Photovoltaic tile assembly and preparation method

Abstract

The invention relates to the technical field of solar cells, and particularly discloses a photovoltaic tile assembly and a preparation method thereof, and the photovoltaic tile assembly comprises a plurality of back contact cells and interconnection strips, and the positive leads and the negative leads of the plurality of back contact battery pieces are arranged on the back surfaces of the back contact battery pieces and are connected in series through the interconnection strips. The photovoltaic tile assembly can improve the photoelectric conversion efficiency and improve the use safety of the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, in particular to a photovoltaic tile assembly and a preparation method thereof. Background Art

[0002] In current photovoltaic tile assemblies, the power generation unit modules generally utilize double-sided soldered crystalline silicon cells. After the photovoltaic tile is manufactured, numerous silvery-white interconnecting strips are evenly distributed on the front of the cell. These silvery-white interconnecting strips create a noticeable color difference from the deep blue cell, resulting in a poorly consistent surface appearance of the photovoltaic tile. Currently, double-sided soldered cell panels have a high number of interconnecting strips on the front. When sunlight strikes the cell, these interconnecting strips partially block the light, preventing the double-sided soldered crystalline silicon cell from effectively absorbing the light, thus severely impacting its photoelectric conversion efficiency.

[0003] During the current manufacturing process of double-sided crystalline silicon solar cells, a gap of 0.5 to 2.0 mm is typically maintained between adjacent cells for welding. This design exposes the interconnecting strips connecting the two halves of the solar cells on the front of the photovoltaic tile after welding. The cells cannot completely cover these interconnects, which not only affects the appearance of the photovoltaic tile but also reduces the overall aesthetics of the product. Summary of the Invention

[0004] The object of the present invention is to provide a photovoltaic tile assembly that can improve the photoelectric conversion efficiency and enhance the safety of battery use.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A photovoltaic tile assembly includes multiple back-contact cells and interconnecting strips. One end of adjacent back-contact cells overlaps. The positive leads and negative leads of the multiple back-contact cells are all arranged on the back side of the back-contact cells and are connected in series through the interconnecting strips.

[0007] In a further embodiment, the back-contact cell includes a concentrating matrix, a P-type semiconductor region and an N-type semiconductor region, and the P-type semiconductor region and the N-type semiconductor region are arranged at intervals within the concentrating matrix. The positive lead and the negative lead include a main grid line and a secondary grid line. The sides of the P-type semiconductor region and the N-type semiconductor region that are away from the concentrating matrix and facing the light source are both connected to the secondary grid line, and the secondary grid line connected to the P-type semiconductor region and the secondary grid line connected to the N-type semiconductor region are respectively connected in parallel through the main grid line, and the interconnection strip is connected to the main grid line.

[0008] In a further solution, the auxiliary grid lines are arranged in sequence, the main grid lines are arranged in sequence on the auxiliary grid lines, and insulating glue is coated between the main grid lines and the auxiliary grid lines of different polarities.

[0009] In a further embodiment, adjacent back contact cells are symmetrical to each other along their connection center lines.

[0010] In a further embodiment, the back contact cells connected in series form a rectangular plate, and the plurality of interconnecting strips extend beyond both ends of the rectangular plate and are connected to bus bars for connecting interconnecting strips of the same polarity in parallel.

[0011] In a further embodiment, a reverse biased diode is connected to the other end of the busbar that is connected to the interconnection bar.

[0012] In a further solution, multiple strings of the back-contact battery cells connected in series are included, and there is a string spacing between two adjacent strings of the back-contact battery cells connected in series, and the string spacing ranges from 2 to 5 mm; the busbar of each string of back-contact battery cells is preset with a creepage distance on the side away from the back-contact battery cell; and there is an anti-short-circuit spacing between the busbar and the back-contact battery cell.

[0013] The present invention also provides a method for preparing a photovoltaic tile assembly, comprising:

[0014] Producing a plurality of back-contact solar cells connected in series, wherein the back-contact solar cells are overlapped at one end and connected in series via interconnecting strips;

[0015] The positive and negative leads of the back-contact solar cell are arranged on the back side of the back-contact solar cell.

[0016] In a further solution, a P-type semiconductor region and an N-type semiconductor region are formed on the back contact cell concentrating substrate and are spaced apart from each other;

[0017] Auxiliary grid lines are covered on the side of the P-type semiconductor region and the N-type semiconductor region away from the focusing substrate and facing the light source, and the auxiliary grid lines of different polarities are connected in sequence through the main grid lines to form a plurality of main grid lines arranged in sequence. Interconnection bars are connected to the main grid lines to polarize and conduct the charges generated by the P-type semiconductor region and the N-type semiconductor region out of the P-type semiconductor region and the N-type semiconductor through the auxiliary grid lines, the main grid lines and the interconnection bars in sequence.

[0018] In a further embodiment, all P-type semiconductor regions and N-type semiconductor regions are interconnected by interconnection strips according to polarity to form a rectangular plate, and the interconnection strips are extended to the ends of the rectangular plate;

[0019] The interconnection strips outside the two ends of the rectangular plate are connected in parallel according to polarity through the busbar;

[0020] A reverse biased diode is connected to the other end of the bus ribbon which is connected to the interconnection bar.

[0021] Beneficial effects of the present invention:

[0022] The photovoltaic tile assembly of the present invention utilizes internal back-contact cells and connects multiple back-contact cells in series through interconnection strips to form a whole string of cells. This design not only shields the silver-white interconnection strips on the back, but also allows more cells to be arranged in the same area, thereby effectively improving the power generation efficiency of the product. The front of the photovoltaic tile assembly can be free of grid line obstruction, allowing all shielding parts to be arranged on the back of the back-contact cells, which not only improves the aesthetics of the real question, but also improves the photoelectric conversion efficiency.

[0023] Through the half-cut welding technology of the back-contact battery, the back-contact battery cell is separated from the original substrate, and the overlapping welding method of two adjacent symmetrical back-contact battery cells is adopted to successfully eliminate the spacing between the two adjacent back-contact battery cells.

[0024] Multiple battery strings are connected through a busbar to form a circuit with positive and negative lead-out terminals, and a reverse diode is set at the total busbar point at the end of the busbar to improve the safety of battery use. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 This is a schematic diagram of the connection of a photovoltaic tile assembly in an embodiment of the present invention;

[0027] Figure 2 Schematic diagram of the connection between the main grid line and the auxiliary grid line in an embodiment of the present invention;

[0028] Figure 3 Schematic diagram of a back contact cell cut into half in an embodiment of the invention;

[0029] Figure 4 Schematic diagram of the lamination area of two adjacent back contact solar cells in an embodiment of the present invention;

[0030] Figure 5 This is a schematic diagram of the interconnection strips according to an embodiment of the present invention;

[0031] Figure 6 is a schematic diagram of parallel interconnected busbars in an embodiment of the present invention;

[0032] Figure 7 : is a connection diagram of the diode in the embodiment of the invention.

[0033] In the figure: 1. Back contact cell; 11. Concentrating substrate; 12. P-type semiconductor region; 13. N-type semiconductor region; 14. Secondary grid line; 15. Main grid line; 16. Silicon wafer; 17. Insulation glue; 2. Interconnection strip; 3. Busbar; 4. Diode; 5. Passivation isolation region. DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0035] like Figure 1 As shown, a photovoltaic tile assembly includes a plurality of back contact cells 1 and interconnecting strips 2, see Figure 4 As shown, one end of adjacent back contact battery cells 1 overlaps, and the positive and negative leads of the plurality of back contact battery cells 1 are arranged as shown in FIG. Figure 1 The back side of the back contact cell 1 is connected in series via the interconnection bars 2. This allows the front side of the back contact cell 1 to be free from grid lines or interconnection bars 2, thus reducing the amount of grid lines or other factors blocking sunlight, thereby improving the photoelectric conversion efficiency of the solar cell.

[0036] The entire photovoltaic tile assembly can contain 1 to 24 commonly used back contact cells 1, and can also contain more back contact cells 1. The entire photovoltaic tile assembly can be welded with overlapping R distances to remove the original spacing between the two pieces, which can improve the power generation conversion efficiency of the product. Overlap welding here can also play a role in shielding the silver-white interconnection strips 2, thereby improving the aesthetics of the front of the product. Not only can overlapping welding be used to shield the silver-white interconnection strips 2, but also the spacing between the two back contact cells 1 can be covered by film (the film color can be selected to be close to the film layer of the cell), and the film layer is located between the cell and the interconnection strip 2, thereby shielding the silver-white interconnection strips 2 and improving the aesthetics of the front of the product.

[0037] In some embodiments, the back contact cell 1 includes a light concentrating substrate 11, a P-type semiconductor region 12 and an N-type semiconductor region 13, wherein the P-type semiconductor region 12 and the N-type semiconductor region 13 are arranged in a spaced relationship within the light concentrating substrate 11, and the positive lead and the negative lead include: Figure 2As shown, the main grid lines 15 and the auxiliary grid lines 14, the P-type semiconductor region 12 and the N-type semiconductor region 13 are connected to the auxiliary grid lines 14 on the side away from the focusing substrate 11 and facing the light source, and the auxiliary grid lines 14 connected to the P-type semiconductor region 12 and the auxiliary grid lines 14 connected to the N-type semiconductor region 13 are respectively connected in parallel through the main grid lines 15, and the interconnection bars 2 are connected to the main grid lines 15. In this way, the P-type semiconductor region 12 and the N-type semiconductor region 13 in the back-contact solar cell 1 are concentrated on the back side and isolated by a fine interdigital pattern. The P-type semiconductor region 12 and the N-type semiconductor region 13 correspond to the positive and negative poles respectively. The P-type semiconductor region 12 refers to the P region formed by doping the silicon wafer 16 with boron elements. Its majority carriers are holes. The P-type semiconductor region 12 acts as the positive electrode (+) and is responsible for collecting photogenerated holes (minority carriers) and conducting current through the metal electrode on the back side. The N-type semiconductor region 13 is formed by phosphorus doping the silicon wafer 16. Its majority carriers are electrons (negative charge). The N-type semiconductor region 13 acts as a negative electrode, collecting photogenerated electrons (minority carriers) and conducting current through the back electrode. Electron-hole pairs generated by light separate under the built-in electric field of the PN junction, with holes migrating to the P-type semiconductor region 12 and electrons to the N-type semiconductor region 13, thus generating a current. The back-contacted solar cell 1 has a secondary gate 14 on the back side, which is a metal electrode covering the P-type and N-type semiconductor regions 12, 13. It is used to conduct charge from the semiconductor regions to the main gate 15. One fine gate line covers the P-type semiconductor region 12, while another adjacent secondary gate line 14 covers the N-type semiconductor region 13. These alternating secondary gate lines 14 are arranged in a sequence, forming a metallization pattern. The negative secondary gate line 14 is located within the laser trough, while the positive secondary gate line 14 is located on a flat surface. The auxiliary grid lines 14 are at the bottom, and the main grid lines 15 are at the top, and the auxiliary grid lines 14 and the main grid lines 15 are arranged in a vertical orientation.

[0038] In some embodiments, the auxiliary grid lines 14 are arranged in sequence, and the main grid lines 15 are arranged in sequence on the auxiliary grid lines 14, and insulating glue 17 is applied between the main grid lines 15 and the auxiliary grid lines 14 of different polarities. The insulating glue 17 is a special polymer composite material applied to the electrode area on the back of the back contact cell 1, which realizes the physical isolation and electrical insulation of the positive and negative electrodes through chemical formula design. Its core function is to prevent short circuits caused by contact between adjacent electrodes (main grids and auxiliary grids of different polarities) and form an insulating barrier. The back contact cell 1 reduces the precision requirements of component string welding by precisely printing the insulating glue 17, and the automated production is more efficient. Because the auxiliary grid lines 14 and the main grid lines 15 on the back of the back contact cell 1 are arranged in an alternating positive and negative arrangement, in order to ensure correct alignment during the subsequent packaging component welding or connection process, "Mark points" are used for marking, and other marking methods can also be used. Correct electrode connection plays an important role in component packaging.

[0039] In some embodiments, adjacent back contact cells 1 are symmetrical along their connection center lines. Back contact cells 1 are usually cut in half during the module packaging process to form Figure 3 The back contact cell 1 of the half-piece shown is intended to reduce resistance loss and improve efficiency. When the entire cell is divided into two pieces, the cutting position is usually in the original middle area, that is, the position of the passivation isolation area 5. The passivation isolation area 5 is an intermediate passivation area pre-designed before slicing, which is electrically isolated by an ultra-thin oxide layer or passivation technology. The main function is to suppress the defects caused by cutting that lead to carrier recombination, while maintaining the conversion efficiency of each cell. The back contact cell 1 has chamfers on the four corners of the entire cell. The upper and lower halves of the entire cell are diced from the midpoint position, and each half forms a chamfered edge and a cutting edge after cutting. After the lower half is rotated 180°, the electrode pattern is the same as the pattern of the upper half. This design facilitates the electrode connection between the half pieces during the component packaging process.

[0040] The interconnection bar 2 is the core component for achieving electrical connection between the back contact battery cells 1 and the back contact battery cells 1. Low resistance materials such as tinned copper strips are usually used to optimize the current path and reduce energy loss during transmission. The interconnection bar 2 connects the positive and negative poles of adjacent back contact battery cells 1 in series through welding to form a complete circuit to achieve current transmission. The entire back contact battery cell 1 is cut in half and rearranged, and a shorter interconnection bar 2 is used to reduce resistance. The shape of the interconnection bar 2 can be a flat solder strip or a round solder strip, and its diameter can range from φ0.20mm to 0.4mm. Figure 4 As shown, the connection method of adjacent back-contact battery cells 1 is as follows: first, two back-contact battery cells 1, such as the upper and lower back-contact battery cells 1 that can be cut by slicing, are stacked, and the overlapping distance R can be selected to be 0.3mm, 0.5mm, 0.8mm, 1.0mm, 1.2mm or more. Then, the negative main grid lines 15 of the upper half of the whole battery and the positive main grid lines 15 of the lower half are sequentially welded using interconnection bars 2. When welding, the side with the "Mark" point on the main grid line 15 can be referred to as the negative electrode. Then, the positive main grid lines 15 of the upper half of the whole battery are sequentially welded using interconnection bars 2 to form the positive lead of the back-contact battery cell 1 circuit. Finally, the negative main grid lines 15 of the lower half of the whole battery are sequentially welded using interconnection bars 2 to form the negative lead of the back-contact battery cell 1 circuit.

[0041] In some embodiments, as Figure 5 As shown, the back contact cells 1 connected in series form a rectangular plate, and the plurality of interconnection bars 2 extend to both ends of the rectangular plate and are connected with bus bars 3, which are used to connect the interconnection bars 2 of the same polarity in parallel.

[0042] The rectangular plate-type battery string is connected by first welding the positive electrode of the left half of the string to an interconnecting bar 2. This interconnecting bar 2 covers the half and extends to the left beyond the concentrating substrate 11 by a distance L. These bars are then welded sequentially to form a single electrode, such as the positive electrode. The negative electrode of the left half of the string is then welded to the positive electrode of the next half using interconnecting bar 2, and the two left half cells are then welded together. The negative electrode of the second half is then welded to the positive electrode of the third half using interconnecting bar 2, and the second half is then welded to the third half. During welding, interconnecting bar 2 maintains a distance M from the first half to prevent short circuits. The entire string is then welded together using the same method, until the rightmost half of the string is reached. Interconnecting bar 2 extends beyond the rightmost half by a distance L, where it is welded to busbar 3. Busbar 3 is the core material used to connect the battery string to the junction box in the photovoltaic tile assembly. Its main function is to gather the current of multiple battery strings to form a complete power generation circuit. Figure 6 As shown, the busbar 3 is located on the left and right sides of the battery string, collecting the current of the entire string of cells, with one side collecting the positive current and the other side collecting the negative current. The specifications of the busbar 3 are usually 7×0.3mm, 5×0.35mm, 4×0.3mm, 4×0.35mm or other specifications. There is a distance D between the busbar 3 and the cell, which is usually 2 to 5mm. If this distance is too small, the busbar 3 may contact the cell and cause a short circuit or leakage. Under the long-term operation of the photovoltaic tile assembly, the difference in thermal expansion coefficient between the cell and the busbar 3 may lead to mechanical stress concentration, which may cause hidden cracks in the cell or breakage of the interconnection strip 2, affecting the service life of the photovoltaic tile.

[0043] In some embodiments, the other end of the busbar 3 connected to the interconnection bar 2 is connected to a reverse biased diode 4. Figure 7As shown, multiple back-contact solar cells 1 are connected in series, forming a battery string with independent power supply. A battery string is represented by a battery symbol. Alternatively, the battery string can be connected to an external battery, and the battery string and the external battery are connected in series to form a series group. The series groups can then be connected in parallel. For example, two or more battery strings can be connected in parallel, with a total positive point formed on the left side of the busbar 3 and a total negative point on the right, or a total negative point on the left side of the busbar 3 and a total positive point on the right. Diodes 4 are used to reverse-bias the positive and negative points on both sides. If a portion of the solar cells in the PV tile assembly is blocked or damaged, diodes 4 automatically conduct and bypass the problem area, preventing local overheating and causing module burnout. This ensures that the unaffected cells continue to generate power, minimizing power losses, ensuring stable overall power output, and preventing hot spots and current interruptions. By routing busbars 3 out to the total busbar, the number of diodes used can be reduced.

[0044] In some embodiments, the length of the overlapping area is less than or equal to the short-circuit safety distance between adjacent back-contact solar cells 1. This can minimize the overlapping area and maximize the use of the upper surface of the back-contact solar cell 1 to receive sunlight.

[0045] In some embodiments, all back-contact cells 1 of a photovoltaic tile are connected in parallel (or in series). Figure 6 In parallel connection, two strings of cells are arranged with a certain string spacing S, typically 2-5mm, taking into account factors such as thermal expansion, mechanical stress release, avoiding hidden cracks, and electrical safety. After the cell strings are interconnected and welded using interconnecting bars 2 via busbars 3, a creepage distance is preset on the outside, such as a creepage distance U formed with the glass edge of the concentrating substrate 11. If the photovoltaic module passes testing (such as the B1 sequence test of IEC61730-2) to reduce the pollution level to Level 1, this creepage distance U can be reduced to 6.4mm for a 1000V system and 10.4mm for a 1500V system. Figure 6 The center busbar draws the current from the two strings of positive batteries on the left and negative batteries on the right to the center of the top of the photovoltaic tile, parallel to the battery string. The busbars 3 on both sides are bent 90 degrees, forming a distance T of 5 to 10 mm to maintain a safe distance. This distance also ensures that the busbars 3 can be welded to the terminals in the external junction box of the photovoltaic tile assembly. A certain short-circuit protection distance P is maintained between the busbar 3 parallel to the battery string and the battery string. This distance is usually 2 to 5 mm. This safety distance prevents contact between the busbar 3 and the battery string, which may cause a short circuit or hidden cracks in the battery cells.

[0046] According to the above embodiments, it is obvious that an embodiment of a method for preparing a photovoltaic tile assembly can be obtained, which specifically includes:

[0047] S1. Prepare multiple back-contact battery cells 1 connected in series, wherein the back-contact battery cells 1 are connected in series by overlapping one end and interconnecting with each other through interconnection bars 2; set the positive lead and the negative lead of the back-contact battery cell 1 on the back side of the back-contact battery cell 1.

[0048] In some embodiments, step S1 includes: S11, forming a P-type semiconductor region 12 and an N-type semiconductor region 13 arranged alternately on a light-concentrating substrate 11 of a back contact cell 1;

[0049] A secondary grid line 14 is covered on the side of the P-type semiconductor region 12 and the N-type semiconductor region 13 that is away from the focusing substrate 11 and faces the light source, and the secondary grid lines 14 of different polarities are connected in sequence through the main grid line 15 to form a plurality of main grid lines 15 arranged in sequence, and the interconnection bar 2 is connected to the main grid line 15 to polarize and conduct the charges generated by the P-type semiconductor region 12 and the N-type semiconductor region 13 out of the P-type semiconductor region 12 and the N-type semiconductor in sequence through the secondary grid line 14, the main grid line 15 and the interconnection bar 2.

[0050] In some embodiments, step S1 further includes: S12, interconnecting all P-type semiconductor regions 12 and N-type semiconductor regions 13 according to polarity through interconnection bars 2 to form a rectangular plate, and extending the interconnection bars 2 to both ends of the rectangular plate;

[0051] The interconnection bars 2 outside the two ends of the rectangular plate are connected in parallel according to polarity through the busbar 3;

[0052] A reverse biased diode 4 is connected to the other end of the bus ribbon 3 which is connected to the interconnection bar 2 .

[0053] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0054] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications fall within the scope of the invention as claimed.

Claims

1. A photovoltaic tile assembly, characterized in that: The invention comprises a plurality of back contact battery sheets (1) and interconnection bars (2), wherein one end of adjacent back contact battery sheets (1) overlaps, and the positive electrode leads and negative electrode leads of the plurality of back contact battery sheets (1) are arranged on the back side of the back contact battery sheets (1) and are connected in series via the interconnection bars (2).

2. A photovoltaic tile assembly according to claim 1, characterized in that: The back contact cell (1) comprises a light-concentrating matrix (11), a P-type semiconductor region (12) and an N-type semiconductor region (13); the P-type semiconductor region (12) and the N-type semiconductor region (13) are arranged in a spaced relationship within the light-concentrating matrix (11); the positive electrode lead and the negative electrode lead comprise a main grid line (15) and a secondary grid line (14); the sides of the P-type semiconductor region (12) and the N-type semiconductor region (13) facing the light source and away from the light-concentrating matrix (11) are both connected to the secondary grid line (14); the secondary grid line (14) connected to the P-type semiconductor region (12) and the secondary grid line (14) connected to the N-type semiconductor region (13) are respectively connected in parallel via the main grid line (15); and the interconnection bar (2) is connected to the main grid line (15).

3. A photovoltaic tile assembly according to claim 2, characterized in that: The auxiliary grid lines (14) are arranged in sequence, and the main grid lines (15) are arranged in sequence on the auxiliary grid lines (14). Insulation glue (17) is applied between the main grid lines (15) and the auxiliary grid lines (14) of different polarities.

4. A photovoltaic tile assembly according to claim 1, characterized in that: Adjacent back contact battery sheets (1) are symmetrical to each other along their connection center lines.

5. The photovoltaic tile assembly according to claim 1, characterized in that: The back contact battery sheets (1) connected in series form a rectangular plate body, and the plurality of interconnection bars (2) extend outside the two ends of the rectangular plate body and are connected to bus bars (3). The bus bars (3) are used to connect interconnection bars (2) of the same polarity in parallel.

6. A photovoltaic tile assembly according to claim 5, characterized in that: The other end of the busbar (3) connected to the interconnection bar (2) is connected to a reverse-biased diode (4).

7. The photovoltaic tile assembly according to claim 5, characterized in that: The invention comprises a plurality of strings of back-contact battery cells (1) connected in series, wherein a string spacing is provided between two adjacent strings of back-contact battery cells (1), and the string spacing ranges from 2 to 5 mm; a creepage distance is preset on a side of a busbar (3) of each string of back-contact battery cells (1) away from the back-contact battery cells (1); and an anti-short-circuit spacing is provided between the busbar (3) and the back-contact battery cells (1).

8. A method for preparing a photovoltaic tile assembly, characterized in that: The method comprises: Producing a plurality of back-contact battery cells (1) connected in series, wherein the back-contact battery cells (1) are connected in series by overlapping at one end and by interconnecting bars (2); The positive electrode lead and the negative electrode lead of the back contact battery sheet (1) are arranged on the back side of the back contact battery sheet (1).

9. The method for preparing a photovoltaic tile assembly according to claim 8, characterized in that: The method comprises: A P-type semiconductor region (12) and an N-type semiconductor region (13) are formed on a light-concentrating substrate (11) of a back contact cell (1) and are arranged spaced apart from each other; A secondary grid line (14) is covered on the side of the P-type semiconductor region (12) and the N-type semiconductor region (13) that is away from the light-concentrating substrate (11) and faces the light source, and the secondary grid lines (14) of different polarities are sequentially connected through the main grid line (15) to form a plurality of main grid lines (15) arranged in sequence. Interconnection bars (2) are connected to the main grid lines (15) to conduct charges generated by the P-type semiconductor region (12) and the N-type semiconductor region (13) to the outside of the P-type semiconductor region (12) and the N-type semiconductor region through the secondary grid lines (14), the main grid lines (15) and the interconnection bars (2) in a polarized manner.

10. A method for preparing a photovoltaic tile assembly according to claim 9, characterized in that: The method comprises: All P-type semiconductor regions (12) and N-type semiconductor regions (13) are interconnected according to polarity through interconnection bars (2) to form a rectangular plate, and the interconnection bars (2) are extended to the outside of both ends of the rectangular plate; The interconnection strips (2) outside the two ends of the rectangular plate are connected in parallel according to polarity through a busbar (3); A reverse biased diode (4) is connected to the other end of the busbar (3) connected to the interconnection bar (2).

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