Heterojunction solar cell and assembly and system comprising same

Abstract

The utility model relates to the technical field of solar power generation, and discloses a heterojunction solar cell and an assembly and a system comprising the same, and the heterojunction solar cell comprises a silicon substrate, a first doped amorphous silicon layer, a second doped amorphous silicon layer, a first transparent conductive film, a second transparent conductive film, a first electrode and a second electrode. The first transparent conductive film is divided into multiple first transparent conductive layers, the carrier concentration of the multiple first transparent conductive layers is gradually increased from the first electrode to the first doped amorphous silicon layer, the carrier concentration of the multiple second transparent conductive layers is gradually increased from the second electrode to the second doped amorphous silicon layer, and the carrier concentration of the multiple second transparent conductive layers is gradually increased from the second electrode to the second doped amorphous silicon layer. The carrier concentration of the multiple second transparent conductive layers is gradually increased, so that the transparent conductive film can be matched with the work function and the energy band of the doped amorphous silicon layer and the electrode, and effective transmission of electrons and holes is further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of solar power generation, in particular to a heterojunction solar cell and components and systems comprising the same. Background Art

[0002] Currently, existing heterojunction solar cells typically incorporate a transparent conductive film on the doped amorphous silicon layer on the front and back sides of the cell. While such heterojunction solar cells offer the advantages of a simple structure, short deposition time for the transparent conductive film, and a single In2O3 content in the transparent conductive film, the transparent conductive film's interface with the doped amorphous silicon layer and the silver electrode can lead to incomplete work function matching between the doped amorphous silicon layer and the transparent conductive film, resulting in band bending. Large band bending prevents effective electron and hole transmission, requiring significant potential barriers to be overcome, which in turn affects the open-circuit voltage and fill factor. Furthermore, the contact resistance between the transparent conductive film and the metal grid lines of the electrode is relatively high, impacting the cell's conversion efficiency. Utility Model Content

[0003] The purpose of the utility model is to provide a heterojunction solar cell and components and systems including the same, which can not only solve the problem of incomplete work function matching between the doped amorphous silicon layer and the transparent conductive film, improve the effective transmission of electrons and holes, but also reduce the contact resistance between the transparent conductive film and the metal grid line of the electrode.

[0004] To achieve the above objectives, the present invention provides a heterojunction solar cell, comprising: a silicon substrate, a first doped amorphous silicon layer, a second doped amorphous silicon layer, a first transparent conductive film, a second transparent conductive film, a first electrode, and a second electrode, wherein the first doped amorphous silicon layer is disposed on one side of the silicon substrate in a first direction, the second doped amorphous silicon layer is disposed on the other side of the silicon substrate in the first direction, the first transparent conductive film is disposed on a side of the first doped amorphous silicon layer facing away from the silicon substrate, the first transparent conductive film comprises at least two first transparent conductive layers stacked along the first direction, the carrier concentration of the multiple first transparent conductive layers gradually increasing along the first direction, the second transparent conductive film is disposed on a side of the second doped amorphous silicon layer facing away from the silicon substrate, the second transparent conductive film comprises at least two second transparent conductive layers stacked along the first direction, the carrier concentration of the multiple second transparent conductive layers gradually decreasing along the first direction, the first electrode is disposed on a side of the first transparent conductive film facing away from the first doped amorphous silicon layer, and the second electrode is disposed on a side of the second transparent conductive film facing away from the second doped amorphous silicon layer.

[0005] Optionally, the first transparent conductive film includes at least three first transparent conductive layers stacked along the first direction, and the carrier concentration of the multiple layers of the first transparent conductive layers gradually increases along the first direction; the second transparent conductive film includes at least three second transparent conductive layers stacked along the first direction, and the carrier concentration of the multiple layers of the second transparent conductive layers gradually decreases along the first direction.

[0006] Optionally, a third transparent conductive film and a fourth transparent conductive film are further included; the third transparent conductive film is arranged between the first transparent conductive film and the first doped amorphous silicon layer, and the carrier concentration of the third transparent conductive film is less than the carrier concentration of the first transparent conductive layer adjacent to the third transparent conductive film; the fourth transparent conductive film is arranged between the second transparent conductive film and the second doped amorphous silicon layer, and the carrier concentration of the fourth transparent conductive film is less than the carrier concentration of the second transparent conductive layer adjacent to the fourth transparent conductive film.

[0007] Optionally, it further includes a first intrinsic amorphous silicon layer and a second intrinsic amorphous silicon layer, wherein the first intrinsic amorphous silicon layer is arranged between the first doped amorphous silicon layer and the silicon substrate, and the second intrinsic amorphous silicon layer is arranged between the second doped amorphous silicon layer and the silicon substrate.

[0008] Optionally, the first doped amorphous silicon layer is an N-type amorphous silicon layer, and the second doped amorphous silicon layer is a P-type amorphous silicon layer.

[0009] Optionally, it includes multiple first electrodes and multiple second electrodes, the multiple first electrodes are arranged at intervals along the second direction on the side of the first transparent conductive film away from the first doped amorphous silicon layer, and the multiple second electrodes are arranged at intervals along the second direction on the side of the second transparent conductive film away from the second doped amorphous silicon layer, and the multiple first electrodes and the multiple second electrodes are arranged in a one-to-one correspondence.

[0010] Optionally, the silicon substrate layer is an N-type silicon wafer.

[0011] In order to achieve the same purpose, the present invention also provides a solar module, including the heterojunction solar cell as described above.

[0012] In order to achieve the same purpose, the present invention also provides a solar energy system, including the solar energy component as described above.

[0013] Compared with the prior art, the present invention provides a heterojunction solar cell and a component and system including the same, which have the following advantages: the present invention divides a first transparent conductive film into multiple first transparent conductive layers stacked along a first direction, and gradually increases the carrier concentration of the multiple first transparent conductive layers from the first electrode to the first doped amorphous silicon layer, so that the first transparent conductive film can match the work function and energy band of the first doped amorphous silicon layer and the first electrode; and divides a second transparent conductive film into multiple second transparent conductive layers stacked along the first direction, and gradually increases the carrier concentration of the multiple second transparent conductive layers from the second electrode to the second doped amorphous silicon layer, so that the second transparent conductive film can match the work function and energy band of the second doped amorphous silicon layer and the second electrode. The combination of the two can solve the problem of incomplete work function matching between the doped amorphous silicon layer and the transparent conductive film, improve the effective transmission of electrons and holes, and further reduce the contact resistance between the transparent conductive film and the metal grid line of the electrode without affecting the light transmittance, effectively resolving the contradiction between light transmittance and conductivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the structure of a heterojunction solar cell according to Example 1 of the present invention;

[0015] Figure 2 Schematic diagram of the structure of a heterojunction solar cell according to Example 2 of the present utility model;

[0016] Figure 3 It is a schematic structural diagram of a heterojunction solar cell according to Example 3 of the present utility model.

[0017] In the figure, 1, silicon substrate; 2, first doped amorphous silicon layer; 3, second doped amorphous silicon layer; 4, first transparent conductive film; 41, first transparent conductive layer; 41a, first TCO layer; 41b, second TCO layer; 41c, fifth TCO layer; 5, second transparent conductive film; 51, second transparent conductive layer; 51a, third TCO layer; 51b, fourth TCO layer; 51c, sixth TCO layer; 6, first electrode; 7, second electrode; 8, third transparent conductive film; 9, fourth transparent conductive film; 10, first intrinsic amorphous silicon layer; 11, second intrinsic amorphous silicon layer; X, first direction; Y, second direction. DETAILED DESCRIPTION

[0018] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0019] In the description of the present invention, it should be understood that the terms "top", "bottom", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "plurality" means two or more, unless otherwise specifically defined.

[0021] Example 1

[0022] like Figure 1 As shown, a heterojunction solar cell according to embodiment 1 of the present invention comprises: a silicon substrate 1, a first doped amorphous silicon layer 2, a second doped amorphous silicon layer 3, a first transparent conductive film 4, a second transparent conductive film 5, a first electrode 6 and a second electrode 7, wherein the first doped amorphous silicon layer 2 is provided on one side of the silicon substrate 1 in a first direction X, the second doped amorphous silicon layer 3 is provided on the other side of the silicon substrate 1 in the first direction X, the first transparent conductive film 4 is provided on the side of the first doped amorphous silicon layer 2 facing away from the silicon substrate 1, and the first transparent conductive film 4 comprises two layers of the second doped amorphous silicon layer 2 stacked along the first direction X. A transparent conductive layer 41, the carrier concentration of the two first transparent conductive layers 41 gradually increases along the first direction X, the second transparent conductive film 5 is provided on the side of the second doped amorphous silicon layer 3 facing away from the silicon substrate 1, the second transparent conductive film 5 includes two second transparent conductive layers 51 stacked along the first direction X, the carrier concentration of the two second transparent conductive layers 51 gradually decreases along the first direction X, the first electrode 6 is provided on the side of the first transparent conductive film 4 facing away from the first doped amorphous silicon layer 2, and the second electrode 7 is provided on the side of the second transparent conductive film 5 facing away from the second doped amorphous silicon layer 3.

[0023] Based on the above solution, the present application divides the first transparent conductive film 4 into two layers of first transparent conductive layers 41 stacked along the first direction X, and gradually increases the carrier concentration of the two layers of first transparent conductive layers 41 from the first electrode 6 to the first doped amorphous silicon layer 2, so that the first transparent conductive film 4 can match the work function and energy band of the first doped amorphous silicon layer 2 and the first electrode 6; and divides the second transparent conductive film 5 into two layers of second transparent conductive layers 51 stacked along the first direction X, and gradually increases the carrier concentration of the two layers of second transparent conductive layers 51 from the second electrode 7 to the second doped amorphous silicon layer 3, so that the second transparent conductive film 5 can match the work function and energy band of the second doped amorphous silicon layer 3 and the second electrode 7. The combination of the two can solve the problem of incomplete work function matching between the doped amorphous silicon layer and the transparent conductive film, improve the effective transmission of electrons and holes, and in addition, can reduce the contact resistance between the transparent conductive film and the metal grid line of the electrode without affecting the light transmittance, effectively resolving the contradiction between light transmittance and conductivity.

[0024] like Figure 1 As shown, in order to facilitate understanding of the change in carrier concentration of the first transparent conductive film 4 and the second transparent conductive film 5 in this embodiment 1, among the two first transparent conductive layers 41, the first transparent conductive layer 41 with a large carrier concentration is the first TCO layer 41a, and the first transparent conductive layer 41 with a small carrier concentration is the second TCO layer 41b; among the two second transparent conductive layers 51, the second transparent conductive layer 51 with a large carrier concentration is the third TCO layer 51a, and the second transparent conductive layer 51 with a small carrier concentration is the fourth TCO layer 51b.

[0025] like Figure 1 As shown, in order to improve the passivation effect of the battery, it also includes a first intrinsic amorphous silicon layer 10 and a second intrinsic amorphous silicon layer 11. The first intrinsic amorphous silicon layer 10 is arranged between the first doped amorphous silicon layer 2 and the silicon substrate 1, and the second intrinsic amorphous silicon layer 11 is arranged between the second doped amorphous silicon layer 3 and the silicon substrate 1.

[0026] Optionally, for ease of use, the first doped amorphous silicon layer 2 is an N-type amorphous silicon layer, ie, it is doped with phosphorus, and the second doped amorphous silicon layer 3 is a P-type amorphous silicon layer, ie, it is doped with boron.

[0027] like Figure 1 As shown, for ease of use, it includes multiple first electrodes 6 and multiple second electrodes 7. The multiple first electrodes 6 are arranged at intervals along the second direction Y on the side of the first transparent conductive film 4 away from the first doped amorphous silicon layer 2, and the multiple second electrodes 7 are arranged at intervals along the second direction Y on the side of the second transparent conductive film 5 away from the second doped amorphous silicon layer 3. The multiple first electrodes 6 and the multiple second electrodes 7 are arranged in a one-to-one correspondence.

[0028] Optionally, for ease of use, the silicon substrate 1 layer is an N-type silicon wafer.

[0029] Example 2

[0030] like Figure 2 As shown, the difference between this embodiment 2 and embodiment 1 is that the first transparent conductive film 4 includes three first transparent conductive layers 41 stacked along the first direction X, and the carrier concentration of the three first transparent conductive layers 41 gradually increases along the first direction X. The second transparent conductive film 5 includes three second transparent conductive layers 51 stacked along the first direction X, and the carrier concentration of the three second transparent conductive layers 51 gradually decreases along the first direction X.

[0031] Based on the above solution, by providing three first transparent conductive layers 41 and three second transparent conductive layers 51, the carrier concentration change of the first transparent conductive film 4 and the second transparent conductive film 5 is further controlled, so that the carrier concentration changes in a gradient, thereby making the first transparent conductive film 4 more adaptable to the work function and energy band of the first doped amorphous silicon layer 2 and the first electrode 6, and making the second transparent conductive film 5 more compatible with the work function and energy band of the second doped amorphous silicon layer 3 and the second electrode 7, thereby further improving the effective transmission of electrons and holes.

[0032] like Figure 2 As shown, in order to facilitate understanding of the carrier concentration changes of the first transparent conductive film 4 and the second transparent conductive film 5 in this embodiment 2, among the three first transparent conductive layers 41, the first transparent conductive layer 41 with the largest carrier concentration is the first TCO layer 41a, the first transparent conductive layer 41 with the intermediate carrier concentration is the second TCO layer 41b, and the first transparent conductive layer 41 with the smallest carrier concentration is the fourth TCO layer 41c. Among the three second transparent conductive layers 51, the second transparent conductive layer 51 with the largest carrier concentration is the third TCO layer 51a, the second transparent conductive layer 51 with the intermediate carrier concentration is the fourth TCO layer 51b, and the second transparent conductive layer 51 with the smallest carrier concentration is the sixth TCO layer 51c.

[0033] Example 3

[0034] like Figure 3 As shown, the difference between this embodiment 3 and embodiment 1 is that: it further includes a third transparent conductive film 8 and a fourth transparent conductive film 9; the third transparent conductive film 8 is provided between the first transparent conductive film 4 and the first doped amorphous silicon layer 2, and the carrier concentration of the third transparent conductive film 8 is lower than the carrier concentration of the first transparent conductive layer 41 adjacent to the third transparent conductive film 8; the fourth transparent conductive film 9 is provided between the second transparent conductive film 5 and the second doped amorphous silicon layer 3, and the carrier concentration of the fourth transparent conductive film 9 is lower than the carrier concentration of the second transparent conductive layer 51 adjacent to the fourth transparent conductive film 9.

[0035] Based on the above scheme, by setting the third transparent conductive film 8 and the fourth transparent conductive film 9, the change in the carrier concentration of the transparent conductive film from the electrode to the doped amorphous silicon layer is adjusted, so that the transparent conductive film can better match the work function and energy band between the doped amorphous silicon layer and the metal electrode.

[0036] An embodiment of the present invention further provides a solar module, comprising the heterojunction solar cell as described above.

[0037] An embodiment of the present invention further provides a solar energy system, comprising the solar energy assembly as described above.

[0038] In summary, the embodiments of the present invention provide a heterojunction solar cell and a component and system including the same. The heterojunction solar cell divides the first transparent conductive film 4 into multiple layers of first transparent conductive layers 41 stacked along a first direction X, and gradually increases the carrier concentration of the multiple layers of the first transparent conductive layers 41 from the first electrode 6 to the first doped amorphous silicon layer 2, so that the first transparent conductive film 4 can match the work function and energy band of the first doped amorphous silicon layer 2 and the first electrode 6; and divides the second transparent conductive film 5 into multiple layers of second transparent conductive layers 51 stacked along the first direction X, and gradually increases the carrier concentration of the multiple layers of the second transparent conductive layers 51 from the second electrode 7 to the second doped amorphous silicon layer 3, so that the second transparent conductive film 5 can match the work function and energy band of the second doped amorphous silicon layer 3 and the second electrode 7. The combination of the two can solve the problem of incomplete work function matching between the doped amorphous silicon layer and the transparent conductive film, improve the effective transmission of electrons and holes, and further reduce the contact resistance between the transparent conductive film and the metal grid line of the electrode without affecting the light transmittance, effectively resolving the contradiction between light transmittance and conductivity.

[0039] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and replacements can be made without departing from the technical principles of the present invention. These improvements and replacements should also be regarded as the scope of protection of the present invention.

Claims

1. A heterojunction solar cell, characterized in that: include: Silicon substrate; A first doped amorphous silicon layer is provided on one side of the silicon substrate in a first direction; a second doped amorphous silicon layer, provided on the other side of the silicon substrate in the first direction; a first transparent conductive film, provided on a side of the first doped amorphous silicon layer facing away from the silicon substrate, the first transparent conductive film comprising at least two first transparent conductive layers stacked along the first direction, wherein the carrier concentration of the multiple first transparent conductive layers gradually increases along the first direction; a second transparent conductive film, provided on a side of the second doped amorphous silicon layer facing away from the silicon substrate, the second transparent conductive film comprising at least two second transparent conductive layers stacked along the first direction, wherein the carrier concentration of the plurality of second transparent conductive layers gradually decreases along the first direction; a first electrode, disposed on a side of the first transparent conductive film away from the first doped amorphous silicon layer; The second electrode is provided on a side of the second transparent conductive film away from the second doped amorphous silicon layer.

2. The heterojunction solar cell according to claim 1, wherein: The first transparent conductive film includes at least three first transparent conductive layers stacked along the first direction, and the carrier concentration of the multiple first transparent conductive layers gradually increases along the first direction; The second transparent conductive film includes at least three second transparent conductive layers stacked along the first direction, and the carrier concentration of the multiple second transparent conductive layers gradually decreases along the first direction.

3. The heterojunction solar cell according to claim 1, wherein: Also includes a third transparent conductive film and a fourth transparent conductive film; The third transparent conductive film is provided between the first transparent conductive film and the first doped amorphous silicon layer, and the carrier concentration of the third transparent conductive film is lower than the carrier concentration of the first transparent conductive layer adjacent to the third transparent conductive film; The fourth transparent conductive film is disposed between the second transparent conductive film and the second doped amorphous silicon layer, and a carrier concentration of the fourth transparent conductive film is lower than a carrier concentration of the second transparent conductive layer adjacent to the fourth transparent conductive film.

4. The heterojunction solar cell according to claim 1, wherein: The first intrinsic amorphous silicon layer is disposed between the first doped amorphous silicon layer and the silicon substrate, and the second intrinsic amorphous silicon layer is disposed between the second doped amorphous silicon layer and the silicon substrate.

5. The heterojunction solar cell according to claim 1, characterized in that: The first doped amorphous silicon layer is an N-type amorphous silicon layer, and the second doped amorphous silicon layer is a P-type amorphous silicon layer.

6. The heterojunction solar cell according to claim 1, characterized in that: It includes multiple first electrodes and multiple second electrodes, the multiple first electrodes are arranged at intervals along the second direction on the side of the first transparent conductive film away from the first doped amorphous silicon layer, and the multiple second electrodes are arranged at intervals along the second direction on the side of the second transparent conductive film away from the second doped amorphous silicon layer, and the multiple first electrodes and the multiple second electrodes are arranged in a one-to-one correspondence.

7. The heterojunction solar cell according to claim 1, characterized in that: The silicon substrate layer is an N-type silicon wafer.

8. A solar module, characterized in that: The invention comprises the heterojunction solar cell according to any one of claims 1 to 7.

9. A solar energy system, characterized in that: Comprising the solar module according to claim 8.

Images