HJT solar cell and preparation method thereof

Abstract

The invention belongs to the technical field of solar cells, and particularly relates to an HJT solar cell and a preparation method thereof. The HJT solar cell provided by the invention comprises an N-type silicon layer substrate, and a first intrinsic amorphous silicon layer, a hydrogen-doped P-type microcrystalline silicon oxide layer, a P-type doped microcrystalline silicon layer, a first TCO layer and a first collector which are sequentially laminated from inside to outside on one side of the front surface of the N-type silicon layer substrate; and a second intrinsic amorphous silicon layer, a hydrogen-doped N-type microcrystalline silicon oxide layer, an N-type doped microcrystalline silicon layer, a second TCO layer and a second collector are sequentially laminated on one side of the back surface of the N-type silicon layer substrate from inside to outside.

Description

Technical Field

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

[0002] The HJT cell is a high-efficiency crystalline silicon solar cell that can be realized at low cost. The cell is a hybrid solar cell made of a crystalline silicon substrate and an amorphous silicon film, that is, with a high-life n-type silicon substrate, a layer of non-doped (intrinsic) hydrogenated amorphous silicon film is added between the P-type hydrogenated amorphous silicon and the N-type hydrogenated amorphous silicon and the N-type silicon substrate. Then a transparent conductive oxide (TCO) film is deposited on both sides of the doped amorphous silicon film, and finally metal electrodes are formed on both sides by screen printing technology to form an HJT solar cell with a symmetrical structure.

[0003] HJT cells deposit a thin film of intrinsic amorphous silicon on the front and back surfaces of silicon wafers for passivation, and then deposit doped p and n amorphous silicon layers on the front and back intrinsic layers, respectively, to form a heterojunction cell structure (p-aSi\i-aSi\c-Si\i-aSi\n-aSi). In related technologies, since amorphous silicon in HJT cells mainly includes intrinsic amorphous silicon and doped amorphous silicon, the passivation effect of intrinsic amorphous silicon on the c-Si interface is crucial. A high-quality passivation layer can reduce interface recombination, thereby increasing minority carrier lifetime and open-circuit voltage. In order to ensure good conductivity, the light-receiving surface doped amorphous silicon layer is doped with impurity atoms, has a high defect density, and has a high parasitic absorption of sunlight, which affects the utilization rate of light, resulting in a low short-circuit current of the HJT cell, which limits the HJT cell from fully utilizing the advantage of high opening voltage. This is a key factor affecting the competitiveness and mass production scale of HJT cells in the photovoltaic industry. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, an embodiment of the present invention provides a HJT solar cell, which reduces the resistance of the doping layer while increasing the light transmission performance and ultimately can increase the current density.

[0005] The HJT solar cell according to an embodiment of the present invention comprises:

[0006] N-type silicon substrate,

[0007] On the front side of the N-type silicon layer substrate, a first intrinsic amorphous silicon layer, a hydrogen-doped P-type microcrystalline silicon oxide layer, a P-type doped microcrystalline silicon layer, a first TCO layer and a first collector are sequentially stacked from inside to outside;

[0008] On the back side of the N-type silicon layer substrate, a second intrinsic amorphous silicon layer, a hydrogen-doped N-type microcrystalline silicon oxide layer, an N-type doped microcrystalline silicon layer, a second TCO layer and a second collector are sequentially stacked from inside to outside.

[0009] The advantages and technical effects brought by the HJT solar cell of the embodiment of the present invention are that the light transmittance is increased while the resistance of the doping layer is reduced, and the current density can be finally increased.

[0010] In some embodiments, the thickness of the N-type silicon layer substrate is 60-170 μm.

[0011] In some embodiments, the thickness of the first intrinsic amorphous silicon layer and / or the second intrinsic amorphous silicon layer is 5-15 nm.

[0012] In some embodiments, the thickness of the hydrogen-doped P-type microcrystalline silicon oxide layer and / or the hydrogen-doped N-type microcrystalline silicon oxide layer is 10-20 nm.

[0013] In some embodiments, the thickness of the hydrogen-doped P-type microcrystalline silicon oxide layer and / or the hydrogen-doped N-type microcrystalline silicon oxide layer is 14-18 nm.

[0014] In some embodiments, the thickness of the P-type doped microcrystalline silicon layer and / or the N-type doped microcrystalline silicon layer is 8-30 nm.

[0015] In some embodiments, the thickness of the P-type doped microcrystalline silicon layer and / or the N-type doped microcrystalline silicon layer is 15-25 nm.

[0016] In some embodiments, the thickness of the first TCO layer and / or the second TCO layer is 70-100 nm.

[0017] The present invention also provides a method for preparing a HJT solar cell, comprising the following steps:

[0018] (1) After cleaning the silicon wafer, a velvet layer is formed on the front and back sides of the silicon wafer;

[0019] (2) depositing a first intrinsic amorphous silicon layer, a hydrogen-doped P-type microcrystalline silicon oxide layer, and a P-type doped microcrystalline silicon layer in sequence on the front side of the silicon wafer;

[0020] (3) depositing a second intrinsic amorphous silicon layer, a hydrogen-doped N-type microcrystalline silicon oxide layer, and an N-type doped microcrystalline silicon layer in sequence on the back side of the silicon wafer;

[0021] (4) depositing a first TCO layer and a second TCO layer on the front and back sides of the silicon wafer, respectively;

[0022] (5) Metallization is performed using screen printing technology or electroplating technology to prepare a first collector and a second collector to obtain a HJT battery.

[0023] In some embodiments, in step (2) and / or step (3), the deposition method is radio frequency plasma chemical vapor deposition, very high frequency chemical vapor deposition or hot wire vapor deposition. DETAILED DESCRIPTION

[0024] Embodiments of the present invention are described in detail below. The embodiments are exemplary and intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0025] The HJT solar cell according to an embodiment of the present invention comprises:

[0026] N-type silicon substrate,

[0027] On the front side of the N-type silicon layer substrate, a first intrinsic amorphous silicon layer, a hydrogen-doped P-type microcrystalline silicon oxide layer, a P-type doped microcrystalline silicon layer, a first TCO layer and a first collector are sequentially stacked from inside to outside;

[0028] On the back side of the N-type silicon layer substrate, a second intrinsic amorphous silicon layer, a hydrogen-doped N-type microcrystalline silicon oxide layer, an N-type doped microcrystalline silicon layer, a second TCO layer and a second collector are sequentially stacked from inside to outside.

[0029] The HJT solar cell of the embodiment of the present invention can increase the light transmittance while reducing the resistance of the doping layer, and can ultimately increase the current density.

[0030] In some embodiments, preferably, the thickness of the N-type silicon layer substrate is 60 to 170 μm, for example, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, etc.

[0031] In some embodiments, preferably, the thickness of the first intrinsic amorphous silicon layer and / or the second intrinsic amorphous silicon layer is 5 to 15 nm, for example, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, etc.

[0032] In some embodiments, preferably, the thickness of the hydrogen-doped P-type microcrystalline silicon oxide layer and / or the hydrogen-doped N-type microcrystalline silicon oxide layer is 10 to 20 nm, for example, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, etc. Further preferably, the thickness of the hydrogen-doped P-type microcrystalline silicon oxide layer and / or the hydrogen-doped N-type microcrystalline silicon oxide layer is 14 to 18 nm.

[0033] In some embodiments, preferably, the thickness of the P-type doped microcrystalline silicon layer and / or the N-type doped microcrystalline silicon layer is 8 to 30 nm, for example, 8 nm, 10 nm, 12 nm, 14 nm, 16 nm, 18 nm, 20 nm, 22 nm, 24 nm, 26 nm, 28 nm, 30 nm, etc. Further preferably, the thickness of the P-type doped microcrystalline silicon layer and / or the N-type doped microcrystalline silicon layer is 15 to 25 nm.

[0034] In some embodiments, preferably, the thickness of the first TCO layer and / or the second TCO layer is 70-100 nm, for example, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, or 100 nm.

[0035] The present invention also provides a method for preparing a HJT solar cell, comprising the following steps:

[0036] (1) After cleaning the silicon wafer, a velvet layer is formed on the front and back sides of the silicon wafer;

[0037] (2) depositing a first intrinsic amorphous silicon layer, a hydrogen-doped P-type microcrystalline silicon oxide layer, and a P-type doped microcrystalline silicon layer in sequence on the front side of the silicon wafer;

[0038] (3) depositing a second intrinsic amorphous silicon layer, a hydrogen-doped N-type microcrystalline silicon oxide layer, and an N-type doped microcrystalline silicon layer in sequence on the back side of the silicon wafer;

[0039] (4) depositing a first TCO layer and a second TCO layer on the front and back sides of the silicon wafer, respectively;

[0040] (5) Metallization is performed using screen printing technology or electroplating technology to prepare a first collector and a second collector to obtain a HJT battery.

[0041] In some embodiments, preferably, in step (2) and / or step (3), the deposition method is radio frequency plasma chemical vapor deposition, very high frequency chemical vapor deposition or hot wire vapor deposition.

[0042] The technical solution of the present invention is described in detail below in conjunction with specific embodiments.

[0043] Example 1

[0044] (1) After cleaning the silicon wafer, a velvet layer is formed on the front and back sides of the silicon wafer;

[0045] (2) using radio frequency plasma chemical vapor deposition to sequentially deposit a first intrinsic amorphous silicon layer with a thickness of 7 nm, a hydrogen-doped P-type microcrystalline silicon oxide layer with a thickness of 12 nm, and a P-type doped microcrystalline silicon layer with a thickness of 10 nm on the front side of the silicon wafer;

[0046] (3) depositing a second intrinsic amorphous silicon layer with a thickness of 7 nm, a hydrogen-doped N-type microcrystalline silicon oxide layer with a thickness of 12 nm, and an N-type doped microcrystalline silicon layer with a thickness of 10 nm on the back side of the silicon wafer by radio frequency plasma chemical vapor deposition;

[0047] (4) depositing a first TCO layer with a thickness of 80 nm and a second TCO layer with a thickness of 80 nm on the front and back sides of the silicon wafer, respectively;

[0048] (5) Metallization is performed using screen printing technology to prepare the first collector and the second collector to obtain a HJT battery.

[0049] Example 2

[0050] (1) After cleaning the silicon wafer, a velvet layer is formed on the front and back sides of the silicon wafer;

[0051] (2) using radio frequency plasma chemical vapor deposition to sequentially deposit a first intrinsic amorphous silicon layer with a thickness of 13 nm, a hydrogen-doped P-type microcrystalline silicon oxide layer with a thickness of 15 nm, and a P-type doped microcrystalline silicon layer with a thickness of 20 nm on the front side of the silicon wafer;

[0052] (3) depositing a second intrinsic amorphous silicon layer with a thickness of 13 nm, a hydrogen-doped N-type microcrystalline silicon oxide layer with a thickness of 15 nm, and an N-type doped microcrystalline silicon layer with a thickness of 20 nm on the back side of the silicon wafer by radio frequency plasma chemical vapor deposition;

[0053] (4) depositing a first TCO layer with a thickness of 90 nm and a second TCO layer with a thickness of 90 nm on the front and back sides of the silicon wafer, respectively;

[0054] (5) Metallization is performed using screen printing technology to prepare the first collector and the second collector to obtain a HJT battery.

[0055] Comparative Example 1

[0056] The preparation method of this comparative example is the same as that of Example 1, except that:

[0057] In step (2): a first intrinsic amorphous silicon layer with a thickness of 13 nm and a hydrogen-doped P-type microcrystalline silicon oxide layer with a thickness of 35 nm are sequentially deposited on the front side of the silicon wafer by radio frequency plasma chemical vapor deposition;

[0058] In step (3): a second intrinsic amorphous silicon layer with a thickness of 13 nm and a hydrogen-doped N-type microcrystalline silicon oxide layer with a thickness of 35 nm are sequentially deposited on the back side of the silicon wafer using radio frequency plasma chemical vapor deposition.

[0059] Comparative Example 2

[0060] In step (2): a first intrinsic amorphous silicon layer with a thickness of 13 nm and a P-type doped microcrystalline silicon layer with a thickness of 35 nm are sequentially deposited on the front side of the silicon wafer by radio frequency plasma chemical vapor deposition;

[0061] In step (3): a second intrinsic amorphous silicon layer with a thickness of 13 nm and an N-type doped microcrystalline silicon layer with a thickness of 35 nm are sequentially deposited on the back side of the silicon wafer using radio frequency plasma chemical vapor deposition.

[0062] The performance of the HJT batteries prepared in Examples 1-2 and Comparative Examples 1-2 was tested, and the results are shown in Table 1.

[0063] Table 1

[0064] Short circuit current (mA) Open circuit voltage(mV) Fill factor (%) Conversion efficiency (%) Example 1 38.16 741.6 80.26 23.18 Example 2 38.41 740.9 80.57 23.20 Comparative Example 1 37.19 738.5 79.95 22.59 Comparative Example 2 37.54 739.8 79.16 22.46

[0065] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0066] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A HJT solar cell, characterized in that: include: N-type silicon substrate, On the front side of the N-type silicon layer substrate, a first intrinsic amorphous silicon layer, a hydrogen-doped P-type microcrystalline silicon oxide layer, a P-type doped microcrystalline silicon layer, a first TCO layer and a first collector are sequentially stacked from inside to outside; On the back side of the N-type silicon layer substrate, a second intrinsic amorphous silicon layer, a hydrogen-doped N-type microcrystalline silicon oxide layer, an N-type doped microcrystalline silicon layer, a second TCO layer and a second collector are sequentially stacked from inside to outside.

2. The HJT solar cell according to claim 1, characterized in that: The thickness of the N-type silicon layer substrate is 60-170 μm.

3. The HJT solar cell according to claim 1, characterized in that: The thickness of the first intrinsic amorphous silicon layer and / or the second intrinsic amorphous silicon layer is 5-15 nm.

4. The HJT solar cell according to claim 1, characterized in that: The thickness of the hydrogen-doped P-type microcrystalline silicon oxide layer and / or the hydrogen-doped N-type microcrystalline silicon oxide layer is 10-20 nm.

5. The HJT solar cell according to claim 4, characterized in that: The thickness of the hydrogen-doped P-type microcrystalline silicon oxide layer and / or the hydrogen-doped N-type microcrystalline silicon oxide layer is 14-18 nm.

6. The HJT solar cell according to claim 1, characterized in that: The thickness of the P-type doped microcrystalline silicon layer and / or the N-type doped microcrystalline silicon layer is 8-30 nm.

7. The HJT solar cell according to claim 6, characterized in that: The thickness of the P-type doped microcrystalline silicon layer and / or the N-type doped microcrystalline silicon layer is 15-25 nm.

8. The HJT solar cell according to claim 1, characterized in that: The thickness of the first TCO layer and / or the second TCO layer is 70-100 nm.

9. The method for preparing a HJT solar cell according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) After cleaning the silicon wafer, a velvet layer is formed on the front and back sides of the silicon wafer; (2) depositing a first intrinsic amorphous silicon layer, a hydrogen-doped P-type microcrystalline silicon oxide layer, and a P-type doped microcrystalline silicon layer in sequence on the front side of the silicon wafer; (3) depositing a second intrinsic amorphous silicon layer, a hydrogen-doped N-type microcrystalline silicon oxide layer, and an N-type doped microcrystalline silicon layer on the back side of the silicon wafer in sequence; (4) depositing a first TCO layer and a second TCO layer on the front and back sides of the silicon wafer, respectively; (5) Metallization is performed using screen printing technology or electroplating technology to prepare a first collector and a second collector to obtain a HJT battery.

10. The method for preparing a HJT solar cell according to claim 9, characterized in that: In step (2) and / or step (3), the deposition method is radio frequency plasma chemical vapor deposition, very high frequency chemical vapor deposition or hot wire vapor deposition.