Heterojunction solar cell and method for manufacturing the same

Abstract

The present invention provides a heterojunction solar cell and a manufacturing method thereof. An amorphous layer is provided on the side surface of the single-crystalline silicon substrate of the heterojunction solar cell involved. Based on the specific structure of the heterojunction solar cell provided by the present invention, it is possible to avoid direct contact between the first transparent conductive film layer, the second transparent conductive film layer and the single-crystalline silicon substrate, resulting in leakage, reduce the risk of damage to the edge of the single-crystalline silicon substrate, and the single-crystalline silicon substrate can effectively improve the passivation effect on the side surface due to the first intrinsic side part and the second intrinsic side part being sequentially covered on the side surface.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic manufacturing, and in particular to a heterojunction solar cell and a manufacturing method thereof. Background Art

[0002] The heterojunction solar cell is a relatively efficient crystalline silicon solar cell at present. It combines the characteristics of crystalline silicon cells and silicon-based thin film cells, and has the advantages of short manufacturing process, low process temperature, high conversion efficiency, and large power generation. Figure 1 The following shows a schematic structural diagram of a heterojunction solar cell involved in the prior art, which successively includes a first collector 51', a first transparent conductive film layer 41', a first doped amorphous layer 31', a first intrinsic amorphous layer 21', a single crystal silicon substrate 10', a second intrinsic amorphous layer 22', a second doped amorphous layer 32', a second transparent conductive film layer 42', and a second collector 52' from top to bottom.

[0003] In the specific manufacturing process of the prior art heterojunction solar cell, usually, the PECVD process is first used to complete the manufacturing of four amorphous layers, namely the first intrinsic amorphous layer 21', the second intrinsic amorphous layer 22', the first doped amorphous layer 31', and the second doped amorphous layer 32' on both surfaces of the single crystal silicon substrate 10'; then the PVD process is used to manufacture the first transparent conductive film layer 41' and the second transparent conductive film layer 42'; finally, the screen printing process is used to manufacture the first collector 51' and the second collector 52'.

[0004] In the specific manufacturing process of the four amorphous layers, the prior art requires arranging a metal mask to make the first intrinsic amorphous layer 21', the second intrinsic amorphous layer 22', the first doped amorphous layer 31', and the second doped amorphous layer 32' only formed on two main surfaces of the single crystal silicon substrate 10', that is, the first intrinsic amorphous layer 21', the second intrinsic amorphous layer 22', the first doped amorphous layer 31', and the second doped amorphous layer 32' do not extend to the side of the single crystal silicon substrate 10'.

[0005] However, the heterojunction solar cell involved in the prior art has the following problems: there is no amorphous layer shielding on the side of the single crystal silicon substrate 10', and it is easy to form direct contact between the first transparent conductive film layer 41' and the second transparent conductive film layer 42' and the single crystal silicon substrate 10', resulting in a risk of leakage; the direct exposure of the edge of the single crystal silicon substrate 10' will increase the risk of edge damage; the passivation of the edge region of the single crystal silicon substrate 10' is insufficient.

[0006] In view of this, it is necessary to provide an improved technical solution to solve the above problems. Summary of the Invention

[0007] The present invention aims to solve at least one of the technical problems existing in the prior art. To achieve the above-mentioned invention object, the present invention provides a heterojunction solar cell, and its specific design is as follows.

[0008] A heterojunction solar cell includes a single-crystalline silicon substrate, the single-crystalline silicon substrate having a first main surface and a second main surface disposed opposite to each other, and a side surface connecting the first main surface and the second main surface, one of the first main surface and the second main surface being a light-receiving surface and the other being a backlight surface; the heterojunction solar cell further includes a first intrinsic amorphous layer, a first doped amorphous layer, a first transparent conductive film layer, and a first collector sequentially disposed on one side of the first main surface, and a second intrinsic amorphous layer, a second doped amorphous layer, a second transparent conductive film layer, and a second collector sequentially disposed on one side of the second main surface. The first intrinsic amorphous layer has a first intrinsic side portion extending in the direction of the second intrinsic amorphous layer to cover all of the side surface, and the second intrinsic amorphous layer has a second intrinsic side portion extending in the direction of the first intrinsic amorphous layer to cover the first intrinsic side portion. The first doped amorphous layer and the second doped amorphous layer have opposite doping types and both have doped side portions extending outside the side surface and connecting with each other.

[0009] Further, the sum of the thicknesses of the two of the first intrinsic amorphous layer, the first doped amorphous layer, the second intrinsic amorphous layer, and the second doped amorphous layer located on the light-receiving surface is less than or equal to the sum of the thicknesses of the two located on the backlight surface.

[0010] Further, the sum of the thicknesses of the two of the first intrinsic amorphous layer, the first doped amorphous layer, the second intrinsic amorphous layer, and the second doped amorphous layer located on the light-receiving surface is 6 - 21 nm, and the sum of the thicknesses of the two located on the backlight surface is 6 - 30 nm.

[0011] Further, the thickness of the first intrinsic amorphous layer and the second intrinsic amorphous layer located on the light-receiving surface is less than or equal to the thickness located on the backlight surface.

[0012] Further, the thickness of the first intrinsic amorphous layer and the second intrinsic amorphous layer located on the light-receiving surface is 3 - 6 nm, and the thickness located on the backlight surface is 3 - 10 nm.

[0013] Further, the thickness of the first doped amorphous layer and the second doped amorphous layer located on the side of the light-receiving surface is less than or equal to the thickness located on the side of the backlight surface.

[0014] Further, the thickness of the first doped amorphous layer and the second doped amorphous layer located on the side of the light-receiving surface is 3 - 15 nm, and the thickness located on the side of the backlight surface is 3 - 20 nm.

[0015] Further, the oxygen content of the first doped amorphous layer and the second doped amorphous layer on the light-receiving surface is greater than or equal to the oxygen content on the backlight surface side.

[0016] Further, in the direction from the backlight surface to the light-receiving surface, the first doped amorphous layer and the second doped amorphous layer on the light-receiving surface sequentially include a first doped amorphous silicon film, and a doped amorphous silicon oxide film, a doped amorphous silicon carbide film, or a doped amorphous silicon carbide / doped amorphous silicon oxide composite film on the surface of the first doped amorphous silicon film.

[0017] Further, the first doped amorphous layer and the second doped amorphous layer on the light-receiving surface further include a second doped amorphous silicon film on the surface of the doped amorphous silicon oxide film, the doped amorphous silicon carbide film, or the doped amorphous silicon carbide / doped amorphous silicon oxide composite film.

[0018] Further, in the direction from the light-receiving surface to the backlight surface, the first doped amorphous layer and the second doped amorphous layer on the backlight surface sequentially include a third doped amorphous silicon film, and a fourth doped amorphous silicon film on the surface of the third doped amorphous silicon film with a doping concentration greater than that of the third doped amorphous silicon film.

[0019] Further, the doped side portions of the first doped amorphous layer and the second doped amorphous layer are stacked outside the second intrinsic side portion.

[0020] Further, the sum of the partial thicknesses of the first intrinsic side portion and the second intrinsic side portion covering the first intrinsic side portion, and the thickness of the second intrinsic side portion covering the region on the side connected to the second main surface are both not less than 1 nm.

[0021] Further, the first intrinsic amorphous layer and the second intrinsic amorphous layer each include at least two stacked intrinsic films, and each intrinsic film is composed of one of intrinsic amorphous silicon, intrinsic amorphous silicon oxide, and intrinsic amorphous silicon carbide.

[0022] Further, the outermost intrinsic film of the first intrinsic amorphous layer and / or the second intrinsic amorphous layer farthest from the single-crystalline silicon substrate is intrinsic amorphous silicon oxide.

[0023] Further, the hydrogen content of the intrinsic film of the first intrinsic amorphous layer close to the single-crystalline silicon substrate is higher than that of the intrinsic film far from the single-crystalline silicon substrate, and the hydrogen content of the intrinsic film of the second intrinsic amorphous layer close to the single-crystalline silicon substrate is higher than that of the intrinsic film far from the single-crystalline silicon substrate.

[0024] Further, the first intrinsic amorphous layer and the second intrinsic amorphous layer each include three stacked intrinsic films. In the direction away from the single-crystalline silicon substrate, the hydrogen content ranges of the three intrinsic films of the first intrinsic amorphous layer and the second intrinsic amorphous layer are sequentially 20%-40%, 10%-25%, and 8%-20%.

[0025] Further, the single-crystalline silicon substrate is an n-type single-crystalline silicon. The n-type doped amorphous layer is on the light-receiving surface side of the first doped amorphous layer and the second doped amorphous layer, and the p-type doped amorphous layer is on the backlight surface side of the first doped amorphous layer and the second doped amorphous layer.

[0026] Further, the first transparent conductive film layer and the second transparent conductive film layer on the light-receiving surface include a first TCO film attached to the surface of the n-type doped amorphous layer and a second TCO film attached to the surface of the first TCO film. The mass ratio of the doped oxide in the first TCO film is greater than the mass ratio of the doped oxide in the second TCO film.

[0027] Further, the mass ratio of the doped oxide in the first TCO film is 5%-20%, and the mass ratio of the doped oxide in the second TCO film is 0.5%-5%.

[0028] Further, the first transparent conductive film layer and the second transparent conductive film layer on the light-receiving surface further include a third TCO film attached to the surface of the second TCO film. The mass ratio of the doped oxide in the third TCO film is greater than the mass ratio of the doped oxide in the second TCO film.

[0029] Further, the first transparent conductive film layer and the second transparent conductive film layer on the backlight surface include a fourth TCO film attached to the surface of the p-type doped amorphous layer and a fifth TCO film attached to the surface of the fourth TCO film. The mass ratio of the doped oxide in the fourth TCO film is less than the mass ratio of the doped oxide in the fifth TCO film.

[0030] Further, the thickness of the first transparent conductive film layer and the second transparent conductive film layer on the light-receiving surface is less than or equal to the thickness of the first transparent conductive film layer and the second transparent conductive film layer on the backlight surface.

[0031] Further, one of the first transparent conductive film layer and the second transparent conductive film layer extends outside the side surface to cover the doped side portion.

[0032] The present invention also provides a method for manufacturing a heterojunction solar cell, which is used to manufacture the heterojunction solar cell as described above, including:

[0033] Texturing step for a single-crystalline silicon substrate, texturing the first major surface, the second major surface and the side surfaces of the single-crystalline silicon substrate;

[0034] Step of fabricating a first intrinsic amorphous layer, placing the single-crystalline silicon substrate with its first major surface facing upward on a first carrier plate, the first carrier plate having a first groove for placing the single-crystalline silicon substrate, and depositing and forming the first intrinsic amorphous layer on the side of the first major surface of the single-crystalline silicon substrate from the upper side of the first carrier plate, the periphery of the first intrinsic amorphous layer extending to cover all the side surfaces;

[0035] Step of fabricating a second intrinsic amorphous layer, placing the single-crystalline silicon substrate after completing the first intrinsic amorphous layer fabrication step with its second major surface facing upward on a second carrier plate, the second carrier plate having a second groove for placing the single-crystalline silicon substrate, and depositing and forming the second intrinsic amorphous layer on the side of the second major surface of the single-crystalline silicon substrate from the upper side of the second carrier plate, the periphery of the second intrinsic amorphous layer extending to cover the side portion of the first intrinsic amorphous layer;

[0036] Step of fabricating a first doped amorphous layer, placing the single-crystalline silicon substrate after completing the second intrinsic amorphous layer fabrication step with its first major surface facing upward on a third carrier plate, the third carrier plate having a third groove for placing the single-crystalline silicon substrate, and forming the first doped amorphous layer on the first intrinsic amorphous layer from the upper side of the third carrier plate, the first doped amorphous layer having a first doped side portion extending outside the side surface;

[0037] Step of fabricating a second doped amorphous layer, placing the single-crystalline silicon substrate after completing the second intrinsic amorphous layer fabrication step with its second major surface facing upward on a fourth carrier plate, the fourth carrier plate having a fourth groove for placing the single-crystalline silicon substrate, and forming the first doped amorphous layer on the second intrinsic amorphous layer from the upper side of the fourth carrier plate, the second doped amorphous layer having a second doped side portion extending outside the side surface and connecting with the first doped side portion, and the order of the second doped amorphous layer fabrication step and the first doped amorphous layer fabrication step can be adjusted;

[0038] Step of fabricating a transparent conductive film layer, respectively depositing and forming the first transparent conductive film layer and the second transparent conductive film layer on the side of the first major surface and the side of the second major surface of the single-crystalline silicon substrate after completing the first doped amorphous layer fabrication step and the second doped amorphous layer fabrication step;

[0039] Step of fabricating a collector, forming a first collector on the surface of the first transparent conductive film layer facing away from the first doped amorphous layer, and forming a second collector on the surface of the second transparent conductive film layer facing away from the second doped amorphous layer.

[0040] Further, the difference range between the side lengths of the first groove, the second groove, the third groove, and the fourth groove and the corresponding side lengths of the single-crystalline silicon substrate is less than 2 mm.

[0041] The beneficial effects of the present invention are as follows: Based on the heterojunction solar cell provided by the present invention, it is possible to avoid direct contact between the first transparent conductive film layer, the second transparent conductive film layer and the single-crystalline silicon substrate, resulting in leakage, and reduce the risk of damage to the edge of the single-crystalline silicon substrate; and since the side surface of the single-crystalline silicon substrate is covered by the first intrinsic side portion and the second intrinsic side portion, the passivation effect of the side surface of the single-crystalline silicon substrate can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0043] Figure 1 Shown is a schematic structural diagram of a heterojunction solar cell in the prior art;

[0044] Figure 2 Shown is a schematic diagram of the first implementation structure of the heterojunction solar cell of the present invention;

[0045] Figure 3 Shown as Figure 2 Shown is a partial schematic diagram of the first specific implementation of the heterojunction solar cell of the shown implementation structure;

[0046] Figure 4 Shown as Figure 2 Shown is a partial schematic diagram of the second specific implementation of the heterojunction solar cell of the shown implementation structure;

[0047] Figure 5 Shown as Figure 2 Shown is a partial schematic diagram of the third specific implementation of the heterojunction solar cell of the shown implementation structure;

[0048] Figure 6 Shown as Figure 2 Shown is a partial schematic diagram of the fourth specific implementation of the heterojunction solar cell of the shown implementation structure;

[0049] Figure 7 Shown as Figure 2 Shown is a partial schematic diagram of the fifth specific implementation of the heterojunction solar cell of the shown implementation structure;

[0050] Figure 8The following shows the schematic diagram of the second implementation structure of the heterojunction solar cell of the present invention;

[0051] Figure 9 The following shows the schematic diagram of the third implementation structure of the heterojunction solar cell of the present invention;

[0052] Figure 10 The following shows the schematic diagram of the fourth implementation structure of the heterojunction solar cell of the present invention;

[0053] Figure 11 The following shows the schematic diagram of the fifth implementation structure of the heterojunction solar cell of the present invention;

[0054] Figure 12 The following shows the schematic diagram of the state of manufacturing the first intrinsic amorphous layer in the heterojunction solar cell of the present invention;

[0055] Figure 13 The following shows the schematic diagram of the state of manufacturing the second intrinsic amorphous layer in the heterojunction solar cell of the present invention;

[0056] Figure 14 The following shows the schematic diagram of the state of manufacturing the first doped amorphous layer in the heterojunction solar cell of the present invention;

[0057] Figure 15 The following shows the schematic diagram of the state of manufacturing the second doped amorphous layer in the heterojunction solar cell of the present invention;

[0058] Figure 16 The following shows the schematic diagram of the state of manufacturing the transparent conductive film layer in the heterojunction solar cell of the present invention. Detailed implementation manners

[0059] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0060] Refer to Figure 2 、 Figure 8 、 Figure 9 、 Figure 10 、 Figure 11As shown in the figure, the heterojunction solar cell of the present invention includes a single-crystal silicon substrate 10, a first intrinsic amorphous layer 21, a first doped amorphous layer 31, a first transparent conductive film layer 41, a first collector 51, a second intrinsic amorphous layer 22, a second doped amorphous layer 32, a second transparent conductive film layer 42, and a second collector 52. Among them, the first intrinsic amorphous layer 21, the first doped amorphous layer 31, the first transparent conductive film layer 41, and the first collector 51 are sequentially arranged on one side of the first main surface, and the second intrinsic amorphous layer 22, the second doped amorphous layer 32, the second transparent conductive film layer 42, and the second collector 52 are sequentially arranged on one side of the second main surface.

[0061] In the present invention, the single-crystal silicon substrate 10 involved has a first main surface and a second main surface arranged opposite to each other, and a side surface connecting the first main surface and the second main surface. Among them, one of the first main surface and the second main surface is a light-receiving surface, and the other is a backlight surface.

[0062] Reference Figure 2 、 Figure 8 、 Figure 9 、 Figure 10 、 Figure 11 As shown in

[0063] In the present invention, both the first doped amorphous layer 31 and the second doped amorphous layer 32 involved have doped side portions that extend outside the side surface and are connected to each other.

[0064] Based on the heterojunction solar cell provided by the present invention, it is possible to avoid direct contact between the first transparent conductive film layer 41, the second transparent conductive film layer 42 and the single-crystal silicon substrate 10, resulting in leakage, and reduce the risk of damage to the edge of the single-crystal silicon substrate 10. In the present invention, the side surface of the single-crystal silicon substrate 10 is covered by the first intrinsic side portion 210 and the second intrinsic side portion 220, which can effectively improve the passivation effect of the side surface of the single-crystal silicon substrate 10, so that the heterojunction solar cell has a higher photoelectric conversion efficiency than the battery chip with unpassivated edges in the prior art.

[0065] In the specific implementation process of the present invention, the doped side portions of the first doped amorphous layer 31 and the second doped amorphous layer 32 may both have portions that are directly formed on the outer surface of the second intrinsic side portion 220 and are connected to each other; preferably, the doped side portion of the first doped amorphous layer 31 and the doped side portion of the second doped amorphous layer 32 are stacked on the outer layer of the second intrinsic side portion 220 to form a connection.

[0066] Referring to Figure 2 the shown implementation structure, the first doped amorphous layer 31 not only has a region covering the first intrinsic amorphous layer 21 corresponding to the first main surface, but also has a region covering the outer surface of the second intrinsic side portion 220 corresponding to the side surface, that is, the first doped amorphous layer 31 has a first doped side portion 310 covering the outer surface of the second intrinsic side portion 220.

[0067] Furthermore, as shown in Figure 2 the second doped amorphous layer 32 not only has a region covering the second intrinsic amorphous layer 22 corresponding to the second main surface, but also has a region covering the outer surface of the first doped side portion 310, that is, the second doped amorphous layer 32 has a second doped side portion 320 covering the outer surface of the second intrinsic side portion 220. In this specific embodiment, the first doped side portion 310 and the second doped side portion 320 are sequentially stacked on the outer surface of the second intrinsic side portion 220.

[0068] In some other implementation structures of the present invention, referring to Figure 8 the shown structure, different from the Figure 2 shown implementation structure, in this implementation structure, the second doped side portion 320 involved covers the outer surface of the second intrinsic side portion 220, and the first doped side portion 310 covers the outer surface of the second doped side portion 320, that is, the second doped side portion 320 and the first doped side portion 310 are sequentially stacked on the outer surface of the second intrinsic side portion 220.

[0069] In some other implementation structures of the present invention (not shown in the figure), the first doped side portion 310 and the second doped side portion 320 can also be directly formed on the outer surface of the second intrinsic side portion 220 and are connected to each other at the edges.

[0070] In the present invention, the doping type of the second doped amorphous layer 32 is opposite to that of the first doped amorphous layer 31. In the specific implementation process, the first doped amorphous layer 31 is one of an N-type doped amorphous layer and a P-type doped amorphous layer, and the second doped amorphous layer 32 is the other of an N-type doped amorphous layer and a P-type doped amorphous layer. Specifically, the N-type doped amorphous layer is doped with phosphorus, and the P-type doped amorphous layer is doped with boron.

[0071] Further, the first transparent conductive film layer 41 involved in the present invention is located on the surface of the first doped amorphous layer 31 facing away from the first intrinsic amorphous layer 21; the first collector 51 is located on the surface of the first transparent conductive film layer 41 facing away from the first doped amorphous layer 31; the second transparent conductive film layer 42 is located on the surface of the second doped amorphous layer 32 facing away from the second intrinsic amorphous layer 22; the second collector 52 is located on the surface of the second transparent conductive film layer 42 facing away from the second doped amorphous layer 32.

[0072] In the present invention Figure 2 、 Figure 8 In the shown implementation structure, the first main surface is the light-receiving surface, and the second main surface is the backlight surface. However, in some other embodiments of the present invention, referring to Figure 9 、 Figure 10 shown, different from the embodiments shown in Figure 2 、 Figure 8 in these two embodiments, the second main surface involved is the light-receiving surface, and the first main surface is the backlight surface.

[0073] In the present invention, the sum of the thicknesses of the two of the first intrinsic amorphous layer 21, the first doped amorphous layer 31, the second intrinsic amorphous layer 22, and the second doped amorphous layer 32 located on the light-receiving surface is less than or equal to the sum of the thicknesses of the two located on the backlight surface. Preferably, the sum of the thicknesses of the two of the first intrinsic amorphous layer 21, the first doped amorphous layer 31, the second intrinsic amorphous layer 22, and the second doped amorphous layer 32 located on the light-receiving surface is less than the sum of the thicknesses of the two located on the backlight surface.

[0074] For a heterojunction solar cell, the light absorption effect on the light-receiving surface has a much greater impact on the photoelectric conversion efficiency of the cell than the light absorption effect on the backlight surface. Since the sum of the thicknesses of the two of the first intrinsic amorphous layer 21, the first doped amorphous layer 31, the second intrinsic amorphous layer 22, and the second doped amorphous layer 32 located on the light-receiving surface is less than or equal to the sum of the thicknesses of the two located on the backlight surface, it can effectively reduce the loss of sunlight when entering the light-receiving surface, improve the short-circuit current of the heterojunction solar cell, and enable the heterojunction solar cell to have better photoelectric conversion efficiency.

[0075] For Figure 2 、 Figure 8 the shown implementation structure, the two of the first intrinsic amorphous layer 21, the first doped amorphous layer 31, the second intrinsic amorphous layer 22, and the second doped amorphous layer 32 located on the light-receiving surface are the first intrinsic amorphous layer 21 and the first doped amorphous layer 31, and the two located on the backlight surface are the second intrinsic amorphous layer 22 and the second doped amorphous layer 32. Among them, the sum of the thicknesses of the first intrinsic amorphous layer 21 and the first doped amorphous layer 31 is less than or equal to the sum of the thicknesses of the second intrinsic amorphous layer 22 and the second doped amorphous layer 32.

[0076] More specifically, inFigure 2 , Figure 8 In the shown implementation structure, the sum of the thicknesses of the first intrinsic amorphous layer 21 and the first doped amorphous layer 31 is 6 - 21 nm, and the sum of the thicknesses of the second intrinsic amorphous layer 22 and the second doped amorphous layer 32 is 6 - 30 nm.

[0077] In Figure 2 , Figure 8 the shown implementation structure, the thickness of the first intrinsic amorphous layer 21 is less than or equal to the thickness of the second intrinsic amorphous layer 22. Preferably, the thickness of the first intrinsic amorphous layer 21 is less than the thickness of the second intrinsic amorphous layer 22. Specifically, in implementation, the thickness of the first intrinsic amorphous layer 21 is 3 - 6 nm, and the thickness of the second intrinsic amorphous layer 22 is 3 - 10 nm.

[0078] Furthermore, the thickness of the first doped amorphous layer 31 is less than or equal to the thickness of the second doped amorphous layer 32. Preferably, the thickness of the first doped amorphous layer 31 is less than the thickness of the second doped amorphous layer 32. Specifically, in implementation, the thickness of the first doped amorphous layer 31 is 3 - 15 nm, and the thickness of the second doped amorphous layer 32 is 3 - 20 nm.

[0079] In the present invention, to ensure a better passivation effect on the side surface of the single-crystalline silicon substrate 10, in the specific implementation process, the sum of the partial thicknesses of the first intrinsic side portion 21 and the second intrinsic side portion 22 covering the first intrinsic side portion 21 is not less than 1 nm, and the thickness of the second intrinsic side portion 22 covering the region on the side connected to the second main surface is also not less than 1 nm.

[0080] In Figure 2 , Figure 8 the shown implementation structure, the oxygen content in the first doped amorphous layer 31 is greater than or equal to the oxygen content in the second doped amorphous layer 32. Generally, the high oxygen content in the first doped amorphous layer 31 will form amorphous silicon oxide with high light transmittance, which can further improve the light-receiving effect of the light-receiving surface of the heterojunction solar cell.

[0081] As Figure 2 , Figure 8 a further specific implementation manner of the shown implementation structure, as shown in Figure 3 , the first doped amorphous layer 31 includes a first doped amorphous silicon film 301 located on the surface of the first intrinsic amorphous layer 21 and a doped amorphous silicon oxide film, a doped amorphous silicon carbide film, or a doped amorphous silicon carbide / doped amorphous silicon oxide composite film 302 located on the surface of the first doped amorphous silicon film 301. It is relatively easy to understand that the doped amorphous silicon carbide / doped amorphous silicon oxide composite film refers to a film layer composed of a doped amorphous silicon oxide film and a doped amorphous silicon carbide film.

[0082] Doped amorphous silicon oxide and doped amorphous silicon carbide have better light transmittance than doped amorphous silicon. In the prior art, the first doped amorphous layer 31' usually has a single-layer doped amorphous silicon film structure; in this embodiment, the first doped amorphous layer 31 adopts a double-layer film design. Among them, the first doped amorphous silicon film 301 can ensure good contact between the first doped amorphous layer 31 and the first intrinsic amorphous layer 21, while the doped amorphous silicon oxide film, doped amorphous silicon carbide film or doped amorphous silicon carbide / doped amorphous silicon oxide composite film 302 is equivalent to replacing part of the doped amorphous silicon in the prior art with doped amorphous silicon oxide or doped amorphous silicon carbide with high light transmittance, so that the overall light transmittance of the first doped amorphous layer 31 can be improved. Based on the cooperation of the first doped amorphous silicon film 301 and the doped amorphous silicon oxide film, doped amorphous silicon carbide film or doped amorphous silicon carbide / doped amorphous silicon oxide composite film 302, the heterojunction solar cell has more excellent performance.

[0083] In Figure 3 In the specific embodiment shown, preferably, the thickness of the first doped amorphous silicon film 301 is usually less than the thickness of the doped amorphous silicon oxide film, doped amorphous silicon carbide film or doped amorphous silicon carbide / doped amorphous silicon oxide composite film 302. In this way, while ensuring good contact between the first doped amorphous layer 31 and the first intrinsic amorphous layer 21, the first doped amorphous layer 31 can have good light transmittance to a great extent.

[0084] In the specific implementation process, the thickness of the doped amorphous silicon oxide film, doped amorphous silicon carbide film or doped amorphous silicon carbide / doped amorphous silicon oxide composite film 302 is 2 - 10 nm. Correspondingly, the thickness of the first doped amorphous silicon film 301 is 1 - 5 nm.

[0085] To ensure good contact between the first doped amorphous layer 31 and the first intrinsic amorphous layer 21, the first doped amorphous silicon film 301 is a highly doped film, and its carrier concentration is 5E19 - 5E21 / cm 3 .

[0086] In Figure 2 , Figure 8 In some other specific embodiments of the shown implementation structure, referring to Figure 4 shown, the first doped amorphous layer 31 further includes a second doped amorphous silicon film 303 on the surface of the doped amorphous silicon oxide film, doped amorphous silicon carbide film or doped amorphous silicon carbide / doped amorphous silicon oxide composite film 302. Doped amorphous silicon usually has relatively excellent conductivity, Figure 4 In the shown embodiment, the setting of the second doped amorphous silicon film 303 can make the first doped amorphous layer 31 have good contact with the first transparent conductive film layer 41. Compared with Figure 3The illustrated embodiments can reduce the contact resistance, thereby enabling the heterojunction solar cell to have a higher fill factor.

[0087] In Figure 4 In the illustrated embodiments, the thickness of the second doped amorphous silicon film 303 is also generally less than the thickness of the doped amorphous silicon oxide film, the doped amorphous silicon carbide film, or the doped amorphous silicon carbide / doped amorphous silicon oxide composite film 302, thereby enabling the first doped amorphous layer 31 to have better light transmittance. In specific implementation, the thickness of the first doped amorphous silicon film 301 involved is 1 - 4 nm, the thickness of the doped amorphous silicon oxide film, the doped amorphous silicon carbide film, or the doped amorphous silicon carbide / doped amorphous silicon oxide composite film 302 is 1 - 7 nm, and the thickness of the second doped amorphous silicon film 303 is 1 - 4 nm.

[0088] To ensure good contact between the first doped amorphous layer 31 and the first transparent conductive film layer 41, the second doped amorphous silicon film 303 is also a highly doped film, and its carrier concentration is 5E19 - 5E21 / cm 3 .

[0089] Referring to Figure 3 、 Figure 4 As shown, in some other embodiments of the present invention, the second doped amorphous layer 32 includes a third doped amorphous silicon film 304 located on the surface of the second intrinsic amorphous layer 22 and a fourth doped amorphous silicon film 305 located on the surface of the third doped amorphous silicon film 304 and having a doping concentration greater than that of the third doped amorphous silicon film 304.

[0090] Preferably, the carrier concentration of the third doped amorphous silicon film 304 is 5E18 - 5E19 / cm 3 , and the carrier concentration of the fourth doped amorphous silicon film 305 is 5E19 - 5E21 / cm 3 .

[0091] In Figure 3 、 Figure 4 In the illustrated embodiments, due to the relatively low doping concentration, the third doped amorphous silicon film 304 can reduce the influence on the second intrinsic amorphous layer 22, reduce the lattice distortion of the second intrinsic amorphous layer 22, and can effectively ensure the passivation effect on the backlight side of the heterojunction solar cell; due to the relatively high doping concentration, the fourth doped amorphous silicon film 305 can improve the contact between the second doped amorphous layer 32 and the second transparent conductive film, reduce the contact resistance therebetween, and improve the cell fill factor.

[0092] As a preference, the thickness of the third doped amorphous silicon film 304 is generally less than that of the fourth doped amorphous silicon film 305. In specific implementation, the thickness of the third doped amorphous silicon film 304 is 1 - 5 nm, and the thickness of the fourth doped amorphous silicon film 305 is 2 - 15 nm.

[0093] It should be understood that in the implementation structure shown in the present invention Figure 9 and Figure 10 among the first intrinsic amorphous layer 21, the first doped amorphous layer 31, the second intrinsic amorphous layer 22 and the second doped amorphous layer 32, the two located on the light-receiving surface are the second intrinsic amorphous layer 22 and the second doped amorphous layer 32, and the two located on the backlight surface are the first intrinsic amorphous layer 21 and the first doped amorphous layer 31. Among them, the sum of the thicknesses of the second intrinsic amorphous layer 22 and the second doped amorphous layer 32 is less than or equal to the sum of the thicknesses of the first intrinsic amorphous layer 21 and the first doped amorphous layer 31.

[0094] More specifically, Figure 9 and Figure 10 in the implementation structure shown, the first intrinsic amorphous layer 21 and the first doped amorphous layer 31 can respectively refer to the design of the second intrinsic amorphous layer 22 and the second doped amorphous layer 32 in the implementation structure shown in Figure 2 and Figure 8 The design of the second intrinsic amorphous layer 22 and the second doped amorphous layer 32 in the implementation structure shown in Figure 9 and Figure 10 the second intrinsic amorphous layer 22 and the second doped amorphous layer 32 in the implementation structure shown can respectively refer to the design of the first intrinsic amorphous layer 21 and the first doped amorphous layer 31 in the implementation structure shown in Figure 2 and Figure 8 This is not specifically elaborated here.

[0095] Preferably, the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 involved in the present invention respectively include at least two stacked intrinsic films, and each intrinsic film is composed of one of intrinsic amorphous silicon, intrinsic amorphous silicon oxide, and intrinsic amorphous silicon carbide.

[0096] Referring to Figure 7 shown, it is a specific implementation manner of the implementation structure shown in Figure 2 In this specific implementation manner, the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 respectively include three stacked intrinsic films. Among them, in the direction away from the single-crystalline silicon substrate 10, the first intrinsic amorphous layer 21 sequentially includes a first intrinsic film 201, a second intrinsic film 202, and a third intrinsic film 203, and the second intrinsic amorphous layer 22 sequentially includes a fourth intrinsic film 204, a fifth intrinsic film 205, and a sixth intrinsic film 206. It can be understood that in other embodiments of the present invention, the number of film layers of the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 is not limited to the three-layer structure.

[0097] In the present invention, since both the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 include at least two stacked intrinsic films, in the specific implementation process, it is convenient to form the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 with better comprehensive performance by controlling the characteristics of each layer of film.

[0098] As a preference of the present invention, in the specific implementation process, the outermost intrinsic film of the first intrinsic amorphous layer 21 away from the single-crystalline silicon substrate 10 is set as intrinsic amorphous silicon oxide. Refer to Figure 7 As shown, in this embodiment, the third intrinsic film 203 is the outermost intrinsic film of the first intrinsic amorphous layer 21 away from the single-crystalline silicon substrate 10, and the third intrinsic film 203 in this embodiment is preferably made of intrinsic amorphous silicon oxide. It can be understood that in some other embodiments of the present invention, the outermost intrinsic film of the second intrinsic amorphous layer 22 away from the single-crystalline silicon substrate 10 can also be set as intrinsic amorphous silicon oxide, that is, the sixth intrinsic film 206 away from the single-crystalline silicon substrate 10 in this embodiment can be set as intrinsic amorphous silicon oxide.

[0099] The passivation effect of intrinsic amorphous silicon oxide is worse than that of intrinsic amorphous silicon and intrinsic amorphous silicon carbide, but it has better light transmittance than intrinsic amorphous silicon and intrinsic amorphous silicon carbide. In the heterojunction solar cell, due to the distance, the outermost intrinsic film of the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 away from the single-crystalline silicon substrate 10 has limited passivation effect on the single-crystalline silicon substrate 10 itself. Setting it as intrinsic amorphous silicon oxide with the best light transmittance can optimize the photoelectric conversion efficiency of the heterojunction solar cell to a certain extent.

[0100] As a further preference of the present invention, in the present invention, the hydrogen content of the intrinsic film of the first intrinsic amorphous layer 21 close to the single-crystalline silicon substrate 10 is higher than that of the intrinsic film away from the single-crystalline silicon substrate, and the hydrogen content of the intrinsic film of the second intrinsic amorphous layer 22 close to the single-crystalline silicon substrate 10 is higher than that of the intrinsic film away from the single-crystalline silicon substrate.

[0101] Refer to Figure 7 As shown, in this embodiment, the hydrogen content of the first intrinsic film 201, the second intrinsic film 202 and the third intrinsic film 203 in the first intrinsic amorphous layer 21 decreases in turn, and the hydrogen content of the fourth intrinsic film 204, the fifth intrinsic film 205 and the sixth intrinsic film 206 in the second intrinsic amorphous layer 22 also decreases in turn. It is relatively easy to understand that the closer the intrinsic film of the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 is to the single-crystalline silicon substrate 10, the more obvious its passivation effect is. The first intrinsic film 201 and the fourth intrinsic film 204 are both directly attached to the single-crystalline silicon substrate 10, and their highest hydrogen content can make the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 have the best passivation effect on the single-crystalline silicon substrate 10.

[0102] As a preference of the present invention, when the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 each include three intrinsic films stacked on top of each other, in the direction away from the single-crystalline silicon substrate 10, the hydrogen content ranges of the three intrinsic films of the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 are successively 20%-40%, 10%-25%, and 8%-20%. That is, the hydrogen content ranges of the first intrinsic film 201 and the fourth intrinsic film 204 are 20%-40%, the hydrogen content ranges of the second intrinsic film 202 and the fifth intrinsic film 205 are 10%-25%, and the hydrogen content ranges of the third intrinsic film 203 and the sixth intrinsic film 206 are 8%-20%.

[0103] Further preferably, in Figure 7 the embodiment, the hydrogen content ranges of the first intrinsic film 201 and the fourth intrinsic film 204 are 24%-30%, the hydrogen content ranges of the second intrinsic film 202 and the fifth intrinsic film 205 are 12%-18%, and the hydrogen content ranges of the third intrinsic film 203 and the sixth intrinsic film 206 are 10%-15%.

[0104] As a further preference of the present invention Figure 7 In the embodiment shown, when the first main surface of the single-crystalline silicon substrate 10 is the light-receiving surface, the thickness ranges of the first intrinsic film 201, the second intrinsic film 202, and the third intrinsic film 203 in the first intrinsic amorphous layer 21 are successively 1-3 nm, 2-4 nm, and 1-3 nm, and the thickness ranges of the fourth intrinsic film 204, the fifth intrinsic film 205, and the sixth intrinsic film 206 in the second intrinsic amorphous layer 22 are successively 1-5 nm, 3-10 nm, and 0-5 nm.

[0105] Correspondingly, it can be understood that when the first main surface of the single-crystalline silicon substrate 10 is the backlight surface, the thickness ranges of the fourth intrinsic film 204, the fifth intrinsic film 205, and the sixth intrinsic film 206 in the second intrinsic amorphous layer 22 are successively 1-3 nm, 2-4 nm, and 1-3 nm, and the thickness ranges of the first intrinsic film 201, the second intrinsic film 202, and the third intrinsic film 203 in the first intrinsic amorphous layer 21 are successively 1-5 nm, 3-10 nm, and 0-5 nm.

[0106] As a further preference, the proportion of bonded hydrogen atoms in the total hydrogen atoms in the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 involved in the present invention is 15%-25%. In the specific passivation effect, the bonded hydrogen atoms play a decisive role. In the prior art, the proportion of bonded hydrogen atoms in the total hydrogen atoms in the intrinsic amorphous layer is usually about 10%. In the present invention, by increasing the proportion of bonded hydrogen atoms in the total hydrogen atoms in the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22, the passivation effect of the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 on the surface of the single-crystalline silicon substrate 10 can also be improved, and further the open-circuit voltage of the corresponding heterojunction solar cell can be improved.

[0107] In some other embodiments of the present invention, the average hydrogen atom concentration in the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 involved is 1e22 - 5e22 / cm 3 ; preferably 2.5e22 - 5e22 / cm 3 . In the prior art, the hydrogen atom concentration in the intrinsic layer amorphous silicon layer of the heterojunction solar cell involved is usually less than 1e22 per cm 3 . The low concentration of hydrogen atoms results in poor passivation effect of the intrinsic layer amorphous silicon layer. In the present invention, by increasing the hydrogen atom concentration in the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22, the passivation effect of the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 on the surface of the single-crystal silicon substrate 10 can be effectively improved, thereby improving the open-circuit voltage of the corresponding heterojunction solar cell.

[0108] Although the single-crystal silicon substrate 10 can specifically be a p-type single-crystal silicon substrate or an n-type single-crystal silicon substrate; as a preferred embodiment of the present invention, the single-crystal silicon substrate 10 is an n-type single-crystal silicon substrate. Further preferably, the first doped amorphous layer 31 and the second doped amorphous layer 32 on the light-receiving side are n-type doped amorphous layers, and the first doped amorphous layer 31 and the second doped amorphous layer 32 on the backlight side are p-type doped amorphous layers.

[0109] When the first doped amorphous layer 31 and the second doped amorphous layer 32 on the light-receiving side are n-type doped amorphous layers and the first doped amorphous layer 31 and the second doped amorphous layer 32 on the backlight side are p-type doped amorphous layers, the first transparent conductive film 41 and the second transparent conductive film 42 involved in the present invention also have the following design.

[0110] For Figure 2 、 Figure 8 the illustrated implementation structure, a specific implementation manner is referred to Figure 5 as shown. The first transparent conductive film layer 41 includes a first TCO film 401 attached to the surface of the n-type doped amorphous layer (the first doped amorphous layer 31) and a second TCO film 402 attached to the surface of the first TCO film 401. Among them, the mass ratio of the doped oxide in the first TCO film 401 is greater than the mass ratio of the doped oxide in the second TCO film 402.

[0111] In the heterojunction solar cell structure provided by this implementation structure, based on its specific design structure, the first TCO film 401 can ensure good contact between the first transparent conductive film layer 41 and the n-type doped amorphous layer (the first doped amorphous layer 31) due to high doping, thereby reducing the contact resistance and improving the fill factor of the heterojunction solar cell; while the second TCO film 402 can increase the light transmittance of the first transparent conductive film layer 41 as a whole due to low doping, which can improve the short-circuit current of the heterojunction solar cell.

[0112] Preferably, in the specific implementation process of this implementation structure, the mass ratio of the doped oxide in the first TCO film 401 is 5%-20%, and the mass ratio of the doped oxide in the second TCO film 402 is 0.5%-5%.

[0113] Furthermore, the carrier concentration of the first TCO film 401 is 3e20 - 1e21 / cm 3 , and the carrier concentration of the second TCO film 402 is 5e19 - 4e20 / cm 3 . In the specific implementation process, the carrier concentration in the first TCO film 401 and the second TCO film 402 has a positive correlation with the mass ratio of the doped oxide in the corresponding film layer. However, in the specific manufacturing process, the carrier concentration can be further adjusted to a certain extent by controlling the film-forming atmosphere of the first TCO film 401 and the second TCO film 402 (such as adjusting the oxygen concentration).

[0114] As a preference of this implementation structure, the thickness of the first TCO film 401 is less than the thickness of the second TCO film 402. More specifically, as shown in Figure 5 , the thickness of the first TCO film 401 is 5 - 15 nm, and 5 - 10 nm is the best; the thickness of the second TCO film 402 is 40 - 90 nm, and 60 - 80 nm is the best.

[0115] The main purpose of setting the first TCO film 401 is to form good contact between the first transparent conductive film layer 41 and the n-type doped amorphous layer (the first doped amorphous layer 31). A relatively thin thickness can meet this requirement. Moreover, since the set thickness of the first TCO film 401 is relatively thin, the problem of poor light transmittance caused by high doping can be greatly reduced. Due to the low doping concentration, the second TCO film 402 has good light transmittance. Setting it to a relatively thick thickness can ensure that the first transparent conductive film layer 41 has sufficient thickness while also ensuring excellent light transmittance, thereby enabling the heterojunction solar cell to have a high short-circuit current.

[0116] Further referring to Figure 6As shown, in some other embodiments of the present invention, the first transparent conductive film layer 41 further includes a third TCO film 403 attached to the surface of the second TCO film 402, and the mass proportion of the doped oxide in the third TCO film 403 is greater than that in the second TCO film 402. Specifically, when implemented, the mass proportion of the doped oxide in the third TCO film 403 is 5%-20%.

[0117] Since the doping concentration of the third TCO film 403 also has a relatively high value, it can ensure good contact between the first transparent conductive film layer 41 and the first collector 51, and can also reduce the contact resistance between the two, thereby further improving the fill factor of the heterojunction solar cell.

[0118] In the specific implementation process, the thickness of the third TCO film 403 is less than that of the second TCO film 402. Figure 6 In the shown embodiment, the thickness of the first TCO film 401 is 5-15 nm, the thickness of the second TCO film 402 is 35-75 nm, and the thickness of the third TCO film 403 is 5-15 nm. Among them, the considerations for setting the thickness of the third TCO film 403 to a relatively small value can refer to the considerations for setting the thickness of the first TCO film 401, and no further description will be given here.

[0119] In the specific implementation process of this implementation structure, the first TCO film 401, the second TCO film 402, and the third TCO film 403 are all formed by doping an oxide in indium oxide or zinc oxide, and the doped oxide is one or several of Al2O3, Ga2O3, In2O3, SnO2, WO3, TiO2, ZrO2, and MoO2. Among them, the doped oxide is preferably SnO2, and the reliability is better. It can be understood that the mass proportion of the doped oxide in the corresponding TCO film refers to the ratio of the mass of the doped oxide to the total mass of the corresponding TCO film.

[0120] Refer to Figure 5 、 Figure 6 As shown, in these embodiments, the second transparent conductive film layer 42 includes a fourth TCO film 404 attached to the surface of the p-type doped amorphous layer (the second doped amorphous layer 32) and a fifth TCO film 405 attached to the surface of the fourth TCO film 404, wherein the mass proportion of the doped oxide in the fourth TCO film 404 is less than that in the fifth TCO film 405.

[0121] Since the fourth TCO film 404 is in direct contact with the p-type doped amorphous layer (the second doped amorphous layer 32), when the fourth TCO film 404 has a low doping concentration, the Schottky contact barrier between the two is reduced, and thus the best contact between the two can be achieved, improving the fill factor of the heterojunction solar cell. In addition, since the fifth TCO film 405 has a high doping concentration, it has good conductivity and good electrical contact with the second collector, which can also improve the fill factor of the heterojunction solar cell. It can be known that since the second transparent conductive film layer 42 is located on the backlight side of the heterojunction solar cell, in specific applications, the proportion of sunlight transmitted through the second transparent conductive film layer 42 to the inside of the heterojunction solar cell is very low, and its light transmittance has little impact on the overall performance of the heterojunction solar cell.

[0122] In the specific implementation process, the mass ratio of the doped oxide in the fourth TCO film 404 is 0.5%-5%, and the mass ratio of the doped oxide in the fifth TCO film 405 is 5%-20%.

[0123] Correspondingly, the carrier concentration of the fourth TCO film 404 is 5e19 - 4e20 / cm 3 , and the carrier concentration of the fifth TCO film 405 is 3e20 - 1e21 / cm 3 .

[0124] Preferably, in the present implementation structure, the thickness of the fourth TCO film 404 is usually less than the thickness of the fifth TCO film 405. Among them, setting the fourth TCO film 404 to a relatively small value can satisfy the excellent contact with the p-type doped amorphous layer (the second doped amorphous layer 32), while setting the fifth TCO film 405 to a relatively large value can not only meet the total thickness requirement of the second transparent conductive film layer 42, but also improve the electrical properties of the second transparent conductive film layer 42.

[0125] In some specific embodiments, the thickness of the fourth TCO film 404 is 5 - 15 nm, and the thickness of the fifth TCO film 405 is 40 - 90 nm.

[0126] The fourth TCO film 404 and the fifth TCO film 405 in the present implementation structure are also both formed by doping an oxide in indium oxide or zinc oxide, and the doped oxide is one or more of Al2O3, Ga2O3, In2O3, SnO2, WO3, TiO2, ZrO2, and MoO2. Among them, the doped oxide is preferably SnO2, and the reliability is better.

[0127] In this implementation structure, the thickness of the first transparent conductive film layer 41 is less than or equal to the thickness of the second transparent conductive film layer 42. Preferably, the thickness of the first transparent conductive film layer 41 is less than the thickness of the second transparent conductive film layer 42. The total thickness of the first transparent conductive film layer 41 is 60 - 120 nm, preferably 60 - 90 nm.

[0128] For a heterojunction solar cell, the light absorption effect on the light-receiving surface has a much greater impact on the photoelectric conversion efficiency of the cell than the light absorption effect on the backlight surface. Since the thickness of the first transparent conductive film layer 41 is small, it can effectively reduce the loss of sunlight on the light-receiving surface when passing through the first transparent conductive film layer 41, and thus the heterojunction solar cell can have better photoelectric conversion efficiency.

[0129] It can be understood that in some other embodiments of this implementation structure, the second transparent conductive film layer 42 involved can also be set as a single-layer structure, that is, only the first transparent conductive film layer 41 is set as a double-layer film or a triple-layer film structure.

[0130] It should be understood that in the present invention Figure 9 、 Figure 10 In the shown implementation structure, the one of the first transparent conductive film layer 41 and the second transparent conductive film layer 42 located on the light-receiving surface is the second transparent conductive film layer 42, and the one located on the backlight surface is the first transparent conductive film layer 41. At this time, Figure 9 、 Figure 10 In the shown implementation structure, the design of the first transparent conductive film layer 41 can refer to Figure 2 、 Figure 8 the design of the second transparent conductive film layer 42 in the shown implementation structure, Figure 9 、 Figure 10 In the shown implementation structure, the design of the second transparent conductive film layer 42 can refer to Figure 2 、 Figure 8 the design of the first transparent conductive film layer 41 in the shown implementation structure. Specifically, it will not be elaborated here.

[0131] Furthermore, in the present invention, one of the first transparent conductive film layer 41 and the second transparent conductive film layer 42 extends to the outside of the side to cover the doped side portion. In this way, the current collection on the surface of the heterojunction solar cell can be more comprehensive, improving the photoelectric conversion efficiency of the cell. More specifically, the following different implementation manners can be referred to.

[0132] Referring to Figure 2 shown, in the embodiment, the first transparent conductive film layer 41 has a first conductive layer side portion 410 that extends to the outside of the side to cover the second doped side portion 320. At this time, the second transparent conductive film layer 42 only covers the area corresponding to the second doped amorphous layer 32 and the second main surface, and a blank area that is insulated from the first conductive layer side portion 410 is formed around it.

[0133] Reference Figure 8 As shown, in this embodiment, the first transparent conductive film layer 41 has a first conductive layer side portion 410 that extends to the outside of the side surface to cover the first doped side portion 310. At this time, the second transparent conductive film layer 42 only covers the area corresponding to the second doped amorphous layer 32 and the second main surface, and a blank area that is insulated from the first conductive layer side portion 410 is formed around the periphery.

[0134] Reference Figure 9 As shown, in this embodiment, the second transparent conductive film layer 42 has a second conductive layer side portion 420 that extends to the outside of the side surface to cover the first doped side portion 310. At this time, the first transparent conductive film layer 41 only covers the area corresponding to the first doped amorphous layer 31 and the first main surface, and a blank area that is insulated from the second conductive layer side portion 420 is formed around the periphery.

[0135] Reference Figure 10 As shown, in this embodiment, the second transparent conductive film layer 42 has a second conductive layer side portion 420 that extends to the outside of the side surface to cover the second doped side portion 320. At this time, the first transparent conductive film layer 41 only covers the area corresponding to the first doped amorphous layer 31 and the first main surface, and a blank area that is insulated from the second conductive layer side portion 420 is formed around the periphery.

[0136] Reference Figure 11 As shown, in this embodiment, the second transparent conductive film layer 42 has a second conductive layer side portion 420 that extends to the outside of the side surface to cover the second doped side portion 320. At this time, the first transparent conductive film layer 41 only covers the area corresponding to the first doped amorphous layer 31 and the first main surface, and a blank area that is insulated from the second conductive layer side portion 420 is formed around the periphery.

[0137] Comparing the above embodiments, Figure 2 , Figure 8 , Figure 9 and Figure 10 in the embodiments shown, in both the first transparent conductive film layer 41 and the second transparent conductive film layer 42, one located on the light-receiving surface side extends to the outside of the side surface to cover the doped side portion. And in Figure 11 the embodiment shown, in the first transparent conductive film layer 41 and the second transparent conductive film layer 42, one located on the backlight surface side extends to the outside of the side surface to cover the doped side portion, and other similar implementation structures will not be further elaborated here.

[0138] In the specific implementation process, the width range of the blank area for insulating the first transparent conductive film layer 41 and the second transparent conductive film layer 42 from each other is 0.5 - 2 mm.

[0139] The present invention also provides a method for manufacturing a heterojunction solar cell, which is used to manufacture the heterojunction solar cell as described above, and includes:

[0140] A step of texturing a single-crystalline silicon substrate, texturing the first major surface, the second major surface and the side surfaces of the single-crystalline silicon substrate 10.

[0141] A step of manufacturing the first intrinsic amorphous layer, referring to Figure 12 As shown, place the single-crystalline silicon substrate 10 with its first major surface facing upward on the first carrier 61. The first carrier 61 has a first groove 610 for placing the single-crystalline silicon substrate 10. Deposit and form a first intrinsic amorphous layer 21 on the side of the first major surface of the single-crystalline silicon substrate 10 from the upper side of the first carrier 61. The periphery of the first intrinsic amorphous layer 21 extends to cover all the side surfaces. Specifically, in implementation, the part where the periphery of the first intrinsic amorphous layer 21 extends to cover all the side surfaces constitutes the first intrinsic side portion 210.

[0142] A step of manufacturing the second intrinsic amorphous layer, referring to Figure 13 As shown, place the single-crystalline silicon substrate 10 with its second major surface facing upward on the second carrier 62 after completing the step of manufacturing the first intrinsic amorphous layer. The second carrier 62 has a second groove 620 for placing the single-crystalline silicon substrate 10. Deposit and form a second intrinsic amorphous layer 22 on the side of the second major surface of the single-crystalline silicon substrate 10 from the upper side of the second carrier 62. The periphery of the second intrinsic amorphous layer 22 extends to cover the first intrinsic side portion 210. The part where the periphery of the second intrinsic amorphous layer 22 covers the first intrinsic side portion 210 constitutes the second intrinsic side portion 220.

[0143] A step of manufacturing the first doped amorphous layer, referring to Figure 14 As shown, place the single-crystalline silicon substrate 10 with its first major surface facing upward on the third carrier 63 after completing the step of manufacturing the second intrinsic amorphous layer. The third carrier 63 has a third groove 630 for placing the single-crystalline silicon substrate 10. Form a first doped amorphous layer 31 on the first intrinsic amorphous layer 21 from the upper side of the third carrier 63. The first doped amorphous layer 31 is formed with a first doped side portion 310 extending outside the side surface.

[0144] A step of manufacturing the second doped amorphous layer, referring to Figure 15 As shown, place the single-crystalline silicon substrate 10 with its second major surface facing upward on the fourth carrier 64 after completing the step of manufacturing the second intrinsic amorphous layer. The fourth carrier 64 has a fourth groove 640 for placing the single-crystalline silicon substrate 10. Form a first doped amorphous layer 32 on the second intrinsic amorphous layer 22 from the upper side of the fourth carrier 640. The second doped amorphous layer 32 is formed with a second doped side portion 320 extending outside the side surface and connecting with the first doped side portion 310.

[0145] Steps for fabricating the transparent conductive film layer. The transparent conductive film layer includes a first transparent conductive film layer 41 and a second transparent conductive film layer 42. On one side of the first major surface and the second major surface of the single-crystalline silicon substrate 10 that has completed the fabrication steps of the first doped amorphous layer and the second doped amorphous layer, the first transparent conductive film layer 41 and the second transparent conductive film layer 42 are respectively deposited.

[0146] Steps for fabricating the collector. The collector includes a first collector 51 and a second collector 52. On the surface of the first transparent conductive film layer 41 facing away from the first doped amorphous layer 31, the first collector 51 is formed. On the surface of the second transparent conductive film layer 42 facing away from the second doped amorphous layer 32, the second collector 52 is formed.

[0147] In the specific implementation process of the present invention, the order of the fabrication steps of the second doped amorphous layer and the first doped amorphous layer can be adjusted. Furthermore, a heterojunction solar cell with different arrangement orders of the first doped side portion 310 and the second doped side portion 320 can be formed.

[0148] In the specific implementation process of the present invention, when the fabrication step of the second doped amorphous layer is before the fabrication step of the first doped amorphous layer, the second carrier plate 62 involved in the fabrication step of the second intrinsic amorphous layer and the fourth carrier plate 64 involved in the fabrication step of the second doped amorphous layer can be the same carrier plate, and during the execution of the two steps, there is no need to move the single-crystalline silicon substrate 10.

[0149] In a specific step for fabricating the transparent conductive film layer, refer to Figure 16 As shown, the single-crystalline silicon substrate 10 with the second non-amorphous film fabrication step completed is placed face-up on the fifth carrier plate 70. The fifth carrier plate 70 includes a through hole 700 that penetrates up and down. Inside the through hole 700, there is a bearing portion 701 that bears the single-crystalline silicon substrate 10 and forms an occlusion for the edge on one side of the second major surface of the single-crystalline silicon substrate 10. The size of the region of the through hole 700 above the bearing portion 701 is larger than the size of the single-crystalline silicon substrate 10, and the common difference range is 2 - 4 mm. By depositing the first transparent conductive film layer 41 and the second transparent conductive film layer 42 on one side of the first major surface and the second major surface respectively through the fifth carrier plate 70, a Figure 2 、 Figure 8 heterojunction solar cell with the structure shown can be formed.

[0150] In this embodiment, since the size of the region of the through hole 700 above the bearing portion 701 is larger than the size of the single-crystalline silicon substrate 10, during the formation of the first transparent conductive film layer 41, it will extend towards the side of the single-crystalline silicon substrate 10 to form a first conductive layer side portion 410, and the portion of the edge on one side of the second major surface of the single-crystalline silicon substrate 10 occluded by the bearing portion 701 forms a blank area.

[0151] In another embodiment of the present invention, the single-crystalline silicon substrate 10 that has completed the second amorphous film manufacturing step can also be placed on the fifth carrier plate 70 with the second main surface facing upward (not shown in the figure). At this time, a heterojunction solar cell with the structure shown in Figure 9 , Figure 10 or Figure 11 can be formed. Details are not further described herein.

[0152] For the second intrinsic side portion 220, the first doped side portion 310, and the second doped side portion 320 to be formed on the side surface of the single-crystalline silicon substrate 10, in the specific implementation process of the present invention, the side length dimensions of the first groove 610, the second groove 620, the third groove 630, and the fourth groove 640 have a difference range of 2 - 4 mm from the corresponding side length dimensions of the single-crystalline silicon substrate 10. Based on the difference between the side length dimensions of the first groove 610, the second groove 620, the third groove 630, and the fourth groove 640 and the corresponding side length dimensions of the single-crystalline silicon substrate 10, when manufacturing the corresponding film layers, a gap of 1 - 2 mm can be formed between each side edge of the single-crystalline silicon substrate 10 and the corresponding groove edge, so that the corresponding film layers can be fully electroless plated on the side of the single-crystalline silicon substrate 10.

[0153] In the present invention, in the step of texturing the single-crystalline silicon substrate, first, the surface oxide layer is removed using an HF solution with a dilution concentration of 5%, and then, using the anisotropic etching characteristics of single-crystalline silicon, a solution of KOH or NaOH or tetramethylammonium hydroxide (TMAH) plus alcohol is used for texturing.

[0154] In the present invention, the four amorphous layers, namely the first intrinsic amorphous layer 21, the second intrinsic amorphous layer 22, the first doped amorphous layer 31, and the second doped amorphous layer 32, are all formed by PECVD deposition process. The first transparent conductive film layer 41 and the second transparent conductive film layer 42 involved in the present invention are formed by PVD deposition, RPD deposition, or magnetron sputtering deposition process. The first collector 51 and the second collector 52 involved in the present invention are formed by screen printing process.

[0155] To better understand the present invention, the following also shows a specific manufacturing method for the four amorphous layers of the heterojunction solar cell wafer: First, pure SiH4 is introduced on the side facing the first main surface of the single-crystalline silicon substrate 10, and then SiH4 diluted with H2 is introduced. The first intrinsic amorphous layer 21 is grown under the action of a 13.56 MHz radio frequency power supply; on the side facing the second main surface of the single-crystalline silicon substrate 10, pure SiH4 is introduced first, and then SiH4 diluted with H2 is introduced. The second intrinsic amorphous layer 22 is grown under the action of a 13.56 MHz radio frequency power supply; gases such as PH3, SiH4, and H2 are introduced on the side facing the first main surface of the single-crystalline silicon substrate 10 to fabricate the first doped amorphous layer 31; gases such as B2H6, SiH4, and H2 are introduced on the side facing the second main surface of the single-crystalline silicon substrate 10 to fabricate the second doped amorphous layer 32.

[0156] It can be understood that the first intrinsic amorphous layer 21, the first doped amorphous layer 31, the second intrinsic amorphous layer 22 and the second doped amorphous layer 32 are respectively formed in different coating chambers. In addition, during the deposition process of the four amorphous layers, before the corresponding amorphous layer is deposited, the temperature and pressure of the coating chamber involved need to reach a predetermined value. Usually, the temperature is 180 °C and the pressure is controlled at 30 - 200 Pa.

[0157] To optimize the passivation effect of the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 on the single - crystal silicon substrate 10, during the specific manufacturing process of the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22, when introducing SiH4 diluted by H2, the dilution ratio of H2 / SiH4 can be adjusted, so that the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 have intrinsic films with multiple different characteristics. Usually, the dilution ratio range of H2 / SiH4 is 5 - 250.

[0158] The above only shows the preparation method in which the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 are all composed of intrinsic amorphous silicon. It can be understood that in some other embodiments of the present invention, the intrinsic films of the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 can also be intrinsic amorphous silicon oxide or intrinsic amorphous silicon carbide. Specific details are not further elaborated here.

[0159] When manufacturing the first doped amorphous layer 31 and the second doped amorphous layer 32, CO2 or CH4 can also be introduced into the corresponding coating chamber, which will make the constituent materials of the first doped amorphous layer 31 and the second doped amorphous layer 32 contain amorphous silicon oxide or amorphous silicon carbide. More specifically, refer to the following description.

[0160] When manufacturing the first doped amorphous film 301, SiH4, H2 and the first - type doping gas are introduced into the vacuum chamber.

[0161] When fabricating a doped amorphous silicon oxide film, a doped amorphous silicon carbide film, or a doped amorphous silicon carbide / doped amorphous silicon oxide composite film 302: If the film layer is a doped amorphous silicon oxide film, SiH4, H2, CO2, and a first type of doping gas are introduced into the vacuum chamber; if the film layer is a doped amorphous silicon carbide film, SiH4, H2, CH4, and a first type of doping gas are introduced into the vacuum chamber; if the film layer is a doped amorphous silicon carbide / doped amorphous silicon oxide composite film, then SiH4, H2, CO2, CH4, and a first type of doping gas are simultaneously introduced into the vacuum chamber to form a composite film, or at least one layer of doped amorphous silicon oxide and at least one layer of doped amorphous silicon carbide are deposited separately, and then a composite film is formed. In the present invention, the doped amorphous silicon oxide film, the doped amorphous silicon carbide film, or the doped amorphous silicon carbide / doped amorphous silicon oxide composite film 302 can increase the optical band gap of the light-receiving surface layer of the heterojunction solar cell, increase light transmittance, and improve the optical performance of the cell.

[0162] When it is necessary to fabricate a second doped amorphous film 303, SiH4, H2, and a first type of doping gas are introduced into the vacuum chamber.

[0163] When fabricating a third doped amorphous film 304 and a fourth doped amorphous film 305, SiH4, H2, and a second type of doping gas are introduced into the vacuum chamber. The difference is that the doping concentration of the second type of doping gas when fabricating the third doped amorphous film 303 is less than the doping concentration of the second type of doping gas when fabricating the fourth doped amorphous film 304.

[0164] It should be understood that the above-mentioned first type of doping gas refers to one of PH3 (phosphine) gas and B2H6 (diborane) gas, and the second type of doping gas refers to the other of PH3 (phosphine) gas and B2H6 (diborane) gas.

[0165] It should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0166] The series of detailed descriptions listed above are only specific descriptions of the feasible embodiments of the present invention, and they are not intended to limit the protection scope of the present invention. Any equivalent embodiments or modifications made without departing from the technical spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A heterojunction solar cell, comprising a single-crystalline silicon substrate having a first main surface and a second main surface arranged opposite to each other, and a side surface connecting the first main surface and the second main surface, one of the first main surface and the second main surface being a light-receiving surface and the other being a backlight surface; characterized in that, The heterojunction solar cell further includes a first intrinsic amorphous layer, a first doped amorphous layer, a first transparent conductive film layer, and a first collector electrode that are sequentially disposed on one side of the first main surface, and a second intrinsic amorphous layer, a second doped amorphous layer, a second transparent conductive film layer, and a second collector electrode that are sequentially disposed on one side of the second main surface. The first intrinsic amorphous layer has a first intrinsic side portion that extends toward the second intrinsic amorphous layer to cover all of the side surfaces. The second intrinsic amorphous layer has a second intrinsic side portion that extends toward the first intrinsic amorphous layer to cover the first intrinsic side portion. The first doped amorphous layer and the second doped amorphous layer have opposite doping types and both have doped side portions that extend outside the side surfaces and are connected to each other; One of the first transparent conductive film layer and the second transparent conductive film layer located on the light-receiving surface only includes a first TCO film attached to the surface of the doped amorphous layer and a second TCO film attached to the surface of the first TCO film. The mass ratio of the doped oxide in the first TCO film is greater than the mass ratio of the doped oxide in the second TCO film; the thickness of the first TCO film is less than the thickness of the second TCO film; the proportion of bonded hydrogen atoms in the total hydrogen atoms in the first intrinsic amorphous layer and the second intrinsic amorphous layer is 15%-25%; the first intrinsic amorphous layer and the second intrinsic amorphous layer respectively include at least two stacked intrinsic films, and each of the intrinsic films is composed of one of intrinsic amorphous silicon, intrinsic amorphous silicon oxide, and intrinsic amorphous silicon carbide; the outermost intrinsic film of the first intrinsic amorphous layer and / or the second intrinsic amorphous layer away from the monocrystalline silicon substrate is intrinsic amorphous silicon oxide.

2. The heterojunction solar cell according to claim 1, wherein The sum of the thicknesses of two of the first intrinsic amorphous layer, the first doped amorphous layer, the second intrinsic amorphous layer, and the second doped amorphous layer located on the light-receiving surface is less than or equal to the sum of the thicknesses of the two located on the backlight surface.

3. The heterojunction solar cell according to claim 2, characterized in that, The sum of the thicknesses of two of the first intrinsic amorphous layer, the first doped amorphous layer, the second intrinsic amorphous layer, and the second doped amorphous layer located on the light-receiving surface is 6-21 nm, and the sum of the thicknesses of the two located on the backlight surface is 6-30 nm.

4. The heterojunction solar cell according to any one of claims 1-3, characterized in that, The thickness of the first intrinsic amorphous layer and the second intrinsic amorphous layer located on the light-receiving surface is less than or equal to the thickness located on the backlight surface.

5. The heterojunction solar cell according to claim 4, wherein The thickness of the first intrinsic amorphous layer and the second intrinsic amorphous layer located on the light-receiving surface is 3-6 nm, and the thickness located on the backlight surface is 3-10 nm.

6. The heterojunction solar cell according to any one of claims 1 to 3, characterized in that, The thickness of the first doped amorphous layer and the second doped amorphous layer located on the light-receiving surface side is less than or equal to the thickness located on the backlight surface side.

7. The heterojunction solar cell according to claim 6, wherein The thickness of the first doped amorphous layer and the second doped amorphous layer located on the light-receiving surface side is 3-15 nm, and the thickness located on the backlight surface side is 3-20 nm.

8. The heterojunction solar cell according to claim 1, wherein, The oxygen content of the first doped amorphous layer and the second doped amorphous layer located on the light-receiving surface is greater than or equal to the oxygen content located on the backlight surface side.

9. The heterojunction solar cell according to claim 1, 2, 3 or 8, characterized in that, In the direction from the backlight surface to the light-receiving surface, the first doped amorphous layer and the second doped amorphous layer located on the light-receiving surface sequentially include a first doped amorphous silicon film, and a doped amorphous silicon oxide film, a doped amorphous silicon carbide film, or a doped amorphous silicon carbide / doped amorphous silicon oxide composite film on the surface of the first doped amorphous silicon film.

10. The heterojunction solar cell according to claim 9, wherein, The first doped amorphous layer and the second doped amorphous layer located on the light-receiving surface further include a second doped amorphous silicon film on the surface of the doped amorphous silicon oxide film, the doped amorphous silicon carbide film, or the doped amorphous silicon carbide / doped amorphous silicon oxide composite film.

11. The heterojunction solar cell according to claim 1, 2, 3 or 8, characterized in that, In the direction from the light-receiving surface to the backlight surface, one of the first doped amorphous layer and the second doped amorphous layer located on the backlight surface sequentially includes a third doped amorphous silicon film and a fourth doped amorphous silicon film located on the surface of the third doped amorphous silicon film and having a doping concentration higher than that of the third doped amorphous silicon film; the carrier concentration of the third doped amorphous silicon film is 5E18 to 5E19 / cm 3 ; the carrier concentration of the fourth doped amorphous silicon film is 5E19 to 5E21 / cm 3 .

12. The heterojunction solar cell according to claim 1, 2, 3 or 8, characterized in that, The doped side portions of the first doped amorphous layer and the second doped amorphous layer are stacked outside the second intrinsic side portion.

13. The heterojunction solar cell according to claim 1, 2, 3 or 8, characterized in that, The sum of the partial thicknesses of the first intrinsic side portion covered by the second intrinsic side portion and the thickness of the second intrinsic side portion covering the region on the side connected to the second main surface are both not less than 1 nm.

14. The heterojunction solar cell according to claim 1, characterized in that, The hydrogen content of the intrinsic film in the first intrinsic amorphous layer close to the single-crystalline silicon substrate is higher than that of the intrinsic film far from the single-crystalline silicon substrate, and the hydrogen content of the intrinsic film in the second intrinsic amorphous layer close to the single-crystalline silicon substrate is higher than that of the intrinsic film far from the single-crystalline silicon substrate.

15. The heterojunction solar cell according to claim 14, wherein, The first intrinsic amorphous layer and the second intrinsic amorphous layer respectively include three stacked intrinsic films. In the direction away from the single-crystalline silicon substrate, the hydrogen content ranges of the three intrinsic films of the first intrinsic amorphous layer and the second intrinsic amorphous layer are sequentially 20%-40%, 10%-25%, and 8%-20%.

16. The heterojunction solar cell according to claim 1, 2, 3 or 8, characterized in that, The single-crystalline silicon substrate is an n-type single-crystalline silicon. The first doped amorphous layer and the second doped amorphous layer on the light-receiving surface side are n-type doped amorphous layers, and the first doped amorphous layer and the second doped amorphous layer on the backlight surface side are p-type doped amorphous layers.

17. The heterojunction solar cell according to claim 1, wherein The mass ratio of the doped oxide in the first TCO film is 5%-20%, and the mass ratio of the doped oxide in the second TCO film is 0.5%-5%.

18. The heterojunction solar cell according to claim 1, wherein, The first transparent conductive film layer and the second transparent conductive film layer on the light-receiving surface further include a third TCO film attached to the surface of the second TCO film. The mass ratio of the doped oxide in the third TCO film is greater than that of the doped oxide in the second TCO film.

19. The heterojunction solar cell according to claim 16, wherein, The first transparent conductive film layer and the second transparent conductive film layer on the backlight surface include a fourth TCO film attached to the surface of the p-type doped amorphous layer and a fifth TCO film attached to the surface of the fourth TCO film. The mass ratio of the doped oxide in the fourth TCO film is less than that of the doped oxide in the fifth TCO film.

20. The heterojunction solar cell according to claim 1, 2, 3 or 8, characterized in that The thickness of the first transparent conductive film layer and the second transparent conductive film layer on the light-receiving surface is less than or equal to the thickness of the first transparent conductive film layer and the second transparent conductive film layer on the backlight surface.

21. The heterojunction solar cell according to claim 1, 2, 3 or 8, characterized in that One of the first transparent conductive film layer and the second transparent conductive film layer extends outside the side surface to cover the doped side portion.

22. A method for fabricating a heterojunction solar cell, characterized in that, Used to manufacture the heterojunction solar cell according to any one of claims 1 to 21, comprising: a step of texturing the single crystal silicon substrate, texturing the first main surface, the second main surface and the side surfaces of the single crystal silicon substrate; A first intrinsic amorphous layer manufacturing step, placing the single crystal silicon substrate with the first main surface facing upward on a first carrier, the first carrier having a first groove for placing the single crystal silicon substrate, depositing the first intrinsic amorphous layer on the first main surface side of the single crystal silicon substrate from the upper side of the first carrier, the first intrinsic amorphous layer extending around to cover all the side surfaces; A second intrinsic amorphous layer manufacturing step, placing the single crystal silicon substrate after the first intrinsic amorphous layer manufacturing step with the second main surface facing upward on a second carrier, the second carrier having a second groove for placing the single crystal silicon substrate, and depositing the second intrinsic amorphous layer on the second main surface of the single crystal silicon substrate from the upper side of the second carrier, the second intrinsic amorphous layer extending around to cover the first intrinsic side edge portion; A first doped amorphous layer manufacturing step, placing the single crystal silicon substrate after the second intrinsic amorphous layer manufacturing step with the first main surface facing upward on a third carrier, the third carrier having a third groove for placing the single crystal silicon substrate, forming the first doped amorphous layer on the first intrinsic amorphous layer from the upper side of the third carrier, the first doped amorphous layer forming a first doped side edge portion extending outside the side surface; a second doped amorphous layer manufacturing step, placing the single crystal silicon substrate after the second intrinsic amorphous layer manufacturing step with the second main surface facing upward on a fourth carrier, the fourth carrier having a fourth groove for placing the single crystal silicon substrate, forming the first doped amorphous layer on the second intrinsic amorphous layer from the upper side of the fourth carrier, the second doped amorphous layer forming a second doped side edge portion extending outside the side surface and connected to the first doped side edge portion, the second doped amorphous layer manufacturing step and the first doped amorphous layer manufacturing step being adjustable in order; a transparent conductive film layer manufacturing step, depositing the first transparent conductive film layer and the second transparent conductive film layer on the first main surface side and the second main surface side of the single crystal silicon substrate after the first doped amorphous layer manufacturing step and the second doped amorphous layer manufacturing step respectively; a collector electrode manufacturing step, forming a first collector electrode on a surface of the first transparent conductive film layer facing away from the first doped amorphous layer, and forming a second collector electrode on a surface of the second transparent conductive film layer facing away from the second doped amorphous layer; The difference between the side lengths of the first groove, the second groove, the third groove and the fourth groove and the corresponding side lengths of the single crystal silicon substrate is in the range of 2-4 mm; The bonded hydrogen atoms in the first intrinsic amorphous layer and the second intrinsic amorphous layer account for 15%-25% of the total hydrogen atoms.

Images