Solar cell and method for manufacturing the same

Abstract

The present invention relates to the technical field of solar cells, and specifically provides a solar cell and a preparation method thereof, wherein the solar cell comprises: a semiconductor substrate layer; a first passivation layer, a first doped semiconductor layer; a first carrier collection layer, which is made of a conductive material and is located between the first passivation layer and the first doped semiconductor layer; a first transparent conductive layer; wherein the conductivity type of the first doped semiconductor layer is the same as that of the semiconductor substrate layer, and the side of the first doped semiconductor layer relative to the semiconductor substrate layer is the light-facing side of the solar cell. The photoelectric conversion efficiency of the solar cell is improved.

Description

Technical Field

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

[0002] As non-renewable energy sources are running out of steam, solar energy as a new energy source provides new possibilities for the global energy structure. Solar energy is inexhaustible, solving the problem of energy shortage. Solar cells are important devices for converting light energy into electrical energy, and heterojunction cells are currently the most promising type of solar cells.

[0003] The amorphous silicon layer in the heterojunction battery of the prior art has poor lateral carrier transport performance, and there are many defect states inside the heterojunction battery and between the interfaces of each film layer, which will cause many carriers to be recombined during the transmission process, resulting in current loss, thereby reducing the conversion efficiency of the heterojunction battery. For example, the doping layer of the existing heterojunction battery is directly bonded to the semiconductor substrate layer or the passivation layer, and the defects at the interface between the doping layer and the semiconductor substrate layer cause the carriers to be recombined during the transmission process, resulting in current loss. Not only heterojunction batteries, but also solar cells with amorphous silicon layer structures have the problem of current loss caused by carrier recombination.

[0004] Overcoming the defect of low conversion efficiency of solar cells in the prior art is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect of low photoelectric conversion efficiency of solar cells in the prior art, thereby providing a solar cell and a preparation method thereof.

[0006] The present invention provides a solar cell, comprising a semiconductor substrate layer, and further comprising: a first passivation layer, located on one side surface of the semiconductor substrate layer, the material of the first passivation layer comprising amorphous silicon or nanocrystalline silicon; a first doped semiconductor layer, located on the side of the first passivation layer away from the semiconductor substrate layer, the material of the first doped semiconductor layer comprising any one of amorphous silicon, nanocrystalline silicon, oxygen-doped amorphous silicon, oxygen-doped nanocrystalline silicon, carbon-doped amorphous silicon or carbon-doped nanocrystalline silicon; a first carrier collection layer, made of conductive material and located between the first passivation layer and the first doped semiconductor layer, pre-collecting and laterally transmitting carriers generated by the semiconductor substrate layer, the conductive material of the first carrier collection layer comprising a mixture of tin oxide and indium oxide, or a mixture of tungsten oxide and indium oxide, when the conductive material of the first carrier collection layer comprises a mixture of tin oxide and indium oxide, the oxide in the first carrier collection layer The ratio of the mass of tin to the mass of indium oxide is 1:9-1:300; when the conductive material of the first carrier collection layer includes a mixture of tungsten oxide and indium oxide, the ratio of the mass of tungsten oxide to the mass of indium oxide in the first carrier collection layer is 1:9-1:300, the refractive index of the first carrier collection layer is 1.8-2.2, the first carrier collection layer is suitable for adjusting the propagation angle of light inside the solar cell, the refractive index of the first carrier collection layer is less than the refractive index of the first passivation layer, and the refractive index of the first carrier collection layer is less than the refractive index of the first doped semiconductor layer; a first transparent conductive layer is located on a side surface of the first doped semiconductor layer away from the semiconductor substrate layer; wherein the conductivity type of the first doped semiconductor layer is the same as the conductivity type of the semiconductor substrate layer, and the side of the first doped semiconductor layer relative to the semiconductor substrate layer is the light-facing surface of the solar cell.

[0007] Optionally, it also includes: a second passivation layer, located on the other side surface of the semiconductor substrate layer; a second doped semiconductor layer, located on the side of the second passivation layer away from the semiconductor substrate layer, the conductivity type of the second doped semiconductor layer is opposite to the conductivity type of the first doped semiconductor layer; a second transparent conductive layer, located on the side surface of the second doped semiconductor layer away from the semiconductor substrate layer; a second carrier collection layer, made of conductive material and located between the second passivation layer and the second doped semiconductor layer.

[0008] Optionally, the ratio of the thickness of the first carrier collection layer to the thickness of the first transparent conductive layer is 1:1-1:5; the thickness of the first carrier collection layer is 20nm-120nm.

[0009] Optionally, the ratio of the thickness of the second carrier collection layer to the thickness of the second transparent conductive layer is 1:1-1:5; the thickness of the second carrier collection layer is 20nm-120nm, and the thickness of the second transparent conductive layer is 50nm-150nm.

[0010] Optionally, the conductive material of the second carrier collection layer includes a mixture of tin oxide and indium oxide, or a mixture of tungsten oxide and indium oxide; when the conductive material of the second carrier collection layer includes a mixture of tin oxide and indium oxide, the ratio of the mass of tin oxide to the mass of indium oxide in the second carrier collection layer is 1:9-1:300; when the conductive material of the second carrier collection layer includes a mixture of tungsten oxide and indium oxide, the ratio of the mass of tungsten oxide to the mass of indium oxide in the second carrier collection layer is 1:9-1:300.

[0011] Optionally, the material of the first transparent conductive layer includes a mixture of tin oxide and indium oxide, or a mixture of tungsten oxide and indium oxide, and the material of the second transparent conductive layer includes a mixture of tin oxide and indium oxide, or a mixture of tungsten oxide and indium oxide.

[0012] Optionally, when the material of the first transparent conductive layer includes a mixture of tin oxide and indium oxide, the ratio of the mass of tin oxide to the mass of indium oxide in the first transparent conductive layer is 1:9-1:300; when the material of the first transparent conductive layer includes a mixture of tungsten oxide and indium oxide, the ratio of the mass of tungsten oxide to the mass of indium oxide in the first transparent conductive layer is 1:9-1:300.

[0013] Optionally, when the material of the second transparent conductive layer includes a mixture of tin oxide and indium oxide, the ratio of the mass of tin oxide to the mass of indium oxide in the second transparent conductive layer is 1:9-1:300; when the material of the second transparent conductive layer includes a mixture of tungsten oxide and indium oxide, the ratio of the mass of tungsten oxide to the mass of indium oxide in the second transparent conductive layer is 1:9-1:300.

[0014] Optionally, it further includes: grid lines respectively arranged on the outer side of the first transparent conductive layer and the outer side of the second transparent conductive layer, and the grid lines at least include fine grids.

[0015] The present invention also provides a method for preparing a solar cell, which is used to prepare the solar cell described above, comprising providing a semiconductor substrate layer, and further comprising: forming a first passivation layer on a surface of one side of the semiconductor substrate layer, wherein the conductive material of the first passivation layer comprises amorphous silicon or nanocrystalline silicon; forming a first carrier collection layer on a surface of the first passivation layer that is away from the semiconductor substrate layer by using a conductive material, wherein the first carrier collection layer pre-collects and laterally transmits carriers generated by the semiconductor substrate layer, wherein the conductive material of the first carrier collection layer comprises a mixture of tin oxide and indium oxide, or a mixture of tungsten oxide and indium oxide, and when the conductive material of the first carrier collection layer comprises a mixture of tin oxide and indium oxide, the ratio of the mass of tin oxide to the mass of indium oxide in the first carrier collection layer is 1:9-1:300; and the conductive material of the first carrier collection layer is When the material includes a mixture of tungsten oxide and indium oxide, the ratio of the mass of tungsten oxide to the mass of indium oxide in the first carrier collection layer is 1:9-1:300, the refractive index of the first carrier collection layer is 1.8-2.2, and the first carrier collection layer is suitable for adjusting the propagation angle of light inside the solar cell; a first doped semiconductor layer is formed on the surface of the first carrier collection layer away from the semiconductor substrate layer, the conductive material of the first doped semiconductor layer includes any one of amorphous silicon, nanocrystalline silicon, oxygen-doped amorphous silicon, oxygen-doped nanocrystalline silicon, carbon-doped amorphous silicon or carbon-doped nanocrystalline silicon, the refractive index of the first carrier collection layer is less than the refractive index of the first passivation layer, and the refractive index of the first carrier collection layer is less than the refractive index of the first doped semiconductor layer; a first transparent conductive layer is formed on the surface of the first doped semiconductor layer away from the semiconductor substrate layer.

[0016] Optionally, it also includes: forming a second passivation layer on the other side surface of the semiconductor substrate layer; forming a second carrier collection layer on the side surface of the second passivation layer facing away from the semiconductor substrate layer using a conductive material; the second carrier collection layer pre-collects and laterally transmits the carriers generated by the semiconductor substrate layer; forming a second doped semiconductor layer on the side surface of the second carrier collection layer facing away from the semiconductor substrate layer, the conductivity type of the second doped semiconductor layer is opposite to that of the first doped semiconductor layer; and forming a second transparent conductive layer on the side surface of the second doped semiconductor layer facing away from the semiconductor substrate layer.

[0017] The technical solution of the present invention has the following advantages:

[0018] In the solar cell provided by the present invention, the first passivation layer is located on one side surface of the semiconductor substrate layer, and the material of the first passivation layer includes amorphous silicon or nanocrystalline silicon; the first doped semiconductor layer is located on the side surface of the first passivation layer away from the semiconductor substrate layer, and the material of the first doped semiconductor layer includes any one of amorphous silicon, nanocrystalline silicon, oxygen-doped amorphous silicon, oxygen-doped nanocrystalline silicon, carbon-doped amorphous silicon or carbon-doped nanocrystalline silicon; the second doped semiconductor layer is located on the other side of the semiconductor substrate layer, and the conductivity type of the second doped semiconductor layer is opposite to that of the first doped semiconductor layer; the first carrier collection layer is located between the semiconductor substrate layer and the first doped semiconductor layer, and the conductive material of the first carrier collection layer includes a mixture of tin oxide and indium oxide, or a mixture of tungsten oxide and indium oxide, and the second doped semiconductor layer is located on the other side of the semiconductor substrate layer. When the conductive material of a carrier collection layer includes a mixture of tin oxide and indium oxide, the ratio of the mass of tin oxide to the mass of indium oxide in the first carrier collection layer is 1:9-1:300; when the conductive material of the first carrier collection layer includes a mixture of tungsten oxide and indium oxide, the ratio of the mass of tungsten oxide to the mass of indium oxide in the first carrier collection layer is 1:9-1:300, the refractive index of the first carrier collection layer is 1.8-2.2, the refractive index of the first carrier collection layer is less than the refractive index of the first passivation layer, and the refractive index of the first carrier collection layer is less than the refractive index of the first doped semiconductor layer; the first transparent conductive layer is located on a side surface of the first doped semiconductor layer away from the semiconductor substrate layer; the second transparent conductive layer is located on a side surface of the second doped semiconductor layer away from the semiconductor substrate layer.On the one hand, the first carrier collection layer is located between the first passivation layer and the first doped semiconductor layer. The first carrier collection layer can pre-collect and laterally transfer the carriers generated by the semiconductor substrate layer. The first carrier collection layer is arranged between the first passivation layer and the first doped semiconductor layer. The reason is that the conductivity of the first passivation layer is poor and the first doped semiconductor layer has many defects. Since the first carrier collection layer itself has good conductivity, high carrier mobility and small square resistance, the first carrier collection layer can have good lateral transmission ability between the first passivation layer and the first doped semiconductor layer, which has the effect of increasing the "activity space" of the carriers. The carriers can avoid the defects at the interface between the first passivation layer and the first doped semiconductor layer, and can selectively pass through the first doped semiconductor layer from a position with fewer defects and then flow to the first transparent conductive layer, thereby reducing the carriers between the first passivation layer and the first doped semiconductor layer. The first doped semiconductor layer can reduce the recombination loss between the first and second doped semiconductor layers, thereby increasing the carrier concentration, carrier mobility and carrier life, improving the conductivity of the solar cell to avoid losses caused by current, thereby improving the photoelectric conversion efficiency of the solar cell; on the other hand, the conductivity type of the first doped semiconductor layer is the same as the conductivity type of the semiconductor substrate layer, the first doped semiconductor layer is on the side relative to the semiconductor substrate layer, and the first carrier collection layer is located on the light-facing surface of the solar cell. The light-facing surface needs to reduce the reflection and absorption of light, so that as much light as possible can enter the solar cell to generate carriers. Since the refractive index of the first carrier collection layer is less than the refractive index of the first passivation layer and less than the refractive index of the first doped semiconductor layer, it can adjust the propagation angle of the light inside the solar cell. Therefore, the path of the light is changed by the refractive index difference, which can increase the optical path of the light in the solar cell and improve the utilization rate of the light. In summary, the photoelectric conversion efficiency of the solar cell is high.

[0019] Furthermore, it also includes: a second carrier collection layer, which is made of conductive material and is located between the semiconductor substrate layer and the second doped semiconductor layer. The second carrier collection layer can pre-collect and laterally transmit the carriers generated by the semiconductor substrate layer, so as to improve the photoelectric conversion efficiency of the solar cell. Furthermore, the ratio of the thickness of the first carrier collection layer to the thickness of the first transparent conductive layer is 1:1-1:5, and the ratio of the thickness of the second carrier collection layer to the thickness of the second transparent conductive layer is 1:1-1:5. The thickness of the first carrier collection layer is less than the thickness of the first transparent conductive layer. The small thickness of the first carrier collection layer is conducive to improving the transmittance of the first carrier collection layer, thereby improving the transmittance of the solar cell to visible light; the large thickness of the first transparent conductive layer is conducive to improving the conductivity of the first transparent conductive layer; the thickness of the second carrier collection layer is less than the thickness of the second transparent conductive layer. The small thickness of the second carrier collection layer is conducive to improving the transmittance of the second carrier collection layer, thereby improving the transmittance of the solar cell to visible light; the large thickness of the second transparent conductive layer is conducive to improving the conductivity of the second transparent conductive layer, thereby improving the photoelectric conversion efficiency of the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic diagram of a solar cell provided by an embodiment of the present invention;

[0022] Figure 2 A flow chart of a method for preparing a solar cell provided by one embodiment of the present invention;

[0023] Figure 3 A flow chart of some steps in a method for preparing a solar cell provided by another embodiment of the present invention;

[0024] Figure 4 A schematic diagram of a semiconductor substrate layer in a step of a method for preparing a solar cell provided by an embodiment of the present invention;

[0025] Figure 5 A schematic diagram of a solar cell manufacturing method according to an embodiment of the present invention after forming a first passivation layer, a second passivation layer, a first carrier collection layer and a second carrier collection layer;

[0026] Figure 6 A schematic structural diagram of forming a first doped semiconductor layer, a second doped semiconductor layer, a first transparent conductive layer, a second transparent conductive layer, a first gate electrode layer, and a second gate electrode layer in the steps of a solar cell preparation method provided in one embodiment of the present invention.

[0027] Description of reference numerals:

[0028] 1-semiconductor substrate layer; 21-first doped semiconductor layer; 22-second doped semiconductor layer;

[0029] 31-first carrier collection layer; 32-second carrier collection layer;

[0030] 41-first transparent conductive layer; 42-second transparent conductive layer;

[0031] 51-first passivation layer; 52-second passivation layer;

[0032] 61 - a first gate line electrode layer; 62 - a second gate line electrode layer. DETAILED DESCRIPTION

[0033] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] Example 1

[0038] This embodiment provides a solar cell, referring to Figure 1 ,include:

[0039] Semiconductor substrate layer 1;

[0040] A first passivation layer 51 is located on one side surface of the semiconductor substrate layer 1, and the material of the first passivation layer includes amorphous silicon or nanocrystalline silicon;

[0041] A first doped semiconductor layer 21 is located on a side of the first passivation layer 51 away from the semiconductor substrate layer 1, and the material of the first doped semiconductor layer includes any one of amorphous silicon, nanocrystalline silicon, oxygen-doped amorphous silicon, oxygen-doped nanocrystalline silicon, carbon-doped amorphous silicon or carbon-doped nanocrystalline silicon;

[0042] The first carrier collection layer 31 is made of a conductive material and is located between the first passivation layer 51 and the first doped semiconductor layer 21. The carriers generated by the semiconductor substrate layer are pre-collected and laterally transmitted. The conductive material of the first carrier collection layer includes a mixture of tin oxide and indium oxide, or a mixture of tungsten oxide and indium oxide. When the conductive material of the first carrier collection layer includes a mixture of tin oxide and indium oxide, the mass ratio of tin oxide to indium oxide in the first carrier collection layer is 1:9-1:300; when the conductive material of the first carrier collection layer includes a mixture of tungsten oxide and indium oxide, the mass ratio of tungsten oxide to indium oxide in the first carrier collection layer is 1:9-1:300. The refractive index of the first carrier collection layer is 1.8-2.2, the refractive index of the first carrier collection layer is less than the refractive index of the first passivation layer, and the refractive index of the first carrier collection layer is less than the refractive index of the first doped semiconductor layer.

[0043] A first transparent conductive layer 41 is located on a surface of the first doped semiconductor layer 21 that is away from the semiconductor substrate layer 1;

[0044] The conductivity type of the first doped semiconductor layer 21 is the same as that of the semiconductor substrate layer 1 , and the side of the first doped semiconductor layer 21 relative to the semiconductor substrate layer 1 is the light-facing side of the solar cell.

[0045] In the solar cell provided in this embodiment, on the one hand, the first carrier collection layer is located between the first passivation layer and the first doped semiconductor layer. The first carrier collection layer can pre-collect and laterally transmit the carriers generated by the semiconductor substrate layer. The first carrier collection layer is arranged between the first passivation layer and the first doped semiconductor layer. The reason is that the conductivity of the first passivation layer is poor and the first doped semiconductor layer has many defects. Since the first carrier collection layer itself has good conductivity, high carrier mobility and small square resistance, the first carrier collection layer can have good lateral transmission ability between the first passivation layer and the first doped semiconductor layer, which has the effect of increasing the "activity space" of the carriers, and the carriers can By avoiding defects at the interface between the first passivation layer and the first doped semiconductor layer, the first doped semiconductor layer can be selectively passed through the first doped semiconductor layer from a position with fewer defects and then flow to the first transparent conductive layer, thereby reducing the recombination loss of carriers between the first passivation layer and the first doped semiconductor layer, thereby increasing the carrier concentration and carrier mobility and the life of the carriers, improving the conductivity of the solar cell to avoid losses caused by current, thereby improving the photoelectric conversion efficiency of the solar cell; on the other hand, the conductivity type of the first doped semiconductor layer 21 is the same as the conductivity type of the semiconductor substrate layer 1, the conductivity type of the second doped semiconductor layer 22 is opposite to the conductivity type of the semiconductor substrate layer 1, and the first doped semiconductor layer 21 is a light-facing surface. The first carrier collection layer is located on the light-facing surface of the solar cell, and the light-facing surface needs to reduce the reflection and absorption of light, so that as much light as possible enters the solar cell to generate carriers. Since the refractive index of the first carrier collection layer is less than the refractive index of the first passivation layer and the refractive index of the first doped semiconductor layer, it can adjust the propagation angle of the light inside the solar cell, so the path of the light is changed by the refractive index difference, which can increase the optical path of the light in the solar cell and improve the utilization rate of the light.

[0046] In the solar cell provided in this embodiment, the matching between the various layers follows the principle of not bringing negative impacts on the effects of other layers, and on this basis bringing gains in one or some performances to the solar cell.

[0047] In one embodiment, the semiconductor substrate layer 1 is an N-type single crystal silicon semiconductor layer.

[0048] In one embodiment, the ratio of the thickness of the first carrier collection layer 31 to the thickness of the first transparent conductive layer 41 is 1:1-1:5, for example, 1:2.

[0049] In one embodiment, the thickness of the first carrier collection layer 31 is less than or equal to the thickness of the first transparent conductive layer 41. The thickness of the first carrier collection layer 31 is 20nm-120nm, such as 30nm, 40nm, 50nm, 60nm, 80nm, 90nm, 100nm or 110nm; the thickness of the first transparent conductive layer 41 is 50nm-150nm, such as 60nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, or 140nm. The thickness of the first transparent conductive layer is greater than or equal to the first carrier collection layer, and the thickness of the first transparent conductive layer cannot be too small in order to meet the requirements of reflectivity and transmittance. In addition, since the thickness of the first carrier collection layer is less than or equal to the thickness of the first transparent conductive layer, the thickness of the first carrier collection layer is ensured to be small, so that the increase in the distance between the first doped semiconductor layer 21 and the second doped semiconductor layer 22 is small, thereby avoiding weakening the strength of the built-in electric field of the solar cell, thereby avoiding weakening the voltage of the solar cell. In addition, the small thickness of the first carrier collection layer is also beneficial to improving the transmittance of the first carrier collection layer, thereby improving the transmittance of the solar cell to visible light. Therefore, it is beneficial to improve the photoelectric conversion efficiency of the solar cell in a comprehensive manner.

[0050] In one embodiment, when the thickness of the first carrier collection layer is 30 nm, the thickness of the first transparent conductive layer is 95 nm.

[0051] In one embodiment, the conductive material of the first carrier collection layer 31 includes a mixture of tin oxide and indium oxide. When the conductive material of the first carrier collection layer 31 includes a mixture of tin oxide and indium oxide, the ratio of the mass of tin oxide to the mass of indium oxide in the first carrier collection layer 31 is 1:9-1:300, for example, 1:99, 1:150 or 1:297. When the ratio of the mass of tin oxide to the mass of indium oxide in the first carrier collection layer 31 is within this range, the carrier concentration and carrier mobility in the carrier collection layer are high.

[0052] In another embodiment, the conductive material of the first carrier collection layer includes a mixture of tungsten oxide and indium oxide. When the conductive material of the first carrier collection layer includes a mixture of tungsten oxide and indium oxide, the ratio of the mass of tungsten oxide to the mass of indium oxide in the first carrier collection layer is 1:9-1:300, for example, 1:99, 1:150 or 1:297. When the ratio of the mass of tungsten oxide to the mass of indium oxide in the first carrier collection layer is within this range, the carrier concentration and carrier mobility in the first carrier collection layer are high.

[0053] In one embodiment, continue to refer to Figure 1 , the solar cell also includes:

[0054] A second passivation layer 52, located on the other side surface of the semiconductor substrate layer 1;

[0055] A second doped semiconductor layer 22, located on a side of the second passivation layer 52 away from the semiconductor substrate layer 1, wherein the conductivity type of the second doped semiconductor layer 22 is opposite to that of the first doped semiconductor layer 21;

[0056] The second carrier collection layer 32 is made of conductive material and is located between the semiconductor substrate layer 1 and the second doped semiconductor layer 22 .

[0057] The second transparent conductive layer 42 is located on a surface of the second doped semiconductor layer 22 that is away from the semiconductor substrate layer 1 .

[0058] The second carrier collection layer can pre-collect the carriers generated by the semiconductor substrate layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0059] In one embodiment, the ratio of the thickness of the second carrier collection layer 32 to the thickness of the second transparent conductive layer 42 is 1:1-1:5; for example, 1:2. Since the second carrier collection layer plays a role in pre-collection of carriers, the thickness of the second carrier collection layer is small, which is beneficial to reducing the resistance inside the solar cell and reducing carrier recombination. The second carrier collection layer has a small thickness, which is also beneficial to reducing the thickness of the solar cell and avoiding weakening the voltage of the solar cell. The small thickness of the second carrier collection layer is also beneficial to improving the transmittance of the second carrier collection layer, thereby improving the transmittance of the solar cell to visible light; the large thickness of the second transparent conductive layer is beneficial to improving the conductivity of the second transparent conductive layer, and therefore, it is beneficial to improve the photoelectric conversion efficiency of the solar cell.

[0060] In one embodiment, the thickness of the second carrier collection layer 32 is 20nm-120nm, for example, 30nm, 40nm, 50nm, 60nm, 80nm, 90nm, 100nm or 110nm; the thickness of the second transparent conductive layer 42 is 50nm-150nm, for example, 60nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, or 140nm.

[0061] In one embodiment, the conductive material of the second carrier collection layer 32 includes a mixture of tin oxide and indium oxide. When the conductive material of the second carrier collection layer 32 includes a mixture of tin oxide and indium oxide, the ratio of the mass of tin oxide to the mass of indium oxide in the first carrier collection layer 31 is 1:9-1:300, for example, 1:99, 1:150 or 1:297. When the ratio of the mass of tin oxide to the mass of indium oxide in the first carrier collection layer 31 is within this range, the carrier concentration and carrier mobility in the carrier collection layer are high.

[0062] In another embodiment, the conductive material of the second carrier collection layer includes a mixture of tungsten oxide and indium oxide. When the conductive material of the second carrier collection layer includes a mixture of tungsten oxide and indium oxide, the ratio of the mass of tungsten oxide to the mass of indium oxide in the first carrier collection layer is 1:9-1:300, for example, 1:99, 1:150 or 1:297. When the ratio of the mass of tungsten oxide to the mass of indium oxide in the second carrier collection layer is within this range, the carrier concentration and carrier mobility in the second carrier collection layer are high.

[0063] In one embodiment, the material of the first transparent conductive layer 41 includes a mixture of tin oxide and indium oxide. When the material of the first transparent conductive layer 41 includes a mixture of tin oxide and indium oxide, the ratio of the mass of tin oxide to the mass of indium oxide in the first transparent conductive layer 41 is 1:9-1:300, for example, 1:99, 1:150 or 1:297. When the ratio of the mass of tin oxide to the mass of indium oxide in the first transparent conductive layer 41 is within this range, the collection and transport rate of carriers in the first transparent conductive layer 41 is high, and the conductivity of the first transparent conductive layer 41 is high.

[0064] In another embodiment, the material of the first transparent conductive layer includes a mixture of tungsten oxide and indium oxide. When the material of the first transparent conductive layer includes a mixture of tungsten oxide and indium oxide, the ratio of the mass of tungsten oxide to the mass of indium oxide in the first transparent conductive layer is 1:9-1:300, for example, 1:99, 1:150 or 1:297. When the ratio of the mass of tungsten oxide to the mass of indium oxide in the first transparent conductive layer is within this range, the collection and transport rate of carriers in the first transparent conductive layer is high, and the conductivity of the first transparent conductive layer is high.

[0065] In one embodiment, the material of the second transparent conductive layer 42 includes a mixture of tin oxide and indium oxide. When the material of the second transparent conductive layer 42 includes a mixture of tin oxide and indium oxide, the ratio of the mass of tin oxide to the mass of indium oxide in the second transparent conductive layer 42 is 1:9-1:300, for example, 1:99, 1:150 or 1:297. When the ratio of the mass of tin oxide to the mass of indium oxide in the second transparent conductive layer 42 is within this range, the collection and transport rate of carriers in the second transparent conductive layer 42 is high, and the conductivity of the first transparent conductive layer 41 is high.

[0066] In another embodiment, the material of the second transparent conductive layer includes a mixture of tungsten oxide and indium oxide. When the material of the second transparent conductive layer includes a mixture of tungsten oxide and indium oxide, the ratio of the mass of tungsten oxide to the mass of indium oxide in the second transparent conductive layer is 1:9-1:300, for example, 1:99, 1:150 or 1:297. When the ratio of the mass of tungsten oxide to the mass of indium oxide in the second transparent conductive layer is within this range, the collection and transport rate of carriers in the second transparent conductive layer is high, and the conductivity of the second transparent conductive layer is high.

[0067] The first doped semiconductor layer and the second doped semiconductor layer may both be amorphous silicon layers, or either of the first doped semiconductor layer and the second doped semiconductor layer may be microcrystalline silicon layers, or both may be microcrystalline silicon layers. In one embodiment, the first doped semiconductor layer 21 is in an amorphous state, a nanocrystalline state, or a microcrystalline state; the second doped semiconductor layer 22 is in an amorphous state, a nanocrystalline state, or a microcrystalline state. Since the microcrystalline doped semiconductor layer has a higher electrical conductivity, a larger optical band gap, and a higher visible light transmittance, the short-circuit current of the solar cell can be increased, and the photoelectric conversion efficiency of the solar cell can be improved.

[0068] In one embodiment, the doping ions of the first doped semiconductor layer 21 are N-type, such as phosphorus ions; and the doping ions of the second doped semiconductor layer 22 are P-type, such as boron ions.

[0069] In one embodiment, continue to refer to Figure 1 The solar cell also includes: a second passivation layer 52, which is located on the other side surface of the semiconductor substrate layer 1, and a second carrier collection layer is arranged between the second passivation layer and the second doped semiconductor layer. The reason is that the conductivity of the second passivation layer is poor and the second doped semiconductor layer has many defects. Since the second carrier collection layer itself has good conductivity, high carrier mobility and small square resistance, the second carrier collection layer can have good lateral transmission ability between the second passivation layer and the second doped semiconductor layer. The carriers can avoid the defects at the interface between the second passivation layer and the second doped semiconductor layer, and can selectively pass through the second doped semiconductor layer from a position with fewer defects and then flow to the second transparent conductive layer, thereby reducing the recombination loss of carriers between the second passivation layer and the second doped semiconductor layer, thereby improving the carrier concentration and carrier mobility as well as the life of the carriers, improving the conductivity of the solar cell to avoid losses caused by current, thereby improving the photoelectric conversion efficiency of the solar cell.

[0070] In one embodiment, continue to refer to Figure 1The solar cell further includes: a first gate line electrode layer 61 and a second gate line electrode layer 62 , wherein the first gate line electrode layer 61 is located on the surface of the first transparent conductive layer 41 facing away from the semiconductor substrate layer 1 , and the second gate line electrode layer 62 is located on the surface of the second transparent conductive layer 42 facing away from the semiconductor substrate layer 1 .

[0071] The solar cell provided in this embodiment includes a main grid solar cell and a non-main grid solar cell. That is to say, based on the structure of the above solar cell, it also includes: grid lines respectively arranged on the outside of the first transparent conductive layer and the outside of the second transparent conductive layer, which can only form a fine grid (or sub-grid) structure on its surface, or can form a structure including a main grid and a fine grid (or sub-grid). The method of forming the grid line can be a screen printing method or an electroplating method, which is not limited here.

[0072] Example 2

[0073] This embodiment provides a method for preparing a solar cell. Figure 2 , including the following steps:

[0074] Step S1: providing a semiconductor substrate layer;

[0075] Step S21: forming a first passivation layer on a surface of one side of the semiconductor substrate layer, wherein the conductive material of the first passivation layer includes amorphous silicon or nanocrystalline silicon;

[0076] Step S31: using a conductive material to form a first carrier collection layer on a surface of the first passivation layer facing away from the semiconductor substrate layer, the first carrier collection layer pre-collects and laterally transmits carriers generated by the semiconductor substrate layer, the conductive material of the first carrier collection layer includes a mixture of tin oxide and indium oxide, or a mixture of tungsten oxide and indium oxide, when the conductive material of the first carrier collection layer includes a mixture of tin oxide and indium oxide, the ratio of the mass of tin oxide to the mass of indium oxide in the first carrier collection layer is 1:9-1:300; when the conductive material of the first carrier collection layer includes a mixture of tungsten oxide and indium oxide, the ratio of the mass of tungsten oxide to the mass of indium oxide in the first carrier collection layer is 1:9-1:300, the refractive index of the first carrier collection layer is 1.8-2.2, and the first carrier collection layer is suitable for adjusting the propagation angle of light inside the solar cell;

[0077] Step S41: forming a first doped semiconductor layer on a surface of the first carrier collection layer facing away from the semiconductor substrate layer, wherein the conductive material of the first doped semiconductor layer includes any one of amorphous silicon, nanocrystalline silicon, oxygen-doped amorphous silicon, oxygen-doped nanocrystalline silicon, carbon-doped amorphous silicon or carbon-doped nanocrystalline silicon, and the refractive index of the first carrier collection layer is less than the refractive index of the first passivation layer, and the refractive index of the first carrier collection layer is less than the refractive index of the first doped semiconductor layer;

[0078] Step S51: forming a first transparent conductive layer on a surface of the first doped semiconductor layer facing away from the semiconductor substrate layer.

[0079] refer to Figure 3 , in some other embodiments, further comprising:

[0080] Step S22: forming a second passivation layer on one side surface of the semiconductor substrate layer;

[0081] Step S32: using a conductive material to form a second carrier collection layer on a surface of the second passivation layer facing away from the semiconductor substrate layer, wherein the second carrier collection layer pre-collects and laterally transmits carriers generated by the semiconductor substrate layer;

[0082] Step S42: forming a second doped semiconductor layer on a surface of the second carrier collection layer facing away from the semiconductor substrate layer;

[0083] Step S52: forming a second transparent conductive layer on a surface of the second doped semiconductor layer facing away from the semiconductor substrate layer.

[0084] In this embodiment, the first passivation layer, the second passivation layer, the first doped semiconductor layer, and the second doped semiconductor layer can be formed on one side in sequence or on both sides in alternation using the same type of equipment. That is, it can be: the first passivation layer and the first doped semiconductor layer on one side are formed on one side in sequence, and then the second passivation layer and the second doped semiconductor layer on the other side are formed on the one side after turning over; or it can be: the first passivation layer is formed on one side first, then the second passivation layer is turned over to form the second passivation layer, then the first doped semiconductor layer is turned over to form the first doped semiconductor layer, and finally the second doped semiconductor layer is turned over to form the second doped semiconductor layer. The specific formation order is not limited.

[0085] Reference below Figures 4 to 6 The preparation method of solar cells is introduced in detail.

[0086] refer to Figure 4, providing a semiconductor substrate layer 1. In one embodiment, the semiconductor substrate layer 1 needs to be cleaned, and then subjected to a texturing treatment or a polishing treatment. The purpose of the cleaning treatment is to remove the mechanical damage layer, oil stains and metal ions on the surface of the semiconductor substrate layer, and reduce the surface recombination of the semiconductor substrate layer. The purpose of the texturing treatment is to form a semiconductor substrate layer with a pyramid velvet surface. The purpose of the polishing treatment is to form a semiconductor substrate layer with a smooth surface.

[0087] refer to Figure 5 A first passivation layer 51 is formed on one side surface of the semiconductor substrate layer 1, and a second passivation layer 52 is formed on the other side surface of the semiconductor substrate layer.

[0088] In one embodiment, the process of forming the first passivation layer 51 and the second passivation layer 52 includes: a plasma enhanced chemical vapor deposition process (PECVD), and the process parameters of forming the first passivation layer 51 and the second passivation layer 52 include: the gas used includes a mixed gas of hydrogen, silane, diborane and phosphine, which can passivate the semiconductor substrate layer, and the pressure in the chamber is 100Pa-300Pa, for example, 200Pa; the RF power density is 600W / m 2 -2600W / m 2 ; For example, 2000W / m 2 This is conducive to fully decomposing the gas under optimal conditions, so that atoms or molecular clusters have optimal energy, and the first passivation layer 51 and the second passivation layer 52 formed on the semiconductor substrate layer will also be optimal, so that the photoelectric conversion efficiency of the formed solar cell is the highest.

[0089] Continue to refer Figure 5 A first carrier collection layer 31 is formed on a surface of the first passivation layer 51 facing away from the semiconductor substrate layer 1 , and a second carrier collection layer 32 is formed on a surface of the second passivation layer 52 facing away from the semiconductor substrate layer 1 .

[0090] In one embodiment, the process of forming the first carrier collection layer 31 and the second carrier collection layer 32 includes a magnetron sputtering process or a plasma deposition process; the process parameters of forming the first carrier collection layer 31 and the second carrier collection layer 32 include: the gas used includes hydrogen, a mixed gas of argon and oxygen, and the target material used includes a mixture of tin oxide and indium oxide, or a mixture of tungsten oxide and indium oxide. The main function of argon is to bombard the target material, so that the elements on the surface of the target material are separated and adsorbed on the surface of the first passivation layer 51 and the second passivation layer 52 under the action of the electric field to finally form the first carrier collection layer 31 and the second carrier collection layer 32. Oxygen is a doping gas that can improve the light transmittance of the carrier collection layer.

[0091] refer to Figure 6A first doped semiconductor layer 21 is formed on the surface of the first carrier collection layer 31 on one side facing away from the semiconductor substrate layer 1 ; and a second doped semiconductor layer 22 is formed on the surface of the second carrier collection layer 32 on the other side facing away from the semiconductor substrate layer 1 .

[0092] In one embodiment, the process of forming the first doped semiconductor layer 21 and the second doped semiconductor layer 22 includes: a plasma enhanced chemical vapor deposition process; the process parameters of forming the first doped semiconductor layer 21 and the second doped semiconductor layer 22 include: the gas used includes a mixed gas of hydrogen, silane, diborane and phosphine, the pressure in the chamber is 100Pa-300Pa, for example, 200Pa; the RF power density is 600W / m 2 -2600W / m 2 ; For example, 2000W / m 2 The silicon atoms generated after the decomposition of silane and hydrogen will combine with the silicon atoms in the semiconductor substrate layer to form silicon-silicon bonds, and the hydrogen atoms will combine with the silicon dangling bonds on the surface of the semiconductor substrate layer, reducing the recombination centers and exposed dangling bonds; diborane and phosphine are doping gases, and their main function is to generate free electrons and holes in the first doped semiconductor layer 21 and the second doped semiconductor layer 22, thereby forming a built-in electric field in the semiconductor substrate layer, which plays a role in directional carrier transport.

[0093] Continue to refer Figure 6 A first transparent conductive layer 41 is formed on the surface of the first doped semiconductor layer 21 on one side facing away from the semiconductor substrate layer 1 ; and a second transparent conductive layer 42 is formed on the surface of the second doped semiconductor layer 22 on the other side facing away from the semiconductor substrate layer 1 .

[0094] In one embodiment, the processes for forming the first transparent conductive layer 41 and the second transparent conductive layer 42 include: a magnetron sputtering process or a plasma deposition process; the process parameters for forming the first transparent conductive layer 41 and the second transparent conductive layer 42 include: the gas used includes a mixed gas of hydrogen, argon and oxygen, and the target material used includes a mixture of tin oxide and indium oxide, or a mixture of tungsten oxide and indium oxide.

[0095] In one embodiment, continue to refer to Figure 5 The method for preparing a solar cell further includes: forming a first gate electrode layer 61 on a surface of the first transparent conductive layer 41 facing away from the semiconductor substrate layer 1 ; and forming a second gate electrode layer 62 on a surface of the second transparent conductive layer 42 facing away from the semiconductor substrate layer 1 .

[0096] In one embodiment, the process of forming the first gate electrode layer 61 and the second gate electrode layer 62 also includes curing the first gate electrode layer 61 and the second gate electrode layer 62, and then performing an annealing process. The annealing process includes simultaneously irradiating the first gate electrode layer and the second gate electrode layer with light and heating. During the annealing process of the first gate electrode layer and the second gate electrode layer, the activity of some atoms in the solar cell can be stimulated to fill defects, which is conducive to stimulating the semiconductor substrate layer to generate a small amount of hole pairs, improving various properties of the semiconductor substrate layer, and thus improving the photoelectric conversion efficiency of the solar cell.

[0097] In one embodiment, the processes for forming the first gate electrode layer 61 and the second gate electrode layer 62 include: screen printing process, electroplating process or evaporation process. The materials of the first gate electrode layer 61 and the second gate electrode layer 62 include silver paste, mixed paste of silver and copper, and copper paste. In other embodiments, the materials of the first gate electrode layer 61 and the second gate electrode layer 62 may also include other metals.

[0098] The parts of this embodiment that are the same as the previous embodiment will not be described in detail.

[0099] Comparative Example 1

[0100] This comparative example provides a solar cell, which is different from the solar cell provided in Example 1 in that the solar cell provided in this comparative example does not include the first carrier collection layer and the second carrier collection layer.

[0101] The solar cell provided in Example 1 and the solar cell provided in Comparative Example 1 were tested respectively. The photoelectric conversion efficiency of the solar cell provided in Example 1 was improved by 0.02%-0.05% compared with that of the solar cell provided in Comparative Example 1.

[0102] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A solar cell comprising a semiconductor substrate layer, characterized in that: Also includes: A first passivation layer, located on one side surface of the semiconductor substrate layer, wherein the material of the first passivation layer includes amorphous silicon or nanocrystalline silicon; A first doped semiconductor layer is located on a side of the first passivation layer away from the semiconductor substrate layer, wherein the material of the first doped semiconductor layer includes any one of amorphous silicon, nanocrystalline silicon, oxygen-doped amorphous silicon, oxygen-doped nanocrystalline silicon, carbon-doped amorphous silicon or carbon-doped nanocrystalline silicon; The first carrier collection layer is made of a conductive material and is located between the first passivation layer and the first doped semiconductor layer, and pre-collects and laterally transmits the carriers generated by the semiconductor substrate layer. The conductive material of the first carrier collection layer includes a mixture of tin oxide and indium oxide, or a mixture of tungsten oxide and indium oxide. When the conductive material of the first carrier collection layer includes a mixture of tin oxide and indium oxide, the ratio of the mass of tin oxide to the mass of indium oxide in the first carrier collection layer is 1:9-1:300; when the conductive material of the first carrier collection layer includes a mixture of tungsten oxide and indium oxide, the ratio of the mass of tungsten oxide to the mass of indium oxide in the first carrier collection layer is 1 : 9-1: 300, the refractive index of the first carrier collection layer is 1.8-2.2, the first carrier collection layer is suitable for adjusting the propagation angle of light inside the solar cell, the refractive index of the first carrier collection layer is less than the refractive index of the first passivation layer, and the refractive index of the first carrier collection layer is less than the refractive index of the first doped semiconductor layer; the process of pre-collecting carriers and performing lateral transmission enables the carriers to avoid defects at the interface between the first passivation layer and the first doped semiconductor layer, selectively pass through the first doped semiconductor layer from a position with fewer defects and then flow to the first transparent conductive layer, thereby reducing the recombination loss of carriers between the first passivation layer and the first doped semiconductor layer; A first transparent conductive layer is located on a surface of the first doped semiconductor layer facing away from the semiconductor substrate layer; Wherein, the conductivity type of the first doped semiconductor layer is the same as the conductivity type of the semiconductor substrate layer, and the side of the first doped semiconductor layer relative to the semiconductor substrate layer is the light-facing side of the solar cell; The solar cell further comprises: A second passivation layer is located on the other side surface of the semiconductor substrate layer; a second doped semiconductor layer, located on a side of the second passivation layer away from the semiconductor substrate layer, wherein the conductivity type of the second doped semiconductor layer is opposite to that of the first doped semiconductor layer; A second carrier collection layer, made of conductive material and located between the second passivation layer and the second doped semiconductor layer; The conductive material of the second carrier collection layer includes a mixture of tin oxide and indium oxide, or a mixture of tungsten oxide and indium oxide; When the conductive material of the second carrier collection layer includes a mixture of tin oxide and indium oxide, the ratio of the mass of tin oxide to the mass of indium oxide in the second carrier collection layer is 1:9-1:300; when the conductive material of the second carrier collection layer includes a mixture of tungsten oxide and indium oxide, the ratio of the mass of tungsten oxide to the mass of indium oxide in the second carrier collection layer is 1:9-1:

300.

2. The solar cell according to claim 1, characterized in that Also includes: The second transparent conductive layer is located on a surface of the second doped semiconductor layer that is away from the semiconductor substrate layer.

3. The solar cell according to claim 2, characterized in that: The ratio of the thickness of the first carrier collection layer to the thickness of the first transparent conductive layer is 1:1-1:5; The thickness of the first carrier collection layer is 20nm-120nm, and the thickness of the first transparent conductive layer is 50nm-150nm.

4. The solar cell according to claim 2, characterized in that: The ratio of the thickness of the second carrier collection layer to the thickness of the second transparent conductive layer is 1:1-1:5; The thickness of the second carrier collection layer is 20nm-120nm, and the thickness of the second transparent conductive layer is 50nm-150nm.

5. The solar cell according to claim 2, characterized in that: The material of the first transparent conductive layer includes a mixture of tin oxide and indium oxide, or a mixture of tungsten oxide and indium oxide, and the material of the second transparent conductive layer includes a mixture of tin oxide and indium oxide, or a mixture of tungsten oxide and indium oxide; When the material of the first transparent conductive layer includes a mixture of tin oxide and indium oxide, the mass ratio of tin oxide to indium oxide in the first transparent conductive layer is 1:9-1:300; when the material of the first transparent conductive layer includes a mixture of tungsten oxide and indium oxide, the mass ratio of tungsten oxide to indium oxide in the first transparent conductive layer is 1:9-1:300; When the material of the second transparent conductive layer includes a mixture of tin oxide and indium oxide, the ratio of the mass of tin oxide to the mass of indium oxide in the second transparent conductive layer is 1:9-1:300; when the material of the second transparent conductive layer includes a mixture of tungsten oxide and indium oxide, the ratio of the mass of tungsten oxide to the mass of indium oxide in the second transparent conductive layer is 1:9-1:

300.

6. The solar cell according to any one of claims 2 to 4, characterized in that: Also includes: The gate lines are respectively arranged outside the first transparent conductive layer and outside the second transparent conductive layer, and the gate lines at least include fine grids.

7. A method for preparing a solar cell, for preparing the solar cell according to any one of claims 1 to 6, comprising providing a semiconductor substrate layer, characterized in that: Also includes: Forming a first passivation layer on a surface of one side of the semiconductor substrate layer, wherein the conductive material of the first passivation layer includes amorphous silicon or nanocrystalline silicon; A first carrier collection layer is formed on a surface of the first passivation layer on a side away from the semiconductor substrate layer by using a conductive material, the first carrier collection layer pre-collects and laterally transmits carriers generated by the semiconductor substrate layer, the conductive material of the first carrier collection layer includes a mixture of tin oxide and indium oxide, or a mixture of tungsten oxide and indium oxide, when the conductive material of the first carrier collection layer includes a mixture of tin oxide and indium oxide, the mass ratio of tin oxide to indium oxide in the first carrier collection layer is 1:9-1:300; the conductive material of the first carrier collection layer includes tungsten oxide and indium oxide When the first carrier collection layer is a mixture of tungsten oxide and indium, the ratio of the mass of tungsten oxide to the mass of indium oxide in the first carrier collection layer is 1:9-1:300, the refractive index of the first carrier collection layer is 1.8-2.2, and the first carrier collection layer is suitable for adjusting the propagation angle of light inside the solar cell; the process of pre-collecting carriers and performing lateral transmission enables the carriers to avoid defects at the interface between the first passivation layer and the first doped semiconductor layer, selectively pass through the first doped semiconductor layer from a position with fewer defects and then flow to the first transparent conductive layer, thereby reducing the recombination loss of carriers between the first passivation layer and the first doped semiconductor layer; A first doped semiconductor layer is formed on a surface of the first carrier collection layer on a side away from the semiconductor substrate layer, wherein the conductive material of the first doped semiconductor layer includes any one of amorphous silicon, nanocrystalline silicon, oxygen-doped amorphous silicon, oxygen-doped nanocrystalline silicon, carbon-doped amorphous silicon or carbon-doped nanocrystalline silicon, the refractive index of the first carrier collection layer is less than the refractive index of the first passivation layer, and the refractive index of the first carrier collection layer is less than the refractive index of the first doped semiconductor layer; forming a first transparent conductive layer on a surface of the first doped semiconductor layer facing away from the semiconductor substrate layer; The method for preparing the solar cell further comprises: forming a second passivation layer on the other side surface of the semiconductor substrate layer; A second carrier collection layer is formed on a surface of the second passivation layer on a side away from the semiconductor substrate layer by using a conductive material; the second carrier collection layer pre-collects and laterally transmits the carriers generated by the semiconductor substrate layer; forming a second doped semiconductor layer on a surface of the second carrier collection layer facing away from the semiconductor substrate layer, wherein the conductivity type of the second doped semiconductor layer is opposite to that of the first doped semiconductor layer; A second transparent conductive layer is formed on a surface of the second doped semiconductor layer facing away from the semiconductor substrate layer.

Images