Photovoltaic cell string and photovoltaic module

Abstract

The invention provides a photovoltaic cell string and a photovoltaic module, and relates to the technical field of photovoltaic cell string manufacturing. Comprising at least two photovoltaic cells, and the first surface of each photovoltaic cell is provided with first electrodes and second electrodes which are alternately arranged; the conductive interconnection pieces are used for connecting adjacent photovoltaic battery pieces; and the functional isolation layer is arranged on the surface area corresponding to the opposite electrodes spanned by the conductive interconnection piece. According to the invention, the functional isolation layer with the characteristics of the voltage dependent resistor is arranged between the battery electrode and the anisotropic conductive interconnection piece, so that a reverse bias electric leakage channel is constructed. When the functional isolation layer has the characteristic of a piezoresistor, the reverse bias voltage capable of clamping the back contact cell is lower than the reverse bias breakdown voltage of the main PN junction of the photovoltaic cell string, so that a large amount of heat burnout caused by avalanche breakdown generated during reverse bias of the cell is avoided.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic cells, and in particular to a photovoltaic cell string and a photovoltaic module. Background Technology

[0002] With the development of photovoltaic cell technology, back contact cells have the potential to improve performance due to their structural characteristics. However, back contact cells and modules face certain challenges in application due to their low parallel resistance, easy breakdown, and high risk of hot spots.

[0003] Currently, back-contact batteries commonly employ the method of constructing leakage channels to reduce the reverse bias voltage and disperse the reverse bias current, preventing localized overheating and burn-out failure. The common approach involves building the leakage channel within the silicon structure region inside the back-contact battery. This requires special design of the battery's NP diffusion region and its implementation in the battery manufacturing process.

[0004] The currently common method of constructing leakage channels within the silicon structure region of back-contact batteries requires special design of the NP diffusion region. For example, for TBC batteries, multiple heterogeneous contact points are typically designed in the N / P-poly region, or a diffusion junction is designed within the silicon substrate to connect the N / P region, which is then implemented in the battery manufacturing process. While these designs create leakage channels, they further reduce the battery's parallel resistance, degrading low-light power generation efficiency. They also increase process complexity, making process windows difficult to control, thus affecting production yield and cost.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] One of the objectives of this invention is to provide a photovoltaic cell string to at least solve one of the technical problems existing in the prior art.

[0007] The second objective of this invention is to provide a photovoltaic module.

[0008] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: In a first aspect, the present invention provides a photovoltaic cell string, comprising: At least two photovoltaic cells, each of which has alternating first and second type electrodes on its first surface; A conductive interconnect is used to connect adjacent photovoltaic cells. One end of the conductive interconnect is connected to the first type of electrode of the preceding cell, and the other end of the conductive interconnect is connected to the second type of electrode of the following cell to form a current path. A functional isolation layer is disposed on at least a portion of the surface of the first type of electrode or the second type of electrode, and is disposed in the surface region corresponding to the opposite electrode spanned by the conductive interconnect. The functional isolation layer contains a material whose resistance decreases as the voltage it is subjected to increases.

[0009] Furthermore, the functional isolation layer is disposed on the surface area of ​​the dissimilar electrode that is non-connected by the conductive interconnect on each photovoltaic cell, and forms a conductive path when the voltage reaches a threshold.

[0010] Furthermore, the functional isolation layer has voltage-dependent resistor (VDR) characteristics; Preferably, the on-threshold voltage of the functional isolation layer is 0.8-5V.

[0011] Furthermore, the material used in the functional isolation layer includes any one or more combinations of zinc oxide, silicon carbide, titanium oxide, tin oxide, and nano-ZnO-based composite materials; Furthermore, the thickness of the functional isolation layer is 1-5 μm.

[0012] Furthermore, the conductive interconnect includes one or more of conductive solder strips, metal foils, conductive tapes, and flexible circuit strips.

[0013] Furthermore, the functional isolation layer is disposed on the second type of electrode, and the first type of electrode is insulated from the dissimilar conductive interconnects that cross it through an insulating layer.

[0014] Furthermore, the functional isolation layer is disposed on both the first type of electrode and the second type of electrode.

[0015] Furthermore, the functional isolation layer is formed by printing or inkjet printing.

[0016] Furthermore, the first surface is the back surface of the photovoltaic cell.

[0017] Secondly, the present invention provides a photovoltaic module, including the aforementioned photovoltaic cell string.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The photovoltaic cell string provided by this invention constructs a controllable leakage path external to the cell body by setting a functional isolation layer with varistor characteristics between the heterogeneous electrodes of the photovoltaic cell string body and the heterogeneous conductive interconnects spanning above them. When the cell is in reverse bias, the functional isolation layer quickly conducts after reaching the threshold voltage, effectively clamping the reverse bias voltage, preventing avalanche breakdown of the main PN junction, significantly reducing the risk of hot spots, and improving the safety and reliability of the module under complex operating conditions. At the same time, this design does not require modification of the diffusion structure inside the cell, retains the cell's high parallel resistance and excellent low-light response characteristics, which is conducive to improving power generation efficiency, and is compatible with existing module packaging processes, possessing good manufacturability and application prospects. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a photovoltaic cell string provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of a partial cross-sectional structure of a photovoltaic cell in a photovoltaic cell string provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of two types of electrodes with functional isolation layers designed on them, as provided in the embodiments of the present invention. Figure 4 This is a schematic diagram of the structure of a functional isolation layer on an electrode, as provided in an embodiment of the present invention. Figure 5 This is a schematic diagram of a structure using other isolation layers provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of another structure using other isolation layers provided in an embodiment of the present invention; Figure 7 The voltage clamping effect diagrams are provided for different leakage current channels in the embodiments of the present invention.

[0021] Icons: 1-First solar cell; 2-Second solar cell; 100-First type of electrode; 200-Second type of electrode; 300-First conductive solder strip; 400-Second conductive solder strip; 500-Functional isolation layer; 600-Insulating layer. Detailed Implementation

[0022] Unless otherwise defined herein, the scientific and technical terms used in conjunction with this invention shall have the meanings commonly understood by one of ordinary skill in the art. The meaning and scope of terms shall be clear; however, in any case of potential ambiguity, the definitions provided herein shall prevail over any dictionary or foreign definitions. In this application, unless otherwise stated, the use of "or" means "and / or". Furthermore, the use of the term "comprising" and other forms is non-limiting.

[0023] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Currently, traditional back-contact batteries typically incorporate reverse-biased leakage channels within the battery substrate to address hot spot issues. This approach requires specialized design of the NP diffusion region of the battery. For example, for TBC (Telephoto Base Cell), multiple contact points are typically designed in the N / P-poly region, or a diffusion junction is designed within the silicon substrate to connect the N / P region, which is then implemented during the battery manufacturing process. While these designs create leakage channels, they further reduce the battery's parallel resistance, degrading low-light power generation efficiency. They also increase process complexity, making process windows difficult to control, thus impacting production yield and cost.

[0025] This invention addresses the design of reverse-biased leakage channels in back-contact solar cells. A functional isolation layer with varistor characteristics is established between the cell electrode and the irregularly shaped solder ribbon to construct the reverse-biased leakage channel. When the functional isolation layer exhibits varistor characteristics, it can clamp the reverse-bias voltage of this back-contact solar cell below the reverse-biased breakdown voltage of the main PN junction of this photovoltaic cell (set at 0.8-5V), preventing avalanche breakdown and subsequent excessive heat and burnout during reverse bias.

[0026] In view of this, such as Figure 1 and Figure 2 As shown, the first aspect of the present invention provides a photovoltaic cell string, comprising: At least two photovoltaic cells, including but not limited to 2, 3, 4, 5, 6, etc., each photovoltaic cell having an alternately arranged first type electrode 100 and second type electrode 200 on its first surface; a conductive interconnect for connecting adjacent photovoltaic cells, one end of the conductive interconnect being connected to the first type electrode of the preceding cell, and the other end of the conductive interconnect being connected to the second type electrode of the following cell to form a current path; a functional isolation layer 500 disposed on at least a portion of the surface of the first type electrode 100 or the second type electrode 200, and disposed on the surface area corresponding to the opposite-shaped electrode traversed by the conductive interconnect; wherein the functional isolation layer 500 contains a material whose resistance decreases as the voltage it withstands increases.

[0027] The functional isolation layer 500 of the present invention is disposed on at least a portion of the surface of the first type of electrode 100 or the second type of electrode 200, and is disposed on the surface region corresponding to the opposite electrode that needs to be crossed by the conductive interconnect.

[0028] The photovoltaic cell of the present invention contains multiple electrodes of two polarities arranged at intervals on the same surface, defined as a first type of electrode 100 and a second type of electrode 200, and multiple conductive interconnects located above the two types of electrodes are connected to the two types of electrodes.

[0029] Optionally, the present invention includes a plurality of conductive interconnects for connecting at least two photovoltaic cells in series; wherein one end of each conductive interconnect is electrically connected to a first type electrode 100 of the preceding cell and the other end is electrically connected to a second type electrode 200 of the following cell, thereby establishing a current path between adjacent cells.

[0030] Specifically, adjacent photovoltaic cells are electrically connected through a wiring layout of conductive interconnects. One end of each conductive interconnect is connected to the first type of electrode 100 of the preceding cell, and the other end is connected to the second type of electrode 200 of the following cell, thus forming a series path between adjacent cells. The conductive interconnects are preferably conductive solder strips. Figure 1 As shown, one end of the first conductive solder strip 300 is connected to the first type of electrode 100 on the first battery cell 1. The conductive solder strip above the electrode crosses over the opposite electrode at multiple locations without contacting it. These multiple crossing locations are isolated from the opposite electrode by a locally provided functional isolation layer 500. The other end of the first conductive solder strip 300 is connected to the second type of electrode 200 on the second battery cell 2. Figure 1 The second conductive solder strip 400 on the first battery cell 1 is connected to the second type electrode 200 on the first battery cell 1, and the other end of the second conductive solder strip 400 on the first battery cell 1 is connected to the first type electrode 100 on the battery cell located before the first battery cell. Figure 1 The upstream cell to which the second conductive solder strip is connected is not shown in the image.

[0031] Multiple conductive interconnects are arranged sequentially along the extension direction of the cell string, forming a cyclic connection structure: a repeating unit of "first type electrode of the front cell → conductive interconnect → second type electrode of the rear cell," ultimately connecting at least two photovoltaic cells in series to form a complete current path. This connection method ensures the orderly transmission of photocurrent while avoiding the risk of misconnection of the same polarity or short circuit.

[0032] The key feature of the functional isolation layer 500 is that it has varistor characteristics, and its resistance changes with the applied voltage. When the applied voltage exceeds its threshold, the resistance drops sharply while the current increases, thus achieving current bypass. The functional isolation layer 500 will ultimately be encapsulated within the photovoltaic module along with the cell string.

[0033] The external reverse-biased leakage channel of the present invention can be set after the main production of the battery is completed without interfering with the battery structure and process design. At the same time, the leakage channel design and process can be flexibly and quickly adjusted, and an appropriate discharge threshold voltage can be selected. This allows the final product to solve the hot spot problem while adapting to different application scenarios and maximizing benefits.

[0034] In some preferred embodiments, the functional isolation layer is disposed on the surface region of the opposite electrode on each photovoltaic cell that is non-connected by conductive interconnects, and is turned on when the voltage reaches a threshold to construct a reverse-biased leakage channel.

[0035] In some preferred embodiments, the functional isolation layer 500 has piezoresistive characteristics; Preferably, the conduction threshold voltage of the functional isolation layer 500 is 0.8-5V, for example, it can be 0.8V, 1V, 1.5V, 2V, 2.5V, 3V, 3.5V, 4V, 4.5V, 5V, etc.

[0036] This invention prevents avalanche breakdown of the battery's main PN junction by providing a functional isolation layer 500 with varistor characteristics between the opposite electrode and the conductive interconnect on the back contact battery. When the functional isolation layer 500 has varistor characteristics, it can clamp the reverse bias voltage of this back contact battery (set at 0.8-5V), creating a leakage path when the battery is reverse biased, thus preventing the battery from overheating and burning out.

[0037] In some preferred embodiments, the conductive interconnect refers to a conductive structure used to achieve electrical connection between adjacent photovoltaic cells. This conductive interconnect includes, but is not limited to, materials with conductive connection functions such as conductive solder strips, metal foils, conductive tapes, or flexible circuit strips. These materials not only enable reliable electrical connections and mechanical fixation but also possess a certain degree of flexibility to adapt to stress changes during the encapsulation process.

[0038] Preferably, the conductive interconnect is a conductive solder strip.

[0039] Regarding the arrangement, the functional isolation layer 500 can be disposed only on the second type of electrode 200, in which case the first type of electrode 100 is insulated from the dissimilar conductive interconnects crossing it using other insulating layers 600. Alternatively, it can be disposed on both types of dissimilar electrodes, in which case all electrodes are isolated from the dissimilar conductive interconnects crossing them using this functional isolation layer 500.

[0040] Specifically: in some preferred embodiments, such as Figure 3 As shown, a functional isolation layer 500 is simultaneously disposed on both the first type of electrode 100 and the second type of electrode 200. All electrodes are isolated from the dissimilar conductive interconnects spanning above using this functional isolation layer 500, ensuring that all electrodes have voltage response capability. This approach improves system symmetry and consistency, enhancing overall reliability.

[0041] As an alternative preferred implementation, such as Figure 4 As shown, a functional isolation layer 500 is designed only on the second type of electrode 200.

[0042] As an alternative preferred implementation, such as Figure 5 As shown, the functional isolation layer 500 is disposed on the second type of electrode 200, and the first type of electrode 100 is insulated from the dissimilar conductive interconnects crossing it by other conventional insulating layers (such as silicone, epoxy resin, or polyimide). Figure 6 As shown, the functional isolation layer 500 and other conventional insulating layers can be freely combined and disposed on the surface area corresponding to the dissimilar electrodes spanned by the conductive interconnect. For example... Figure 5 and Figure 6 This asymmetrical design reduces the area of ​​functional materials used, lowers costs, and is suitable for applications with moderate reliability requirements.

[0043] Optionally, given that some BC batteries are optimized to reduce the risk of short circuits, avoiding structures where the solder strip crosses over dissimilar electrodes, the functional isolation layer 500 in this invention, in addition to being disposed between electrodes and conductive interconnects that have a crossing relationship, can also be disposed between two adjacent dissimilar electrodes or solder strips on the battery plate. The film layer laterally connects the two dissimilar electrodes or conductive interconnects, achieving the same function.

[0044] Optionally, in this invention, the functional isolation layer 500 can be made of a material with varistor characteristics or a material or structure with unidirectional conductivity and rectifier diode characteristics. This diode is connected in reverse parallel with the photovoltaic cell string diode to clamp the reverse bias of the photovoltaic cell string diode.

[0045] In some preferred embodiments, the functional isolation layer 500 is formed by printing or inkjet printing.

[0046] Specifically, this invention, in conjunction with the current conventional back contact assembly production process, replaces the printing of insulating adhesive step with the setting of the functional isolation layer 500. The functional isolation layer 500 can be set from a liquid or slurry precursor via printing, inkjet printing, or other methods. The location of the functional isolation layer 500 is essentially the same as the location of the insulating adhesive in traditional processes, resulting in good process compatibility and allowing integration without significant equipment modifications.

[0047] In some preferred embodiments, the functional isolation layer 500 is first cured and connected to the conductive interconnect in a liquid or slurry state, or the functional isolation layer 500 is cured and connected to the conductive interconnect during the welding process.

[0048] Optionally, the functional isolation layer 500 may be made of one or more combinations of zinc oxide, silicon carbide, titanium oxide, tin oxide, and nano-ZnO-based composite materials. Specifically, the material of the functional isolation layer 500 mainly includes semiconductor oxides such as zinc oxide (ZnO), silicon carbide (SiC), titanium oxide (TiO2), and tin oxide (SnO2), or their doped and modified products; more preferably, it is a composite material system formed by dispersing nanoscale functional particles in an organic resin matrix. By adjusting the particle size, doping type, filling ratio, and functional layer thickness, its conduction threshold voltage can be precisely set.

[0049] Preferably, the thickness of the functional isolation layer 500 is 1-5 μm, for example, it can be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, etc.

[0050] In some preferred embodiments, the first surface is the backlight surface of the photovoltaic cell. This surface is typically also covered with a passivation layer, a dielectric layer, or a polycrystalline silicon layer, and the functional isolation layer 500 is directly disposed on the metallized electrode surface.

[0051] A second aspect of the present invention provides a photovoltaic module, including the aforementioned photovoltaic cell string. During the module encapsulation process, the individual photovoltaic cells are connected in series to form a photovoltaic cell string via conductive interconnects, and the functional isolation layer 500 is encapsulated inside the module along with the cells.

[0052] The present invention will be further illustrated by the following examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or purchased directly from the market.

[0053] Example 1 This embodiment provides a photovoltaic cell string, in which a first type of electrode and a second type of electrode are disposed on the cell, and are alternately arranged on the back of the silicon wafer; the solder strip is arranged such that one end of the conductive solder strip is connected to the first type of electrode of the previous cell, and the other end of the conductive solder strip is connected to the second type of electrode of the next cell, so as to form a current path. A functional isolation layer is simultaneously disposed on the surface of both the first and second type electrodes in the area spanned by the conductive connectors that are connected to the output electrodes of opposite polarity. The functional isolation layer is made of nano-ZnO-based composite material; the functional isolation layer is prepared by printing process and has a thickness of 3 μm.

[0054] Example 2 This embodiment provides a back-contact photovoltaic cell string. The cells have a first type of electrode and a second type of electrode arranged alternately on the back of the silicon wafer. The solder strips are arranged such that one end of the conductive solder strip connects to the first type of electrode of the preceding cell, and the other end connects to the second type of electrode of the following cell, forming a current path. A functional isolation layer is only disposed on the surface of the first type of electrode in the area crossed by the conductive connector connected to the opposite polarity output electrode. Simultaneously, the second type of electrode and the area crossed by the first type of solder strip are insulated using conventional methods.

[0055] The functional isolation layer is made of nano-ZnO-based composite material; the functional isolation layer is prepared by printing process and has a thickness of 3 μm.

[0056] Example 3 This embodiment provides a photovoltaic cell string, in which a first type of electrode and a second type of electrode are disposed on the cell, alternately arranged on the back of the silicon wafer; the solder strip is arranged such that one end of the conductive solder strip is connected to the first type of electrode of the previous cell, and the other end of the conductive solder strip is connected to the second type of electrode of the next cell to form a current path; a functional isolation layer is disposed on the surface of the first type of electrode and the second type of electrode in the area spanned by the conductive connector connected to the opposite polarity output electrode. The functional isolation layer is made of nano-ZnO-based composite material; the functional isolation layer is prepared by printing process and has a thickness of 1 μm.

[0057] Example 4 This embodiment provides a photovoltaic cell string, in which a first type of electrode and a second type of electrode are disposed on the cell, alternately arranged on the back of the silicon wafer; the solder strip is arranged such that one end of the conductive solder strip is connected to the first type of electrode of the previous cell, and the other end of the conductive solder strip is connected to the second type of electrode of the next cell to form a current path; a functional isolation layer is disposed on the surface of the first type of electrode and the second type of electrode in the area spanned by the conductive connector connected to the opposite polarity output electrode. The functional isolation layer is made of nano-ZnO-based composite material; the functional isolation layer is prepared by printing process and has a thickness of 5 μm.

[0058] Example 5 This embodiment provides a photovoltaic cell string, which differs from Embodiment 1 in that the thickness of the functional isolation layer is 0.5 μm.

[0059] Example 6 This embodiment provides a photovoltaic cell string, which differs from Embodiment 1 in that the thickness of the functional isolation layer is 6µm.

[0060] Example 7 This embodiment provides a photovoltaic cell string, which differs from Embodiment 1 in that the material of the functional isolation layer is zinc oxide.

[0061] Example 8 This embodiment provides a photovoltaic cell string, which differs from Embodiment 1 in that the material of the functional isolation layer is silicon carbide.

[0062] Example 9 This embodiment provides a photovoltaic cell string, which differs from Embodiment 1 in that the material of the functional isolation layer is titanium oxide.

[0063] Example 10 This embodiment provides a photovoltaic cell string, which differs from Embodiment 1 in that the material of the functional isolation layer is tin oxide.

[0064] Comparative Example 1 This comparative example provides a back-contact photovoltaic cell string, which is a primitive cell with no leakage current channel, without any reverse bias protection design, and the electrodes are completely insulated, without any built-in or external leakage current mechanism.

[0065] Comparative Example 2 This comparative example provides a back-contact photovoltaic cell string, which is an existing in-situ leakage channel cell. A diffusion junction is designed in the silicon substrate to connect the N / P region to construct the leakage channel. The positive and negative electrodes of the cell and the positive and negative solder strips connecting them are completely insulated.

[0066] Test case The electrical performance of the battery samples from Examples 1 and 2, and Comparative Examples 1 and 2 was evaluated using reverse bias IV characteristic testing.

[0067] Test results are as follows Figure 7As shown, the reverse bias IV curves of the four examples exhibit significant differences: Comparative Example 1 (without a leakage channel) shows a low current response before the reverse voltage reaches approximately -7.5 V, indicating the lack of an effective protection mechanism, until avalanche breakdown occurs, belonging to the "hard failure" mode with extremely high hot spot risk; Comparative Example 2 (with an internal leakage channel) although it begins to slowly discharge current at around -4 V, possessing a certain pre-protection capability, its turn-on process is gradual and still requires a relatively high voltage (approximately -5 V) before abruptly turning on, resulting in an insufficiently timely response; In contrast, Example 1 (Design 1 of this case) rapidly and significantly turns on when the reverse voltage rises to approximately -2 V, achieving rapid and steep current discharge, while maintaining a low leakage state below -2 V, demonstrating excellent threshold controllability and nonlinear response characteristics. Example 2 (Design 2 of this case) rapidly and significantly turns on when the reverse voltage rises to approximately -2.2 V, achieving rapid current discharge, with a steeper rate than Example 1, while maintaining a low leakage state below -2 V, demonstrating excellent threshold controllability and nonlinear response characteristics.

[0068] The results show that the externally built-in varistor functional isolation layer used in this invention can actively activate the protection mechanism at a lower and safer voltage, avoiding damage to the main PN junction while ensuring high insulation and high reliability.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A photovoltaic cell string, characterized in that, include: At least two photovoltaic cells, each of which has alternating first and second type electrodes on its first surface; A conductive interconnect is used to connect adjacent photovoltaic cells. One end of the conductive interconnect is connected to the first type of electrode of the preceding cell, and the other end of the conductive interconnect is connected to the second type of electrode of the following cell to form a current path. A functional isolation layer is disposed on at least a portion of the surface of the first type of electrode or the second type of electrode, and is disposed in the surface region corresponding to the opposite electrode spanned by the conductive interconnect. The functional isolation layer contains a material whose resistance decreases as the voltage it is subjected to increases.

2. The photovoltaic cell string according to claim 1, characterized in that, The functional isolation layer is disposed on the surface area of ​​the opposite electrode on each photovoltaic cell that is non-connected by the conductive interconnect and forms a conductive path when the voltage reaches a threshold.

3. The photovoltaic cell string according to claim 1, characterized in that, The functional isolation layer has piezoresistive properties.

4. The photovoltaic cell string according to claim 1, characterized in that, The on-threshold voltage of the functional isolation layer is 0.8-5V; Preferably, the material used for the functional isolation layer includes any one or more combinations of zinc oxide, silicon carbide, titanium oxide, tin oxide, and nano-ZnO-based composite materials; Preferably, the thickness of the functional isolation layer is 1-5 μm.

5. The photovoltaic cell string according to claim 1, characterized in that, The conductive interconnects include one or more of conductive solder strips, metal foils, conductive tapes, and flexible circuit strips.

6. The photovoltaic cell string according to claim 1, characterized in that, The functional isolation layer is disposed on the second type of electrode, and the first type of electrode is insulated from the dissimilar conductive interconnects that cross it through an insulating layer.

7. The photovoltaic cell string according to claim 1, characterized in that, The functional isolation layer is disposed on both the first type of electrode and the second type of electrode.

8. The photovoltaic cell string according to claim 1, characterized in that, The functional isolation layer is formed by printing or inkjet printing processes.

9. The photovoltaic cell string according to claim 1, characterized in that, The first surface is the back surface of the photovoltaic cell.

10. A photovoltaic module, characterized in that, Includes the photovoltaic cell string as described in claim 9.

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