high-performance electrochromic infrared emissivity devices with a wide electrochemically stable bias window, fast response, and long lifetime. Summary of the Invention

[0005] This invention aims to address the problems of existing purely electronic control mechanisms leading to high driving voltage but poor high voltage tolerance, slow response speed, and poor cycle stability in all-solid-state devices, and thus provides a cation-assisted enhanced electrovariable emissivity device.

[0006] A cation-assisted enhanced electrochromic emissivity device is obtained by constructing a cation source layer on a FP cavity electrochromic emissivity device. Specifically, a bottom electrode layer, a dielectric layer and a composite functional layer are sequentially prepared on a substrate, and then heat treatment is performed.

[0007] The composite functional layer consists of a top electrode layer and a cation source layer, and during the heat treatment process, cations in the cation source layer diffuse into the top electrode layer and the dielectric layer.

[0008] The beneficial effects of this invention are:

[0009] The electrovariable emissivity structure provided by this invention has four layers. Based on the traditional optical resonant cavity structure, a cation source layer (together with the top electrode layer, forming a composite functional layer) is added and thermally treated. This successfully constructs a stable ion-doped region and efficient ion migration channels in situ within the device, transforming the traditional "single physical mechanism" relying on high-electric-field electron tunneling into a more efficient reversible electrochemical mechanism dominated by "ion-electron synergy." This not only solves the performance limitation problem of traditional all-solid-state electrovariable emissivity devices due to "ion scarcity," but also induces unique memristor-capacitor dual-control characteristics, laying the foundation for multi-modal modulation of a single device. The cation source layer possesses excellent mid- and far-infrared spectral transmittance, while the top electrode layer has infrared semi-transparent properties, reflecting some infrared light while allowing some infrared light to pass through. Furthermore, with cation assistance, its carrier concentration is highly tunable with the applied bias voltage, thus affecting the infrared transmittance of the top electrode layer. Infrared light passing through the composite functional layer oscillates in the optical resonant cavity structure. The oscillation effect of the optical resonant cavity structure can significantly increase the infrared emissivity of the electrovariable emissivity structure, and the infrared emissivity modulation amplitude Δε is not less than 0.3.

[0010] Based on the aforementioned working mechanism, this invention achieves a significant leap in the overall performance of the electrochromic infrared emissivity device. Its stability is 500% higher than that of cation-free electrochromic emissivity devices. It can operate efficiently within a wide electrochemically stable bias window of -10 V to 10 V, achieving a sub-second (<1 s) response speed, far exceeding the tens of seconds of traditional devices, thus meeting the real-time requirements of dynamic control. After undergoing over 10,000 continuous cycle tests, its control performance remains excellent, demonstrating outstanding cycle stability and durability. Based on memristor characteristics, the device can maintain a relatively stable emissivity state for a long time after power is removed, possessing non-volatile control capability, which is beneficial for significantly reducing the overall power consumption of the system.

[0011] Therefore, the device of the present invention has both electro-modulation and memory effect, which can realize continuous and rapid adjustment of infrared emissivity, while the service life is significantly improved compared with traditional FP cavity type electro-modulated infrared emissivity device. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of the cation-assisted enhanced electrochromic emissivity device of the present invention. 1 is the substrate, 2 is the bottom electrode layer, 3 is the dielectric layer, 4 is the top electrode layer, 5 is the cation source layer, 6 and 7 are both conductive electrodes, and A is the composite functional layer.

[0013] Figure 2 The infrared emissivity spectrum of the cation-assisted enhanced electrochromic emissivity device described in Example 1;

[0014] Figure 3The carrier concentrations of the cation-assisted enhanced electrochromic emissivity devices prepared at different heat treatment temperatures in Examples 1 and 3 are shown.

[0015] Figure 4 To improve the cycling stability of the cation-assisted enhanced electrovariable emissivity device described in Example 1;

[0016] Figure 5 The real-time surface infrared temperature change of the cation-assisted enhanced electrochromic emissivity device described in Example 1;

[0017] Figure 6 This is an EDS surface scan of the cross-section of the cation-assisted enhanced electrochromic emissivity device described in Example 1. Detailed Implementation

[0018] Specific implementation method one, combined with Figure 1 Detailed description: This embodiment is a cation-assisted enhanced electrochromic emissivity device, which is obtained by constructing a cation source layer on an FP cavity electrochromic emissivity device. Specifically, a bottom electrode layer, a dielectric layer and a composite functional layer are sequentially prepared on a substrate, and then heat treatment is performed.

[0019] The composite functional layer consists of a top electrode layer and a cation source layer, and during the heat treatment process, cations in the cation source layer diffuse into the top electrode layer and the dielectric layer.

[0020] The methods for preparing the bottom electrode layer, dielectric layer, and composite functional layer include one or a combination of evaporation deposition, sputtering deposition, chemical vapor deposition, molecular beam epitaxy, electrochemical deposition, hydrothermal growth, spin coating, blade coating, and dip-coating. The preparation environment is one or a combination of air, oxygen, nitrogen, argon, and helium, and the pressure of the preparation environment is high vacuum (≤ 10). -3 Pa), low vacuum (10 -1 Pa~10 5 Pa) or normal pressure (~10) 5 Pa).

[0021] The bottom electrode layer described in this specific embodiment is used to reflect infrared light and connect electrodes; the composite functional layer consists of a top electrode layer and a cation source layer, used to connect electrodes and form an optical resonant cavity structure with the bottom electrode layer, providing additional cations and controlling infrared transmittance and absorptivity; the cation source layer has excellent mid- and far-infrared spectral transmittance, and after heat treatment, the carrier concentration of the composite functional layer is 5 × 10⁻⁶. 19 cm -3 ~5×10 22 cm -3 Meanwhile, the ions it provides diffuse into the top electrode layer and the dielectric layer, forming a cation-doped top electrode layer and a biphase mixed dielectric layer.

[0022] In this specific embodiment, when infrared light irradiates the composite functional layer of the device, the unreflected infrared light passes through the composite functional layer and oscillates in the optical resonant cavity structure between the composite functional layer and the bottom electrode layer. The oscillation of the optical resonant cavity structure can significantly increase the infrared emissivity of the infrared modulation structure, which is used to regulate the absorption of infrared light. By adjusting the voltage of the power supply, the carrier concentration at the interface between the composite functional layer and the dielectric layer is changed, thereby adjusting the infrared transmittance and absorptivity of the composite functional layer, so as to control the infrared light flux entering the optical resonant cavity structure, and thus regulate the infrared light emissivity of the device.

[0023] In this specific embodiment, the cation source layer acts as both an "ion source precursor" and a "dynamic control hub." As the heat-treated cations diffuse into the device, reaching the interface between the top electrode layer lattice and the dielectric layer, an in-situ carrier replenishment layer is formed, transforming into a permanent high-performance functional interface within the device. Under an applied bias electric field, this interface achieves synergistic operation of both capacitive and memristor mechanisms through strong coupling of ion migration and electron injection. The structure evolves from an initial physical stack to form a carrier replenishment layer with gradient doping characteristics and a two-phase mixed dielectric layer. Under the drive of the electric field, dynamic ion migration and interface reconstruction occur, forming an adjustable space charge layer. When the positive terminal of the power supply is connected to the composite functional layer and a positive bias is applied, the infrared emissivity of the cation-assisted enhanced electrochromic emissivity device increases; when the negative terminal of the power supply is connected to the composite functional layer and a negative bias is applied, the infrared emissivity of the cation-assisted enhanced electrochromic emissivity device decreases. Therefore, the emissivity regulation mechanism of the device includes memristor characteristics induced by ion migration and capacitive characteristics induced by carrier interface aggregation, forming a synergistic regulation effect of electrical and optical responses.

[0024] The performance of the cation-assisted enhanced electro-emissivity device in this specific embodiment includes emissivity modulation amplitude, response time, cycle life, electrochemical stable bias window, and memory characteristics. These performance characteristics are mainly related to the following four factors: a) Intrinsic material properties: The carrier transport capacity of the bottom / top electrode layer and the dielectric properties of the dielectric layer together determine the electric field modulation efficiency and infrared optical response; b) Structural parameters: The thickness of each layer, the thickness of the dielectric layer directly determines the resonance wavelength and interference conditions of the FP resonant cavity, the thickness of the top electrode layer affects the infrared half-transmittance and conductivity, and the thickness of the cation source layer is related to the total amount of available ions, diffusion depth, and interface morphology; c) Process conditions: The heat treatment temperature, time, and atmosphere of the cation source layer are critical, as they determine the doping effect of the cations and the interface quality; d) Driving strategy: The amplitude and polarity of the applied bias directly control the kinetics of ion migration and charge injection, achieving capacitive and memristor dual-mode modulation.

[0025] In this specific embodiment, the infrared emissivity is determined by both the optical resonant cavity structure and the electrical control capability. The dielectric layer thickness is a core parameter of the FP resonant cavity, directly setting the resonant wavelength and interference phase, thus pre-setting the initial emissivity state and its tunable band. The composite functional layer and the bottom electrode layer together constitute the two end mirrors of the resonant cavity. The former dynamically controls the transmittance of incident infrared light through changes in carrier concentration; a thicker initial thickness results in lower initial infrared transmittance, and a thinner initial thickness results in higher initial infrared transmittance. The latter provides a stable infrared light reflection substrate. The properties and thicknesses of both layers jointly determine the quality factor (Q value) and optical field distribution of the resonant cavity, ultimately working synergistically with the dielectric layer to achieve precise control over the dynamic modulation amplitude and sensitivity of the infrared emissivity.

[0026] The beneficial effects of this embodiment are:

[0027] The electrovariable emissivity structure provided in this embodiment has four layers. Based on the traditional optical resonant cavity structure, a cation source layer (together with the top electrode layer, forming a composite functional layer) is added and thermally treated. This successfully constructs a stable ion-doped region and efficient ion migration channels in situ within the device, transforming the traditional "single physical mechanism" relying on high-field electron tunneling into a more efficient reversible electrochemical mechanism dominated by "ion-electron synergy." This not only solves the performance limitation problem of traditional all-solid-state electrovariable emissivity devices due to "ion scarcity," but also induces unique memristor-capacitor dual-control characteristics, laying the foundation for multi-modal modulation of a single device. The cation source layer possesses excellent mid- and far-infrared spectral transmittance, while the top electrode layer has infrared semi-transparent properties, reflecting some infrared light while allowing some infrared light to pass through. Furthermore, with cation assistance, its carrier concentration is highly adjustable with the applied bias voltage, thus affecting the infrared transmittance of the top electrode layer. Infrared light passing through the composite functional layer oscillates in the optical resonant cavity structure. The oscillation effect of the optical resonant cavity structure can significantly increase the infrared emissivity of the electrovariable emissivity structure, and the infrared emissivity modulation amplitude Δε is not less than 0.3.

[0028] Based on the aforementioned working mechanism, this embodiment achieves a significant leap in the overall performance of the electrochromic infrared emissivity device. Its stability is 500% higher than that of cation-free electrochromic emissivity devices. It can operate efficiently within a wide electrochemically stable bias window of -10 V to 10 V, achieving a sub-second (<1 s) response speed, far exceeding the tens of seconds of traditional devices, thus meeting the real-time requirements of dynamic control. After undergoing over 10,000 continuous cycle tests, its control performance remains excellent, demonstrating outstanding cycle stability and durability. Based on memristor characteristics, the device can maintain a relatively stable emissivity state for a long time after power is removed, possessing non-volatile control capability, which is beneficial for significantly reducing the overall power consumption of the system.

[0029] Therefore, the device in this embodiment combines electro-modulation and memory effect, enabling continuous and rapid adjustment of infrared emissivity, while significantly improving its lifespan compared to traditional FP cavity electro-modulated infrared emissivity devices.

[0030] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the substrate is either a rigid substrate or a flexible substrate; the rigid substrate is an oxide glass, transparent ceramic, or an optical crystal with high transmittance in the infrared band; the flexible substrate is polyethylene terephthalate, polyethylene naphthalate, polyimide, or a flexible infrared-transmitting material modified with polyethylene terephthalate, polyethylene naphthalate, or polyimide. Everything else is the same as in Specific Implementation Method One.

[0031] The substrate described in this specific embodiment is a pretreated substrate. The pretreatment specifically involves ultrasonic cleaning in sequence using detergent, acetone, ethanol, sodium hydroxide solution with a mass percentage of 0.1% to 5%, and ultrapure water as cleaning solutions, followed by drying with nitrogen gas. The ultrasonic cleaning is specifically performed at a power of 10W to 100W and at a room temperature to 80°C for a total ultrasonic cleaning time of 10 to 100 minutes.

[0032] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that: the bottom electrode layer is a conductor that reflects infrared light and transmits visible light, or a semiconductor that reflects infrared light and transmits visible light; the conductor that reflects infrared light and transmits visible light is one or a combination of gold, silver, copper, iron, and aluminum; the semiconductor that reflects infrared light and transmits visible light is one or a combination of indium tin oxide, fluorine-doped tin oxide, titanium oxide, zinc oxide, aluminum-doped zinc oxide, and graphene; and the thickness of the bottom electrode layer is 5 nm to 1000 nm. Everything else is the same as in Specific Implementation Method One or Two.

[0033] In this specific embodiment, the infrared reflectivity of the bottom electrode layer can come from the material itself, or the bottom electrode layer can be heat-treated to increase its conductivity (greater than 1000 S / cm) to give it infrared reflectivity.

[0034] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that: the dielectric layer is one or a combination of several of the following: a high-dielectric-constant oxide, a doped high-dielectric-constant oxide, a ferroelectric material, a nitride, and a polymer electrolyte; the high-dielectric-constant oxide is one or a combination of several of the following: zirconium oxide, hafnium oxide, tungsten oxide, aluminum oxide, nickel oxide, vanadium oxide, beryllium oxide, magnesium oxide, silicon oxide, titanium oxide, tantalum oxide, yttrium oxide, and barium titanate; and the thickness of the dielectric layer is 50 nm to 1000 nm. Everything else is the same as in Specific Implementation Methods One to Three.

[0035] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that: the top electrode layer is a semiconductor that reflects infrared light and transmits visible light; the semiconductor that reflects infrared light and transmits visible light is one or a combination of several of indium tin oxide, fluorine-doped tin oxide, titanium oxide, zinc oxide, aluminum-doped zinc oxide, and graphene; the thickness of the top electrode layer is 5 nm to 1000 nm. Everything else is the same as in Specific Implementation Methods One to Four.

[0036] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that: the cation source layer is a mid-to-far-infrared spectral transmissive material with mobile cations or a mid-to-far-infrared spectral transmissive oxide containing oxygen vacancies; the mobile cations are protons, alkali metal ions, alkaline earth metal ions, Ag... + or Cu + The thickness of the cation source layer is 5 nm to 500 nm. Other aspects are the same as in embodiments one through five.

[0037] The thickness of the cation source layer described in this specific embodiment directly affects the proportion of ions entering the top electrode layer lattice. When the thickness is between 10 nm and 200 nm, the effective doping ratio of ions is relatively high and the distribution is uniform. When the thickness increases to 200 nm to 500 nm, the total doping amount increases, but the surface area may become saturated, and the actual proportion entering the lattice may decrease. The preferred thickness is 10 nm to 200 nm.

[0038] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that the surface morphology of the composite functional layer after heat treatment is one or a combination of several of the following: an atomically flat surface, a nanoporous structure, a nanoisland structure, a continuous polycrystalline structure with clear grain boundaries, and a particle stacking structure with a grain size of 10 nm to 5 μm; the root mean square value of the surface roughness of the composite functional layer is 1 nm to 1000 nm. Everything else is the same as in Specific Implementation Methods One to Six.

[0039] In this specific embodiment, the preparation method, coating rate, heat treatment temperature, and thickness of the composite functional layer directly affect the surface morphology and structural changes.

[0040] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that the heat treatment specifically involves a heating rate of 1℃ / min to 10℃ / min, heating to 50℃ to 600℃, and heat-treating at 50℃ to 600℃ for 10 min to 1000 min. Everything else is the same as in Specific Implementation Methods One to Seven.

[0041] The heat treatment described in this specific embodiment is carried out in a specific atmosphere; the specific atmosphere is air, oxygen, nitrogen, argon, helium, or a mixture of nitrogen and hydrogen; the pressure of the heat treatment environment is high vacuum (≤10). -3 Pa), low vacuum (10 -1 Pa~10 5 Pa) or normal pressure (~10) 5 Pa).

[0042] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One to Eight in that: the bottom of the bottom electrode layer and the top of the composite functional layer are both led out by conductive electrodes and connected to a power source; the conductive electrodes are conductors or semiconductor materials with conductive functions. Everything else is the same as in Specific Implementation Methods One to Eight.

[0043] In this specific embodiment, the conductive electrode is led out from a point, line, surface, or any combination thereof in the bottom electrode layer and the composite functional layer.

[0044] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods One to Nine in that: the power supply is applied to the device with a positive or negative bias voltage; the negative bias voltage is -10V to 0V; and the positive bias voltage is 0V to 10V. Everything else is the same as Specific Implementation Methods One to Nine.

[0045] This specific embodiment only requires a low voltage to change the infrared transmittance of the top electrode layer, so that the adjustment range of infrared emissivity reaches the maximum value. Preferably, the voltage applied to the composite functional layer by the power supply is -3~0 V or 0~3 V, and the electric drive signal adopts AC or pulse mode.

[0046] The beneficial effects of the present invention are verified using the following embodiments:

[0047] Example 1:

[0048] A cation-assisted enhanced electrochromic emissivity device is obtained by constructing a cation source layer on a FP cavity electrochromic emissivity device. Specifically, a bottom electrode layer, a dielectric layer and a composite functional layer are sequentially prepared on a substrate, and then heat treatment is performed.

[0049] The composite functional layer consists of a top electrode layer and a cation source layer from bottom to top, and during the heat treatment process, cations in the cation source layer diffuse into the top electrode layer and the dielectric layer.

[0050] The substrate is heat-resistant glass capable of withstanding process temperatures above 300°C, and the substrate is a pre-treated substrate. The pre-treatment specifically involves ultrasonic cleaning in sequence using detergent, acetone, ethanol, 1% sodium hydroxide solution and ultrapure water as cleaning solutions, followed by nitrogen drying. The ultrasonic cleaning is specifically performed at a power of 80W and a temperature of 50°C for a total ultrasonic cleaning time of 75 minutes.

[0051] The bottom electrode layer is indium tin oxide; the thickness of the bottom electrode layer is 240 nm; the bottom electrode layer is specifically prepared according to the following steps: using magnetron sputtering technology, with 99.99% indium tin oxide as the target material, it is prepared under the conditions of a temperature of 350℃, an argon flow rate of 98 sccm, an oxygen flow rate of 2 sccm, a working pressure of 0.5 Pa, and a power of 8 kilowatts.

[0052] The dielectric layer is zirconium dioxide; the thickness of the dielectric layer is 940 nm; the dielectric layer is specifically prepared according to the following steps: using electron beam evaporation deposition technology, using 99.99% zirconium dioxide particles as the evaporation coating material, it is prepared under the conditions of vacuum environment, room temperature, electron beam current of 135 mA, working pressure of 0.06 Pa and deposition rate of 3 Å / s.

[0053] The top electrode layer is indium tin oxide; the thickness of the top electrode layer is 450 nm; the top electrode layer is specifically prepared according to the following steps: using electron beam evaporation deposition technology, low-density particles of indium tin oxide (95% indium oxide and 5% tin oxide) with a mass ratio of 95:5 are used as the evaporation coating material, and the top electrode layer is prepared under the conditions of vacuum environment, room temperature, electron beam current of 25 mA, working pressure of 0.03 Pa and evaporation rate of 2.5 Å / s.

[0054] The cation source layer is sodium chloride; the thickness of the cation source layer is 40 nm; the cation source layer is specifically prepared according to the following steps: using thermal evaporation coating technology, 99.99% sodium chloride particles are used as the evaporation coating material, and the layer is prepared under the conditions of vacuum environment, room temperature, electron beam current of 75 mA, working pressure of 0.01 Pa and evaporation rate of 1.5 Å / s.

[0055] The surface morphology of the composite functional layer after heat treatment is a nanorod-shaped porous structure; the root mean square value of the surface roughness of the composite functional layer is 10 nm to 100 nm.

[0056] The heat treatment specifically involves heating to 500°C in an air atmosphere at a heating rate of 3°C / min, and then heat-treating at 500°C for 120 minutes.

[0057] The bottom of the bottom electrode layer and the top of the composite functional layer are both led out by conductive electrodes and connected to the power supply; the conductive electrodes are copper wires, and the conductive electrodes at the bottom of the bottom electrode layer and the top of the composite functional layer serve as the counter electrode and the working electrode during the electrochromic emissivity period, respectively.

[0058] Example 2:

[0059] A cation-assisted enhanced electrochromic emissivity device is obtained by constructing a cation source layer on a FP cavity electrochromic emissivity device. Specifically, a bottom electrode layer, a dielectric layer and a composite functional layer are sequentially prepared on a substrate, and then heat treatment is performed.

[0060] The composite functional layer consists of a top electrode layer and a cation source layer from bottom to top, and during the heat treatment process, cations in the cation source layer diffuse into the top electrode layer and the dielectric layer.

[0061] The substrate is heat-resistant glass capable of withstanding process temperatures above 300°C, and the substrate is a pre-treated substrate. The pre-treatment specifically involves ultrasonic cleaning in sequence using detergent, acetone, ethanol, 1% sodium hydroxide solution and ultrapure water as cleaning solutions, followed by nitrogen drying. The ultrasonic cleaning is specifically performed at a power of 100W and a temperature of 60°C for a total of 50 minutes.

[0062] The bottom electrode layer is indium tin oxide; the thickness of the bottom electrode layer is 240 nm; the bottom electrode layer is specifically prepared according to the following steps: using magnetron sputtering technology, with 99.99% indium tin oxide as the target material, it is prepared under the conditions of a temperature of 350℃, an argon flow rate of 98 sccm, an oxygen flow rate of 2 sccm, a working pressure of 0.5 Pa, and a power of 8 kilowatts.

[0063] The dielectric layer is silicon dioxide; the thickness of the dielectric layer is 550 nm; the dielectric layer is specifically prepared according to the following steps: using electron beam evaporation deposition technology, using 99.99% silicon dioxide particles as the evaporation coating material, it is prepared under the conditions of vacuum environment, room temperature, electron beam current of 56 mA, working pressure of 0.04 Pa and deposition rate of 2.5 Å / s.

[0064] The top electrode layer is indium tin oxide; the thickness of the top electrode layer is 450 nm; the top electrode layer is specifically prepared according to the following steps: using electron beam evaporation deposition technology, low-density particles of indium tin oxide (90% indium oxide and 10% tin oxide) with a mass ratio of 90:10 are used as the evaporation coating material, and the top electrode layer is prepared under the conditions of vacuum environment, room temperature, electron beam current of 25 mA, working pressure of 0.02 Pa and evaporation rate of 2.5 Å / s.

[0065] The cation source layer is sodium chloride; the thickness of the cation source layer is 32 nm; the cation source layer is prepared according to the following steps: using the dip-coating technique, dip-coating is performed twice in a 0.2 M NaCl solution at a speed of 1 cm / min under room temperature and air atmosphere.

[0066] The surface morphology of the composite functional layer after heat treatment is an atomically smooth surface, accompanied by uniform NaCl nanocrystals; the root mean square value of the surface roughness of the composite functional layer is 1 nm to 50 nm.

[0067] The heat treatment specifically involves heating to 200°C in an air atmosphere at a heating rate of 3°C / min, and then heat-treating at 200°C for 120 minutes.

[0068] The bottom of the bottom electrode layer and the top of the composite functional layer are both led out by conductive electrodes and connected to the power supply; the conductive electrodes are copper wires, and the conductive electrodes at the bottom of the bottom electrode layer and the top of the composite functional layer serve as the counter electrode and the working electrode during the electrochromic emissivity period, respectively.

[0069] Example 3: This example differs from Example 1 in that the heat treatment temperature is adjusted to 50℃, 100℃, 200℃, 300℃, 400℃, or 600℃. Everything else is the same as in Example 1.

[0070] Comparative Experiment: This comparative experiment differs from Example 1 in that the surface cation source layer NaCl is omitted. Everything else is the same as in Example 1.

[0071] The following emissivity values ​​are integral emissivity, calculated by integrating blackbody radiation (0.25~25μm band);

[0072] Example 1: A cation-assisted enhanced electrochromic emissivity device exhibits a high emission state with an emissivity of 0.73 when a positive bias voltage (3V) is applied, and a low emission state with an emissivity of 0.29 when a negative bias voltage (-3V) is applied. The mid-to-far infrared modulation amplitude Δε is 0.44, and the response time is <1s. Cyclic testing was performed on it, and the testing process is as follows: at 4mA / cm... 2 Under constant current testing conditions, after 11,000 reversible cycles, the infrared emissivity modulation amplitude of the device can still be maintained at 83% of the initial modulation amplitude, i.e., 0.36.

[0073] Example 2: A cation-assisted enhanced electrochromic emissivity device exhibited an emissivity of 0.72 with a positive bias (3V) and 0.29 with a negative bias (-3V). The mid-to-far infrared modulation amplitude Δε was 0.43, and the response time was 0.9s. Cyclic testing was performed on the device, and the testing process is as follows: at 4mA / cm... 2Under constant current testing conditions, after 9500 reversible cycles, the infrared emissivity modulation amplitude of the device can still be maintained at 79% of the initial modulation amplitude, i.e., 0.34.

[0074] In the comparative experiment, the emissivity of the electrovariable emissivity device was 0.72 when a positive bias voltage (3V) was applied and 0.31 when a negative bias voltage (-3V) was applied. The mid- and far-infrared modulation amplitude Δε was 0.41, the response time was 35s, and the cycle stability was only 200 cycles.

[0075] Figure 2 The image shows the infrared emissivity spectrum of the cation-assisted enhanced electrochromic emissivity device described in Example 1. As can be seen from the image, emissivity variations of 0.73 (high emissivity) and 0.29 (low emissivity) were achieved at a positive bias of 3V and a negative bias of -3V, respectively. A high emissivity modulation range was maintained even at a positive bias of 10V and a negative bias of -10V, without dielectric layer breakdown. It exhibits a high electrochemically stable bias window.

[0076] Figure 3 The figure shows the carrier concentrations of cation-assisted enhanced electrochromic emissivity devices prepared at different heat treatment temperatures in Examples 1 and 3; as can be seen from the figure, the carrier concentration is 5 × 10⁻⁶. 19 cm -3 ~5×10 22 cm -3 .

[0077] Figure 4 The cycling stability of the cation-assisted enhanced electrochromic emissivity device described in Example 1 is shown in the figure; as can be seen from the figure, at 4 mA / cm 2 Under constant current testing conditions, after 11,000 reversible cycles, the infrared emissivity modulation amplitude of the device can still be maintained at 83% of the initial modulation amplitude, i.e., 0.36.

[0078] Figure 5 The figure shows the real-time surface infrared temperature change of the cation-assisted enhanced electrochromic emissivity device described in Example 1. As can be seen from the figure, under a bias voltage of ±3V, the device exhibits a dynamic response of <1000ms. When the bias voltage is stopped, it can maintain a relatively stable static emissivity within 1 minute, demonstrating excellent emissivity memory characteristics and non-volatile control capability.

[0079] Figure 6 This is an EDS surface scan of the cross-section of the cation-assisted enhanced electrochromic emissivity device described in Example 1; as shown in the figure, Na + Ions successfully diffused from the upper NaCl source and permeated throughout the entire device structure, exhibiting a gradient-varying bulk phase distribution.

Claims

1. A cation-assisted enhanced electrovariable emissivity device, characterized in that... It is obtained after constructing a cation source layer on a FP cavity electrochromic emissivity device. Specifically, a bottom electrode layer, a dielectric layer and a composite functional layer are sequentially prepared on the substrate, and then heat treatment is performed. The composite functional layer consists of a top electrode layer and a cation source layer, and during the heat treatment process, cations in the cation source layer diffuse into the top electrode layer and the dielectric layer.

2. The cation-assisted enhanced electrovariable emissivity device according to claim 1, characterized in that... The substrate is a rigid substrate or a flexible substrate; the rigid substrate is an oxide glass, a transparent ceramic, or an optical crystal with high transmittance in the infrared band; the flexible substrate is polyethylene terephthalate, polyethylene naphthalate, polyimide, or a flexible infrared high transmittance material modified with polyethylene terephthalate, polyethylene naphthalate, or polyimide.

3. The cation-assisted enhanced electrovariable emissivity device according to claim 1, characterized in that... The bottom electrode layer is a conductor that reflects infrared light and transmits visible light or a semiconductor that reflects infrared light and transmits visible light; the conductor that reflects infrared light and transmits visible light is one or a combination of gold, silver, copper, iron and aluminum; the semiconductor that reflects infrared light and transmits visible light is one or a combination of indium tin oxide, fluorine-doped tin oxide, titanium oxide, zinc oxide, aluminum-doped zinc oxide and graphene; the thickness of the bottom electrode layer is 5nm~1000nm.

4. The cation-assisted enhanced electrovariable emissivity device according to claim 1, characterized in that... The dielectric layer is one or a combination of several of the following: high dielectric constant oxide, doped high dielectric constant oxide, ferroelectric material, nitride, and polymer electrolyte; the high dielectric constant oxide is one or a combination of several of the following: zirconium oxide, hafnium oxide, tungsten oxide, aluminum oxide, nickel oxide, vanadium oxide, beryllium oxide, magnesium oxide, silicon oxide, titanium oxide, tantalum oxide, yttrium oxide, and barium titanate; the thickness of the dielectric layer is 50 nm to 1000 nm.

5. A cation-assisted enhanced electrovariable emissivity device according to claim 1, characterized in that... The top electrode layer is a semiconductor that reflects infrared light and transmits visible light; the semiconductor that reflects infrared light and transmits visible light is one or a combination of several of indium tin oxide, fluorine-doped tin oxide, titanium oxide, zinc oxide, aluminum-doped zinc oxide and graphene; the thickness of the top electrode layer is 5nm~1000nm.

6. The cation-assisted enhanced electrovariable emissivity device according to claim 1, characterized in that... The cation source layer is a mid- to far-infrared spectrally transmissive material with mobile cations or a mid- to far-infrared spectrally transmissive oxide containing oxygen vacancies; the mobile cations are protons, alkali metal ions, alkaline earth metal ions, or Ag. + or Cu + The thickness of the cation source layer is 5nm~500nm.

7. A cation-assisted enhanced electrovariable emissivity device according to claim 1, characterized in that... The surface morphology of the composite functional layer after heat treatment is one or a combination of several of the following: atomically flat surface, nanoporous structure, nanoisland structure, continuous polycrystalline structure with clear grain boundaries, and particle stacking structure with grain size of 10nm~5μm; the root mean square value of the surface roughness of the composite functional layer is 1nm~1000nm.

8. A cation-assisted enhanced electrovariable emissivity device according to claim 1, characterized in that... The heat treatment specifically involves raising the temperature at a rate of 1℃ / min to 10℃ / min, raising it to 50℃ to 600℃, and then heat-treating it for 10 min to 1000 min at a temperature of 50℃ to 600℃.

9. A cation-assisted enhanced electrovariable emissivity device according to claim 1, characterized in that... The bottom of the bottom electrode layer and the top of the composite functional layer are both led out by conductive electrodes and connected to a power source; the conductive electrodes are conductors or semiconductor materials with conductive functions.

10. A cation-assisted enhanced electrovariable emissivity device according to claim 9, characterized in that... The power supply applies a positive or negative bias voltage to the device; the negative bias voltage is -10V to 0V; the positive bias voltage is 0V to 10V.

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