Dynamic color-adjusting semitransparent organic photovoltaic cell and preparation method thereof

Abstract

The invention discloses a dynamic color-adjusting semitransparent organic photovoltaic cell which sequentially comprises the following components from bottom to top: a transparent substrate which is made of a transparent glass material; the first transparent electrode layer is an ITO (Indium Tin Oxide) conductive film; the semitransparent organic photovoltaic layer sequentially comprises a PEDOT: PSS hole transport layer, a PM6: L8-BO active layer and a PNDIT-F3N electron transport layer; the second transparent electrode layer comprises a 1nm Au seed layer and a 10nm Ag conductive film; the electrochromic layer comprises a WO3 thin film layer and a NiO counter electrode layer which are respectively positioned on two sides of the ionic gel layer; the third transparent electrode layer is an ITO conductive film; and the transparent top layer is made of a transparent glass material. The dynamic color-adjusting semitransparent organic photovoltaic cell provided by the invention can dynamically adjust indoor illumination and heat in all weathers and all regions, and can effectively adjust and control transmission and reflection energy of sunlight while generating power, that is, productivity and photo-thermal management are realized at the same time, and building energy consumption is remarkably reduced.

Description

Technical Field

[0001] This invention relates to the field of building-integrated photovoltaics (BIPV) technology, and in particular to a dynamically color-tuned semi-transparent organic photovoltaic cell and its preparation method. Background Technology

[0002] Currently, the use of ordinary float glass with poor thermal insulation performance leads to high overall building energy consumption, making it difficult to meet current energy-saving standards. While static energy-saving technologies such as low-emissivity (LOW-E) glass have some energy-saving effects, they cannot respond to the dynamic demands of diurnal and seasonal climate changes, limiting their energy-saving potential. Against this backdrop, semi-transparent organic photovoltaic (ST-OPV) devices, which combine light transmission and power generation capabilities, have become an ideal technological approach due to their high compatibility with building-integrated photovoltaics (BIPV). Further endowing them with dynamic dimming capabilities to enhance overall energy-saving benefits has become a key research topic.

[0003] While traditional ST-OPV devices possess both light transmission and power generation functions, their light transmittance is typically fixed, making it difficult to adapt to varying environmental conditions and limiting their energy-saving effects in actual buildings. Therefore, achieving dynamic control over the light transmittance characteristics of ST-OPV is crucial for enhancing its energy adaptability and energy-saving potential in real-world scenarios. Among various dynamic dimming technologies, electrochromic smart windows, due to their reversible and controllable optical adjustment capabilities, are considered an ideal solution to complement ST-OPV. EC smart windows, based on the redox reaction of electrochromic materials under an electric field, can reversibly adjust their transmittance to the solar spectrum, thereby achieving dynamic management of visible and near-infrared radiation. Specifically, in summer or under strong radiation conditions, EC windows can switch to a dark or shading state, effectively blocking solar radiation heat and reducing indoor cooling load; in winter or under weak light conditions, they can return to a high-transmittance state, maximizing the introduction of solar heat, reducing heating needs, and achieving intelligent control for "warm in winter and cool in summer." Integrating the EC dimming unit with the ST-OPV overcomes the technical bottlenecks of traditional EC windows, which rely on external power supply and have limited functionality, creating a new type of intelligent window system that integrates power generation and dynamic dimming. This integrated device not only achieves closed-loop operation of "self-powered and self-regulated"—the electricity generated by the ST-OPV can be directly used to drive the color-changing process of the EC unit and generate additional power output to the building microgrid when there is sufficient sunlight—but also has the ability to flexibly adjust the incident solar spectrum, dynamically balancing lighting comfort and building energy consumption according to environmental and usage needs, thereby achieving synergistic optimization among power generation, energy saving, and comfort.

[0004] However, current multi-mode smart window technology for ST-OPV and EC integrated devices still faces many challenges. On the one hand, ST-OPV and EC units differ significantly in material properties, fabrication processes, and operating mechanisms. Achieving interface compatibility and collaborative operation at the microscopic level is a key challenge in constructing high-performance integrated devices. On the other hand, existing technologies still fall short of meeting the needs of practical building applications in core indicators such as transmittance, photoelectric conversion efficiency, and dynamic color adjustment range. Furthermore, the response speed and cycle life of the dynamic color adjustment function are also important factors restricting technological development. Therefore, developing multi-mode smart window technology with good interface compatibility and combining high transmittance, high efficiency, and dynamic color adjustment capabilities has significant practical value.

[0005] In the prior art, the invention patent with publication number CN117153922A provides a dimmable cadmium telluride power generation energy-saving method and its preparation method. This scheme takes into account that the technology route and process of cadmium telluride battery are similar to those of electrochromic process. A periodic cadmium telluride sub-cell and electrochromic device are connected in series on the same side of the glass. This scheme solves well the problems of light control, color uniformity and compatibility with cadmium telluride battery stacking process of electrochromic device. However, this scheme has the following problems: 1. The visible light transmittance of the electrochromic device is directly proportional to the generation voltage of the cadmium telluride sub-cell. When the two are connected in series, the transmittance decreases when the generation voltage is low. Indoor lighting is limited during cloudy, rainy, or winter when radiation is weak, requiring additional lighting, which increases energy consumption and makes all-weather, all-region dynamic dimming impossible; 2. The stacking process requires repeated masking and laser scribing, which is complex, requires high equipment precision, is costly, and difficult to maintain, hindering industrialization; 3. With the cadmium telluride battery and electrochromic device connected in series, the failure of any color-changing unit will cause the entire circuit to break, shortening its lifespan. Patent CN120112062A discloses a color-changing solar cell and its preparation method. This scheme utilizes the characteristic of dye-sensitized cells to prepare semi-transparent cells, combined with electrochromic technology, stacking dye-sensitized cells and color-changing devices on the same glass side to achieve power generation and spectral color changing. However, this scheme is limited in industrialization due to the low efficiency and short lifespan of dye-sensitized cells. Both of the above schemes require high voltage to trigger color changing, posing safety hazards. Therefore, existing technologies still need improvement. To this end, the purpose of this application is to provide a color-changing photovoltaic device and its fabrication method, which has advantages in solving problems such as low energy efficiency, limited light transmission, complex processes, and safety hazards. Summary of the Invention

[0006] In view of the aforementioned deficiencies in the prior art, the technical problem to be solved by the present invention is that existing color-changing photovoltaic devices and preparation methods suffer from low energy efficiency, limited light transmission, complex processes, and safety hazards. The present invention provides a dynamically color-tuned semi-transparent organic photovoltaic cell that can dynamically adjust indoor light and heat in all weather conditions and regions. While generating electricity, this device can effectively regulate the transmission and reflection of sunlight, thus simultaneously achieving power generation and solar thermal management, significantly reducing building energy consumption.

[0007] To achieve the above objectives, the present invention provides a dynamically color-tuned semi-transparent organic photovoltaic cell, comprising an organic photovoltaic cell and an electrochromic layer, wherein the electrochromic layer comprises a WO3 thin film layer and a NiO counter electrode layer, the WO3 thin film layer being disposed on the electrode of the organic photovoltaic cell, the NiO counter electrode layer being disposed on commercial ITO glass, and the WO3 thin film layer and the NiO counter electrode layer being bonded together by iontophoresis.

[0008] Furthermore, from bottom to top, it specifically includes the following layers:

[0009] (1) Transparent substrate, which is made of transparent glass material;

[0010] (2) The first transparent electrode layer is an ITO conductive film;

[0011] (3) A semi-transparent organic photovoltaic layer, comprising, in sequence, a PEDOT:PSS hole transport layer, a PM6:L8-BO active layer and a PNDIT-F3N electron transport layer, with an active layer thickness of 80 nm;

[0012] (4) The second transparent electrode layer is a 1nm Au seed layer and a 10nm Ag conductive film;

[0013] (5) A WO3 thin film layer is vacuum-deposited onto the second transparent electrode layer;

[0014] (6) Ion gel layer, used to connect WO3 thin film layer and NiO counter electrode layer, is a mixture of LiClO4:PC electrolyte and polymethyl methacrylate at a mass ratio of 1:3;

[0015] (7) NiO counter electrode layer, spin-coated onto the third transparent electrode layer;

[0016] (8) The third transparent electrode layer is an ITO conductive film;

[0017] (9) The top layer is made of transparent glass.

[0018] Furthermore, the average visible light transmittance (AVT) of the semi-transparent organic photovoltaic layer is 32.28%.

[0019] Furthermore, the thickness of the first transparent electrode layer and the second transparent electrode layer is 150 nm.

[0020] Furthermore, PM6 is the donor and L8-BO is the acceptor, with a donor-to-acceptor mass ratio of 0.6:1.2 in the semi-transparent organic photovoltaic layer.

[0021] Furthermore, the WO3 thin film layer was prepared by vacuum evaporation and had a thickness of 200 nm, while the NiO thin film layer was prepared by solution spin coating at 2000 rpm for 30 s, with two layers being spin coated.

[0022] In another preferred embodiment of the present invention, a method for preparing a dynamically color-tuned semi-transparent organic photovoltaic cell is provided, comprising the following steps:

[0023] (1) The commercial ITO glass substrate is pretreated as the first transparent electrode layer and the third transparent electrode layer: it is subjected to ultrasonic cleaning, blower drying and plasma treatment in sequence;

[0024] (2) Preparation of electrochromic layer: WO3 thin film layer was deposited by vacuum evaporation, and NiO thin film layer was prepared by solution spin coating;

[0025] (3) Preparation of ion gel: LiClO4:PC electrolyte and polymethyl methacrylate are mixed at a mass ratio of 1:3;

[0026] (4) Preparation of semi-transparent organic photovoltaic layer: each functional layer is sequentially deposited on a commercial ITO substrate by solution spin coating. The active layer is spin coated at 3000 rpm, annealed at 130℃, and held for 10 min.

[0027] (5) Preparation of the second transparent electrode layer: A 1 nm Au seed layer and a 10 nm Ag conductive film were deposited by vacuum evaporation;

[0028] (6) Assembly: Take an appropriate amount of ion gel with a syringe and integrate the electrochromic device with the semi-transparent organic photovoltaic device.

[0029] Furthermore, when depositing WO3 thin films using the vacuum evaporation method, the vacuum level is ≤8×10⁻⁶. -4 Pa, evaporation rate 0.15-0.2 nm / s.

[0030] Furthermore, NiO thin films were prepared by solution spin coating at a speed of 2000 rpm, with two layers spin-coated, and annealed at 300℃ for 60 min.

[0031] Furthermore, the thickness of the WO3 electrochromic active layer is 100-200 nm.

[0032] Technical effect

[0033] This invention provides a dynamically color-tuned semi-transparent organic photovoltaic cell capable of dynamically adjusting indoor light and heat in all weather conditions and regions. While generating electricity, this device effectively regulates the transmission and reflection of sunlight, achieving both power generation and photothermal management, significantly reducing building energy consumption. Specifically, when using electrochromic glass based on organic photovoltaic cells, a faded state is used in winter, allowing efficient transmission of visible and near-infrared light, utilizing the solar thermal effect to raise indoor temperature and reduce building heating energy consumption. In summer, it switches to a semi-colored state, selectively blocking near-infrared light while maintaining a certain level of visible light transmittance, reducing cooling load while avoiding increased lighting energy consumption, thus improving overall energy efficiency. The nighttime mode uses a fully colored state with visible light transmittance ≤5%, ensuring privacy.

[0034] This invention combines a semi-transparent organic solar cell with an electrochromic device to obtain a dynamically color-tuning semi-transparent organic photovoltaic cell. This organic photovoltaic cell can convert absorbed light energy into electrical energy using the semi-transparent organic solar cell, not only reducing the thermal effect of sunlight but also providing power to the electrochromic device. Simultaneously, the direction of the current flowing through the electrochromic device can be adjusted according to the intensity of sunlight, thereby controlling the transparency of the electrochromic glass. The organic photovoltaic cell of this invention can achieve intelligent light modulation, darkening to block strong light during periods of high illumination and becoming transparent with high transmittance during periods of low illumination. Furthermore, the organic photovoltaic cell of this invention also has excellent heat insulation performance, achieving energy saving and carbon reduction effects, making it suitable for use as a glass window in the building industry.

[0035] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure and performance of a dynamically color-tuned semi-transparent organic photovoltaic cell according to a preferred embodiment of the present invention;

[0037] Figure 2 This is a high-throughput screening simulation diagram of a dynamically color-tuned semi-transparent organic photovoltaic cell according to a preferred embodiment of the present invention;

[0038] Figure 3 This is an IV curve of a dynamically color-tuned semi-transparent organic photovoltaic cell according to a preferred embodiment of the present invention;

[0039] Figure 4 This is a CV curve of a dynamically color-tuned semi-transparent organic photovoltaic cell according to a preferred embodiment of the present invention;

[0040] Figure 5This is a preferred embodiment of the transmittance of a dynamically color-tuned semi-transparent organic photovoltaic cell under different bias voltages;

[0041] Figure 6 This is a preferred embodiment of the coloring / fading transmittance of a dynamically color-tuned semi-transparent organic photovoltaic cell according to the present invention;

[0042] Figure 7 This is a preferred embodiment of the response time of a dynamically color-tuned semi-transparent organic photovoltaic cell. Detailed Implementation

[0043] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0044] In the following description, specific details, such as particular internal procedures and techniques, are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will appreciate that the invention may be practiced in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of the invention with unnecessary detail.

[0045] like Figure 1 As shown, this embodiment of the invention provides a dynamically color-tuned semi-transparent organic photovoltaic cell, including an organic photovoltaic cell and an electrochromic layer. The electrochromic layer includes a WO3 thin film layer and a NiO counter electrode layer. The WO3 thin film layer is disposed on the electrode of the organic photovoltaic cell, and the NiO counter electrode layer is disposed on commercial ITO glass. The WO3 thin film layer and the NiO counter electrode layer are bonded together by iontophoresis.

[0046] Furthermore, this embodiment of the invention provides a dynamically color-tuned semi-transparent organic photovoltaic cell, which specifically includes the following layers from bottom to top:

[0047] (1) Transparent substrate, which is made of transparent glass material;

[0048] (2) The first transparent electrode layer is an ITO conductive film;

[0049] (3) A semi-transparent organic photovoltaic layer, comprising, in sequence, a PEDOT:PSS hole transport layer, a PM6:L8-BO active layer, and a PNDIT-F3N electron transport layer, with an active layer thickness of 80 nm; the average visible light transmittance (AVT) of the semi-transparent organic photovoltaic layer is 32.28%. In the semi-transparent organic photovoltaic layer, PM6 is the donor and L8-BO is the acceptor, with a donor-acceptor mass ratio of 0.6:1.2. The average visible light transmittance (AVT) of the semi-transparent organic photovoltaic layer in this embodiment of the invention is 32.28%.

[0050] (4) The second transparent electrode layer is a 1nm Au seed layer and a 10nm Ag conductive film;

[0051] (5) A WO3 thin film layer is vacuum-deposited onto the second transparent electrode layer;

[0052] (6) Ion gel layer, used to connect WO3 thin film layer and NiO counter electrode layer, is a mixture of LiClO4:PC electrolyte and polymethyl methacrylate at a mass ratio of 1:3;

[0053] (7) NiO counter electrode layer, spin-coated onto the third transparent electrode layer;

[0054] (8) The third transparent electrode layer is an ITO conductive film;

[0055] (9) The top layer is made of transparent glass.

[0056] The thickness of the first transparent electrode layer and the third transparent electrode layer is 150 nm.

[0057] The dynamically color-tuned semi-transparent organic photovoltaic cell in this embodiment of the invention is an integrated device, which is prepared in two parts, namely, separately prepared on two pieces of commercial ITO glass.

[0058] On the first piece of commercial ITO (i.e., the first transparent electrode) glass, a PEDOT:PSS hole transport layer, a PM6:L8-BO active layer, and a PNDIT-F3N electron transport layer were sequentially prepared. Then, a second transparent electrode (consisting of a 1nm Au seed layer and a 10nm Ag conductive film) was deposited on it. Following this, a WO3 thin film layer was deposited on the second transparent electrode. Thus, the first part of the preparation was completed.

[0059] NiO counter electrode layers were sequentially fabricated on the second piece of commercial ITO (i.e., the third transparent electrode) glass. This completes the second part of the fabrication.

[0060] Then, ionogel is used to assemble these two parts into an integrated device.

[0061] Because the ITO in commercial ITO glass is prepared on top of the glass, the first part of the glass serves as a transparent substrate, and the second part is bonded to the first part in an inverted form using iontophoresis, so the second part of the glass is the transparent top layer.

[0062] To improve the performance of dynamically color-tuned semi-transparent organic photovoltaic cells, enhance the photoelectric conversion efficiency of organic solar cell layers, better power the electrochromic layer, and achieve a better electrochromic effect, the hole transport layer uses PEDOT:PSS, model Clevios™ PVP AI 4083, rotated at 3000 rpm for 30 seconds, and the resulting thickness is 30nm.

[0063] The semi-transparent organic photovoltaic layer, PM6:L8-BO active layer, comprises electron donor and electron acceptor materials. In this embodiment, PM6 and L8-BO are used as the photoelectric active layer. To achieve better coordination between the electron donor and electron acceptor materials and improve the performance of the photoelectric active layer, the mass ratio of electron donor to electron acceptor materials is 0.6:1.2, the rotation speed is 3000 rpm, and the duration is 30 seconds, resulting in a thickness of 80 nm.

[0064] The electron transport layer of the semi-transparent organic photovoltaic layer was PNDIT-F3N, with a solution concentration of 0.95 mg / mL dissolved in methanol and 5 wt% acetic acid added as a co-solvent. The rotation speed was 3000 rpm for 30 seconds, and the resulting thickness was 10 nm.

[0065] In this embodiment of the invention, when the first transparent electrode layer is located at the end furthest from the electrochromic layer, its transparent electrode material can be selected from a wide range. In order to form a better organic solar cell layer, preferably, the transparent electrode material of the first transparent electrode layer can be indium tin oxide glass.

[0066] In this embodiment of the invention, to achieve better coordination between the organic photovoltaic cell and the electrochromic layer—that is, to improve both the photoelectric conversion efficiency of the organic solar cell layer and the color-changing performance of the electrochromic layer, thereby obtaining a more sensitive electrochromic glass—the materials of the other layers can be selected. The hole transport material of the hole transport layer can be selected from a wide range. To obtain good hole mobility and improve the photoelectric efficiency of the organic solar cell layer, preferably, in this embodiment of the invention, the hole transport material of the hole transport layer can be poly(3,4-ethylenedioxythiophene)-(polystyrene sulfonate), also known as PEDOT:PSS. The electron transport material of the electron transport layer can be selected from a wide range. In order to improve the electron migration rate, the preferred electron transport material of the electron transport layer is poly[(9,9-bis(3′-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-5,5′-bis(2,2′-thiophene)-2,6-naphthalene-1,4,5,8-tetracarboxylic acid-N,N′-bis(2-ethylhexyl)amide], which can also be called PNDIT-F3N.

[0067] In this embodiment of the invention, an ion-gel-mediated heterogeneous integration method is used to stack the organic solar cell layer and the electrochromic layer to obtain an integrated organic photovoltaic cell. The ion-gel is prepared by mixing LiClO4:PC electrolyte and polymethyl methacrylate at a mass ratio of 1:3, stirring at 150°C for 1 h, and then allowing it to stand at room temperature for 5 h to remove air bubbles. The ion-gel possesses excellent ionic conductivity, interfacial adhesion, and light transmittance. While achieving tight coupling between the ST-OPV and ECD colorimetric unit, it reduces the negative impact on the photovoltaic efficiency and optical control range of both devices after integration, ensuring that the integrated device has both a stable structure and synergistic functions. The integrated device can simultaneously generate electricity, provide transparency, provide heat insulation, and adjust color, making it suitable for multi-functional application scenarios.

[0068] In this embodiment of the invention, the electrochromic layer can be selected from a wide range, as long as it can achieve the electrochromic function. To better coordinate with the organic solar cell layer and improve heat insulation performance, preferably, such as... Figure 1 As shown, the electrochromic layer uses WO3.

[0069] Typically, the electrochromic ion transport layer comprises an electrochromic material and a gel polymer electrolyte. In this embodiment of the invention, the content of the electrochromic material is 2-16 wt%, preferably 4-12 wt%; the content of the gel polymer electrolyte is 20-25 wt%, preferably 25 wt%. The electrochromic material can be selected from a variety of electrochromic materials, such as metal oxides, inorganic salts, and organic electrochromic materials; in this embodiment, LiClO4 is preferred. The gel polymer electrolyte can be selected from one or more of polymethyl methacrylate, polyvinylpyrrolidone, polyethylene oxide, and hydroxyethyl cellulose; in this embodiment, polymethyl methacrylate is preferred. LiClO4 is mixed with PC solvent at a ratio of 4-12 wt%, stirred at room temperature for 1 h, and then 25 wt% of polymethyl methacrylate is added. The mixture is stirred at 150°C for 1 h, and then allowed to stand at room temperature for 5 h to remove air bubbles.

[0070] In this embodiment of the invention, the conductive material of the second transparent electrode layer can be selected from a wide range. Preferably, the conductive material of the second transparent electrode layer is selected from one or more of conductive copper electrodes, conductive aluminum electrodes, conductive silver electrodes, and conductive gold electrodes, and is preferably conductive silver electrodes and / or conductive gold electrodes.

[0071] Figure 2 To improve the performance of dynamically color-tuned semi-transparent organic photovoltaic cells (OLEDs) and further enhance the results of high-throughput simulation screening, the thickness of each layer can be adjusted to achieve better inter-layer coordination and control the overall thickness and weight of the OLED. This invention utilizes a high-throughput optical screening model, using the thickness of each layer of the electrochromic active layer as a variable, to simulate and obtain the optimal thickness parameters, thereby synergistically improving the average visible light transmittance and photoelectric conversion efficiency. Figure 2 As shown in Figure a, we can adjust the thickness of each layer of the electrochromic active layer to achieve high average visible light transmittance in the faded state while maintaining low average visible light transmittance in the colored state. For example... Figure 2 As shown in b, we can adjust the thickness of each layer of the electrochromic active layer so that the PCE of the organic photovoltaic cell can have good photoelectric conversion efficiency regardless of whether it is in the bleached or colored state.

[0072] Specifically, the thickness of the photoelectric active layer is 60-120 nm, more preferably 80-100 nm, for example, it can be 80 nm, 90 nm, 100 nm, or any value between these ranges. The thickness of the hole transport layer is 25-50 nm, preferably 25-35 nm, for example, 27 nm, 30 nm, 32 nm, 34 nm, or any value between these ranges. The thickness of the electron transport layer is 10-20 nm, preferably 10-15 nm, for example, 10 nm, 12 nm, 15 nm, or any value between these ranges. The thickness of the WO3 electrochromic active layer is 100-200 nm, preferably 180-200 nm, for example, 180 nm, 185 nm, 190 nm, 195 nm, 200 nm, or any value between these ranges. The NiO electrochromic ion storage layer is spin-coated 1-4 layers at 2000 rpm, preferably 1-2 layers.

[0073] In this embodiment of the invention, the first transparent electrode layer is the anode of the organic solar cell layer, the second transparent electrode layer is the cathode of the organic solar cell layer and the cathode of the electrochromic device, and the third transparent electrode layer is the anode of the electrochromic layer.

[0074] In another preferred embodiment of the present invention, a method for preparing a dynamically color-tuned semi-transparent organic photovoltaic cell is provided, comprising the following steps:

[0075] (1) The commercial ITO glass substrate is pretreated as the first transparent electrode layer and the third transparent electrode layer: it is subjected to ultrasonic cleaning, blower drying and plasma treatment in sequence;

[0076] (2) Preparation of electrochromic layer: WO3 thin film layer was deposited by vacuum evaporation, and NiO thin film layer was prepared by solution spin coating; WO3 thin film layer was prepared by vacuum evaporation with a thickness of 200 nm, and NiO thin film layer was prepared by solution spin coating, spin coating at 2000 rpm for 30 s, two layers were spin coated; when depositing WO3 thin film layer by vacuum evaporation, the vacuum degree was ≤8×10 -4 Pa, evaporation rate 0.15-0.2 nm / s. NiO thin films were prepared by solution spin coating at 2000 rpm, two layers were spin-coated, and the annealing temperature was 300℃ for 60 min. The thickness of the WO3 electrochromic active layer was 100-200 nm.

[0077] (3) Preparation of ion gel: LiClO4:PC electrolyte and polymethyl methacrylate are mixed at a mass ratio of 1:3;

[0078] (4) Preparation of semi-transparent organic photovoltaic layer: each functional layer is sequentially deposited on a commercial ITO substrate by solution spin coating. The active layer is spin coated at 3000 rpm, annealed at 130℃, and held for 10 min.

[0079] (5) Preparation of the second transparent electrode layer: A 1 nm Au seed layer and a 10 nm Ag conductive film were deposited by vacuum evaporation;

[0080] (6) Assembly: Take an appropriate amount of ion gel with a syringe and integrate the electrochromic device with the semi-transparent organic photovoltaic device.

[0081] This method includes fabricating an electrochromic layer and an organic photovoltaic cell. In this embodiment of the invention, the method includes sequentially fabricating an electron transport layer, a photoactive layer, a hole transport layer, and a second transparent electrode layer on commercial ITO glass to obtain an organic solar cell layer. An electrochromic complementary layer is fabricated on another piece of commercial ITO glass to obtain an electrochromic ion storage layer.

[0082] The method includes providing an electron transport material on commercial ITO glass and performing a first thermal annealing treatment to form an electron transport layer, providing an electron donor material and an electron acceptor material on the electron transport layer and performing a second thermal annealing treatment to form a photoelectric active layer, providing a hole transport material on the photoelectric active layer to form a hole transport layer, providing a transparent electrode material on the hole transport layer to form a second transparent electrode layer, thereby obtaining an organic solar cell layer, and further vacuum evaporating a WO3 electrochromic layer on the second transparent electrode layer. Alternatively, a hole transport material is provided on commercial ITO glass and subjected to a first thermal annealing treatment to form a hole transport layer. An electron donor material and an electron acceptor material are provided on the hole transport layer and subjected to a second thermal annealing treatment to form a photoelectric active layer. An electron transport material is provided on the photoelectric active layer to form an electron transport layer. A transparent electrode material is provided on the hole transport layer to form a second transparent electrode layer, thereby obtaining an organic solar cell layer. A WO3 electrochromic layer is further vacuum-deposited on the second transparent electrode layer. A NiO precursor solution is spin-coated on another piece of commercial ITO glass and subjected to thermal annealing treatment to form an electrochromic ion storage layer. The two parts of the device are then heterogeneously integrated using ion gel.

[0083] The UV-Vis absorption spectrum and visible light transmission spectrum were measured using a UV-Vis spectrophotometer; the IV curve was measured using a precision current source meter, from which parameters such as short-circuit current, open-circuit voltage, fill factor, and photoelectric conversion efficiency can be obtained; the electrochemical cyclic voltammetry curve was measured using a Shanghai Chenhua CHI650F electrochemical workstation.

[0084] The IV curve of the dynamically color-tuned semi-transparent organic photovoltaic cell in this embodiment of the invention is as follows: Figure 3 As shown, through Figure 3 The IV curve shown indicates the open-circuit voltage V of the dynamically color-tuned semi-transparent organic photovoltaic cell. OC The voltage is 0.864V, and the short-circuit current J is...SC 21.05 mA·cm -2 The fill factor (FF) is 67.39%, and the photoelectric conversion efficiency (PCE) is 12.25%.

[0085] The cyclic current-voltage curve of the dynamically color-tuned semi-transparent organic photovoltaic cell in this embodiment of the invention is as follows: Figure 4 As shown in the figure, the peaks in the curve correspond to the redox reactions of the electrochromic material. The figure shows distinct oxidation and reduction peaks, indicating that oxidation and reduction reactions occurred at different potentials. The relatively regular curves and clear peak shapes suggest that the material possesses certain electrochemical activity and can effectively participate in the electrochromic process.

[0086] The transmittance variation curves of the dynamically color-tuned semi-transparent organic photovoltaic cell under different bias voltages in embodiments of the present invention are as follows: Figure 5 As shown, the dynamic color adjustment process of organic photovoltaic cells is clearly demonstrated, revealing that its turn-on voltage is 0.8V, providing a basis for its self-powered function.

[0087] The transmission spectra of the dynamically color-tuned semi-transparent organic photovoltaic cell in its colored and faded states according to embodiments of the present invention are as follows: Figure 6 As shown, the average visible light transmittance is 1.9% when in the colored state and 32.28% when in the faded state.

[0088] The response speed of the dynamically color-tuned semi-transparent organic photovoltaic cell in this embodiment of the invention is as follows: Figure 7 As shown, the coloring response time is 1.3 s, and the fading response time is 0.5 s. The calculated coloring efficiency CE is 118.6 cm⁻¹. 2 C -1 .

[0089] This invention employs a solution spin-coating method to fabricate ST-OPV devices. By adjusting the mass ratio of donor / acceptor materials in the active layer, the internal phase separation structure and crystallinity are precisely controlled, balancing the device's transmittance and photoelectric conversion efficiency. The spin-coating process parameters are optimized, with a focus on adjusting the spin-coating speed to precisely control the active layer film thickness, reducing film defects and pinholes. Post-treatment with appropriate annealing temperature and time further improves the film morphology and interfacial contact characteristics, ultimately achieving a synergistic improvement in the key performance characteristics of the ST-OPV device.

[0090] This invention employs a method of preparing NiO films on two ITO substrates by vacuum evaporation of WO3 films and solution spin coating, respectively, followed by bonding and encapsulation with ionomer gel. The optimized thickness of the WO3 film is 100-200 nm, preferably 180-200 nm, for example, values ​​such as 180 nm, 185 nm, 190 nm, 195 nm, and 200 nm, or any value between these values. The number of NiO film spin coatings is 1-4 layers at 2000 rpm, preferably 1-2 layers. Optimizing these parameters yields an ECD device with excellent optical modulation performance and cycle stability.

[0091] Furthermore, a WO3 thin film was deposited on the high-performance ST-OPV device using vacuum evaporation. Then, using an ion gel with good ionic conductivity, interfacial adhesion, and light transmittance as a bonding medium, a heterogeneous integration method mediated by the ion gel was used to achieve tight coupling between the ST-OPV and the ECD color-tuning unit. While achieving tight coupling between the ST-OPV and the ECD color-tuning unit, the negative impact of integration on the photovoltaic efficiency and optical control range of the two devices was reduced, ensuring that the integrated device has both a stable structure and synergistic function. Finally, a multifunctional ST-OPV device with high light transmittance, high photoelectric conversion efficiency, and dynamic color-tuning function was successfully fabricated.

[0092] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A dynamically color-tuned semi-transparent organic photovoltaic cell, characterized in that, The invention includes an organic photovoltaic cell and an electrochromic layer, wherein the electrochromic layer comprises a WO3 thin film layer and a NiO counter electrode layer. The WO3 thin film layer is disposed on the electrode of the semi-transparent organic photovoltaic cell, and the NiO counter electrode layer is disposed on commercial ITO glass. The WO3 thin film layer and the NiO counter electrode layer are bonded together by iontophoresis.

2. The dynamically color-tuned semi-transparent organic photovoltaic cell as described in claim 1, characterized in that, From bottom to top, the specific layers include the following: (1) Transparent substrate, which is made of transparent glass material; (2) The first transparent electrode layer is an ITO conductive film; (3) A semi-transparent organic photovoltaic layer, comprising, in sequence, a PEDOT:PSS hole transport layer, a PM6:L8-BO active layer and a PNDIT-F3N electron transport layer, with an active layer thickness of 80 nm; (4) The second transparent electrode layer is a 1nm Au seed layer and a 10nm Ag conductive film; (5) A WO3 thin film layer is vacuum-deposited onto the second transparent electrode layer; (6) Ion gel layer, used to connect WO3 thin film layer and NiO counter electrode layer, is a mixture of LiClO4:PC electrolyte and polymethyl methacrylate at a mass ratio of 1:3; (7) NiO counter electrode layer, spin-coated onto the third transparent electrode layer; (8) The third transparent electrode layer is an ITO conductive film; (9) The top layer is made of transparent glass.

3. The dynamically color-tuned semi-transparent organic photovoltaic cell as described in claim 2, characterized in that, The average visible light transmittance (AVT) of the semi-transparent organic photovoltaic layer is 32.28%.

4. The dynamically color-tuned semi-transparent organic photovoltaic cell as described in claim 2, characterized in that, The thickness of the first transparent electrode layer and the second transparent electrode layer is 150 nm.

5. The dynamically color-tuned semi-transparent organic photovoltaic cell as described in claim 2, characterized in that, PM6 is the donor and L8-BO is the acceptor. The donor-acceptor mass ratio of the semi-transparent organic photovoltaic layer is 0.6:1.

2.

6. The dynamically color-tuned semi-transparent organic photovoltaic cell as described in claim 2, characterized in that, The WO3 thin film layer was prepared by vacuum evaporation and had a thickness of 200 nm. The NiO thin film layer was prepared by solution spin coating, with two layers coated at 2000 rpm for 30 s.

7. The method for preparing a dynamically color-tuned semi-transparent organic photovoltaic cell as described in any one of claims 1-6, characterized in that, Includes the following steps: (1) The commercial ITO glass substrate is pretreated as the first transparent electrode layer and the third transparent electrode layer: it is subjected to ultrasonic cleaning, blower drying and plasma treatment in sequence; (2) Preparation of electrochromic layer: WO3 thin film layer was deposited by vacuum evaporation, and NiO thin film layer was prepared by solution spin coating; (3) Preparation of ion gel: LiClO4:PC electrolyte and polymethyl methacrylate are mixed at a mass ratio of 1:3; (4) Preparation of semi-transparent organic photovoltaic layer: each functional layer is sequentially deposited on a commercial ITO substrate by solution spin coating. The active layer is spin coated at 3000 rpm, annealed at 130℃, and held for 10 min. (5) Preparation of the second transparent electrode layer: A 1 nm Au seed layer and a 10 nm Ag conductive film were deposited by vacuum evaporation; (6) Assembly: Take an appropriate amount of ion gel with a syringe and integrate the electrochromic device with the semi-transparent organic photovoltaic device.

8. The method for preparing a dynamically color-tuned semi-transparent organic photovoltaic cell as described in claim 7, characterized in that, When depositing WO3 thin films using the vacuum evaporation method, the vacuum level should be ≤8×10. -4 Pa, evaporation rate 0.15-0.2 nm / s.

9. The method for preparing a dynamically color-tuned semi-transparent organic photovoltaic cell as described in claim 7, characterized in that, NiO thin films were prepared by solution spin coating at 2000 rpm, with two layers applied. The annealing temperature was 300℃, and the annealing time was 60 min.

10. The method for preparing a dynamically color-tuned semi-transparent organic photovoltaic cell as described in claim 8, characterized in that, The thickness of the WO3 electrochromic active layer is 100-200 nm.

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