Full back electrode photovoltaic cell

Abstract

The utility model provides a full back electrode photovoltaic cell. The full back electrode photovoltaic cell comprises a substrate layer, and a transparent electrode layer, a buffer layer, a light absorption layer and a back electrode layer which are sequentially arranged on the substrate layer, the first groove is filled with a back electrode layer material, and the first groove penetrates through the buffer layer and the light absorption layer; the second groove at least penetrates through the buffer layer and the light absorption layer; and the third groove at least penetrates through the transparent electrode layer, the buffer layer and the light absorption layer, and divides the full back electrode photovoltaic cell into a plurality of sub-cells. According to the utility model, the voltage of the thin film assembly is reduced by realizing parallel connection of the sub-batteries, and the electrical safety is improved; and when the low-voltage assembly is applied, more photovoltaic assemblies can be connected in series with an inverter, so that the cable consumption of a photovoltaic system is reduced, and wiring is simplified.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaics, and in particular to a full back electrode photovoltaic cell. Background Art

[0002] In the field of photovoltaic technology, photovoltaic system components such as inverters play a vital role. At present, the mainstream photovoltaic system components on the market are mainly designed and manufactured based on silicon-based photovoltaic technology. Silicon-based photovoltaic technology has occupied a dominant position in the photovoltaic market with its mature technical system, stable performance and relatively low cost.

[0003] However, when thin-film photovoltaics use the above configurations, due to their high voltage and low current characteristics, a large number of parallel settings are usually required to adapt to their voltage and current requirements. This parallel setting not only increases the complexity of the system, but also leads to a significant increase in the amount of cables used. A large number of cables not only complicates the layout of the entire photovoltaic system, increases the difficulty of installation and maintenance, but also leads to an increase in costs. In addition, the complex cable layout and a large number of parallel settings also bring great risks to the electrical safety of the photovoltaic system. Utility Model Content

[0004] The main purpose of the embodiment of the utility model is to provide a full back electrode photovoltaic cell to reduce the voltage of the thin film component, simplify the wiring, and improve the electrical safety.

[0005] In order to achieve the above-mentioned purpose, the embodiment of the utility model provides a full back electrode photovoltaic cell, comprising:

[0006] A substrate layer and a transparent electrode layer, a buffer layer, a light absorbing layer and a back electrode layer sequentially arranged on the substrate layer;

[0007] a first groove, wherein the first groove is filled with a back electrode layer material, and the first groove at least penetrates the buffer layer and the light absorption layer;

[0008] a second groove, wherein the second groove at least penetrates the buffer layer and the light absorbing layer;

[0009] A third groove, wherein the third groove at least penetrates the transparent electrode layer, the buffer layer and the light absorption layer, and the third groove divides the full back electrode photovoltaic cell into a plurality of sub-cells.

[0010] In one embodiment, the second groove also penetrates the back electrode layer and is located between the positive electrode and the negative electrode of the back electrode layer; the third groove also penetrates the back electrode layer; and the first groove corresponds to the negative electrode of the back electrode layer.

[0011] In one embodiment, the third groove also penetrates the back electrode layer; and the full back electrode photovoltaic cell further comprises:

[0012] a fourth groove, wherein the fourth groove penetrates the back electrode layer and divides the cross section of the back electrode layer into a positive electrode part and a negative electrode part;

[0013] an insulating layer, the insulating layer being located between the light absorbing layer and the negative electrode portion of the back electrode layer;

[0014] The first groove also penetrates the insulating layer.

[0015] In one embodiment, the second groove is filled with an insulating layer material.

[0016] In one embodiment, it also includes:

[0017] a fifth groove, wherein the fifth groove penetrates the transparent electrode layer, the buffer layer and the light absorbing layer;

[0018] The fifth groove is filled with an insulating layer material.

[0019] In one embodiment, the second groove also penetrates the back electrode layer and is located between the positive electrode and the negative electrode of the back electrode layer; the second groove is an annular groove surrounding the first groove;

[0020] The third groove is filled with an insulating layer material.

[0021] In one embodiment, the second groove is opened along a first direction of the plane where the back electrode layer is located;

[0022] The third groove is opened along the first direction and the second direction of the plane where the back electrode layer is located;

[0023] The first direction and the second direction are perpendicular to each other.

[0024] In one embodiment, the second groove is located between different third grooves in the first direction and connected to the third grooves.

[0025] In one embodiment, the second groove is opened along a first direction of the plane where the back electrode layer is located;

[0026] The third groove is opened along the first direction and the second direction of the plane where the back electrode layer is located;

[0027] The first direction and the second direction are perpendicular to each other;

[0028] The second groove is located between different third grooves in the first direction and connected to the third grooves;

[0029] The fifth groove is opened along the first direction and is located in the extension direction of the second groove or the third groove. One end of the fifth groove is connected to the third groove, and the other end of the fifth groove extends to the edge of the full back electrode photovoltaic cell.

[0030] In one embodiment, it further includes: a bus bar for connecting the multiple sub-batteries in parallel.

[0031] The full back electrode photovoltaic cell of the embodiment of the utility model reduces the voltage of the thin film component by connecting sub-cells in parallel, thereby improving electrical safety; and when low-voltage components are used, more photovoltaic components can be connected in series to the inverter, reducing the amount of cables used in the photovoltaic system and simplifying the wiring. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 is a top view of the full back electrode photovoltaic cell in the first embodiment or the second embodiment of the utility model;

[0034] Figure 2 is a1-a1 cross-sectional view of the full back electrode photovoltaic cell in the first embodiment of the utility model;

[0035] Figure 3 is a1-a1 cross-sectional view of a full back electrode photovoltaic cell in the second embodiment of the utility model;

[0036] Figure 4 is a top view of a full back electrode photovoltaic cell in the third embodiment of the utility model;

[0037] Figure 5 It is a bb cross-sectional view of a full back electrode photovoltaic cell in the third embodiment of the utility model;

[0038] Figure 6 is a2-a2 cross-sectional view of a full back electrode photovoltaic cell in the third embodiment of the utility model;

[0039] Figure 7 is a cc cross-sectional view of a full back electrode photovoltaic cell in the third embodiment of the utility model;

[0040] Figure 8 is a top view of a full back electrode photovoltaic cell in a fourth embodiment of the utility model;

[0041] Fig. 9It is a dd cross-sectional view of the full back electrode photovoltaic cell in the fourth embodiment of the utility model. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0043] At present, thin-film photovoltaics usually need to be set up in parallel in large quantities to meet their voltage and current requirements, which not only increases the complexity of the system, but also leads to a significant increase in the amount of cables used. A large number of cables not only increases the difficulty of installation and maintenance, but also leads to an increase in costs, which brings great risks to the electrical safety of the photovoltaic system. To this end, the utility model provides a full back electrode photovoltaic cell to simplify wiring, reduce costs, and improve electrical safety.

[0044] Figure 1 It is a top view of the full back electrode photovoltaic cell in the first embodiment or the second embodiment of the utility model. Figure 2 It is the a1-a1 cross-sectional view of the full back electrode photovoltaic cell in the first embodiment of the utility model. Figure 1 and Figure 2 The arrow in the figure indicates the direction of current movement. Figure 1-Figure 2 As shown, the full back electrode photovoltaic cell includes: a substrate layer 10, a transparent electrode layer 14, an N-type buffer layer 13, a P-type light absorption layer 12, a back electrode layer 11, a first groove 1, a second groove 2 and a third groove 3.

[0045] The transparent electrode layer 14 , the N-type buffer layer 13 , the P-type light absorbing layer 12 and the back electrode layer 11 are sequentially arranged on the substrate layer 10 .

[0046] The first groove 1 is filled with a back electrode layer material, and the first groove 1 at least penetrates the buffer layer 13 and the light absorption layer 12;

[0047] The second groove 2 at least penetrates the buffer layer 13 and the light absorbing layer 12;

[0048] The third groove 3 at least penetrates the transparent electrode layer 14 , the buffer layer 13 and the light absorption layer 12 , and the third groove 3 divides the full back electrode photovoltaic cell into a plurality of sub-cells.

[0049] Among them, the material of the back electrode layer filled in the first groove 1 allows the back electrode and the front electrode of the sub-cell to be electrically connected; the second groove 2 is used to divide the sub-cell into a power generation part and a non-power generation part, and at the same time divide the back electrode into a positive electrode part and a negative electrode part.

[0050] In one embodiment, when the full back electrode photovoltaic cell is a cadmium telluride photovoltaic cell, the material of the substrate layer 10 can be glass, the material of the transparent electrode layer can be TCO (Transparent Conductive Oxide, transparent oxide semiconductor film), the buffer layer material can be CdS (cadmium sulfide), the light absorption layer material can be CdTe (cadmium telluride), and the back electrode layer 11 material can be Al (aluminum).

[0051] In one embodiment, the full back electrode photovoltaic cell in the embodiment of the utility model further includes a bus bar 20, which is used to connect multiple sub-cells in parallel, so as to balance the current between the sub-cells connected in parallel and avoid energy loss due to imbalance. By effectively balancing the current, the bus bar improves the power conversion efficiency of the full back electrode photovoltaic cell, so that the power generated by the full back electrode photovoltaic cell can be more efficiently transmitted to the load or energy storage device.

[0052] like Figure 2 As shown, in the first embodiment, the second groove 2 also penetrates the back electrode layer 11 and is located between the positive pole and the negative pole of the back electrode layer; the third groove 3 also penetrates the back electrode layer 11; the first groove 1 corresponds to the negative pole of the back electrode layer 11, and the positive pole and the negative pole are determined by the position of the first groove 1.

[0053] like Figure 1 As shown, in the first embodiment and the second embodiment, the second groove 2 is opened along the first direction y of the plane where the back electrode layer 11 is located;

[0054] The third groove 3 is opened along the first direction y and the second direction x of the plane where the back electrode layer 11 is located;

[0055] The first direction y and the second direction x are perpendicular to each other.

[0056] The second groove 2 is located between different third grooves 3 in the first direction y and is connected to the third groove 3 .

[0057] Specifically, Figure 1 As shown, in the horizontal direction, one end of the third groove 3 is connected to the second groove 2, and the other end extends to the edge of the full back electrode photovoltaic cell.

[0058] In specific implementation, the first embodiment of the utility model can be obtained through the following process:

[0059] 1. A transparent electrode layer 14, an N-type buffer layer 13 and a P-type light absorbing layer 12 are sequentially plated on the substrate layer 10.

[0060] 2. Laser scribes a first groove 1 , which penetrates the light absorbing layer 12 and the buffer layer 13 .

[0061] 3. A back electrode layer 11 is plated on the P-type light absorption layer 12, and the material of the back electrode layer is used to fill the first groove 1 to improve the power transmission efficiency.

[0062] 4. Laser scribe the second groove 2 so that the second groove 2 penetrates the back electrode layer 11 , the light absorption layer 12 and the buffer layer 13 .

[0063] 5. Laser-scribe the third groove 3 so that the third groove 3 penetrates the back electrode layer 11, the light absorption layer 12, the buffer layer 13 and the transparent electrode layer 14, so as to divide the full back electrode photovoltaic cell into a plurality of sub-cells.

[0064] 6. Set up positive and negative bus bars to connect multiple sub-batteries in parallel.

[0065] In summary, in the first embodiment of the utility model, the current transmission efficiency is optimized through the structure of each slot, and the voltage of the thin-film component is reduced by connecting the sub-batteries in parallel, thereby improving electrical safety.

[0066] Figure 3 1 is a cross-sectional view of the full back electrode photovoltaic cell in the second embodiment of the present utility model taken along line a1-a1. Figure 3 As shown, Figure 3 The arrow in the figure indicates the direction of current movement. In the second embodiment, the third groove 3 also penetrates the back electrode layer 11; the full back electrode photovoltaic cell further includes:

[0067] The fourth groove 4 runs through the back electrode layer 11, and divides the cross section of the back electrode layer 11 into a positive electrode part and a negative electrode part, so as to match the positive and negative electrode charge transfer amounts, wherein the cross section is the plane where the back electrode layer 11 is located;

[0068] An insulating layer 15, wherein the insulating layer 15 is located between the light absorbing layer 12 and the negative electrode portion of the back electrode layer 11;

[0069] The first groove 1 also penetrates the insulating layer 15 .

[0070] In one embodiment, the second slot 2 is filled with an insulating layer material, so that the layers on both sides of the slot are absolutely insulated from each other, thereby optimizing the charge transfer path inside the battery.

[0071] In specific implementation, the second embodiment of the utility model can be obtained through the following process:

[0072] 1. A transparent electrode layer 14, an N-type buffer layer 13 and a P-type light absorbing layer 12 are sequentially plated on the substrate layer 10.

[0073] 2. Laser scribe the second groove 2 so that the second groove 2 penetrates the light absorbing layer 12 and the buffer layer 13 .

[0074] 3. An insulating layer 15 is plated on the P-type light absorbing layer 12 , and the material of the insulating layer fills the second groove 2 .

[0075] 4. Laser scribe the first groove 1 so that the first groove 1 penetrates the insulating layer 15 , the light absorbing layer 12 and the buffer layer 13 .

[0076] 5. Laser scribing the insulating groove 16. Figure 3 As shown, the insulating groove 16 is Figure 3 In the virtual frame part, part of the insulating layer is removed through the insulating groove 16.

[0077] 6. Plate a back electrode layer 11 on the insulating layer 15 and a portion of the P-type light absorption layer, and fill the first groove 1 and the insulating groove 16 with the material of the back electrode layer.

[0078] 7. The fourth groove 4 is scribed by laser so that the fourth groove 4 penetrates the back electrode layer 11 and the edge portion of the insulating layer 15 connected to the insulating groove 16 is cut off.

[0079] 8. Laser-scribe the third groove 3 so that the third groove 3 penetrates the back electrode layer 11 , the insulating layer 15 , the light absorbing layer 12 , the buffer layer 13 and the transparent electrode layer 14 .

[0080] In summary, the second embodiment of the present invention can match the positive and negative electrode charge transfer amounts by making the positive and negative electrode current cross-sectional areas of the full back electrode photovoltaic cell the same.

[0081] Figure 4 It is a top view of a full back electrode photovoltaic cell in the third embodiment of the utility model. Figure 5 It is a bb cross-sectional view of a full back electrode photovoltaic cell in the third embodiment of the utility model. Figure 6 It is a cross-sectional view taken along line a2-a2 of a full back electrode photovoltaic cell in the third embodiment of the present utility model. Figure 7 cc is a cross-sectional view of a full back electrode photovoltaic cell in the third embodiment of the present utility model. Figure 4-Figure 7 As shown, the arrow in the figure is the direction of movement of the current. In the third embodiment, the full back electrode photovoltaic cell also includes:

[0082] The fifth groove 5 penetrates the transparent electrode layer 14, the buffer layer 13 and the light absorption layer 12, and is used to divide the full back electrode photovoltaic cell into a plurality of sub-cells.

[0083] In one embodiment, the fifth groove 5 is filled with an insulating layer material to prevent the material of the back electrode layer from filling it, thereby ensuring absolute insulation between the layers on both sides of the groove and optimizing the charge transfer path inside the battery.

[0084] Specifically, Figure 4 As shown, Figure 4 The dotted line portion in the figure is the fifth groove 5. In the third embodiment, the second groove 2 is opened along the first direction y of the plane where the back electrode layer 11 is located;

[0085] The third groove 3 is opened along the first direction y and the second direction x of the plane where the back electrode layer 11 is located;

[0086] The first direction y and the second direction x are perpendicular to each other.

[0087] The second groove 2 is located between different third grooves 3 in the first direction y and is connected to the third groove 3 .

[0088] One end of the third groove 3 is connected to the second groove 2, and the other end is connected to another second groove 2; or, the other end of the third groove 3 extends to the edge of the full back electrode photovoltaic cell.

[0089] The second groove 2 is located between different third grooves 3 in the first direction y and is connected to the third groove 3 .

[0090] The fifth groove 5 is opened along the first direction and is located in the extension direction of the second groove 2 or the third groove 3 . One end of the fifth groove 5 is connected to the third groove 3 , and the other end of the fifth groove 5 extends to the edge of the full back electrode photovoltaic cell.

[0091] In specific implementation, the third embodiment of the utility model can be obtained through the following process:

[0092] 1. A transparent electrode layer 14, an N-type buffer layer 13 and a P-type light absorbing layer 12 are sequentially plated on the substrate layer 10.

[0093] 2. Laser scribe the first groove 1 so that the first groove 1 penetrates the light absorbing layer 12 and the buffer layer 13 .

[0094] 3. The fifth groove 5 is scribed by laser so that the fifth groove 5 penetrates the light absorbing layer 12 , the buffer layer 13 and the transparent electrode layer 14 .

[0095] 4. Fill the fifth slot 5 with the material of the insulating layer to prevent it from being filled with the material of the back electrode layer, thereby ensuring absolute insulation between the layers on both sides of the slot and optimizing the charge transfer path inside the battery.

[0096] 5. Plate a back electrode layer 11 on the P-type light absorption layer 12 so that the material of the back electrode layer fills the first groove 1 .

[0097] 6. Laser-scribe the second groove 2 so that the second groove 2 penetrates the back electrode layer 11 , the light absorption layer 12 and the buffer layer 13 .

[0098] 7. Laser scribe the third groove 3 so that the third groove 3 penetrates the back electrode layer 11 , the light absorption layer 12 , the buffer layer 13 and the transparent electrode layer 14 .

[0099] In summary, the third embodiment of the present invention can reduce the use of bus bars by sharing positive and negative electrodes.

[0100] Figure 8It is a top view of a full back electrode photovoltaic cell in the fourth embodiment of the utility model. Fig. 9 DD is a cross-sectional view of a full back electrode photovoltaic cell in the fourth embodiment of the present utility model. Figure 8-Figure 9 In the fourth embodiment, the second groove 2 also penetrates the back electrode layer 11 and is located between the positive electrode and the negative electrode of the back electrode layer 11 ; the second groove 2 is an annular groove surrounding the first groove 1 .

[0101] In one embodiment, the third groove 3 is filled with an insulating layer material. Figure 8 The dotted line portion in FIG. 1 is the third groove 3 .

[0102] In specific implementation, the fourth embodiment of the utility model can be obtained through the following process:

[0103] 1. A transparent electrode layer 14, an N-type buffer layer 13 and a P-type light absorbing layer 12 are sequentially plated on the substrate layer 10.

[0104] 2. Laser scribe the first groove 1 so that the first groove 1 penetrates the light absorption layer 12 (P-type semiconductor) and the buffer layer 13 (N-type semiconductor).

[0105] 3. Laser scribe the third groove 3 so that the third groove 3 penetrates the light absorbing layer 12 , the buffer layer 13 and the transparent electrode layer 14 .

[0106] 4. Fill the third groove 3 with the material of the insulating layer to prevent the material of the back electrode layer from filling it, ensure absolute insulation between the layers on both sides of the groove, and optimize the charge transmission path inside the battery.

[0107] 5. Plate a back electrode layer 11 on the P-type light absorption layer 12 so that the material of the back electrode layer fills the first groove 1 .

[0108] 6. Laser-scribe the second groove 2 so that the second groove 2 penetrates the back electrode layer 11 , the light absorption layer 12 and the buffer layer 13 .

[0109] In summary, the fourth embodiment of the present invention can allow each sub-battery to share a common positive electrode.

[0110] In summary, the full back electrode photovoltaic cell provided by the embodiment of the utility model has the following beneficial effects:

[0111] (1) The parallel connection of sub-cells reduces the voltage of thin-film modules, improves electrical safety and personnel maintenance safety, reduces hot spots and reduces the risk of fire;

[0112] (2) Due to the low voltage, more photovoltaic modules can be connected in series. A traditional inverter can connect several photovoltaic modules in series, while the utility model can connect dozens of photovoltaic modules in series, reducing the parallel connection and the amount of cables used in the photovoltaic system, simplifying the wiring.

[0113] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the utility model in detail. It should be understood that the above description is only a specific embodiment of the utility model and is not intended to limit the scope of protection of the utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the utility model should be included in the scope of protection of the utility model.

Claims

1. A full back electrode photovoltaic cell, characterized in that: include: A substrate layer and a transparent electrode layer, a buffer layer, a light absorbing layer and a back electrode layer sequentially arranged on the substrate layer; a first groove, wherein the first groove is filled with a back electrode layer material, and the first groove at least penetrates the buffer layer and the light absorption layer; a second groove, wherein the second groove at least penetrates the buffer layer and the light absorbing layer; A third groove, wherein the third groove at least penetrates the transparent electrode layer, the buffer layer and the light absorption layer, and the third groove divides the full back electrode photovoltaic cell into a plurality of sub-cells.

2. The full back electrode photovoltaic cell according to claim 1, characterized in that: The second groove also penetrates the back electrode layer and is located between the positive electrode and the negative electrode of the back electrode layer; the third groove also penetrates the back electrode layer; and the first groove corresponds to the negative electrode of the back electrode layer.

3. The full back electrode photovoltaic cell according to claim 1, characterized in that: The third groove also penetrates the back electrode layer; the full back electrode photovoltaic cell also includes: a fourth groove, wherein the fourth groove penetrates the back electrode layer and divides the cross section of the back electrode layer into a positive electrode part and a negative electrode part; an insulating layer, the insulating layer being located between the light absorbing layer and the negative electrode portion of the back electrode layer; The first groove also penetrates the insulating layer.

4. The full back electrode photovoltaic cell according to claim 3, characterized in that: The second groove is filled with an insulating layer material.

5. The full back electrode photovoltaic cell according to claim 2, characterized in that: Also includes: a fifth groove, wherein the fifth groove penetrates the transparent electrode layer, the buffer layer and the light absorbing layer; The fifth groove is filled with an insulating layer material.

6. The full back electrode photovoltaic cell according to claim 1, characterized in that: The second groove also penetrates the back electrode layer and is located between the positive electrode and the negative electrode of the back electrode layer; the second groove is an annular groove surrounding the first groove; The third groove is filled with an insulating layer material.

7. The full back electrode photovoltaic cell according to any one of claims 2 to 5, characterized in that: The second groove is opened along a first direction of the plane where the back electrode layer is located; The third groove is opened along the first direction and the second direction of the plane where the back electrode layer is located; The first direction and the second direction are perpendicular to each other.

8. The full back electrode photovoltaic cell according to claim 7, characterized in that: The second groove is located between different third grooves in the first direction and is connected to the third grooves.

9. The full back electrode photovoltaic cell according to claim 5, characterized in that: The second groove is opened along a first direction of the plane where the back electrode layer is located; The third groove is opened along the first direction and the second direction of the plane where the back electrode layer is located; The first direction and the second direction are perpendicular to each other; The second groove is located between different third grooves in the first direction and connected to the third grooves; The fifth groove is opened along the first direction and is located in the extension direction of the second groove or the third groove. One end of the fifth groove is connected to the third groove, and the other end of the fifth groove extends to the edge of the full back electrode photovoltaic cell.

10. The full back electrode photovoltaic cell according to claim 1, characterized in that: Also includes: A bus bar is used to connect the plurality of sub-batteries in parallel.

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