Copper-indium-gallium-selenium thin-film solar cell module and preparation method thereof

Abstract

The invention discloses a copper-indium-gallium-selenium thin-film solar cell module and a preparation method, and relates to the technical field of thin-film solar cells, and the copper-indium-gallium-selenium thin-film solar cell module comprises a glass substrate and tempered cover plate glass, a light-permeable barrier layer, a back electrode layer, a PN layer, a front electrode layer and an adhesive film are sequentially arranged between the glass substrate and the tempered cover plate glass, a plurality of through holes are further formed in the back surface of the back electrode layer, and the through holes penetrate through the back electrode layer to form a pulse light-permeable channel. When the CIGS thin-film solar cell module is used, the CIGS absorption layer can simultaneously receive incident light rays from the front side and the back side through two light absorption paths, double-side power generation is realized, the short-circuit current and the filling factor of the CIGS solar cell are improved, the performance of the cell is improved, the total light absorption amount is greatly improved, and the service life of the CIGS thin-film solar cell module is prolonged. More energy sources are provided for subsequent photoelectric conversion, and the generating capacity is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of thin-film solar cell technology, and more specifically, to a copper indium gallium selenide (CIGS) thin-film solar cell module and its preparation method. Background Technology

[0002] Copper indium gallium selenide (CIGS) thin-film solar cells are a type of compound semiconductor thin-film solar cell that uses Cu(In,Ga)Se2 as the absorber material. Due to their excellent performance in low-light conditions, low temperature coefficient, low production cost, and environmentally friendly production process, they have attracted widespread attention from many research institutions and enterprises. CIGS has a theoretical conversion efficiency of up to 33%, with the highest mass-produced conversion efficiency reaching 18%, and it possesses broad development prospects.

[0003] However, in current copper indium gallium selenide (CIGS) thin-film solar cells, the back electrode layer mostly uses conductive metallic materials such as molybdenum, copper-zinc, and silver. These materials lack light transmittance, causing sunlight to only enter from the front of the cell and be absorbed by the absorption layer, while the back cannot utilize solar energy, thus limiting further improvements in battery power generation. Furthermore, in traditional fabrication processes, the etching and separation methods of the electrode layer and functional layer lack coordination with light transmittance design, making it difficult to balance conductivity and light transmittance, and thus hindering the achievement of efficient bifacial power generation. Summary of the Invention

[0004] This invention provides a copper indium gallium selenide (CIGS) thin-film solar cell module and its preparation method, which can solve the problems of opaque back electrode layer and inability to generate electricity from both sides in existing CIGS thin-film solar cells.

[0005] A copper indium gallium selenide thin-film solar cell module, comprising: A glass substrate and a tempered cover glass, wherein a light-transmitting barrier layer, a back electrode layer, a PN layer, a front electrode layer, and an adhesive film are sequentially disposed between the glass substrate and the tempered cover glass; The PN layer is used for photoelectric conversion, wherein the PN layer includes a copper indium gallium selenide (CIGS) absorber layer, a buffer layer, and a high-resistivity layer arranged sequentially. The back electrode layer is provided with a plurality of first scribing lines, and the plurality of first scribing lines divide the back electrode layer to form a plurality of first slits, and the first slits are filled with a copper indium gallium selenide absorber layer. The PN layer has several second scribing lines, which separate the copper indium gallium selenide absorber layer, the buffer layer and the high-resistivity layer to form several second slits. The second slits are filled with the front electrode layer to form a current connection channel. The upper surface of the front electrode layer is provided with a plurality of third scribing lines, which separate the front electrode layer and the PN layer. The back electrode layer also has several through holes on its back side, and these through holes penetrate the back electrode layer to form a pulse light transmission channel.

[0006] The copper indium gallium selenide (CIGS) thin-film solar cell module provided by this invention has, but is not limited to, the following beneficial effects compared to existing technologies: Sunlight passes through the tempered cover glass, the encapsulant film, the front electrode layer, the high-resistivity layer and the buffer layer in the PN layer, and finally reaches the copper indium gallium selenide (CIGS) absorber layer, achieving light absorption through the aforementioned front-side absorption path. Ambient light passes through the glass substrate, through the blocking layer and the pulsed light transmission channel of the back electrode layer, and finally enters the CIGS absorber layer in the PN layer, achieving light absorption through the aforementioned back-side absorption path. These two absorption paths allow the CIGS absorber layer to simultaneously receive light incident from both sides, enabling bifacial power generation. This increases the short-circuit current and fill factor of the CIGS solar cell, thereby improving cell performance and significantly increasing total light absorption. This provides more energy for subsequent photoelectric conversion, resulting in a substantial increase in power generation.

[0007] The first line divides the continuous back electrode layer into multiple independent back electrode units. Each back electrode unit corresponds to a local power generation area, which can avoid hole transmission loss caused by the resistance of the back electrode layer, and at the same time prevent holes in adjacent areas from interfering with each other.

[0008] The second line can separate the PN layer to form a current connection channel, allowing electrons in the front electrode layer to merge with holes in the adjacent back electrode unit through the current connection channel, realizing the series connection of current in multiple local power generation regions and improving the overall output voltage.

[0009] The third line divides the continuous front electrode layer into front electrode units corresponding to the back electrode units, preventing lateral flow of electrons in the front electrode layer and ensuring that the current in each local power generation area is transmitted independently and directionally to the confluence point.

[0010] After optimization through the first, second, and third scribing steps, the problems of low current collection efficiency and current interference in adjacent areas of large-area components were solved, ensuring that the component's current can be output stably.

[0011] A method for fabricating a copper indium gallium selenide (CIGS) thin-film solar cell module as described above, comprising: S1: Deposit a barrier layer and a back electrode layer sequentially on a glass substrate; S2: The first scribing line is etched using a laser scribing method. The first scribing line separates the back electrode layer and forms the first slit. S3: Using laser scribing, a single laser pulse is used to independently process several pulse light-transmitting channels arranged in an array. The pulse light-transmitting channels penetrate the back electrode layer on the upper side of the glass substrate. S4: A copper indium gallium selenide (CIGS) absorber layer, a buffer layer, and a high-resistivity layer are sequentially fabricated on the back electrode layer to form a PN layer; S5: A second scribing line is etched using a laser scribing method. The second scribing line separates the PN layer to form a second slit. S6: A front electrode layer is prepared on the upper side of the PN layer, and the front electrode layer is filled into the second slit to form a current connection channel. S7: The third scribing line is etched using laser or mechanical scribing methods. The third scribing line separates the front electrode layer and the PN layer. S8: Clean the edges of the module, remove excess film layers, complete the busbar welding, and encapsulate it with encapsulant film and tempered cover glass to obtain a copper indium gallium selenide thin-film solar cell module.

[0012] Since the technical improvements and beneficial effects of the preparation method are at least the same as those of the copper indium gallium selenide thin-film solar cell module, the preparation method will not be described in detail here.

[0013] Furthermore, in S1, the barrier layer is one of a silicon nitride thin film layer, a titanium nitride thin film layer, or a titanium oxide thin film layer.

[0014] Furthermore, in S1, the back electrode layer is one of a molybdenum electrode film, a copper-zinc electrode film, or a silver electrode film.

[0015] Furthermore, in S3, a single pulse transmission channel is focused onto the back electrode layer at high speed and low frequency by a picosecond laser and obtained by blasting the back electrode layer.

[0016] Furthermore, in S2, the depth of the first scribing line terminates inside the barrier layer.

[0017] Furthermore, in S4, the method for preparing the copper indium gallium selenide absorber layer is one or two of sputtering copper indium gallium followed by selenization and co-evaporation. The methods for preparing the buffer layer and the high-resistivity layer are one or two of co-evaporation, sputtering, and chemical bath deposition.

[0018] Furthermore, in S5, the scribing depth of the second scribing line remains on the upper surface of the back electrode layer.

[0019] Furthermore, in S6, the material of the front electrode layer is one or more of aluminum-doped zinc oxide, magnesium-doped zinc oxide, and boron-doped zirconium oxide.

[0020] Furthermore, in S7, the scribing depth of the third scribing line remains on the upper surface of the back electrode layer or the upper surface of the copper indium gallium selenide absorber layer. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view of a copper indium gallium selenide thin-film solar cell module according to an embodiment of the present invention; Figure 2This is a partial cross-sectional view of a copper indium gallium selenide thin-film solar cell module according to an embodiment of the present invention. Figure 3 This is a partial bottom view of a copper indium gallium selenide thin-film solar cell module according to an embodiment of the present invention; Figure 4 This is a flowchart illustrating a method for preparing a copper indium gallium selenide (CIGS) thin-film solar cell module according to an embodiment of the present invention.

[0022] Explanation of reference numerals in the attached figures: 1. Glass substrate; 2. Barrier layer; 3. Back electrode layer; 301. First molybdenum layer; 302. Molybdenum nitride layer; 303. Second molybdenum layer; 4. Copper indium gallium selenide absorber layer; 5. High-resistivity layer; 6. Front electrode layer; 7. Adhesive film; 8. Tempered cover glass; 9. First scribing line; 10. Second scribing line; 11. Third scribing line; 12. Pulse light transmission channel; 13. Through hole. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings showing multiple embodiments according to this application. It should be understood that the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort will fall within the scope of protection of this application.

[0024] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing specific embodiments only and is not intended to limit this application; the terms "comprising," "including," "having," "containing," etc., in the description, claims, and accompanying drawings of this application are open-ended terms. Therefore, "comprising," "including," or "having" refers to, for example, a method or apparatus having one or more steps or elements, but is not limited to having only these one or more elements. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0025] In the description of this invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0026] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0027] It should be emphasized that when the term "comprising / including" is used in this specification, it is used to explicitly indicate the presence of the stated feature, integer, step, or component, but does not exclude the presence or addition of one or more other features, integers, steps, parts, or groups of features, integers, steps, or parts.

[0028] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0029] Traditional copper indium gallium selenide (CIGS) batteries typically use metallic conductive materials (such as molybdenum film, copper-zinc alloy film, and silver film) as the back electrode layer. While these materials have advantages such as low resistivity and high adhesion, they are completely opaque, meaning the battery can only absorb sunlight through the front side. The back side is blocked by the metallic back electrode layer, preventing the use of reflected light (such as ground reflection or building wall reflection) or transmitted light from the environment, resulting in a significant waste of light energy.

[0030] From practical application data, in typical outdoor scenarios, the intensity of light reflected from the ground can reach 15%-30% of the total incident light, and even exceed 40% in snowy or light-colored ground environments. Traditional single-sided CIGS modules cannot utilize this portion of light energy at all, resulting in actual power generation being 20%-35% lower than the theoretical value. For example, in rooftop photovoltaic systems, the average daily power generation of a single-sided CIGS module is approximately 1.2 kWh / m², while if bifacial power generation can be achieved, the power generation can be increased by more than 25% by utilizing only reflected light, significantly improving the return on investment.

[0031] Furthermore, the traditional full-coverage design of the back electrode layer has a hidden drawback: the metal layer has a high thermal conductivity (molybdenum's thermal conductivity is approximately 138 W / (m²)). Under strong light, the battery is prone to heat accumulation, which leads to an increase in battery operating temperature and further exacerbates efficiency degradation (the temperature coefficient of CIGS batteries is about -0.25% / ℃, and the efficiency decreases by 2.5% for every 10℃ increase in temperature), forming a vicious cycle of insufficient light absorption - increased temperature - efficiency degradation.

[0032] See Figures 1-3 As shown, an embodiment of the present invention provides a copper indium gallium selenide thin-film solar cell module, comprising: A light-transmitting barrier layer 2, a back electrode layer 3, a PN layer, a front electrode layer 6, and an adhesive film 7 are sequentially disposed between a glass substrate 1 and a tempered cover glass 8.

[0033] The PN layer is used for photoelectric conversion. The PN layer includes a copper indium gallium selenide absorber layer 4, a buffer layer, and a high-resistivity layer 5, which are sequentially distributed.

[0034] The back electrode layer 3 has several first scribing lines 9, which separate the back electrode layer 3 to form several first slits. The first slits are filled with a copper indium gallium selenide absorber layer 4.

[0035] The PN layer has several second scribing lines 10. The second scribing lines 10 separate the copper indium gallium selenide absorber layer 4, the buffer layer and the high-resistivity layer 5 to form several second slits. The second slits are filled with the front electrode layer 6 to form a current connection channel.

[0036] The upper surface of the front electrode layer 6 is provided with several third scribing lines 11, which separate the front electrode layer 6 and the PN layer.

[0037] Several through holes 13 are also formed on the back side of the back electrode layer 3, and the through holes 13 penetrate the back electrode layer 3 to form a pulse light transmission channel 12.

[0038] In this embodiment, sunlight passes through the tempered cover glass 8, the adhesive film 7, the front electrode layer 6, the high-resistivity layer 5 in the PN layer, and the buffer layer, and finally reaches the copper indium gallium selenide absorption layer 4. The light absorption of the component is achieved through the aforementioned front light absorption path.

[0039] Ambient light, such as some refracted and reflected light, can pass through the pulsed light transmission channel 12 of the back electrode layer of the barrier layer 2 from the glass substrate 1, and finally enter the copper indium gallium selenide absorption layer 4 in the PN layer, so that the light absorption of the component can be achieved through the above-mentioned back light absorption path.

[0040] By employing two light absorption paths, the copper indium gallium selenide (CIGS) absorber layer 4 can simultaneously receive light incident from both the front and back sides, enabling bifacial power generation. This improves the Isc (short-circuit current) and FF (fill factor) of the CIGS solar cell, thereby enhancing the cell's performance and significantly increasing the total light absorption. This provides more energy sources for subsequent photoelectric conversion and significantly increases power generation.

[0041] It should be noted that the first line 9 divides the continuous back electrode layer 3 into multiple independent back electrode units. Each back electrode unit corresponds to a local power generation area, which can avoid hole transmission loss caused by the resistance of the back electrode layer, and at the same time prevent holes in adjacent areas from interfering with each other.

[0042] The second line 10 can separate the PN layer to form a current connection channel, so that electrons in the front electrode layer 6 can merge with holes in the adjacent back electrode unit through the current connection channel, realizing the series connection of current in multiple local power generation regions and improving the overall output voltage.

[0043] The third line 11 divides the continuous front electrode layer 6 into front electrode units corresponding to the back electrode unit, avoiding lateral flow of electrons in the front electrode layer and ensuring that the current in each local power generation area is transmitted independently and directionally to the confluence point.

[0044] After optimization using the first line 9, the second line 10, and the third line 11, the problems of low current collection efficiency and current interference in adjacent areas of large-area components were solved, ensuring that the current of the component can be output stably and balancing conductivity and light transmittance.

[0045] In addition, the pulse light transmission channel 12 can form a breathable heat dissipation structure. On the one hand, it reduces the metal coverage area of ​​the back electrode layer 3 and reduces the continuity of the heat conduction path. On the other hand, the pulse light transmission channel 12 penetrates the back electrode layer 3, which can accelerate the convection exchange of heat inside the module with the outside, reduce the battery operating temperature and efficiency thermal decay rate. Especially in the strong sunlight environment in summer, the efficiency decay of traditional modules is relatively high, while the decay of the module in this design is relatively low, and the stability of power generation is significantly improved.

[0046] See Figure 4 As shown in the figure, an embodiment of the present invention provides a method for preparing a copper indium gallium selenide thin-film solar cell module as described above, comprising: S1: A barrier layer 2 and a back electrode layer 3 are sequentially deposited on a glass substrate 1.

[0047] The glass substrate 1 is made of one of soda-lime glass, medium-aluminum glass, or high-aluminum glass, and its thickness ranges from 1.2 mm to 3.5 mm. The barrier layer 2 is one of a silicon nitride thin film, a titanium nitride thin film, or a titanium oxide thin film, and its thickness ranges from 10 nm to 120 nm. The back electrode layer 3 is one of a molybdenum electrode film, a copper-zinc electrode film, or a silver electrode film, and its thickness ranges from 80 nm to 500 nm.

[0048] In this embodiment, the back electrode layer 3 is a molybdenum electrode film. The back electrode layer 3 includes a first molybdenum layer 301, a molybdenum nitride layer 302, and a second molybdenum layer 303. The first molybdenum layer 301 is connected to the barrier layer 2. The first molybdenum layer 301, the molybdenum nitride layer 302, and the second molybdenum layer 303 are arranged sequentially from the barrier layer 2 toward the back electrode layer 3. The thickness of the first molybdenum layer 301 is 100nm to 300nm, the thickness of the molybdenum nitride layer 302 is 10nm to 30nm, and the thickness of the second molybdenum layer 303 is 30nm to 50nm.

[0049] S2: The first scribing line 9 is etched using a laser scribing method. The first scribing line 9 separates the back electrode layer 3, forming the first slit.

[0050] The scribing depth of the first scribing line 9 terminates inside the barrier layer 2, and the scribing width of the first scribing line 9 is 20μm~80μm, the laser power is 0.45W~0.8W, the pulse width is 1ps~100ps, the processing speed is 1000mm / s~1500mm / s, and the laser frequency is 45KHz~100KHz.

[0051] S3: Using a laser scribing method and a single laser pulse independent processing technology, several pulse light-transmitting channels 12 are arranged in an array. The pulse light-transmitting channels 12 penetrate the back electrode layer 3 on the upper side of the glass substrate 1.

[0052] The single-pulse light transmission channel 12 is focused onto the back electrode layer 3 by a picosecond laser at high speed and low frequency, and is obtained by blasting the back electrode layer 3.

[0053] Specifically, a picosecond laser (pulse width < 15 ps), high speed (scribing speed > 1000 mm / s), and low frequency (< 200 kHz) is focused on the first molybdenum layer 301 in the back electrode layer 3. The first molybdenum layer 301, molybdenum nitride layer 302, and second molybdenum layer 303 in the back electrode layer 3 on the upper side of the glass substrate 1 are removed by "cold processing" through the explosion of the back electrode layer 3.

[0054] The center-to-center distance between two adjacent pulse light transmission channels 12 in the same array is 50μm to 1000μm, the diameter of the pulse light transmission channel 12 is 20μm to 100μm, and the cross-section of the circular hole 13 is clear, without molten area, and without burrs on the surface.

[0055] The array-like distribution of the pulsed light transmission channels 12 indirectly divides the back electrode layer 3 into a mesh-like conductive region, shortening the hole transport path and transforming the overall transmission into concentrated transmission in local areas, effectively reducing the series resistance Rs. Simultaneously, the spacing of the pulsed light transmission channels 12 can be precisely adjusted according to the module size, ensuring a balance between current collection efficiency and light transmittance, ultimately further improving the module's fill factor (FF).

[0056] The inventors discovered that traditional full-coverage back electrode layers are continuous metal films, which are prone to thermal expansion differences between the film layer and the glass substrate 1 and barrier layer 2 during deposition (such as sputtering processes) (molybdenum's thermal expansion coefficient is 5.3 × 10⁻⁶). -6 / ℃, glass is 9×10 -6 The internal stress generated at -40℃ to 85℃ can easily lead to cracking and peeling during long-term use (especially in thermal cycling tests, the peeling rate can reach 5%-8%). The advantage of this design is that the pulsed light transmission channel 12 removes part of the metal layer through laser cold processing, which can release the internal stress accumulated during the deposition of the back electrode layer 3, reducing the risk of cracking. At the same time, the edge of the pulsed light transmission channel 12 is a "smooth cross-section formed by explosion", without melting burrs. During the subsequent deposition of the PN layer, it can avoid the film layer from accumulating at the defect, improve the adhesion between the layers, effectively reduce the film peeling rate, and improve the reliability of the battery module.

[0057] S4: A copper indium gallium selenide absorber layer 4, a buffer layer, and a high-resistivity layer 5 are sequentially fabricated on the back electrode layer 3 to form a PN layer.

[0058] The method for preparing the copper indium gallium selenide absorber layer 4 is one or two of sputtering copper indium gallium followed by selenization and co-evaporation. The method for preparing the buffer layer and the high-resistivity layer (5) is one or two of co-evaporation, sputtering and chemical bath deposition.

[0059] Specifically, the copper indium gallium selenide (CIGS) absorber layer 4 comprises Cu metal, In metal, Ga metal, and Se metal, with a thickness of 1500 nm to 2500 nm. It can be formed by sputtering CIGS followed by selenization.

[0060] In addition, the copper indium gallium selenide (CIGS) absorber layer 4 can be achieved using the following four methods, all of which can achieve the same effect, as follows: (a) A method of selenization following sputtering of copper indium gallium; Alternatively, (b) a method of electroplating copper indium gallium followed by selenization; Alternatively, (c) a three-step co-evaporation method may be used; Alternatively, (d) a method of co-sputtering copper indium gallium followed by selenization.

[0061] The buffer layer is made of InS (CdS can also be used), and it can be formed by chemical bath method or evaporation method. The thickness of the buffer layer is 50nm to 100nm.

[0062] The high-resistivity layer 5 is made of ZnO and can be formed by sputtering. The thickness of the high-resistivity layer is 10 nm to 80 nm. In the sputtering method, the sputtering temperature is 100℃ to 250℃, the sputtering power is 10 kW to 50 kW, and the sputtering pressure is 1... 10 - 3 mbar~4 10 -3 mbar.

[0063] S5: The second scribing line 10 is scribed using a laser scribing method. The second scribing line 10 separates the PN layer (copper indium gallium selenide absorber layer 4, buffer layer, high resistivity layer 5) to form the second slit.

[0064] The scribing depth of the second scribing line 10 remains on the upper surface of the back electrode layer 3, and the scribing width of the second scribing line 10 is 5μm to 50μm, the laser power is 0.9W to 1.6W, the pulse width is 1ps to 100ps, the processing speed is 1000mm / s to 1500mm / s, and the laser frequency is 500KHz to 2000KHz.

[0065] S6: A front electrode layer 6 is prepared on the upper side of the PN layer, and the front electrode layer 6 is filled into the second slit to form a current connection channel.

[0066] The material of the front electrode layer 6 is one or more of aluminum-doped zinc oxide, magnesium-doped zinc oxide, and boron-doped zirconium oxide, preferably aluminum-doped zinc oxide.

[0067] Specifically, the front electrode layer 6 was fabricated on the PN layer using magnetron sputtering at a sputtering temperature of 100℃ to 250℃, a sputtering power of 5KW to 50KW, and a sputtering gas pressure of 1. 10 -3 mbar~4 10 -3 mbar. The thickness of the front electrode layer 6 is 100nm to 500nm, which is 500nm to 900nm thinner than the prior art, and the transmittance is increased by 3% to 8%.

[0068] S7: The third scribing line 11 is etched using laser or mechanical scribing methods. The third scribing line 11 separates the front electrode layer 6 and the PN layer.

[0069] The third scribing line 11 is etched to a depth that stops on the upper surface of the back electrode layer 3 or the upper surface of the copper indium gallium selenide absorber layer 4, with a scribing width of 30 μm to 200 μm.

[0070] In this embodiment, a third scribing line 11 is etched using a mechanical scribing method to separate the copper indium gallium selenide (CIGS) absorber layer 4, buffer layer, high-resistivity layer 5, and front electrode layer 6. In the mechanical scribing method, the scribing needle pressure is 0.8N to 2.5N, the scribing speed is 500mm / s to 1500mm / s, and the scribing needle size is 200μm to 1500μm.

[0071] When using laser scribing, the scribing line width is 30μm to 100μm. In the laser scribing method, the laser power is 0.6W to 2W, the pulse width is 1ps to 50ps, the processing speed is 1000mm / s to 1500mm / s, and the laser frequency is 50KHz to 500KHz.

[0072] S8: Clean the edges of the module, remove excess film layers, complete the busbar welding, and laminate and encapsulate it with film 7 and tempered cover glass 8 to obtain copper indium gallium selenide thin-film solar cell modules.

[0073] The materials of the encapsulant film 7 include, but are not limited to, EVA, PVB, and POE. The tempered cover glass 8 is a traditional photovoltaic cover glass, and its thickness is 2mm to 4mm.

[0074] The copper indium gallium selenide (CIGS) thin-film solar cell module prepared using the above method can achieve bifacial power generation. Through the pulsed light transmission channel 12 on the back electrode layer 3, sunlight (or reflected, refracted, or ambient light) from the back side can penetrate to the CIGS absorption layer 4, overcoming the limitation of traditional cells that only absorb light from the front side, thus significantly increasing power generation. It also optimizes photoelectric conversion efficiency. The pulsed light transmission channel 12 is prepared using a "cold processing" process, resulting in a clear cross-section without molten areas, avoiding damage to the performance of the back electrode layer 3. Simultaneously, the thickness of the front electrode layer 6 is optimized, increasing transmittance by 3%–8%, further improving conversion efficiency.

[0075] In this embodiment, the copper indium gallium selenide (CIGS) thin-film solar cell module prepared by this method exhibits strong structural stability, with reasonable material selection and thickness design for each layer. Precise separation using three scribing lines ensures smooth current transmission, while the lamination and encapsulation process guarantees the module's weather resistance and lifespan. The preparation process is highly compatible, with core processes adapted to existing CIGS battery production lines, requiring no large-scale equipment modifications, facilitating mass production and reducing production line costs.

[0076] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A copper indium gallium selenide thin-film solar cell module, characterized in that, include: A glass substrate (1) and a tempered cover glass (8) are provided in sequence between the glass substrate (1) and the tempered cover glass (8), including a light-transmitting barrier layer (2), a back electrode layer (3), a PN layer, a front electrode layer (6), and an adhesive film (7). The PN layer is used for photoelectric conversion, wherein the PN layer includes a copper indium gallium selenide absorber layer (4), a buffer layer and a high-resistivity layer (5) distributed sequentially. The back electrode layer (3) is provided with a plurality of first scribing lines (9), and the plurality of first scribing lines (9) separate the back electrode layer (3) to form a plurality of first slits, and the first slits are filled with a copper indium gallium selenide absorber layer (4). The PN layer is provided with a number of second scribing lines (10). The second scribing lines (10) separate the copper indium gallium selenide absorption layer (4), the buffer layer and the high-resistivity layer (5) to form a number of second slits. The second slits are filled with the front electrode layer (6) to form a current connection channel. The upper surface of the front electrode layer (6) is provided with a plurality of third scribing lines (11), which separate the front electrode layer (6) and the PN layer. The back electrode layer (3) also has several through holes (13) on its back side, and the several through holes (13) penetrate the back electrode layer (3) to form a pulse light transmission channel (12).

2. A method for preparing a copper indium gallium selenide thin-film solar cell module as described in claim 1, characterized in that, include: S1: A barrier layer (2) and a back electrode layer (3) are sequentially deposited on a glass substrate (1). S2: The first scribing line (9) is scribing using a laser scribing method. The first scribing line (9) separates the back electrode layer (3) and forms the first scribing groove. S3: Using laser scribing, a single laser pulse is used to independently process several pulse light-transmitting channels (12) arranged in an array. The pulse light-transmitting channels (12) penetrate the back electrode layer (3) on the upper side of the glass substrate (1). S4: A copper indium gallium selenide absorber layer (4), a buffer layer and a high-resistivity layer (5) are sequentially prepared on the back electrode layer (3) to form a PN layer; S5: The second scribing line (10) is scribed using a laser scribing method. The second scribing line (10) separates the PN layer to form the second scribing groove. S6: A front electrode layer (6) is prepared on the upper side of the PN layer, and the front electrode layer (6) is filled into the second slit to form a current connection channel; S7: The third scribing line (11) is scribed by laser or mechanical scribing method. The third scribing line (11) separates the front electrode layer (6) and the PN layer. S8: Clean the edges of the module, remove excess film layers, complete the busbar welding, and laminate and encapsulate it with adhesive film (7) and tempered cover glass (8) to obtain copper indium gallium selenide thin film solar cell module.

3. The preparation method according to claim 2, characterized in that, In S1, the barrier layer (2) is one of a silicon nitride thin film layer, a titanium nitride thin film layer, or a titanium oxide thin film layer.

4. The preparation method according to claim 2, characterized in that, In S1, the back electrode layer (3) is one of a molybdenum electrode film, a copper-zinc electrode film, or a silver electrode film.

5. The preparation method according to claim 2, characterized in that, In S3, a single pulse light transmission channel (12) is focused onto the back electrode layer (3) by a picosecond laser at high speed and low frequency, and is obtained by blasting the back electrode layer (3).

6. The preparation method according to claim 2, characterized in that, In S2, the depth of the first scribing line (9) terminates inside the barrier layer (2).

7. The preparation method according to claim 2, characterized in that, In S4, the method for preparing the copper indium gallium selenide absorber layer (4) is one or two of sputtering copper indium gallium followed by selenization and co-evaporation. The method for preparing the buffer layer and the high-resistivity layer (5) is one or two of co-evaporation, sputtering and chemical bath deposition.

8. The preparation method according to claim 2, characterized in that, In S5, the scribing depth of the second scribing line (10) remains on the upper surface of the back electrode layer (3).

9. The preparation method according to claim 2, characterized in that, In S6, the material of the front electrode layer (6) is one or more of aluminum-doped zinc oxide, magnesium-doped zinc oxide and boron-doped zirconium oxide.

10. The preparation method according to claim 2, characterized in that, In S7, the scribing depth of the third scribing line (11) remains on the upper surface of the back electrode layer (3) or the upper surface of the copper indium gallium selenide absorber layer (4).

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