A space-oriented photovoltaic CIGS-perovskite four-terminal laminated component, solar wing and system

Abstract

The application discloses a CIGS-perovskite four-terminal laminated component for space photovoltaics, a solar wing and a system. The component comprises a CIGS bottom cell and a perovskite top cell which are independently prepared, and the two are connected through space-grade adhesive low-temperature curing to form an interconnection layer and realize physical lamination; four terminals of the two cells are independently led out without sharing a circuit. A flexible solar wing constructed based on an array of the components has a flexible form capable of multi-dimensional storage and flat expansion; a corresponding photovoltaic energy system adopts double-path independent MPPT control and energy storage dynamic scheduling logic to cooperatively cope with space illumination changes. The application breaks through the limitations of large volume, unbending and two-terminal laminated current mismatch of traditional rigid cells, can effectively absorb in-orbit thermal expansion and cold contraction deformation, realizes high power-to-quality ratio and light weight, and meets the needs of high-power satellite-borne equipment and large-scale satellite networking.

Description

Technical Field

[0001] This invention relates to the field of space photovoltaic and new energy technology, and more specifically to a CIGS-perovskite four-terminal stacked module, solar array and system for space photovoltaic. Background Technology

[0002] The aerospace field is currently experiencing rapid development of high-power satellites and onboard AI computing payloads, which has created an urgent demand for space photovoltaic power sources in terms of large area, high power-to-weight ratio and low cost.

[0003] Current mainstream technologies, represented by rigid triple-junction gallium arsenide solar cells (GaAs solar cells), suffer from poor adaptability to large sizes due to their rigid structure. To construct ultra-large-scale spatial arrays of hundreds of square meters, thousands of independent cells need to be spliced ​​together, which not only increases structural complexity but also significantly increases the deployment failure rate. Currently, there is no mature 600m... 2 Case studies of on-orbit applications of GaAs solar panels; Meanwhile, GaAs batteries are relatively heavy, with an overall power-to-weight ratio generally only 150-180 W / kg, making it difficult to meet the energy requirements of high-power satellites. Furthermore, a system of this size, covering hundreds of square meters, costs as much as 150,000 to 200,000 yuan per square meter, significantly increasing both weight and cost, thus raising the overall cost of satellite manufacturing and launch. In addition, this technology lacks flexibility. sex Storage and fairing space are large, making it difficult to adapt to the application scenarios of commercial aerospace, such as launching multiple satellites and ultra-large solar arrays. On the other hand, although single-junction flexible copper indium gallium selenide (CIGS) or perovskite technology has the advantage of flexibility, it is limited by band gap and has low conversion efficiency. Traditional two-end stacked structures also have current matching constraints, making it impossible for existing solutions to achieve both high efficiency and flexibility. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a CIGS-perovskite four-terminal stacked module, solar array, and system for space photovoltaics.

[0005] In a first aspect, the present invention provides a CIGS-perovskite four-terminal stacked module for space photovoltaics, which adopts the following technical solution: A CIGS-perovskite four-terminal stacked module for space photovoltaics includes: a CIGS bottom cell and a perovskite top cell stacked on top of each other; the CIGS bottom cell and the perovskite top cell are independently fabricated and physically laminated together by an interconnect layer formed by curing an adhesive to form a four-terminal stacked structure; the perovskite top cell leads out independent negative and positive electrodes, and the CIGS bottom cell leads out independent negative and positive electrodes. The two sets of cells each have independent current charging, and their circuits are not connected to each other and have no shared loop; The adhesive is an aerospace-grade adhesive, which refers to low-temperature curing RTV silicone rubber suitable for the aerospace field. Its performance parameters are as follows: 1) Total mass loss <0.1-1.0%; 2) Shear strength after curing is 4.0-6.0 MPa; 3) Working temperature is -115~260℃; 4) Elongation at break is 100-200%; 5) Coefficient of thermal expansion is 200-300 ppm.

[0006] Furthermore, the CIGS-perovskite four-terminal stacked module for space photovoltaics includes: flexible perovskite-flexible CIGS, flexible perovskite-rigid CIGS, and rigid perovskite-flexible CIGS combined structures.

[0007] Furthermore, the CIGS bottom cell has a layer-by-layer stacked structure from bottom to top, specifically consisting of a flexible encapsulation layer, a protective layer, a substrate layer, a back electrode layer, a CIGS absorption layer, a buffer layer, a first transparent conductive layer, and a flexible encapsulation layer.

[0008] Wherein, when the CIGS bottom cell is a rigid structure, the substrate layer is a radiation-resistant glass with a thickness of 50-300μm; when the CIGS bottom cell is a flexible structure, the substrate layer is a polyimide film that has been activated by surface plasma cleaning and magnetron sputtering and has a Na barrier layer and a stress buffer layer deposited thereon. The back electrode layer is a Mo layer with a thickness of 500-800 nm deposited by DC magnetron sputtering and subjected to segmented annealing at 350-400℃ to eliminate internal stress; the CIGS absorber layer is a thin film with a thickness of 1.6-2.0 μm deposited at a substrate temperature of 380-460℃ by a three-step co-evaporation method or a sputtering-selenization method, and has a regulated Ga gradient and Na co-doped structure; the buffer layer is a CdS layer with a thickness of 30-50 nm formed by chemical bath deposition, or a Zn(O,S) or In2S3 cadmium-free buffer layer formed by atomic layer deposition; the first transparent conductive layer is composed of an i-ZnO layer with a thickness of 30-50 nm deposited by magnetron sputtering and a ZnO:Al or ITO layer with a thickness of 300-500 nm.

[0009] Furthermore, the perovskite top solar cell has a layer-by-layer stacked structure from bottom to top, specifically consisting of a flexible encapsulation layer, a protective layer, a substrate layer, a second transparent conductive layer, a hole transport layer, a perovskite layer, an electron transport layer, a third transparent conductive layer, a protective layer, and a flexible encapsulation layer.

[0010] Wherein, when the perovskite top solar cell is a rigid structure, the substrate layer is a radiation-resistant glass with a thickness of 50-300μm; when the perovskite top solar cell is a flexible structure, the substrate layer is a polyimide film that has been activated by surface plasma cleaning and magnetron sputtering and has a Na barrier layer and a stress buffer layer deposited thereon. Radiation-resistant glass, also known as aerospace-grade radiation-resistant glass, refers to cerium-doped microcrystalline glass or cerium-doped borosilicate glass coverslips suitable for the aerospace field, resisting ultraviolet radiation, proton / electron radiation, etc. Key component indicators are as follows: 1) Cerium oxide (CeO2) content: 0.5-3.0%, the core radiation-resistant component, absorbing high-energy particles and preventing glass discoloration. 2) Resistance to electron radiation (1MeV, 1x10⁻¹²). 15 e / cm 2 400-1000nm band transmission attenuation <2%; 3) Proton irradiation resistance (10MeV, 1x10 12 p / cm 2 4) Transmission attenuation in the 400-1000nm band <3%; 4) Resistance to ultraviolet radiation (10-year geostationary orbit equivalent ultraviolet dose) Transmission attenuation in the 400-1000nm band <1%.

[0011] The second transparent conductive layer is a thin film formed by depositing a transparent conductive metal oxide layer on the surface, annealing it at 200°C for 5 minutes, and then cooling it to room temperature. Its preparation process is a combination of one or more of the following deposition processes: magnetron sputtering, reactive plasma sputtering, electron beam deposition, atomic layer deposition, and chemical vapor deposition. The transparent conductive metal oxide includes one or more of the following: indium tin oxide (ITO), fluorine-doped tin oxide (FTO), indium tungsten oxide (IWO), and indium zinc oxide (IZO). The hole transport layer is a material layer with a thickness of 10 nm deposited on the surface of the conductive layer by a combination of one or more processes, including spin coating, blade coating, slot coating, screen printing, magnetron sputtering, reactive plasma deposition, atomic layer deposition, and chemical vapor deposition; wherein the material of the hole transport layer includes one or more of nickel oxide (NiOx), polytriarylamine (PTAA), cuprous thiocyanate (CuSCN), poly(3,4-ethylenedioxythiophene):polystyrene sulfonate composite (PEDOT:PSS), and molybdenum disulfide (MoS2); The perovskite layer is formed by depositing a perovskite precursor film on the surface of the hole transport layer through a combination of one or more processes, including spin coating, blade coating, slot coating, screen printing, and thermal evaporation coating. The film is then solvent-extracted and annealed at 100-200°C for 10-30 minutes to form a film with a thickness of 1 μm. The solvent extraction process includes one or more of vacuum chamber drying (VCD), air knife purging, and anti-solvent methods. The perovskite film material includes one or more of formamidinium perovskite, methylamino perovskite, and cesium-based perovskite. The electron transport layer is a material layer formed on the surface of the perovskite layer by a combination of one or more processes, including spin coating, blade coating, slot coating, screen printing, magnetron sputtering, reactive plasma deposition, atomic layer deposition, and chemical vapor deposition; wherein the electron transport layer material includes one or more of tin oxide (SnOx), fullerene (C60), titanium oxide (TiO2), zinc oxide (ZnO), and fullerene derivatives (PCBM); The third transparent conductive layer is an electrode layer prepared on the surface of the electron transport layer by a combination of one or more processes, namely thermal evaporation coating, magnetron sputtering and plasma deposition; wherein the material of the electrode layer includes gold, silver, copper and one or more of ITO, FTO, IWO and IZO.

[0012] In some embodiments, the flexible encapsulation layer is a water- and oxygen-barrier polyimide film or an aluminum vapor-deposited polyester film, and the edges are sealed with UV-curable sealant; the protective layer is a 20nm thick SiNx layer and a 20nm thick Al2O3 layer deposited alternately by plasma-enhanced chemical vapor deposition and magnetron sputtering technology. Water- and oxygen-barrier polyimide film is an aerospace-grade water- and oxygen-barrier polyimide film. It refers to a colorless, transparent polyimide film suitable for the aerospace field, resisting ultraviolet radiation, proton / electron irradiation, etc. Key component indicators are as follows: 1) Resistance to electron irradiation (1 MeV, 1x10⁻¹⁰). 15 e / cm 2 1) Transmission attenuation <2% in the 400-1000nm band; 2) Proton irradiation resistance (10MeV, 1x10 12 p / cm 2 3) Transmission attenuation in the 400-1000nm band <3%; 4) Resistance to ultraviolet radiation (10-year geostationary orbit equivalent ultraviolet dose) Transmission attenuation in the 400-1000nm band <1%.

[0013] Furthermore, the CIGS-perovskite four-terminal tandem module for space photovoltaics is fabricated by the following method: S1. CIGS bottom cells and perovskite top cells were prepared independently, and single-cell testing and screening were performed. S2. On the surface of the first transparent conductive layer of the CIGS bottom cell that has passed the test, aerospace-grade adhesive is uniformly coated. Then the perovskite top cell is placed in the alignment fixture so that its third transparent conductive layer faces down and is precisely aligned with the first transparent conductive layer. S3. The laminated components are then subjected to thermal curing or UV curing at a temperature not exceeding 100°C to form the interconnect layer, thereby preventing the perovskite material from being degraded by heat and completing the physical lamination of the four-end stacked components. S4. The third transparent conductive layer and the second transparent conductive layer of the perovskite top cell are respectively connected to an independent busbar by conductive adhesive or ultrasonic welding to serve as the negative and positive electrodes of the top cell. The back electrode layer and the first transparent conductive layer of the CIGS bottom cell are respectively connected to an independent busbar by conductive adhesive or ultrasonic welding to serve as the negative and positive electrodes of the bottom cell, ensuring that the four sets of terminals are not connected to each other. S5. Apply aerospace-grade silicone resin or epoxy resin sealant to the four edges of the completed four-terminal lead-out module. If necessary, perform edge-wrapping welding of aluminum vapor deposition barrier film treatment to complete edge encapsulation and obtain the CIGS-perovskite four-terminal stacked module for space photovoltaics.

[0014] Secondly, the flexible solar array for space photovoltaics provided by this invention adopts the following technical solution: A flexible solar panel for space photovoltaics includes: a flexible support substrate for the solar panel, using an aerospace-grade high and low temperature resistant yellow PI film as the substrate (specific requirements are as follows: 1. Operating temperature range tolerance -269~+280℃; 2) Tensile strength > 180MPa; 3. Elongation at break > 30%, dielectric strength > 150 kV / mm); and a CIGS-perovskite four-terminal stacked module array for space photovoltaics, as described above, bonded to the surface of the substrate in a matrix arrangement using an aerospace-grade adhesive; aerospace-grade Kovar electrodes (Kova alloy grade: GB / T 15018 4J29, key indicators: 1) Coefficient of thermal expansion 4.6-5.2 ppm / K (30-40℃) matching the glass; 2) Helium leakage rate < 1×10 -9 Pa m 3 / s; 3) Thermal cycling stability (-150~+150℃), >3000 cycles without failure), and a large-area photovoltaic array surface is formed by interconnection through flexible wires; the overall thickness of the solar wing is controlled between 0.1-10mm.

[0015] Thirdly, the satellite photovoltaic energy system provided by this invention adopts the following technical solution: A satellite photovoltaic energy system includes: a flexible photovoltaic subsystem, a maximum power point tracking (MPPT) energy control subsystem, and an energy storage subsystem; wherein the flexible photovoltaic subsystem is composed of the flexible solar array for space photovoltaics described in the second aspect above; The flexible photovoltaic subsystem is electrically divided into a top perovskite cell array and a bottom CIGS cell array that are physically and electrically isolated from each other, for independently outputting a first DC power and a second DC power respectively. The MPPT energy control subsystem includes a first maximum power point tracker, a second maximum power point tracker, and a primary bus voltage regulation and current combiner module. The input of the first maximum power point tracker is independently connected to the top perovskite solar cell array to track the maximum power point of the top cell in real time and perform DC-DC power conversion on the first DC power supply. The input of the second maximum power point tracker is independently connected to the bottom CIGS solar cell array to track the maximum power point of the bottom cell in real time and perform DC-DC power conversion on the second DC power supply. The two DC power supplies after power conversion are jointly output to the primary bus voltage regulation and current combiner module for current combining and voltage regulation to supply power to the satellite load. The energy storage subsystem includes a charge / discharge regulation module and an aerospace-grade lithium-ion battery pack (specifically, a battery pack composed of 18650 lithium batteries, with the following key indicators: 1) nominal voltage 3.6V; 2) energy density > 130 Wh / kg; 3) cycle life > 500 cycles; 4) calendar life > 7 years; 5) no explosion / fire after nail penetration / external short circuit; 6) capacity decay < 10% after radiation resistance > 50 krad (Si). The aerospace-grade lithium-ion battery pack is bidirectionally electrically connected to the primary bus voltage regulator module through the charge / discharge regulation module, so as to absorb and store electrical energy during the solar irradiation period when the photovoltaic output power is abundant, or to discharge to the primary bus voltage regulator module when the photovoltaic output power is insufficient or during the shadow period.

[0016] Furthermore, the satellite photovoltaic energy system is equipped with dynamic energy scheduling and control logic based on the alternating environment of space illumination and Earth shadow, specifically including the following steps: 1) Dual-path independent tracking and merging: When the satellite is in sunlight, the first maximum power point tracker and the second maximum power point tracker are activated simultaneously to independently track the top perovskite battery array and the bottom CIGS battery array, respectively, so that the two battery arrays output the optimal power. The dual DC power is merged into the primary bus voltage stabilization and merging module after the DC-DC power conversion. 2) Power supply and charging scheduling under sufficient sunlight: The system makes judgments based on real-time collected power data. If the total photovoltaic power is greater than or equal to the load demand power, the primary bus voltage stabilization and current combiner module will prioritize powering the satellite load. The surplus power will be used to perform constant current or constant voltage charging on the aerospace-grade lithium-ion battery pack through the charge and discharge regulation module. During the charging process, if the aerospace-grade lithium-ion battery pack is detected to be fully charged, the shunt regulator will be activated to modulate and dissipate the excess energy to maintain the stability of the bus voltage. 3) Joint power supply scheduling under insufficient sunlight: If insufficient sunlight causes the total photovoltaic power to be less than the load demand power, the discharge function of the charge and discharge regulation module will be activated immediately, and the aerospace-grade lithium-ion battery pack will supplement the difference in power, and jointly supply power to the satellite load with the flexible photovoltaic subsystem; 4) Full energy storage power supply scheduling during the shadow period: When the satellite enters the shadow period and the system determines that there is no light, the operation of the first maximum power point tracker and the second maximum power point tracker is stopped, and the system is completely switched to the energy storage power supply mode. The aerospace-grade lithium-ion battery pack is fully and independently discharged to ensure that all subsystems of the satellite and high-power onboard (AI computing payload) receive a stable power supply that is uninterrupted throughout the day.

[0017] In summary, the present invention has the following beneficial effects: 1. The CIGS-perovskite four-terminal flexible tandem photovoltaic module of the present invention has a basis weight ≤ 1.0 kg / m³. 2 This is far lower than the 3.0-4.0 kg / m³ of existing aerospace-grade GaAs rigid batteries. 2 Furthermore, the overall thickness of the component is controlled between 0.1-10mm. Its excellent flexibility supports repeated winding and bending operations, which solves the physical defects of traditional rigid GaAs batteries that are bulky and inflexible. It can also significantly reduce the volume occupied by the fairing during spacecraft launch and is highly compatible with various space satellite platforms. 2. This invention employs a four-terminal stacked physical lamination structure, effectively breaking through the photoelectric conversion efficiency limit of single-junction solar cells. In ultra-large-scale applications at the hundred-square-meter level, the overall power-to-weight ratio of the system jumps to ≥350W / kg, theoretically reaching over 2000W / kg, and the power surface density is ≥250W / m². 2 This matches and ensures the energy supply needs of high-power equipment such as high-power spaceborne AI computing payloads in the future; 3. Unlike conventional roll-to-roll processes, the CIGS bottom cell and perovskite top cell in this invention are both fabricated independently with a single-cell inspection and screening mechanism. This process effectively avoids the accumulation and transmission of defects at the bottom layer, and the process control precision is extremely high, ensuring that the photovoltaic modules have excellent consistency and high yield, meeting the stringent aerospace-grade high reliability application standards. 4. The flexible solar array provided by this invention breaks through the physical limitation of traditional rigid solar arrays in terms of deployment area, matches the construction requirements of ultra-large area solar arrays of hundreds of square meters, compresses the storage space of solar arrays, and fits the batch networking and high-density launch mode of "one rocket, multiple satellites" in the commercial aerospace era. 5. The CIGS-perovskite four-terminal flexible tandem photovoltaic module involved in this invention does not rely on the expensive epitaxial growth process in the traditional GaAs scheme. The scheme consumes less raw materials and has low energy consumption in preparation, which makes the overall manufacturing cost of the 100-square-meter system decrease exponentially, making it extremely suitable for the commercial mass application of large-scale low-orbit satellite Internet networking in the future. 6. At the electrical control level, the four terminals are independently led out and combined with dual-path MPPT control, avoiding the risk of series current mismatch faced by traditional two-terminal stacked batteries; the bottom CIGS battery naturally has excellent resistance to space radiation stability, ensuring long-term on-orbit operation life. In addition, the energy system is compatible with existing satellite platforms in terms of electrical and mechanical interfaces, and can serve as a direct and seamless replacement upgrade solution for traditional rigid solar panels. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the CIGS / perovskite four-terminal flexible stacked assembly provided in an embodiment of the present invention, where a is the stacked shape and b is the flexible shape; Figure 2 This is a schematic diagram of a CIGS sub-cell structure provided in an embodiment of the present invention, wherein a is a flexible cell and b is a rigid cell; Figure 3 This is a schematic diagram of a perovskite sub-cell structure provided in an embodiment of the present invention, wherein a is a flexible cell and b is a rigid cell; Figure 4 This is a schematic diagram of the working logic of a satellite photovoltaic energy system provided in an embodiment of the present invention.

[0019] Reference numerals: 101, CIGS bottom cell; 102, interconnect layer; 103, perovskite top cell. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0021] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are all available through conventional commercial channels.

[0022] Example 1: Flexible perovskite-flexible CIGS four-terminal stacked module and solar panel Reference Figure 1 -a、 Figure 1 -b、 Figure 2 -a and Figure 3 -a, This embodiment 1 provides a CIGS-perovskite four-terminal stacked component with a fully flexible structure and its mounted solar array. The specific preparation and assembly steps are as follows: S1. Single-cell fabrication of flexible CIGS bottom cell 101: (1) Substrate pretreatment: A 25μm thick aerospace-grade water- and oxygen-barrier polyimide film was cut as a flexible substrate. After the surface was activated by plasma cleaning, a 30nm thick Al2O3 layer was deposited by magnetron sputtering as a Na barrier layer and an 80nm thick In2S3 layer as a stress buffer layer. (2) Thin film deposition: A 600 nm thick Mo layer was deposited as the back electrode layer by DC magnetron sputtering, and the film was subjected to segmented annealing at 380 °C to release the internal stress of the film. The specific annealing steps were set as follows: first, the temperature was raised from room temperature to 200 °C at a heating rate of 5-8 °C / min and held at the temperature for 30-40 minutes; then, the temperature was raised to 380 °C at a lower heating rate of 3-5 °C / min and held at the temperature for 60-90 minutes; finally, the temperature was cooled naturally to room temperature with the furnace at a cooling rate of no more than 5 °C / min. (3) Absorber and Conductor Layers: Under a substrate temperature of 450℃, a CIGS absorber layer with a thickness of 1.8 μm was deposited using a three-step co-evaporation method (sequentially evaporating In-Ga-Se, Cu-Se, and In-Ga-Se). In the first stage (In-Ga-Se deposition), the initial CIGS deposition layer near the back electrode was designed to have a Ga / (In+Ga) atomic ratio of 0.30-0.35. In the second stage (Cu-Se deposition), the Ga / (In+Ga) ratio was controlled at 0.15-0.20. In the third stage (In-Ga-Se re-deposition), ... To increase the near-surface Ga / (In+Ga) ratio to 0.25-0.30, an independent sodium fluoride (NaF) evaporation source was simultaneously activated, controlling the NaF evaporation rate to 0.1-0.5 Å / s. The total Na atom concentration in the CIGS film after doping was strictly controlled at 0.1-0.5 at% to improve grain quality. Subsequently, a 40 nm thick CdS buffer layer was generated by chemical bath deposition (CBD) at 70 °C. Finally, a 40 nm thick i-ZnO layer and a 350 nm thick ITO layer were sputtered by magnetron sputtering to form the first transparent conductive layer. After the monolithic fabrication was completed, IV performance and appearance screening were performed.

[0023] S2, Monolithic fabrication of flexible perovskite top solar cell 103: (1) Preparation of flexible substrate: Transparent polyimide (PI) slurry is uniformly coated onto a rigid glass slide by slit coating method, and then placed in a 300℃ oven for constant temperature baking for 4 hours to solidify and form a transparent PI film with a thickness of 15μm as the substrate layer. (2) Electrode and transport layer: A 120 nm thick ITO layer is magnetron sputtered on the surface of the transparent PI film to form a second transparent conductive layer. After annealing at 200 °C for 5 min on a heating stage, it is cooled. Subsequently, a 10 nm thick NiOx layer is deposited as a hole transport layer by spin coating. (3) Preparation of perovskite layer: In a glove box, formamidine perovskite (FAPbI3) precursor solution was spin-coated onto the hole transport layer. Chlorobenzene was added dropwise at the 15th second of spin-coating for anti-solvent extraction. Then, it was placed on a heating stage at 150℃ for annealing for 20 min to form a dense perovskite layer with a thickness of 1 μm. (4) Top electrode deposition: A 30 nm thick C60 layer is deposited by thermal evaporation as an electron transport layer, and finally a 100 nm thick IWO layer is sputtered by magnetron sputtering as a third transparent conductive layer.

[0024] S3, Precise physical lamination of wafer to wafer (fabrication of interconnect layer 102): On the surface of the first transparent conductive layer of the CIGS bottom cell 101 that has passed the inspection, aerospace-grade adhesive (SILTRUST™ RTV560-XB) is uniformly coated by screen printing. Using a vacuum alignment fixture, the perovskite top cell 103 (with the third transparent conductive layer facing down) is precisely bonded to the bottom cell. The bonded components are then placed in an 85°C vacuum drying oven for 30 minutes to heat-cur and form a strong physical interconnect layer 102.

[0025] S4, Four-terminal independent lead-out and edge packaging: The third transparent conductive layer (negative electrode) and the second transparent conductive layer (positive electrode) of the perovskite top cell 103, and the back electrode layer (negative electrode) and the first transparent conductive layer (positive electrode) of the CIGS bottom cell 101 are connected to four independent flexible copper foil busbars. Insulation is achieved by applying adhesive to the gap between the conductive layers of the top and bottom cells to ensure that the four terminals do not short-circuit. Aerospace-grade epoxy resin sealant (Tianjin Yanhai HY-914) is applied around the module, and alternating protective layers of 20nm SiNx / 20nm Al2O3 and PI encapsulation layers are applied to the front and back sides to obtain a flexible perovskite-flexible CIGS four-terminal stacked module.

[0026] S5, Solar Panel Array Integration and Assembly: A 30μm thick PI yellow film (DJ-020D from Dajia New Materials) was selected as the flexible support substrate for the solar array. Hundreds of flexible perovskite-flexible CIGS four-terminal stacked module units prepared above were then bonded to the substrate in a matrix arrangement using aerospace-grade adhesive (SILTRUST™ RTV560-XB). Aerospace-grade Kovar electrodes (Kovar alloy grade: GB / T15018 4J29, key indicators: 1) thermal expansion coefficient 4.6-5.2 ppm / K (30-40℃) matching the glass; 2) helium leakage rate <1×10⁻⁶. -9 Pa m 3 / s; 3) Thermal cycling stability (-150~+150℃, >3000 cycles without failure) and flexible wires are connected in series and parallel, and the overall wing thickness is controlled at 0.6mm to obtain the solar wing.

[0027] The flexible photovoltaic module prepared in Example 1 has a single cell weight of only 0.38 kg / m². 2 Tests show that after 2000 cycles of winding with a bending radius of 5mm, the photoelectric conversion efficiency decreases by less than 2%, and the overall power-to-mass ratio of the solar array reaches 850W / kg.

[0028] Example 2: Rigid perovskite-flexible CIGS combined four-terminal stacked module and solar array To cope with the extremely intense radiation environment of deep space, see [link / reference] Figure 1 -a、 Figure 1 -b、 Figure 2 -a and Figure 3 -b, This embodiment 2 provides a combined structure of "rigid top battery + flexible bottom battery" and its mounted solar array.

[0029] S1. Battery fabrication: The fabrication of the flexible CIGS bottom battery was the same as in Example 1.

[0030] Fabrication of a rigid perovskite top solar cell: A 100 μm thick aerospace radiation-resistant glass was selected as a rigid substrate. FTO was sequentially magnetron sputtered on its surface as the second transparent conductive layer, and PTAA was coated as the hole transport layer. A cesium-based perovskite film was deposited using a vacuum chamber drying method and annealed at 180 °C for 15 min to form a 1 μm thick perovskite layer. SnOx was atomically deposited as the electron transport layer, and finally, a 100 nm thick gold grid line was thermally evaporated in conjunction with an ITO film as the third transparent conductive layer.

[0031] S2, UV-cured lamination: A UV-sensitive aerospace-grade adhesive is coated on the surface of the first transparent conductive layer of the bottom cell. After the rigid top cell and the flexible bottom cell are aligned and bonded, constant pressure is applied, and the cells are cured for 5 minutes at room temperature of 25°C using a UV light source with a wavelength of 365nm to form an interconnect layer, thus avoiding damage to the cell structure caused by thermal stress. Subsequently, the four-terminal independent lead-out and edge-sealing encapsulation are completed according to the method of Example 1 to obtain a rigid perovskite-flexible CIGS four-terminal stacked module.

[0032] S3. Solar array integration and assembly: A 30μm thick PI yellow film (DJ-020D from Dajia New Materials) was selected as the flexible support substrate for the solar fin. Hundreds of rigid perovskite-flexible CIGS four-terminal stacked module units prepared above were attached to the substrate in a matrix arrangement using aerospace-grade adhesive (SILTRUST™ RTV560-XB). Aerospace-grade Kovar electrodes (Kovar alloy grade: GB / T15018 4J29, key indicators: 1) thermal expansion coefficient 4.6-5.2 ppm / K (30-40℃) matching the glass; 2) helium leakage rate <1×10-9Pa m3 / s; 3) thermal cycling stability (-150~+150℃), >3000 cycles without failure) were connected in series and parallel with flexible wires. The overall fin thickness was controlled at 0.6mm, thus obtaining the solar fin.

[0033] The four-terminal photovoltaic module prepared in Example 2 has a single cell weight of only 0.86 kg / m². 2 Tests show that after 2000 cycles of winding with a bending radius of 100mm, the photoelectric conversion efficiency decreases by less than 2%, and the overall power-to-mass ratio of the solar array reaches 384W / kg.

[0034] Example 3: Application of energy dispatch and control logic in satellite photovoltaic energy systems Combination Figure 4 Based on the 100-square-meter flexible solar array prepared in Example 1, this invention describes the whole-satellite energy scheduling process including a dual-path MPPT (maximum power point tracking) energy control subsystem and an energy storage subsystem. Assume the fully deployed area of ​​the solar array is 100m². 2 The satellite payload (including AI computing power payload) has a peak power of 15kW and a normal power of 8kW. The system is equipped with an independent first maximum power point tracker (connected to the perovskite array), a second maximum power point tracker (connected to the CIGS array), a primary bus voltage regulator module (bus voltage set to 100V), and a 500Ah aerospace-grade lithium-ion battery pack. The system operates in orbit according to the following control logic: (1) Dual-path tracking and charging under sufficient light conditions: Once the satellite's solar panels deploy and enter the sunlight-exposed area, the first maximum power point tracker rapidly scans the IV curve of the perovskite top cell array and locks in the maximum power point with the higher open-circuit voltage. The second maximum power point tracker simultaneously locks in the maximum power point of the CIGS bottom cell array with the narrower bandgap and higher current. The two DC currents are converted to DC-DC and then converged to the primary bus, with a total output power of 28kW. The system determines that the total photovoltaic power of 28kW is greater than the load demand of 15kW. At this time, the primary bus voltage stabilization and current combining module stably outputs 15kW of power to the satellite load. The charge and discharge regulation module detects that the SOC (state of charge) of the lithium-ion battery pack is 40%. Then, it uses the surplus 13kW of power to charge the lithium-ion battery pack in a "constant current first, then constant voltage" manner. When the SOC reaches 100% full, the charging automatically stops. The system activates the shunt regulator and converts the excess power into heat energy radiated into space through the external dissipation resistor, forcibly maintaining the bus voltage at 100V without exceeding the limit. (2) Seamless power supply with full energy storage during the shadow period: As the satellite moved along its orbit into the Earth's shadow, the light intensity suddenly dropped to 0. The system's power acquisition sensor detected that the total photovoltaic power had dropped below the threshold, and immediately determined that it had entered a state of no light. At this moment, the energy control subsystem quickly shuts down the first and second maximum power point trackers to prevent backflow of bus current, and the charge / discharge regulation module switches from charging mode to discharging mode within milliseconds. The aerospace-grade lithium-ion battery pack, as the sole energy source, takes full control of the bus, and through the discharge regulator, it stabilizes the voltage to 100V, continuously providing a stable 15kW of power to high-power devices such as AI computing loads; (3) Combined power supply under complex spatial attitude / obstruction conditions: When the satellite performs large-scale attitude maneuvers or when part of the wing surface is blocked by the antenna, the incident angle of the photovoltaic array deviates, causing the total photovoltaic power to drop to 10kW. At this time, due to the adoption of a four-terminal independent architecture with physical lamination, even if the CIGS current drops due to partial shading, the MPPT output of the perovskite top cell is still not affected by series mismatch and maintains the maximum possible output. The system determined that the total photovoltaic power was 10kW, which was less than the load requirement of 15kW. The charge and discharge regulation module immediately started the auxiliary discharge function, controlling the lithium-ion battery pack to output 5kW of power to make up the difference. It was connected to the grid and jointly powered with the flexible photovoltaic subsystem of the solar wings, ensuring the safety of the on-board equipment under complex operating conditions.

[0035] The above are all modifications that can be made to this embodiment without contributing any inventive step, or solutions that clearly constitute technical teaching, after reading this specification. However, as long as they are within the scope of the claims of this invention, they should be protected by patent law.

Claims

1. A CIGS-perovskite four-terminal tandem module for space photovoltaics, comprising: The CIGS bottom cell and the perovskite top cell are stacked on top of each other. The CIGS bottom cell and the perovskite top cell are fabricated independently and are physically laminated together by an interconnecting layer formed by curing an adhesive to form a four-terminal stacked structure. The perovskite top cell has independent negative and positive electrodes, and the CIGS bottom cell has independent negative and positive electrodes. The two sets of cells have independent current charging, and their circuits are not connected to each other and have no shared loop.

2. The CIGS-perovskite four-terminal tandem module for space photovoltaics according to claim 1, characterized in that, The component includes any of the following combined structures: flexible perovskite-flexible CIGS combined structure, flexible perovskite-rigid CIGS combined structure, and rigid perovskite-flexible CIGS combined structure.

3. The CIGS-perovskite four-terminal tandem module for space photovoltaics according to claim 2, characterized in that, Both the CIGS bottom cell and the perovskite top cell have a layer-by-layer stacked structure from bottom to top: the CIGS bottom cell is specifically composed of a flexible encapsulation layer, a protective layer, a substrate layer, a back electrode layer, a CIGS absorption layer, a buffer layer, a first transparent conductive layer, and a flexible encapsulation layer from bottom to top; the perovskite top cell is specifically composed of a flexible encapsulation layer, a protective layer, a substrate layer, a second transparent conductive layer, a hole transport layer, a perovskite layer, an electron transport layer, a third transparent conductive layer, a protective layer, and a flexible encapsulation layer from bottom to top.

4. The CIGS-perovskite four-terminal tandem module for space photovoltaics according to claim 3, characterized in that, The specific structural parameters of each film layer of the CIGS bottom battery are as follows: When the CIGS bottom cell is a rigid structure, the substrate layer is a radiation-resistant glass with a thickness of 50-300μm; when the CIGS bottom cell is a flexible structure, the substrate layer is a polyimide film that has been activated by surface plasma cleaning and magnetron sputtering and has a Na barrier layer and a stress buffer layer deposited on it. The back electrode layer is a Mo layer with a thickness of 500-800 nm deposited by DC magnetron sputtering; The CIGS absorber layer is a thin film with a thickness of 1.6-2.0 μm deposited by a three-step co-evaporation method or sputtering-selenization method at a substrate temperature of 380-460℃, and has a regulated Ga gradient and Na co-doped structure. The buffer layer is a CdS layer with a thickness of 30-50 nm formed by chemical bath deposition, or a Zn(O,S) or In2S3 cadmium-free buffer layer formed by atomic layer deposition. The first transparent conductive layer is composed of an i-ZnO layer with a thickness of 30-50 nm deposited by magnetron sputtering and a ZnO:Al or ITO layer with a thickness of 300-500 nm.

5. The CIGS-perovskite four-terminal tandem module for space photovoltaics according to claim 3, characterized in that, The specific structural parameters of each film layer in the perovskite top solar cell are as follows: When the perovskite top solar cell is a rigid structure, the substrate layer is a radiation-resistant glass with a thickness of 50-300 μm; when the perovskite top solar cell is a flexible structure, the substrate layer is a transparent polyimide film with a thickness of 3-50 μm. The second transparent conductive layer is a transparent conductive metal oxide thin film layer, wherein the transparent conductive metal oxide is selected from one or more combinations of tin-doped indium oxide, fluorine-doped tin oxide, indium tungsten oxide and indium zinc oxide; The hole transport layer is a material layer deposited on the surface of the second transparent conductive layer with a film thickness of 10 nm. The material is selected from one or more combinations of nickel oxide, polytriarylamine, cuprous thiocyanate, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate complex and molybdenum disulfide. The perovskite layer is a 1 μm thick film formed by depositing a perovskite precursor film on the surface of the hole transport layer, followed by solvent extraction and annealing at 100-200°C. The material of the perovskite layer is selected from one or more combinations of formamidinium perovskite, methylamino perovskite and cesium-based perovskite. The electron transport layer is a material layer formed on the surface of the perovskite layer, and the material is selected from one or more combinations of tin oxide, fullerene, titanium oxide, zinc oxide and fullerene derivatives. The third transparent conductive layer is an electrode layer prepared on the surface of the electron transport layer, and its material is selected from one or more combinations of gold, silver, copper, tin-doped indium oxide, fluorine-doped tin oxide, indium tungsten oxide and indium zinc oxide.

6. The method for fabricating a CIGS-perovskite four-terminal stacked module for space photovoltaics as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. CIGS bottom cell and perovskite top cell are fabricated independently, wherein the CIGS bottom cell is fabricated with a back electrode layer and a first transparent conductive layer, and the perovskite top cell is fabricated with a second transparent conductive layer and a third transparent conductive layer, and single-cell testing and screening are performed. S2. On the surface of the first transparent conductive layer of the CIGS bottom cell that has passed the test, an adhesive is uniformly coated. Then the perovskite top cell is placed in the alignment fixture so that its third transparent conductive layer faces down and is precisely aligned with the first transparent conductive layer. S3. The laminated components are then subjected to thermal curing or UV curing at a temperature not exceeding 100°C to form the interconnect layer, thus completing the physical lamination of the four-terminal stacked components. S4. Connect the third transparent conductive layer and the second transparent conductive layer of the perovskite top cell to an independent busbar as the negative and positive electrodes of the top cell, respectively. Connect the back electrode layer and the first transparent conductive layer of the CIGS bottom cell to an independent busbar as the negative and positive electrodes of the bottom cell, ensuring that the four sets of terminals are not connected to each other. S5. Apply sealant to the edges of the four-terminal lead-out component to complete edge encapsulation, thereby obtaining the CIGS-perovskite four-terminal stacked module for space photovoltaics.

7. A solar panel, characterized in that, include: Flexible load-bearing substrate for solar panels; And a CIGS-perovskite four-terminal stacked module array made of any one of the CIGS-perovskite four-terminal stacked modules for space photovoltaics as described in claims 1-5 and / or made by the preparation method of the CIGS-perovskite four-terminal stacked module for space photovoltaics as described in claim 6, which is attached to the substrate surface in a matrix arrangement by an adhesive; Kovar electrodes are arranged between the modules and interconnected by flexible wires to form a large-area photovoltaic array surface; the overall thickness of the solar fin is 0.1-10 mm.

8. A satellite photovoltaic energy system, characterized in that, include: The system comprises a flexible photovoltaic subsystem, a maximum power point tracking (MPPT) energy control subsystem, and an energy storage subsystem. The flexible photovoltaic subsystem is composed of solar panels as described in claim 7, and is electrically divided into a top perovskite battery array and a bottom CIGS battery array, which are physically and electrically isolated from each other, for independently outputting a first DC power supply and a second DC power supply, respectively. The MPPT energy control subsystem includes a first maximum power point tracker, a second maximum power point tracker, and a primary bus voltage regulator module. The first and second maximum power point trackers are independently connected to the top perovskite battery array and the bottom CIGS battery array, respectively, to track the maximum power point in real time and perform DC-DC power conversion, and then jointly output to the primary bus voltage regulator module for current collection and voltage regulation. The energy storage subsystem includes a lithium-ion battery pack, which is bidirectionally electrically connected to the primary bus voltage regulator module through a charge / discharge regulation module.

9. The system according to claim 8, characterized in that, The system is equipped with dynamic energy dispatch control based on the alternating environment of spatial illumination and ground shadow. The specific control logic is as follows: When in the illumination period, dual maximum power point trackers are activated simultaneously. If the total photovoltaic power is greater than or equal to the load demand power, the primary bus voltage stabilization and current combiner module is given priority to supply power, and the surplus power is used to charge the lithium-ion battery pack. If the total photovoltaic power is less than the load demand power, the lithium-ion battery pack supplements the difference in power supply. When in the ground shadow period and without illumination, the dual maximum power point trackers are stopped, and the system switches to energy storage power supply mode, where the lithium-ion battery pack discharges independently.

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