CN213184317U - Heterojunction solar cell - Google Patents

Abstract

The utility model provides a heterojunction solar cell, it includes the battery piece body, heterojunction solar cell still including set up in the collecting electrode on battery piece body surface, the collecting electrode including set up in the main bars on battery piece body surface and perpendicular be connected to the vice bars of main bars, the thickness of vice bars is greater than the thickness of main bars the utility model relates to an among the heterojunction solar cell, the vice bars of collecting electrode adopt the design that thickness is great relatively, can effectively reduce the bulk resistance of collecting electrode, and then improve heterojunction solar cell's battery packing factor.

Description

Heterojunction solar cell

Technical Field

The utility model relates to a photovoltaic field of making especially relates to a heterojunction solar cell.

Background

The heterojunction solar cell is a relatively high-efficiency crystalline silicon solar cell at present, combines the characteristics of a crystalline silicon cell and a silicon-based thin film cell, and has the advantages of short manufacturing process, low process temperature, high conversion efficiency, more generated energy and the like. The heterojunction solar cell has a small temperature degradation coefficient and double-sided power generation, so that the annual power generation amount can be 15-30% higher than that of a common polycrystalline silicon cell under the condition of the same area, and therefore the heterojunction solar cell has great market potential.

However, the heterojunction solar cell is limited by a low-temperature process, and only low-temperature slurry can be adopted when the collector is printed by adopting a silk screen plate, the low-temperature slurry has higher electrical performance and poor electrical performance, and the collector prepared by the low-temperature slurry has high electrical resistivity, so that the loss of a cell filling factor is increased. In addition, the low-temperature paste is poor in printability compared with high-temperature paste, the risk of grid breakage of a metal grid line forming a collector during rapid printing is easy to occur, particularly, the probability of grid breakage at the connecting position of a main grid and an auxiliary grid is higher, so that collection of photo-generated current of the heterojunction solar cell is influenced, and the efficiency of the heterojunction solar cell is not improved.

In view of the above, there is a need to provide an improved solution to the above problems.

SUMMERY OF THE UTILITY MODEL

The utility model discloses aim at solving one of the technical problem that prior art exists at least, for realizing the utility model purpose of the aforesaid, the utility model provides a heterojunction solar cell, its concrete design as follows.

The utility model provides a heterojunction solar cell, includes the battery piece body, heterojunction solar cell still including set up in the collecting electrode on battery piece body surface, the collecting electrode including set up in main bars and the perpendicular connection to on battery piece body surface the vice bars of main bars, the thickness of vice bars is greater than the thickness of main bars.

Furthermore, the thickness of the main grid is 20-30 μm, and the thickness of the auxiliary grid is 20-40 μm.

Further, the auxiliary grid is provided with a first auxiliary grid part which is partially lapped on the surface of one side, away from the battery piece body, of the main grid.

Furthermore, a fracture is formed at the position of the main grid by the first auxiliary grid part, and the overlapping length of the part of the first auxiliary grid part, which is positioned at each side of the main grid, on the surface of the corresponding main grid is 0.03-0.2 mm.

Further, the first auxiliary grid part is continuously formed at the position of the main grid.

Further, the auxiliary grid also has a second auxiliary grid part integrally formed with the main grid, and the first auxiliary grid part is stacked and arranged on the corresponding second auxiliary grid part deviating from one side surface of the battery piece body.

Further, the thicknesses of the first auxiliary grid part and the second auxiliary grid part are both 10-20 μm.

Further, the sum of the thicknesses of the main grid and the first auxiliary grid part at the lap joint position is 30-50 μm.

Further, the width of the first sub-gate portion is not greater than the width of the second sub-gate portion.

Further, the sub-gate has an expansion region connected to the main gate, and a width of the expansion region is gradually increased in a direction close to the main gate.

Furthermore, the width of the expansion area at the edge position of the main grid is 2-5 times of the width of one end of the expansion area far away from the main grid.

Further, the cell body comprises a monocrystalline silicon substrate, a first intrinsic amorphous layer and a first doped amorphous layer which are sequentially stacked on a light receiving surface of the monocrystalline silicon substrate, a second intrinsic amorphous layer and a second doped amorphous layer, wherein the second intrinsic amorphous layer and the first doped amorphous layer are sequentially arranged on a backlight surface of the monocrystalline silicon substrate; the sum of the thicknesses of the first intrinsic amorphous layer and the first doped amorphous layer is less than the sum of the thicknesses of the second intrinsic amorphous layer and the second doped amorphous layer.

Further, the sum of the thicknesses of the first intrinsic amorphous layer and the first doped amorphous layer is 6-21nm, and the sum of the thicknesses of the second intrinsic amorphous layer and the second doped amorphous layer is 7-30 nm.

Further, the thickness of the first intrinsic amorphous layer is less than or equal to the thickness of the second intrinsic amorphous layer, and the thickness of the first doped amorphous layer is less than or equal to the thickness of the second doped amorphous layer.

Further, the thickness of the first doped amorphous layer is 3-15nm, and the thickness of the second doped amorphous layer is 3-20 nm.

Further, the cell body further comprises a first transparent conductive film layer arranged on the outer surface of the first doped amorphous layer and a second transparent conductive film layer arranged on the outer surface of the second doped amorphous layer, and the thickness of the first transparent conductive film layer is smaller than or equal to that of the second transparent conductive film layer.

The utility model has the advantages that: the utility model relates to an among the heterojunction solar cell, the vice bars of collecting electrode adopt the great design mode of thickness relatively, can effectively reduce the bulk resistance of collecting electrode, and then improve heterojunction solar cell's battery fill factor.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts. The front and back sides referred to herein are only defined with respect to the positional relationship in the drawings of the embodiments, that is, the front side corresponds to the upper surface of the drawings, and the back side corresponds to the lower surface of the drawings.

Fig. 1 is a schematic cross-sectional view of a heterojunction solar cell according to the present invention;

fig. 2 is a schematic plan view of a collector in a heterojunction solar cell according to the present invention;

FIG. 3 is an enlarged view of a portion a of the first embodiment of the collector shown in FIG. 2;

FIG. 4 is a perspective view of the structure shown in FIG. 3;

FIG. 5 is an enlarged view of a portion a of the second embodiment of the collector shown in FIG. 2;

FIG. 6 is a perspective view of the structure shown in FIG. 5;

FIG. 7 is an enlarged view of a portion a of the third embodiment of the collector shown in FIG. 2;

FIG. 8 is an enlarged view of a portion a of a fourth embodiment of the collector shown in FIG. 2;

FIG. 9 is an enlarged view of a portion a of the fifth embodiment of the collector shown in FIG. 2

Fig. 10 is a perspective view of the structure shown in fig. 9.

In the figure, 10 is a single crystal silicon substrate, 21 is a first intrinsic amorphous layer, 31 is a first doped amorphous layer, 41 is a first transparent conductive film layer, 51 is a first collector, 22 is a second intrinsic amorphous layer, 32 is a second doped amorphous layer, 42 is a second transparent conductive film layer, 52 is a second collector, 500 is a collector, 501 is a main gate, 502 is a sub-gate, 5021 is a first sub-gate portion, 5022 is a second sub-gate portion, 5023 is an extension region.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The utility model provides a heterojunction solar cell, it is shown with reference to fig. 1, it includes the battery piece body. In a specific implementation process, the battery piece body comprises: the semiconductor device includes a single crystal silicon substrate 10, a first intrinsic amorphous layer 21, a first doped amorphous layer 31, and a first transparent conductive film 41 sequentially stacked on a light-receiving surface of the single crystal silicon substrate 10, and a second intrinsic amorphous layer 22, a second doped amorphous layer 32, and a second transparent conductive film 42 sequentially disposed on a back-light surface of the single crystal silicon substrate 10.

In a specific implementation, the light receiving surface of the monocrystalline silicon substrate 10 is a surface of the heterojunction solar cell directly receiving sunlight, and the back surface is a surface of the heterojunction solar cell not directly receiving sunlight, that is, a surface opposite to the light receiving surface. The first and second intrinsic amorphous layers 21 and 22 are intrinsic amorphous silicon. The doping types of the first doped amorphous layer 31 and the second doped amorphous layer 32 are opposite, wherein one of the first doped amorphous layer and the second doped amorphous layer is doped with N type, namely phosphorus is adopted for doping; the other is P-type doping, namely boron doping is adopted.

In the present invention, although the single crystal silicon substrate 10 may be a P-type single crystal silicon substrate, an N-type single crystal silicon substrate may be selected; however, according to 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 is an N-type doped amorphous layer, and the second doped amorphous layer 32 is a P-type doped amorphous layer.

The utility model discloses in, heterojunction solar cell still including setting up in the collecting electrode 500 on cell body surface, refer to and show in fig. 1, in this embodiment, the sensitive surface one side of cell body is provided with first collecting electrode 51, and the backlight surface one side of cell body is provided with second collecting electrode 52.

Referring to fig. 2, a collector 500 according to the present invention includes a main grid 501 disposed on a surface of a cell body and a sub-grid 502 vertically connected to the main grid 501.

In the present invention, the thickness of the sub-grid 502 is greater than the thickness of the main grid 501. The auxiliary grid 502 of the collector 500 adopts a design mode with relatively large thickness, so that the body resistance of the collector 500 can be effectively reduced, and further the cell filling factor of the heterojunction solar cell is improved.

Particularly, when the present invention is adopted to manufacture a photovoltaic module with a heterojunction solar cell, the main grid 501 generally has the same setting direction with the solder strip and the two are directly attached and soldered, the transmission distance of the current on the main grid 501 is short, and the main grid 501 generally has a relatively large width, so that the main grid 501 itself has a relatively small bulk resistance, that is, the bulk resistance of the collector 500 is mainly determined by the sub-grid 502. The utility model discloses in adopt vice bars 502 thickness to be greater than the mode of setting of the 501 thickness of main bars, also reduce the bulk resistance of collecting electrode 500 when reducing the thick liquids consumption as far as possible.

In the specific implementation process of the utility model, the thickness of the main grid is 20-30 μm, and the thickness of the auxiliary grid is 20-40 μm.

As further shown in fig. 3 to 10, the secondary grid 502 of the present invention has a first secondary grid portion 5021 partially overlapping the primary grid 501 on the side surface away from the cell body.

Based on the utility model provides a concrete structure of heterojunction solar cell, overlap joint mode between first vice bars portion 5021 and the main grid 501 can be so that main grid 501 and vice grid 502 during the concrete shaping have sufficient connected material in hookup location department, and then ensure to form reliable electric connection between main grid 501 and the vice grid 502, can effectively avoid appearing the risk of main grid and vice grid in hookup location department disconnection among the prior art, guarantee the effect that heterojunction solar cell photoproduction electric current was collected, can optimize heterojunction solar cell's photoelectric conversion efficiency.

The more detailed structure of the heterojunction solar cell of the present invention can be further described with reference to the following descriptions:

referring to fig. 3, 4, 5, 6, 9, and 10, in these embodiments, the first secondary grid part 5021 forms a break at the position of the primary grid 501, i.e., the first secondary grid part 5021 is discontinuous at the position of the primary grid 501. In the specific implementation process, the design mode can save the slurry loss in the printing process of the auxiliary grid 501 to a certain extent, and further reduce the manufacturing cost of the heterojunction solar cell.

As shown in the drawing, in order to ensure a reliable lap joint between the first secondary grid part 5021 and the main grid 501, in practice, the lap length d of the part of the first secondary grid part 5021 on each side of the main grid 501 on the surface of the corresponding main grid 501 is 0.03-0.2 mm. Preferably, the overlap length d is 0.05-0.1 mm.

Referring to fig. 7 and 8, in other embodiments of the present invention, the first secondary fence portion 5021 may also be continuously formed at the position of the main fence 501, i.e., there is no fracture in the first secondary fence portion 5021 at the position of the main fence 501.

As some preferred implementation structures of the present invention, referring to fig. 3, fig. 4, fig. 5, fig. 6, fig. 7, and fig. 8, in these embodiments, the secondary grid 502 further has a second secondary grid portion 5022 integrally formed with the primary grid 501, wherein the first secondary grid portion 5021 is stacked on a side surface of the corresponding first secondary grid portion facing away from the cell body. When the specific auxiliary grid 502 is manufactured, the structure can be formed through twice printing, the grid breaking probability of the auxiliary grid 502 can be further reduced through the two-layer stacking structure, the height-width ratio of the auxiliary grid 502 can be increased, the series resistance of the photovoltaic module is reduced, and the photoelectric efficiency of the photovoltaic module can be further improved.

In a specific implementation process, the thicknesses of the first secondary grid part 5021 and the second secondary grid part 5022 are both 10-20 μm.

Preferably, the sum of the thicknesses of the main grid 501 and the first sub-grid part 5021 at the overlapped position is 30-50 μm. The design ensures that enough conductive paste is provided at the connecting position of the main grid 501 and the auxiliary grid 502 when the collector 500 is printed and molded.

Further, the width of the first secondary grid part 5021 is not greater than that of the second secondary grid part 5022, so that the surface shielding of the cell body 100 by the secondary grid 502 is not increased when the first secondary grid part 5021 is arranged on the surface of the second secondary grid part 5022.

In general, when the sub-gate 502 is configured by stacking the first sub-gate portion 5021 and the second sub-gate portion 5022, referring to fig. 3-8, the width of the first sub-gate portion 5021 is 20-50 μm, and the width of the second sub-gate portion 5022 is 20-60 μm; preferably, the width of the first sub-gate 5021 is 25-40 μm, and the width of the second sub-gate 5022 is 30-50 μm. When the sub-gate 502 is constituted only by the first sub-gate portion 5021, as shown in fig. 9, 10, the width of the first sub-gate portion 5021 is 20-60 μm; preferably 30-50 μm.

As still other preferred embodiments of the present invention, referring to fig. 5, 6, 8, 9 and 10, in these embodiments, the sub-grid 502 has a expanding region 5023 connected to the main grid 501, and the expanding region 5023 gradually increases in width in a direction close to the main grid 501. Based on the arrangement structure of the expanded region 5023, the connection between the main grid 501 and the auxiliary grid 502 can be more reliable.

In a specific implementation process, as shown in the figure, the width w1 of the expanded region 5023 at the edge of the main gate 501 is 2-5 times the width w2 of the expanded region 5023 away from the end of the main gate 501; preferably, the width w1 of the expanded region 5023 at the edge of the main gate 501 is 3-4 times the width w2 of the expanded region 5023 away from the end of the main gate 501. The utility model discloses in, the width w2 that main bars 501 one end was kept away from in expansion district 5023 is unanimous with the width of vice bars 502 except that the remaining part of expansion district 5023, and when vice bars 502 had first vice bars portion 5021 and the range upon range of constitution of the vice bars portion 5022 of second, the width of vice bars 502 except that the remaining part of expansion district 5023 can be understood as the width of the vice bars portion 5022 of second except that the expansion district 5023 remaining part.

In the present invention, in the embodiment shown in fig. 5, 6 and 8, the expansion region 5023 and the second auxiliary grid part 5022 are integrally formed; in the embodiment shown in fig. 9 and 10, the expanded region 5023 is integrally formed with the first secondary gate portion 5021.

In addition, in the present invention, the length of the expanding region 5023 in the extending direction of the auxiliary grid 502 is 0.5-2mm, preferably 0.8-1.5 mm.

For a heterojunction solar cell, the process temperature is not higher than 200 ℃, and the conductive paste used for printing the collector 500 is a low-temperature conductive paste, which generally comprises metal conductive particles (such as silver), resin, solvent, coupling agent, and the like, wherein the solid content represents the content of the metal conductive particles (such as silver) in the conductive paste. Based on this, the high solid content conductive paste has better conductivity due to the high content of the metal conductive particles, and the low solid content conductive paste has better adhesion due to the high content of the resin and the like (i.e., the part of the non-metal conductive particles).

In view of this, as another preferred embodiment of the present invention, in a concrete implementation, the solid content of the conductive paste constituting the main grid 501 is smaller than the solid content of the conductive paste constituting the first sub-grid part 5022. The main grid 501 adopts low-content conductive paste, so that the high tensile force requirement of the heterojunction solar cell in the subsequent photovoltaic module assembling process can be ensured, and the reliability of the module can be ensured; and the high-content conductive paste adopted by the first secondary grid part 5022 can enable the collector 500 to have relatively small series resistance, so that the battery conversion efficiency is improved.

It is to be understood that in the embodiment shown in fig. 3, 4, 5, 6, 7 and 8, when the collector 500 has the second sub-gate 5022, the second sub-gate 5022 is printed with the same conductive paste as the main gate 501.

In the present invention, the sum of the thicknesses of the first intrinsic amorphous layer 21 and the first doped amorphous layer 31 is smaller than the sum of the thicknesses of the second intrinsic amorphous layer 22 and the second doped amorphous layer 32.

For the heterojunction solar cell, the influence of the light absorption effect of the light receiving surface on the photoelectric conversion efficiency of the cell is far larger than the influence of the light absorption effect of the backlight surface on the photoelectric conversion efficiency of the cell, and because the sum of the thicknesses of the first intrinsic amorphous layer 21 and the first doped amorphous layer 31 is smaller than the sum of the thicknesses of the second intrinsic amorphous layer 22 and the second doped amorphous layer 32, the loss of sunlight on the light receiving surface when the sunlight passes through the first intrinsic amorphous layer 21 and the first doped amorphous layer 31 can be effectively reduced, the short-circuit current of the heterojunction solar cell can be improved, and the heterojunction solar cell has better photoelectric conversion efficiency.

In some more specific embodiments of the present invention, the sum of the thicknesses of the first intrinsic amorphous layer 21 and the first doped amorphous layer 31 is 6-21nm, and the sum of the thicknesses of the second intrinsic amorphous layer 22 and the second doped amorphous layer 32 is 7-30 nm.

It is further preferable that the thickness of the first intrinsic amorphous layer 21 is less than or equal to the thickness of the second intrinsic amorphous layer 22, and the thickness of the first doped amorphous layer 31 is less than or equal to the thickness of the second doped amorphous layer 32.

In specific implementation, the thickness of the first doped amorphous layer 31 is 3-15nm, and the thickness of the second doped amorphous layer 32 is 3-20 nm. Accordingly, in the embodiment shown in FIG. 1, the first intrinsic amorphous layer 21 has a thickness of 3-6nm and the second intrinsic amorphous layer 22 has a thickness of 4-10 nm.

Further, in the present invention, 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. For the heterojunction solar cell, because the thickness of the first transparent conductive film layer 41 is relatively small, the loss of sunlight on the light receiving surface when the sunlight passes through the first transparent conductive film layer 41 can be effectively reduced, and the heterojunction solar cell can have better photoelectric conversion efficiency.

Preferably, in the present invention, the distance between two adjacent sub-grids 502 in the first collector 51 is greater than the distance between two adjacent sub-grids 502 in the second collector 52. The large distance between the two adjacent auxiliary grids 502 on the light receiving surface can improve the effective illumination area of the light receiving surface, the small distance between the two adjacent auxiliary grids 502 on the backlight surface can reduce the series resistance of the heterojunction solar cell, and the photoelectric conversion efficiency of the heterojunction solar cell can be effectively optimized by combining the two.

In specific implementation, the distance between two adjacent sub-grids 502 on the light receiving surface is not less than 1.5 times of the distance between two adjacent sub-grids 502 on the backlight surface. In general, the distance between two adjacent auxiliary grids 300 on the light receiving surface is 1-3mm, preferably 1.5-2.5 mm; the distance between two adjacent sub-grids 502 on the backlight surface is 0.1-1.5mm, preferably 0.5-1 mm.

In addition, in the present invention, the distance between two adjacent main grids 501 on the light receiving surface and the distance between two adjacent main grids 501 on the backlight surface are substantially the same, and usually ranges from 10 mm to 55mm, and preferably ranges from 13 mm to 30 mm.

For better understanding the utility model discloses, the utility model also provides a heterojunction solar cell manufacturing approach, it is used for the heterojunction solar cell more than the preparation, and this manufacturing approach includes:

providing a cell body;

forming a main grid 501 on one surface of the cell body;

a first auxiliary grid part 5021 which is lapped to the surface of the main grid 501, which is far away from the cell body, is formed at one side of the cell body, where the main grid 501 is formed.

In a specific implementation process, the main grid 501 and the first sub-grid 5021 are sequentially printed and formed by different screens. Since the main grid 501 is formed first and then the first auxiliary grid part 5021 is formed, the first auxiliary grid part 5021 can be prevented from being collapsed due to being extruded by the printing screen again after being printed.

In some embodiments of the present invention, before forming the first secondary grid part 5021, the manufacturing method further includes forming a second secondary grid part 5022 perpendicular to and integrally connected with the primary grid 501, wherein the first secondary grid 5021 is formed on a side surface of the second secondary grid 5022 away from the cell body.

Further, the solid content of the conductive paste for forming the main gate 501 is less than that of the conductive paste for forming the first sub-gate part 5021.

The above list of details is only for the practical implementation of the present invention, and they are not intended to limit the scope of the present invention, and all equivalent implementations or modifications that do not depart from the technical spirit of the present invention should be included in the scope of the present invention.

Claims (16)

1. The utility model provides a heterojunction solar cell, includes the battery piece body, its characterized in that, heterojunction solar cell still including set up in the collecting electrode on battery piece body surface, the collecting electrode including set up in the main bars on battery piece body surface and perpendicular connection to the vice bars of main bars, the thickness of vice bars is greater than the thickness of main bars.

2. The heterojunction solar cell of claim 1, wherein the primary gate thickness is 20-30 μ ι η and the secondary gate thickness is 20-40 μ ι η.

3. The heterojunction solar cell of claim 1, wherein the secondary grid has a first secondary grid portion partially overlapping a surface of the primary grid on a side facing away from the cell body.

4. The heterojunction solar cell of claim 3, wherein the first sub-grid portion is formed with a discontinuity at the location of the main grid, and the overlapping length of the first sub-grid portion on each side of the main grid on the surface of the corresponding main grid is 0.03-0.2 mm.

5. The heterojunction solar cell of claim 3, wherein the first secondary grid portion is continuously patterned at the primary grid location.

6. The heterojunction solar cell of claim 3, wherein the secondary grid further comprises a second secondary grid portion integrally formed with the primary grid, and the first secondary grid portion is stacked on a side surface of the corresponding second secondary grid portion facing away from the cell body.

7. The heterojunction solar cell of claim 6, wherein the first and second sub-gate portions are each 10-20 μ ι η thick.

8. The heterojunction solar cell of claim 7, wherein the sum of the thicknesses of the primary grid and the first secondary grid portion at the location of the overlap is 30-50 μm.

9. The heterojunction solar cell of claim 6, wherein the width of the first sub-gate portion is not greater than the width of the second sub-gate portion.

10. The heterojunction solar cell of any of claims 1 to 9, wherein said sub-grid has a region of extension connected to said main grid, said region of extension increasing in width in a direction closer to said main grid.

11. The heterojunction solar cell of claim 10, wherein the width of the expanded region at the edge of the main gate is 2-5 times the width of the expanded region at the end away from the main gate.

12. The heterojunction solar cell of any one of claims 1 to 9, wherein the cell body comprises a monocrystalline silicon substrate, a first intrinsic amorphous layer and a first doped amorphous layer sequentially stacked on a light receiving surface of the monocrystalline silicon substrate, a second intrinsic amorphous layer sequentially stacked on a backlight surface of the monocrystalline silicon substrate, and a second doped amorphous layer with a doping type opposite to that of the first doped amorphous layer; the sum of the thicknesses of the first intrinsic amorphous layer and the first doped amorphous layer is less than the sum of the thicknesses of the second intrinsic amorphous layer and the second doped amorphous layer.

13. The heterojunction solar cell of claim 12, wherein the sum of the thicknesses of the first intrinsic amorphous layer and the first doped amorphous layer is 6-21nm and the sum of the thicknesses of the second intrinsic amorphous layer and the second doped amorphous layer is 7-30 nm.

14. The heterojunction solar cell of claim 12, wherein the thickness of the first intrinsic amorphous layer is less than or equal to the thickness of the second intrinsic amorphous layer, and the thickness of the first doped amorphous layer is less than or equal to the thickness of the second doped amorphous layer.

15. The heterojunction solar cell of claim 14, wherein the thickness of the first doped amorphous layer is 3-15nm and the thickness of the second doped amorphous layer is 3-20 nm.

16. The heterojunction solar cell of claim 12, wherein the cell body further comprises a first transparent conductive film layer disposed on the outer surface of the first doped amorphous layer and a second transparent conductive film layer disposed on the outer surface of the second doped amorphous layer, wherein the thickness of the first transparent conductive film layer is less than or equal to the thickness of the second transparent conductive film layer.

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