A photosensitive structure, a self-reactive photosensitive device and an actively controlled photosensitive device

Abstract

The embodiment of the application provides a photosensitive structure, a self-reaction photosensitive device and an active control type photosensitive device, which comprise a front end layer, a mixed conductive interface layer and a rear end layer which are stacked in sequence along a light path direction, realize seamless coupling of photoelectric conversion and electrochemical response through a self-driven charge transport channel, realize self-powered and self-regulated photosensitive response, thereby solving the problem of slow response of an existing photosensitive material; absorption spectrum is regulated through selection and material design of a photoelectric conversion structure in the front end layer, thereby solving the problem of poor spectrum adaptability of the existing photosensitive material, and the photosensitive structure has fast kinetic response and wide spectrum adaptability.

Description

Technical Field

[0001] This application relates to the field of semiconductor optoelectronic technology, and in particular to a photosensitive structure, a self-reactive photosensitive device, and an actively controlled photosensitive device. Background Technology

[0002] Photosensitive materials are functional materials whose molecular structure or electronic state can undergo reversible changes when irradiated with light of a specific wavelength (usually ultraviolet light), resulting in a significant change in their absorption spectrum of visible light; after the light is removed, the material can spontaneously or by applying other energy (such as heat or light of another wavelength) to return to its initial state.

[0003] Currently, photosensitive materials are mainly divided into three categories: inorganic photochromic materials, organic photochromic materials, and organic-inorganic composite materials. They generally face two technical problems in practical applications: First, in terms of response speed, the color-changing response time of existing materials is generally in the range of tens of seconds to minutes. This sluggish dynamic characteristic severely restricts their application in scenarios requiring rapid response. Second, in terms of spectral response range, current materials are often only sensitive to specific wavelengths in the ultraviolet region and lack the ability to controllably excite and adjust responses to a wider wavelength range, including the visible light band. This greatly limits the expansion of their application scenarios.

[0004] Therefore, there is an urgent need for a photosensitive material and a photosensitive device that can achieve a response speed closer to real-time milliseconds and can be adjusted to accommodate a wider range of light wavelengths as needed. Summary of the Invention

[0005] This application provides a photosensitive structure capable of achieving millisecond-level response speeds and selectively responding to light within a specific wavelength range through material structure modulation as needed. A second objective of this invention is to provide a self-reactive photosensitive device that completes circuit closed-loop within the structural layer, simplifying the overall device design and forming a zero-bias integrated self-driven device. A third objective of this invention is to provide an actively controlled photosensitive device that can actively adjust the degree of photosensitive color change within a certain range.

[0006] In a first aspect, embodiments of this application provide a photosensitive structure, including a front-end layer, a hybrid conductive interface layer, and a rear-end layer stacked sequentially along the optical path direction;

[0007] The front-end layer includes a photoelectric conversion structure for converting incident light into an electrical signal. The front-end layer adopts a high-transmittance photoelectric conversion structure.

[0008] A hybrid conductive interface layer is used to connect the front-end layer and the back-end layer to form a self-driven charge transport channel. The hybrid conductive interface layer is made of a transparent material.

[0009] The back-end layer includes an electrochromic structure, and the electrical energy generated by the front-end layer drives the electrochromic structure to undergo a reversible redox reaction.

[0010] In one possible implementation, the photoelectric conversion structure includes a front-transmitting conductive layer and a light-absorbing layer arranged sequentially from the optical path direction;

[0011] The electrochromic structure includes an electrochromic layer and a back-transmitting conductive layer arranged sequentially from the optical path direction.

[0012] In one possible implementation, an ion storage layer is disposed between the electrochromic layer and the hybrid conductive interface layer.

[0013] In one possible implementation, an ion transport layer is provided between the electrochromic layer and the hybrid conductive interface layer.

[0014] In one possible implementation, an electron transport layer is disposed between the front-transmitting conductive layer and the light-absorbing layer.

[0015] In one possible implementation, a hole transport layer is provided between the light-absorbing layer and the hybrid conductive interface layer.

[0016] Secondly, embodiments of this application provide a self-reactive photosensitive device, including the photosensitive structure described above. The front transparent conductive layer and the rear transparent conductive layer extend beyond the functional layer region to form an electrode lead-out area. A conductive bridging channel is provided between the electrode lead-out areas of the front transparent conductive layer and the rear transparent conductive layer. The conductive bridging channel is used for charge transfer between the front transparent conductive layer and the rear transparent conductive layer to form a self-driven circuit.

[0017] In one possible implementation, an insulating layer is provided between the conductive bridging channel and the light-absorbing layer, the hybrid conductive interface layer, and the electrochromic layer.

[0018] Thirdly, embodiments of this application also provide an actively controlled photosensor, comprising:

[0019] The aforementioned photosensitive structure;

[0020] The external circuit is electrically connected to the front and rear light-transmitting conductive layers of the photosensitive structure to form a controllable current path.

[0021] A control switch is connected in series in the external circuit and is used to connect or disconnect the current path.

[0022] In one possible implementation, it also includes:

[0023] A control component, connected in series in the external circuit, is used to adjust the voltage level of the external circuit.

[0024] The photosensitive structure, self-reactive photosensitive device, and actively controlled photosensitive device provided in this application have the following technical advantages:

[0025] (1) The photoelectric conversion function and the electrochromic function are integrated into one. Through the efficient connection of the hybrid conductive interface, the photosensitive response is self-powered and self-regulated. The photovoltaic physical effect is used to generate electron-hole pairs through photon excitation in the light absorption layer. Under the action of the built-in electric field, they are separated into free electrons and holes. Through the hybrid conductive interface layer, charge-ion coupling is translated into mobile charged ions, which complete the charge compensation of the front end and output the chemical potential of the ions, providing the ion source for the reaction of the back electrochromic layer, driving the electrochromic layer to undergo reversible electrochemical oxidation-reduction reaction, causing changes in its material band structure and light absorption characteristics, and exhibiting transmission spectrum shift and color switching.

[0026] (2) Changes in light intensity within the absorption wavelength range cause changes in the number of excitons and charge carriers, forming a corresponding potential difference in the closed circuit. After conversion, this difference affects the degree of oxidation-reduction of the electrochromic layer, making the color change depth of the device correspond to the incident light intensity. This enables a self-powered, self-adjusting, and visually responsive system, forming a complete loop system that can complete light response and optical changes without external intervention.

[0027] (3) By using a photoelectric conversion structure with high light transmittance and a transparent hybrid conductive interface, the electrochromic layer is made to display color as a whole, thus achieving photosensitive properties. The characteristics of strong electric field driving, low interface impedance, and short ion migration path of electrochromic reaction to achieve millisecond-level response are utilized to achieve fast optical response, overcoming the problem that electrochromic requires external power supply and has no light intensity sensing.

[0028] (4) This application solves the problem of hysteresis response in existing photosensitive materials and has a fast dynamic response capability. Due to the diversity of photoelectric conversion structures, this photosensitive structure has the ability to expand the spectral response range. It can control the absorption spectrum by designing the material of the photoelectric conversion structure, thereby responding to light changes in different ranges, overcoming the limitation of existing photosensitive materials that are only sensitive to ultraviolet light, thus solving the problem of poor spectral adaptability of existing photosensitive materials and having a wide spectral adaptability. Attached Figure Description

[0029] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0030] Figure 1 This application provides a simplified structure of a photosensitive structure.

[0031] Figure 2 This is a schematic diagram of a typical overall structure of a photosensitive structure provided in an embodiment of this application;

[0032] Figure 3 This is a schematic diagram of the overall structure of a self-reactive photosensitizer provided in an embodiment of this application;

[0033] Figure 4 This is a schematic diagram of the overall structure of an active control type photosensitive device provided in an embodiment of this application.

[0034] Reference numerals: 1. Front transparent conductive layer; 2. Electron transport layer; 3. Light absorption layer; 4. Hole transport layer; 5. Hybrid conductive interface layer; 6. Ion storage layer; 7. Ion transport layer; 8. Electrochromic layer; 9. Back transparent conductive layer; 10. Conductive bridging channel; 11. Insulating layer; 12. Control component.

[0035] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0036] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0037] Traditional photosensitive materials generally suffer from slow response speeds and limited spectral selectivity. They rely on intramolecular chemical reactions (heterolytic cleavage-ring closure equilibrium, electrocyclization, or cis-trans isomerism) in thin films or solids to expand conjugated systems and reconfigure energy levels, thereby altering their absorption characteristics for visible light. In solid-state or thin-film environments, molecular motion is restricted, leading to slow reaction kinetics and reduced cyclic reversibility. The color-changing process takes tens of seconds to several minutes, making it difficult to meet the demands of dynamic optical control and limiting their application in scenarios requiring rapid response. Furthermore, traditional materials are primarily sensitive to specific wavelengths in the ultraviolet region, lacking the ability to controllably excite and modulate responses across a wider wavelength range, including the visible light spectrum, further restricting the expansion of their application scenarios.

[0038] To address the aforementioned issues, this application proposes a photosensitive structure comprising a front-end layer, a hybrid conductive interface layer, and a rear-end layer stacked sequentially along the optical path. The hybrid conductive interface layer connects the front-end layer and the rear-end layer, forming a self-driven charge transport channel. The front-end layer converts incident light into electrical energy through photoelectric conversion, and the electrical coupling through the hybrid conductive interface layer drives the electrochromic electrochemical process of the rear-end layer, thus achieving a self-reactive closed-loop structure.

[0039] The technical solution of this application and how it solves the above-mentioned technical problems will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described below with reference to the accompanying drawings.

[0040] Reference Figure 1 This application provides a photosensitive structure, including a front end layer, a hybrid conductive interface layer 5, and a rear end layer stacked sequentially along the optical path direction;

[0041] The front-end layer includes a photoelectric conversion structure for converting incident light into an electrical signal. The front-end layer employs a high-transmittance photoelectric conversion structure.

[0042] A hybrid conductive interface layer 5 is used to connect the front end layer and the back end layer to form a self-driven charge transport channel. The hybrid conductive interface has high light transmittance.

[0043] The back-end layer includes an electrochromic structure, and the electrical energy generated by the front-end layer drives the electrochromic structure to undergo a reversible redox reaction.

[0044] The incident light is converted into electrical energy through photoelectric conversion in the front-end layer, and then electrically coupled through the hybrid conductive interface layer 5 to drive the electrochromic electrochemical process of the back-end layer, thus realizing a self-reactive closed-loop structure.

[0045] The photoelectric conversion structure is the core functional unit in the front-end layer. Its function is to convert incident photon energy into charge carriers, utilizing the photovoltaic effect to generate electron-hole pairs through photoexcitation, thus realizing the conversion of light energy into electrical energy. The photoelectric conversion structure can employ various advanced semiconductor material systems, including perovskite materials, organic OPV materials, dye-sensitized DSSCs, copper indium gallium selenide (CIGS), cadmium telluride (CdTe), and amorphous silicon. For example, perovskite materials can be used. When a photon with energy greater than the bandgap of the perovskite material irradiates the structure, the photon energy excites an electron in the valence band to the conduction band, leaving a hole in the valence band, forming an electron-hole pair, often called an exciton. Under the influence of the built-in electric field provided by the core PN junction, the exciton separates into free electrons and holes, thus forming an electrical signal. When the circuit is closed, these moving charges form a current, thereby outputting electrical energy to the load.

[0046] The front-end layer achieves good transmittance in the visible light band by using a highly transparent photoelectric conversion structure design, such as increasing the band gap width of the perovskite material, adjusting the type and concentration of dyes in the dye-sensitized material, or adjusting the molecules of the organic OPV photoactive layer material. Furthermore, due to its micron-level thickness, it can maintain approximately 40%-80% visible light transmittance (perovskite lab tests can even achieve near-colorless transparency), meeting the needs of devices with varying levels of transparency.

[0047] The hybrid conductive interface layer 5 is used to connect the front-end layer and the back-end layer. It is a charge-ion translation layer that translates the charge generated by the front-end light absorption layer 3 into mobile charged ions through charge-ion coupling (redox-driven ion insertion / extraction), completes front-end charge compensation, and outputs the chemical potential of the ions to provide an ion source for the reaction of the back-end electrochromic layer 8.

[0048] In the photosensitive structure, the "energy translation" function ensures charge transfer between different functional layers, forming a self-driven charge transport channel. A self-driven charge transport channel refers to a path where the photosensitive structure itself generates a potential difference or charge gradient, driving the directional transport of charges (including electrons and ions) between layers without the need for an external power source. The hybrid conductive interface layer 5 plays a connecting and transporting role in the photosensitive structure. This layer can be composed of materials with mixed conductive properties, such as certain doped oxides (e.g., doped TiO2, ZnO), composite materials of ionic liquids and conductive polymers, or electrolyte materials with specific porous structures. Its design must ensure that the electron and ion transport rates are matched to avoid charge accumulation and maintain the charge neutrality of the entire system.

[0049] To achieve high light transmittance in the hybrid conductive interface layer 5, various materials can be used, such as ion-electron hybrid conductors like sol-gel vanadium pentoxide or manganese dioxide films (with electronic conductivity typically controlled to 10⁻³ Scm⁻¹ to ensure electrons do not leave the front end), or organic polymers like high-ion-content or sulfonated modified PEDOT:PSS composite films (with ion-electron hybrid conductivity, but dominated by ion transport). All of these materials maintain >80% visible light transmittance at a thickness <100 nm, meeting the requirements for transparent devices.

[0050] The back-end layer is the region in the photosensitive structure responsible for responding to the electrical energy generated by the front-end layer and undergoing optical changes. This layer contains an electrochromic structure, the core functional unit of the back-end layer. Its optical properties can be reversibly altered by an electric field or charge injection. Driven by the electric field generated by the front-end layer, it initiates a reversible electrochemical redox reaction, causing changes in the material's band structure and light absorption characteristics, macroscopically manifested as a color change. This achieves light modulation, enabling a self-powered, light-intensity-sensitive visual response. The electrochromic structure can be composed of various electrochromic materials; the selection of these materials is crucial for achieving high-performance photosensitive structures.

[0051] Common electrochromic materials include inorganic materials (such as tungsten trioxide (WO3) and nickel oxide (NiO), organic materials (such as polyaniline and polypyrrole), and materials combining inorganic and organic elements. To achieve efficient photosensitivity, electrochromic structures require low driving voltages (generally not exceeding ±5V) and high charge density. Furthermore, the design of the electrochromic structure must consider its compatibility with the front-end photoelectric conversion structure and the intermediate hybrid conductive interface layer 5 to ensure efficient charge injection and extraction, thereby achieving a rapid and reversible color-changing process.

[0052] In some embodiments, a front encapsulation layer and a back encapsulation layer may also be provided.

[0053] Among them, the front encapsulation layer is the outermost structure of the incident light receiving side of the device. Its inner side is directly and tightly connected to the front light-transmitting conductive layer 1, and its outer side is exposed to the external environment. It is the first structure of the incident photon contact device.

[0054] Rear encapsulation layer: This is the outermost structure of the device away from the incident light side. It is located on the side of the rear transparent conductive layer 9 away from the electrochromic layer 8. The inner side is directly and tightly connected to the rear transparent conductive layer 9, while the outer side is exposed to the external environment. It is the outer protective structure of the rear end of the device.

[0055] The front and rear encapsulation layers work together to form a fully encapsulated outer layer protection system that covers all core optoelectronic structures inside the device, including the front transparent conductive layer 1, light absorption layer 3, hybrid conductive interface layer 5, electrochromic layer 8, and rear transparent conductive layer 9.

[0056] A self-reactive closed-loop structure refers to a photosensitive structure that generates electrical energy through photoelectric conversion in the front-end layer, and then directly drives the electrochromic process in the back-end layer after electrical coupling through the hybrid conductive interface layer 5, forming a complete loop system that can be completed without external intervention, including self-powered, self-regulated light response and optical changes.

[0057] The photosensitivity is achieved by converting incident light into electrical energy through photoelectric conversion in the front-end layer. This electrical energy is then electrically coupled through the hybrid conductive interface layer 5, driving the electrochromic electrochemical process in the back-end layer to achieve a self-reactive closed-loop structure. This integrates photoelectric conversion and electrochromic functions, enabling a self-powered and self-regulating photosensitivity response.

[0058] Specifically, when incident photons of a specific wavelength pass sequentially through the front packaging layer and the front transparent conductive layer 1, and irradiate the light-absorbing layer 3 (such as a perovskite semiconductor material) with a certain structure, due to the physical effect of photovoltaics, when the energy is greater than the bandgap of the semiconductor material, electron-hole pairs are excited in the light-absorbing layer 3. Under the action of the built-in electric field (pn or pin structure), the photogenerated electrons drift towards the n-type front transparent conductive layer 1 and are collected by the external circuit, and then transported to the rear transparent conductive layer 9; the holes migrate towards the mixed conductive interface layer 5 under the drive of the built-in electric field and enter the mixed conductive interface layer 5.

[0059] This layer is an electron-ion hybrid conductor, whose valence band (or defect level) provides a hole transport channel while allowing compensating ions to migrate rapidly under the chemical potential gradient, thus coupling the hole current with the ion current. When the external circuit is closed, the common charge compensation of holes and migrating ions causes the potential of the hybrid conductive interface layer 5 to reach a quasi-equilibrium with the redox state of the electrochromic layer 8. Changes in light intensity cause the quasi-Fermi level of the light absorption layer 3 to split, generating a measurable photovoltage.

[0060] The photovoltage is directly superimposed on the interface between the mixed conductive interface layer 5 and the back-transmitting conductive layer 9, modulating the chemical potential of the active species (redox pairs) in the electrochromic layer 8. Ions insert / extract between the mixed conductive interface layer 5 and the electrochromic layer 8, causing reversible changes in the band structure and light absorption characteristics of the electrochromic layer 8, macroscopically manifested as a shift in the transmission spectrum and color switching. For example, in tungsten trioxide (WO3) electrochromic materials, the injection of cations (such as Li⁺) and electrons will form tungsten bronze (Li⁺). x The presence of WO3 causes the material to change from transparent to blue. When the light intensity decreases or stops, the electrochromic material undergoes a reverse reaction, and the color fades or disappears.

[0061] Therefore, changes in light intensity within the absorption wavelength range cause changes in the number of excitons and charge carriers, forming a corresponding potential difference in the closed circuit. After conversion, this difference affects the redox degree of the electrochromic layer 8, making the color-changing depth of the device correspond to the incident light intensity. This enables a self-powered, light-sensitive, and visually responsive device, achieving photosensitivity.

[0062] Visible light transmittance and color change: The photoelectric conversion structure and the hybrid conductive interface exhibit visible light transmittance. The overall color is altered by the redox reaction of the electrochromic structure at the back end, thus expressing photosensitivity. To achieve high visible light transmittance, the photoelectric conversion structure uses materials with low or selective absorption of visible light. For example, a semiconductor material with a wide bandgap is selected, allowing it to primarily absorb ultraviolet or infrared light while transmitting most visible light. The hybrid conductive interface layer 5 uses a highly transparent material, such as a highly transparent ion-electron hybrid conductor or a transparent organic polymer composite film. Furthermore, the thickness of each functional layer needs precise control to reduce light reflection and absorption. This color-change-based photosensitivity response not only achieves the perception of light intensity but also provides intuitive visual feedback.

[0063] Spectral Response Range Adjustment: The photoelectric conversion structure can also be tuned through material design to control the absorption spectrum, thereby responding to changes in light intensity across different ranges. For example, when the light absorption layer 3 uses perovskite semiconductor material, the typical bandgap range is 1.2–3.5 eV, corresponding to absorbed light wavelengths of approximately 354–1033 nm, covering the near-ultraviolet to near-infrared bands. Currently, the largest bandgap in the laboratory can reach 0.9–3.6 eV. The bandgap width of perovskite materials (general molecular formula ABX3) can be adjusted through compositional engineering (e.g., with X-position halide ions, the bandgap can be adjusted almost linearly within a certain range by changing the ratio of I and Br), enabling control over blue-shifting or red-shifting of the absorption spectrum. This overcomes the limitation of existing photosensitive materials that are only suitable for specific wavelengths of light (such as ultraviolet light) and cannot change the wavelength range. This solves the problem of poor spectral adaptability of existing photosensitive materials, enabling adjustment of the light response across a wider wavelength range, including visible light, thus broadening the application scenarios under different lighting environments.

[0064] Through the above technical solution, the photoelectric conversion of the front-end layer converts incident light into electrical energy. After electrical coupling through the hybrid conductive interface layer 5, this electrical energy directly drives the electrochromic electrochemical process of the back-end layer, thereby realizing a self-reactive closed-loop structure. This allows the entire photosensitizing process to complete the complete cycle from light signal to electrical signal and then to optical change solely relying on incident light, without the need for continuous external power supply. For example, when the illumination is enhanced, the front-end layer generates more electrical energy, driving the back-end layer to undergo a color-changing reaction; when the illumination is weakened or removed, the electrochromic structure reversibly returns to its initial state.

[0065] A self-powered, self-regulating closed-loop reaction system is constructed by directly electrochemically coupling the photoelectric conversion of the front-end layer with the electrochromic reaction of the back-end layer. This structure leverages the strong electric field driving force, low interfacial impedance, and short ion migration path of the electrochromic reaction to achieve millisecond-level response, overcoming the hysteresis problem of existing photosensitive materials. Furthermore, the versatility of the photoelectric conversion structure allows for the expansion of the spectral response range. By designing the materials of the photoelectric conversion structure, the absorption spectrum can be modulated to respond to changes in light intensity across different ranges. This enables controllable excitation and regulation of a wider wavelength range, including visible light, thus broadening its application scenarios under various lighting conditions.

[0066] This application also discloses that the photoelectric conversion structure includes a front light-transmitting conductive layer 1 and a light-absorbing layer 3 arranged sequentially from the light path direction; and the electrochromic structure includes an electrochromic layer 8 and a rear light-transmitting conductive layer 9 arranged sequentially from the light path direction.

[0067] Specifically, the front-transmitting conductive layer 1 is located at the very front of the optical path. Its main function is to allow incident light to pass through to the maximum extent while providing a path for charge collection and transport. Typically, the front-transmitting conductive layer 1 can be made of transparent conductive oxides (such as indium tin oxide (ITO), fluorine-doped tin oxide (FTO), zinc aluminum oxide (AZO)) or transparent conductive polymers, carbon nanotubes, graphene, and other materials. Its thickness, sheet resistance, and transmittance need to be optimized according to the specific application scenario to ensure efficient light transmission and charge collection.

[0068] The light-absorbing layer 3 is located adjacent to the front-transmitting conductive layer 1 and is responsible for absorbing incident photons that pass through the front-transmitting conductive layer 1 and converting them into electron-hole pairs. The light-absorbing layer 3 can be made of various advanced semiconductor materials, such as perovskite materials (e.g., CH3NH3PbI3), organic semiconductor materials (e.g., P3HT:PCBM), dye sensitizers (e.g., N719 dye adsorbed on TiO2 nanoparticles), copper indium gallium selenide (CIGS), cadmium telluride (CdTe), or amorphous silicon. The light-absorbing layer 3 is generally a single layer, but it can also be composed of multiple layers to achieve photoelectric conversion. Selecting a suitable light-absorbing material is crucial for improving photoelectric conversion efficiency, and its absorption spectrum matching degree with incident light, carrier separation efficiency, and stability must be considered.

[0069] The electrochromic layer 8 is the core of the electrochromic structure. Upon receiving electrical energy, it undergoes a reversible redox reaction, thereby altering its optical properties (such as color, transmittance, and reflectivity). Commonly used electrochromic materials include inorganic oxides (such as tungsten trioxide (WO3), nickel oxide (NiO), and vanadium pentoxide (V2O5)), organic polymers (such as polyaniline and polythiophene), and inorganic-organic combined materials. The electrochromic layer 8 is generally a single layer, but it can also be composed of multiple layers to achieve the corresponding functions, such as inorganic-organic combinations. For example, it can simultaneously employ cathodic coloring (reduction coloring): such as tungsten oxide, molybdenum oxide, and nickel oxide, and anodic coloring (oxidation coloring): such as iridium oxide, nickel oxide, and polyaniline. The selection of the electrochromic layer 8 should consider its color-changing efficiency, contrast, response speed, cycle stability, and compatibility with the electrolyte.

[0070] The back-transmitting conductive layer 9 is located behind the electrochromic layer 8, providing a charge transport path while allowing light to pass through (if bidirectional transmission is required). The back-transmitting conductive layer 9 is typically composed of transparent conductive oxides (such as ITO, FTO, AZO) or transparent conductive polymers, carbon nanotubes, graphene, and other materials. Its design must balance conductivity, light transmittance, and interface compatibility with the electrochromic layer 8.

[0071] Through the above technical solution, the photosensitive structure of this application can efficiently achieve the absorption of incident light and the generation of charge, and provide a clear charge collection and transport path for the electrochromic reaction. The hybrid conductive interface layer 5 can simultaneously provide electrical coupling for charges and ions and complete charge compensation, greatly optimizing the energy and mass transfer efficiency between photoelectric conversion and electrochromic processes. This enables the entire photosensitive structure to more accurately perform self-powered, self-regulating, and self-reactive responses under different illumination conditions.

[0072] Reference Figure 2 This application also discloses that an ion storage layer 6 is disposed between the electrochromic layer 8 and the hybrid conductive interface layer 5.

[0073] The ion storage layer 6 is a material layer capable of reversibly adsorbing and releasing ions. Its main function is to act as a "buffer" or "reservoir" of ions required by the electrochromic layer 8 during its redox reaction. When the electrochromic layer 8 needs ions, the ion storage layer 6 can rapidly release ions; when the electrochromic layer 8 releases ions, the ion storage layer 6 can absorb and store these ions. This design helps maintain a stable ion concentration during the electrochromic reaction, ensuring that the electrochromic layer 8 can efficiently and stably undergo color-changing and fading cycles.

[0074] The ion storage layer 6 can be composed of various materials, such as polymer electrolytes, gel electrolytes, or inorganic materials containing intercalating / deintercalating ions, which have high ionic conductivity and good ion storage capacity. The specific material selection depends on the type of electrochromic material used, the type of ions required (e.g., Li+, H+), and the operating environment and performance requirements of the device. For example, for electrochromic systems requiring lithium ions, the ion storage layer 6 can be made of materials capable of efficiently storing and releasing lithium ions. This layer typically has a certain porous or layered structure to provide sufficient ion transport channels and storage sites. Material systems include oxides with reversible intercalation / deintercalation properties such as V2O5, MoO3, Nb2O5, Prussian blue, or CeO2-TiO2 composite oxides; conductive polymers such as polypyrrole (PPy) and polythiophene (PTh) that store ions through doping / dedoping processes; and carbon-based materials such as activated carbon and graphene that utilize double-layer capacitance to store ions.

[0075] Through the above technical solution, this application can effectively solve the problem of insufficient or unstable ion supply during the electrochromic reaction. The ion storage layer 6, as a dynamic ion pool, can rapidly provide ions when the electrochromic layer 8 needs them and absorb them when the electrochromic layer 8 releases ions, thereby ensuring the continuous and efficient completion of the electrochromic reaction. This not only significantly improves the speed and efficiency of the electrochromic response, enabling the photosensitive structure to respond to light signals and achieve color change more quickly, but also greatly enhances the stability of the electrochromic cycle. Because the ion concentration is effectively buffered during the reaction, performance degradation caused by ion depletion or accumulation is avoided, thereby extending the lifespan of the photosensitive structure and ensuring its reliability in long-term use.

[0076] This application also discloses that an ion transport layer 7 is disposed between the electrochromic layer 8 and the hybrid conductive interface layer 5.

[0077] Specifically, the main function of the ion transport layer 7 is to act as an ion-selective channel, ensuring that ions can be efficiently and directionally transported from the mixed conductive interface layer 5 to the electrochromic layer 8, or vice versa. It also acts as a good insulator for electrons, preventing short circuits caused by electronic coupling. Furthermore, it provides an interface buffer; its elastic or microporous structure absorbs the volume expansion of the two end layers during insertion / extraction, maintaining tight contact between the films.

[0078] This layer can be composed of various materials, requiring high ionic conductivity, low electronic conductivity, and good electrochemical stability. For example, solid electrolytes can be used, such as polymer electrolytes (e.g., polyethylene oxide (PEO)-based electrolytes, polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP)-based electrolytes, inorganic solid electrolytes (e.g., NASICON-type, garnet-type materials), or their composites. Alternatively, gel electrolytes or ion-selective membrane materials can be used. To achieve optical transparency, tantalum oxide, PVDF-HFP gel electrolytes, or lithium phosphorus oxynitride compounds can be employed, achieving a transmittance >85% in the 400–800 nm wavelength range without interfering with the electrochromic effect.

[0079] Through the above technical solution, this application can effectively solve the problem of electron leakage that may occur during charge transport. The ion transport layer 7 acts as an "ion gate," ensuring that only ions can efficiently shuttle between the two layers, while electrons are effectively blocked. This not only improves the efficiency and stability of the electrochromic reaction and avoids energy loss and side reactions caused by electron leakage, but also enables the electrochromic process to respond more accurately to the chemical potential signal output by the mixed conductive interface layer 5, thereby achieving a more stable and reliable self-reactive electrochromic function.

[0080] This application also discloses that an electron transport layer 2 is disposed between the front-transmitting conductive layer 1 and the light-absorbing layer 3.

[0081] Electron transport layer 2 is a semiconductor functional thin film whose main function is to promote the efficient and directional transport of electrons from light-absorbing layer 3 to the conductive layer, while effectively suppressing the reverse transport of holes. This layer is typically composed of materials with high electron mobility and suitable energy level alignment, such as zinc oxide (ZnO), titanium dioxide (TiO2), fullerene derivatives (e.g., PCBM), or specific organic semiconductor materials. Electron transport layer 2 can be optimized according to the specific light-absorbing material and device structure to ensure optimal electron transport performance and interface matching. By introducing electron transport layer 2, an optimized transport channel for photogenerated electrons can be provided, reducing the recombination probability of electrons at the interface and forming an energy level gradient conducive to electron transport.

[0082] Through the above technical solution, this application can effectively collect photogenerated electrons generated by the light absorption layer 3 and efficiently transport them to the front transparent conductive layer 1. Simultaneously, the electron transport layer 2 can effectively block the reverse transport of holes, thereby significantly suppressing electron-hole recombination and reducing charge loss. This significantly improves the photoelectric conversion efficiency of the photoelectric conversion structure, enabling the generation of stronger electrical signals and more abundant electrical energy. It also more effectively drives the electrochromic structure of the back-end layer to undergo a reversible redox reaction, achieving a more sensitive and efficient self-reactive closed-loop structure.

[0083] This application also discloses that a hole transport layer 4 is disposed between the light absorption layer 3 and the hybrid conductive interface layer 5.

[0084] Hole transport layer 4 is a functional thin film whose main function is to promote hole transport and block electron transport.

[0085] Specifically, this layer material has a high hole mobility and a suitable energy level structure, which can effectively extract holes from the light absorption layer 3 and guide them to the hybrid conductive interface layer 5. At the same time, its energy level arrangement can form a potential barrier for electrons, thereby inhibiting electrons from the hybrid conductive interface layer 5 back-injection into the light absorption layer 3, or inhibiting electron recombination at the interface between the light absorption layer 3 and the hole transport layer 4.

[0086] The hole transport layer 4 can be composed of various materials. For example, organic semiconductor materials such as poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) and 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamino)-9,9'-spirodifluorene (Spiro-OMeTAD) can be used. In addition, inorganic semiconductor materials such as nickel oxide (NiO) and copper thiocyanate (CuSCN) can also be used. The selection of these materials is typically based on their energy level matching, hole mobility, thin film formation capability, and compatibility with adjacent layers. The thickness of the hole transport layer 4 is typically controlled in the range of tens to hundreds of nanometers to minimize obstruction to light absorption while ensuring effective hole transport.

[0087] Through the above technical solution, this application can significantly optimize the charge transport process inside the photoelectric conversion structure. Specifically, the hole transport layer 4 can efficiently collect photogenerated holes generated in the light absorption layer 3 and rapidly transport them to the hybrid conductive interface layer 5, thereby effectively accelerating charge separation. At the same time, the blocking effect of the hole transport layer 4 on electrons can significantly suppress electron-hole recombination and reduce charge loss. Therefore, the photoelectric conversion efficiency of this photosensitive structure is significantly improved, and the enhanced electrical energy drives the electrochromic structure of the back-end layer to undergo a reversible redox reaction more effectively through the hybrid conductive interface layer 5, making the entire self-reactive closed-loop structure more sensitive and stable in performance, thus achieving a more efficient and reliable self-reactive electrochromic function.

[0088] Reference Figure 3 This application also proposes a self-reactive photosensitive device, which includes the above-mentioned photosensitive structure, wherein the front transparent conductive layer 1 and the rear transparent conductive layer 9 extend beyond the functional layer region to form an electrode lead-out area, and a conductive bridging channel 10 is provided between the electrode lead-out areas of the front transparent conductive layer 1 and the rear transparent conductive layer 9. The conductive bridging channel 10 is used for charge transfer between the front transparent conductive layer 1 and the rear transparent conductive layer 9 to form a self-driven circuit.

[0089] The conductive bridging channel 10 refers to a physical path in a self-reactive photosensitive device that provides a pathway for charge (e.g., electrons or holes) to travel from the front transparent conductive layer 1 to the rear transparent conductive layer 9, or vice versa. This channel is typically constructed from materials with good conductivity, such as metallic wires, conductive polymers, carbon-based materials (e.g., graphene, carbon nanotubes), or transparent conductive oxides (e.g., ITO, FTO). Its design aims to ensure that charge can move efficiently and with low loss between the two key electrode layers, thereby completing the entire electrochemical cycle.

[0090] The function of the conductive bridging channel 10 is to establish an electrical connection between the front transparent conductive layer 1 and the rear transparent conductive layer 9, so that the charge generated by the photoelectric conversion structure of the front layer and collected on the front transparent conductive layer 1 can be effectively transferred to the rear transparent conductive layer 9 required by the electrochromic structure of the rear layer. This completes the circuit loop within the structural layer, simplifying the overall design of the device and forming a zero-bias integrated self-driven device. Charge transfer is a key step in driving the reversible oxidation-reduction reaction of the electrochromic structure. By providing a clear, low-resistance transmission path, the conductive bridging channel 10 ensures that the electrical energy generated by light energy conversion can be effectively utilized, thereby achieving self-driven control of the electrochromic process.

[0091] Through the above technical solution, this application solves the problem of the lack of a compact and efficient directional transport path between the charge generated by photoelectric conversion and the charge required for the electrochromic reaction in photosensitive structures. The conductive bridging channel 10 provides a simplified, compact, and complete closed circuit, enabling the electrical energy generated by the front-end photoelectric conversion structure to be efficiently guided to the back-end electrochromic structure, thereby driving a reversible redox reaction. This achieves the function of a zero-bias integrated self-driven photosensitive device.

[0092] This application also discloses that an insulating isolation layer 11 is provided between the conductive bridging channel 10 and the light absorption layer 3, the mixed conductive interface layer 5 and the electrochromic layer 8.

[0093] The insulating layer 11 is a material layer with high resistivity. Its core function is to prevent current from passing through, thereby achieving effective electrical isolation between different conductive areas.

[0094] In this application, an insulating layer 11 is disposed between the conductive bridging channel 10 and the light-absorbing layer 3, the mixed conductive interface layer 5, and the electrochromic layer 8. Its function is to prevent unintended charge transfer or short circuits between these critical functional layers and the conductive bridging channel 10, ensuring that each layer can independently and efficiently perform its preset function. The insulating layer 11 can be implemented in various ways. In terms of material selection, inorganic dielectric materials such as silicon oxide, silicon nitride, and alumina can be used, as these materials typically possess excellent dielectric properties, thermal stability, and chemical inertness. Alternatively, organic polymer materials such as polyimide, epoxy resin, and polymethyl methacrylate (PMMA) can be selected, as they exhibit good applicability in flexible devices. Regarding the fabrication process, thin film deposition techniques, such as physical vapor deposition (PVD), chemical vapor deposition (CVD), or atomic layer deposition (ALD), can be used to form a uniform and dense insulating film. For polymer materials, patterning can be achieved through spin coating, spraying, or printing. In practical applications, the thickness, dielectric strength, and adhesion to adjacent layers of the insulating isolation layer 11 are key parameters that need to be considered during design and fabrication to ensure that it can provide sufficient electrical isolation and guarantee the long-term reliability of the device.

[0095] Through the above technical solution, this application effectively blocks potential charge leakage paths between the conductive bridging channel 10 and each active functional layer by setting an insulating isolation layer 11. This ensures that the photogenerated charges generated by the photoelectric conversion structure can be efficiently transferred to the electrochromic structure along a predetermined path, i.e., through the conductive bridging channel 10, without being lost due to bypass or short circuit during transmission. Therefore, the internal electrical isolation of the device is enhanced, and the mechanical strength is also improved, avoiding device performance instability or functional failure caused by charge crosstalk, thereby improving the long-term operational stability and reliability of the device.

[0096] Reference Figure 4 This application also proposes an active control type photosensitive device, which includes the above-mentioned photosensitive structure and further incorporates an external circuit and a control switch. The external circuit is electrically connected to the front transparent conductive layer 1 and the rear transparent conductive layer 9 of the photosensitive structure to form a controllable external current path; the control switch is connected in series in the external circuit to connect or disconnect the current path.

[0097] Specifically, the external circuit refers to the electrical loop connected to the outside of the photosensitive structure, and its function is to provide a controllable charge transport path for the photosensitive structure. This external circuit can be composed of electronic components such as wires, resistors, capacitors, and inductors. Its core function is to connect the front transparent conductive layer 1 and the rear transparent conductive layer 9 of the photosensitive structure to form a complete current loop. This connection method allows external power supplies or control signals to electrically intervene in the photosensitive structure through this path. For example, voltage can be applied or current injected through the external circuit, thereby affecting the charge transport and electrochromic reaction inside the photosensitive structure.

[0098] A control switch is a device used to control the on / off state of a circuit. This control switch can be a mechanical switch, such as a push-button switch or toggle switch, or an electronic switch, such as a transistor, relay, or MOSFET. Its core function is to selectively establish or interrupt a current path in an external circuit based on external commands. When the control switch is on, the external circuit forms a closed loop, allowing current to flow; when the control switch is off, the external circuit is broken, preventing current flow.

[0099] Through the above technical solution, this application enables active control of the working state of the photosensitive structure. When the control switch is connected, the external circuit forms a closed loop, allowing the photosensitive structure to perform photoelectric conversion and electrochromic reactions normally, realizing its self-reactive function. When the control switch is disconnected, the external circuit is broken, which can effectively prevent or interrupt the charge transfer and electrochromic process inside the photosensitive structure, thereby stopping its response or maintaining it in a specific state. This active control capability makes the application scenarios of the photosensitive device more flexible. For example, the photosensitive function can be selectively activated or disabled according to user needs or system instructions, avoiding unnecessary energy consumption or misoperation, and improving the intelligence and adaptability of the device.

[0100] This application also discloses that, based on the above-mentioned active control type photosensitive device, an additional control component 12 is provided. The control component 12 is connected in series in the external circuit and is used to adjust the voltage intensity of the external circuit to achieve further intervention and control of the electrochromic reaction.

[0101] The control component 12 is a device or module capable of adjusting electrical parameters such as voltage and current in a circuit. Its core function is to influence the voltage across the electrochromic layer 8 in the photosensitive structure by changing the voltage intensity of the external circuit, thereby achieving precise control over the rate and extent of the oxidation-reduction reaction in the electrochromic structure. This control component 12 can be implemented in various ways. For example, it can be a variable resistor or potentiometer, adjusting the output voltage by changing its resistance; it can also be a DC-DC converter, such as a buck or boost converter, which can efficiently convert the input voltage to the desired output voltage and allows for programmable adjustment; or it can be a pulse width modulation (PWM) controller, which changes the effective value of the output voltage by rapidly switching the power supply, thereby achieving voltage regulation. Regardless of the method used, the design of the control component 12 must consider its voltage regulation range, accuracy, power consumption, and compatibility with the overall system to ensure that it can effectively achieve fine-grained control over the response characteristics of the photosensitive device.

[0102] Through the above technical solution, this application uses control component 12 to adjust the voltage intensity of the external circuit, thereby precisely controlling the voltage across the electrochromic layer 8 in the photosensitive structure. This allows the redox reaction in the electrochromic structure to be adjusted in multiple stages, continuously, or gradually according to actual needs, rather than simply being turned on or off. For example, the color depth or transparency of the electrochromic layer 8 can be actively adjusted based on ambient light intensity, user preferences, or specific application scenarios. This refined voltage intensity adjustment capability greatly enhances the control flexibility, programmability, and functional diversity of the actively controlled photosensitive device, enabling it to adapt to a wider range of application scenarios and provide more intelligent and personalized visual effects or energy management functions. This effectively solves the technical problem that on / off control alone cannot meet the needs of fine adjustment, realizing the function of actively adjusting the degree of photochromic color change within a certain range.

[0103] In other embodiments, a front external encapsulation layer and a rear external encapsulation layer structure can also be provided. The front external encapsulation layer and the rear external encapsulation layer are used to protect the functional layer of the photosensitive structure, completely isolating the functional layer from external moisture and oxygen, and ensuring the material life. Specifically, high barrier glass or composite film can be used in conjunction with edge sealant (such as butyl rubber).

[0104] The working principle of this application is as follows:

[0105] This application provides a photosensitive structure that utilizes the photovoltaic effect to generate electron-hole pairs in the light absorption layer 3 by exciting photons of incident light. These pairs are then separated into free electrons and holes under the influence of a built-in electric field. Through a hybrid conductive interface layer 5, charge-ion coupling is performed, translating the electrons into mobile charged ions. This compensates for the charge at the front end and outputs the chemical potential of the ions, providing an ion source for the reaction in the electrochromic layer 8. This drives a reversible electrochemical redox reaction in the electrochromic layer 8, altering its band structure and light absorption characteristics, resulting in a shift in the transmission spectrum and color switching. Changes in light intensity within the absorption wavelength range of the light absorption layer 3 cause changes in the number of excitons and charge carriers, creating a corresponding potential difference in the closed circuit. This potential difference, after conversion, influences the redox degree of the electrochromic layer 8, making the color-changing depth of the device correspond to the incident light intensity. This achieves a self-powered, self-adjusting, and visually responsive design, forming a complete cyclic system that can complete light response and optical changes without external intervention.

[0106] The entire structure utilizes a highly transparent photoelectric conversion structure and a transparent hybrid conductive interface to make the electrochromic layer 8 uniformly colored, thus achieving photosensitivity. This structure leverages the characteristics of strong electric field driving, low interface impedance, and short ion migration path of the electrochromic reaction to achieve millisecond-level response, overcoming the problems of electrochromism requiring external power supply and lacking light intensity sensing.

[0107] This photosensitive structure solves the problem of sluggish response in existing photosensitive materials, exhibiting rapid dynamic response capability. Due to the diversity of photoelectric conversion structures, this photosensitive structure possesses the ability to extend the spectral response range. The absorption spectrum can be modulated by designing the material of the photoelectric conversion structure, thereby responding to changes in light intensity across different ranges. This overcomes the limitation of existing photosensitive materials that are only sensitive to ultraviolet light. Thus, it solves the problem of poor spectral adaptability of existing photosensitive materials, possessing broad spectral adaptability.

[0108] In summary, the self-reactive photosensitive device provided in this application includes the aforementioned photosensitive structure. By adding a conductive bridging channel 10 between the extended electrode lead-out areas of the front transparent conductive layer and the rear transparent conductive layer, and using an insulating isolation layer 11 to achieve effective electrical isolation from other active functional layers, a three-dimensional integrated structure with electrode lead-out areas + conductive bridging layer + insulating isolation layer 11 is formed. The circuit closed loop is completed within the structural layers, which simplifies the overall design of the device and forms a zero-bias integrated self-driven device.

[0109] This application provides an actively controlled photosensitive device that achieves interventionist active control through external voltage regulation via an external circuit. By changing the voltage intensity of the external circuit, the voltage across the electrochromic layer 8 in the photosensitive structure is affected, enabling precise control over the rate and extent of the redox reaction in the electrochromic structure. This allows for the active adjustment of the color depth or transparency of the photosensitive structure according to actual needs, achieving the function of actively adjusting the degree of photochromic change within a certain range.

[0110] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A photosensitive structure, characterized in that, It includes a front-end layer, a hybrid conductive interface layer, and a back-end layer stacked sequentially along the optical path; The front-end layer includes a photoelectric conversion structure for converting incident light into an electrical signal. The front-end layer adopts a high-transmittance photoelectric conversion structure. A hybrid conductive interface layer is used to connect the front-end layer and the back-end layer to form a self-driven charge transport channel. The hybrid conductive interface layer is made of a transparent material. The back-end layer includes an electrochromic structure, and the electrical energy generated by the front-end layer drives the electrochromic structure to undergo a reversible redox reaction.

2. The photosensitive structure according to claim 1, characterized in that, The photoelectric conversion structure includes a front light-transmitting conductive layer and a light-absorbing layer arranged sequentially from the optical path direction; The electrochromic structure includes an electrochromic layer and a back-transmitting conductive layer arranged sequentially from the optical path direction.

3. The photosensitive structure according to claim 2, characterized in that, An ion storage layer is disposed between the electrochromic layer and the hybrid conductive interface layer.

4. A photosensitive structure according to claim 2, characterized in that, An ion transport layer is disposed between the electrochromic layer and the hybrid conductive interface layer.

5. A photosensitive structure according to claim 2, characterized in that, An electron transport layer is disposed between the front light-transmitting conductive layer and the light-absorbing layer.

6. A photosensitive structure according to claim 2, characterized in that, A hole transport layer is disposed between the light absorption layer and the hybrid conductive interface layer.

7. A self-reactive photosensitizing device, characterized in that, Including the photosensitive structure as described in any one of claims 2-6, the front transparent conductive layer and the rear transparent conductive layer extend beyond the functional layer region to form an electrode lead-out area, and there is a conductive bridging channel between the electrode lead-out areas of the front transparent conductive layer and the rear transparent conductive layer, the conductive bridging channel being used for charge transfer between the front transparent conductive layer and the rear transparent conductive layer to form a self-driven circuit.

8. A self-reactive photosensitizing device according to claim 7, characterized in that, An insulating layer is provided between the conductive bridging channel and the light absorption layer, the hybrid conductive interface layer and the electrochromic layer.

9. An actively controlled photosensor, characterized in that, include: The photosensitive structure as described in any one of claims 2-6; The external circuit is electrically connected to the front and rear light-transmitting conductive layers of the photosensitive structure to form a controllable current path. A control switch is connected in series in the external circuit and is used to connect or disconnect the current path.

10. The actively controlled photosensitive device according to claim 9, characterized in that, Also includes: A control component, connected in series in the external circuit, is used to adjust the voltage level of the external circuit.

Images