TWI511320B - Solar cell, module comprising the same and method of manufacturing the same - Google Patents

Description

Solar battery, module thereof and manufacturing method thereof

The invention relates to a solar cell, a module thereof and a manufacturing method thereof, in particular to a heterojunction combined with an intrinsic thin film solar cell, a module thereof and a manufacturing method thereof.

Referring to FIG. 1 , a Heterojunction with Intrinsic Thin-layer (HIT) solar cell 9 generally includes: a substrate 91 capable of generating a photovoltaic effect, and two opposite sides disposed on the opposite side of the substrate 91 A transparent conductive oxide 92 (TCO), and two electrodes 93 respectively formed on the outer sides of the two transparent conductive oxide layers 92.

The substrate 91 includes an n-type single crystal silicon substrate (n-type c-Si) 911 and two essences respectively formed on opposite sides of the n-type single crystal germanium substrate 911. An intrinsic amorphous silicon layer (i-layer a-Si) 912, and a p-type amorphous silicon layer formed on the outer side of the two intrinsic amorphous germanium layers 912, respectively. , referred to as p-type a-Si) 913 and a n ⁺ -type amorphous silicon layer (n-type amorphous silicon layer, referred to as ^{n + -type a-Si) 914} .

The HIT solar cell 9 can be fabricated at a low temperature of 200 to 300 ° C, thereby avoiding the use of a conventional high temperature (above 900 ° C) diffusion process to fabricate a pn junction. The use of low temperature manufacturing not only saves energy, but also controls the doping depth and range of the p-type, n ⁺ -type amorphous germanium layers 913, 914 more precisely. In addition, the low temperature fabrication is also to maintain the two intrinsic amorphous germanium layers 912 and the p-type, n ⁺ -type amorphous germanium layers 913, 914 with an amorphous structure to avoid the two intrinsic amorphous germanium layers 912. Crystallization occurs due to high temperature.

For the above reasons, the temperature at which the two transparent conductive oxide layers 92 are manufactured must also be limited to a low temperature of 200 to 300 ° C, so that the two transparent conductive oxide layers 92 are not polycrystalline in the entire layer. Instead, a plurality of island-like crystal regions separated from each other and an amorphous region located between the aforementioned island-like crystal regions are formed. Since the amorphous regions have higher impedance, the two transparent conductive oxide layers 92 have higher impedance and poor conductivity, and the contact resistance between the two transparent conductive oxide layers 92 and the two electrodes 93 is also Higher, thereby reducing the photoelectric flow that the HIT solar cell 9 can produce.

Accordingly, it is an object of the present invention to provide a solar cell, a module thereof, and a method of manufacturing the same that can reduce electrode contact resistance and increase conductivity.

Therefore, the method for manufacturing a solar cell of the present invention comprises: preparing a one having a p-n junction structure to generate a photovoltaic effect Substrate; forming a first transparent conductive layer on a first surface of the substrate; treating a first region of the first transparent conductive layer with laser or ultraviolet light to reduce an impedance value of the first region, and the first a region having a plurality of first finger regions extending along a first direction; and forming a first metal layer on the first transparent conductive layer, and the first metal layer includes one of the first directions a first bus bar metal portion extending in the second direction, and a plurality of first finger metal portions extending along the first direction and connecting the first bus bar metal portion; each of the plurality of first finger regions and the number One of the first finger-shaped metal portions is in contact.

The solar cell of the present invention comprises: a substrate, a first transparent conductive layer, a second transparent conductive layer, and a first metal layer.

The substrate has a p-n junction structure to produce a photovoltaic effect and includes a first surface and a second surface opposite the first surface, the first surface being the primary light receiving surface of the solar cell. The first transparent conductive layer is disposed on the first surface, and includes a first region and a first base material region, the impedance value of the first region is smaller than the impedance value of the first base material region, and the first The region has a plurality of first finger regions extending in a first direction. The second transparent conductive layer is disposed on the second surface, and the second transparent conductive layer has an average impedance value smaller than an average impedance value of the first transparent conductive layer. The first metal layer is disposed on the first transparent conductive layer, and includes a first bus bar metal portion extending in a second direction different from the first direction, and extending along the first direction and connecting the first Several parts of the confluence metal department a finger-shaped metal portion, each of the plurality of first finger regions being in contact with one of the plurality of first finger-shaped metal portions.

The solar cell of the present invention comprises: a substrate, a first transparent conductive layer, and a first metal layer.

The substrate has a p-n junction structure to produce a photovoltaic effect and includes a first surface. The first transparent conductive layer is disposed on the first surface, and includes a first region and a first base material region, the impedance value of the first region is smaller than the impedance value of the first base material region, and the first The area has a plurality of first finger regions extending along a first direction, and a first bus pool region extending in a second direction different from the first direction, the first bus pool connecting the plurality of first fingers The first confluence zone has two confluence strips. The first metal layer is disposed on the first transparent conductive layer, and includes a first bus bar metal portion extending along the second direction, and a plurality of first extending in the first direction and connecting the first bus bar metal portion a finger-shaped metal portion having two converging long edges respectively contacting the two confluence strip portions, each of the plurality of first finger regions and the plurality of first finger-shaped metals One of the ministries is in contact.

The solar cell module of the present invention comprises: a first plate and a second plate disposed oppositely, a plurality of solar cells arranged as described above between the first plate and the second plate, and a An encapsulating material between the first plate and the second plate and surrounding the plurality of solar cells.

The effect of the invention is that the first region can be improved by treating the first region of the first transparent conductive layer by laser or ultraviolet light. The degree of crystallization of the domain is such that the impedance value of the first region is lowered, and the contact resistance of the first metal layer disposed on the first transparent conductive layer can be reduced, so that the photocurrent generated by the substrate can be lower via the impedance value. The first region is conducted to the first metal layer and then outwardly, thereby increasing the photoelectric flow that the solar cell can produce.

11‧‧‧ first plate

12‧‧‧Second plate

13‧‧‧Solar battery

14‧‧‧Package

15‧‧‧welding wire

2‧‧‧Substrate

201‧‧‧ first surface

202‧‧‧ second surface

21‧‧‧矽 substrate

22‧‧‧ Essential amorphous layer

23‧‧‧p-type amorphous germanium layer

24‧‧‧n ⁺ type amorphous layer

3‧‧‧First transparent conductive layer

30‧‧‧First base metal area

31‧‧‧First area

32‧‧‧First finger area

321‧‧‧ finger-shaped strip

33‧‧‧First Confluence Area

331‧‧‧Convergence Long Section

34‧‧‧First island area

391‧‧‧ inside

392‧‧‧Outside

4‧‧‧Second transparent conductive layer

40‧‧‧Second base metal area

41‧‧‧Second area

43‧‧‧Second Confluence Area

44‧‧‧Second island

491‧‧‧ inside

492‧‧‧ outside side

5‧‧‧First metal layer

51‧‧‧First finger metal

511‧‧‧ finger long edge

52‧‧‧First Confluence Metals Division

521‧‧ ‧ long edge

6‧‧‧Second metal layer

61‧‧‧First finger metal

62‧‧‧Second Confluence Metals Division

71‧‧‧First direction

72‧‧‧second direction

81~85‧‧‧Steps

D1~d4‧‧‧Width

Other features and effects of the present invention will be apparent from the following description of the drawings, wherein: FIG. 1 is a side view of a known heterojunction bonded intrinsic thin film solar cell; FIG. 2 is a solar energy of the present invention. A schematic cross-sectional view of a first preferred embodiment of a battery module; FIG. 3 is a top plan view of a solar cell of the first preferred embodiment; FIG. 4 is a partial enlarged view of FIG. The enlarged position is shown in the frame A of FIG. 3; FIG. 5 is a schematic cross-sectional view taken along line BB of FIG. 3; FIG. 6 is a bottom view of the solar cell; FIG. 7 is a view similar to FIG. FIG. 8 is a schematic flow chart showing a step of a preferred embodiment of the solar cell manufacturing method of the present invention; FIG. 9 is a block diagram of a step of the manufacturing method; 10 is an enlarged view similar to FIG. 4, showing the solar cell of the present invention a front view of a solar cell of one of the second preferred embodiments of the module; and FIG. 11 is an enlarged view similar to FIG. 4, showing a solar cell of a third preferred embodiment of the solar cell module of the present invention The frontal appearance.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same reference numerals.

Referring to FIG. 2, a first preferred embodiment of the solar cell module of the present invention comprises: a first plate 11 and a second plate 12 disposed at an upper and lower interval, and a plurality of arrays arranged on the first plate 11 A solar cell 13 between the second plate 12 and a package 14 between the first plate 11 and the second plate 12 and surrounding the plurality of solar cells 13.

The material of the first plate 11 and the second plate 12 is not particularly limited, and a glass or plastic plate can be used. If the plurality of solar cells 13 are in the form of single-sided light receiving, the plates on the light receiving side of the plurality of solar cells 13 must be transparent; if the plurality of solar cells 13 are in the form of double-sided light receiving, the first plate Both the 11 and the second sheet 12 must be transparent.

The material of the encapsulant 14 is, for example, a light transmissive ethylene vinyl acetate copolymer (EVA), or other related materials usable for the solar cell module package, and is not limited to the examples of the embodiment. Further, the plurality of solar cells 13 are electrically connected to each other through a plurality of ribbon wires 15. Since the structures of the plurality of solar cells 13 are the same, only one of them will be described below as an example. Of course, the structure of the plurality of solar cells 13 in a module is not absolutely necessary.

Referring to FIGS. 3, 4, and 5, the solar cell 13 includes a substrate 2, a first transparent conductive layer 3 and a second transparent conductive layer 4 disposed on opposite sides of the substrate 2, and disposed on the first transparent layer. a first metal layer 5 on the conductive layer 3 and a second metal layer 6 disposed on the second transparent conductive layer 4.

The substrate 2 has a heterogeneous p-n junction structure to produce a photovoltaic effect and includes a first surface 201 and a second surface 202 opposite the first surface 201.

The substrate further includes a silicon substrate 21, two intrinsic amorphous silicon layers 22 respectively located on opposite sides of the germanium substrate 21, and respectively formed on the two essential non- the outer layer 22 of polysilicon a p-type amorphous silicon layer (p-type amorphous silicon layer) 23 and an n ⁺ -type amorphous silicon layer (n-type amorphous silicon layer) 24. The tantalum substrate 21 may be an n-type or p-shaped single crystal or polycrystalline tantalum substrate. The first surface 201 is located on the outer side of the p-type amorphous germanium layer 23, and the second surface 202 is on the outer side of the n ⁺ -type amorphous germanium layer 24. Through the ruthenium substrate 21, the p-type amorphous germanium layer 23 and the pn junction structure of the n ⁺ -type amorphous germanium layer 24, the substrate 2 can further produce a photovoltaic effect.

The first transparent conductive layer 3 is disposed on the first surface 201 to contact the p-type amorphous germanium layer 23 of the substrate 2, and has anti-reflection and conductive effects. The first transparent conductive layer 3 includes a first region 31, a first base material region 30, an inner side surface 391 contacting the first surface 201, and opposite the inner side surface 392 for the first metal layer 5 to be disposed. One outer side 392. The impedance value of the first region 31 is smaller than the impedance value of the first base material region 30.

The first region 31 extends inwardly from the outer surface 392 of the first transparent conductive layer 3 to the inner side surface 391 of the first transparent conductive layer 3, thereby simultaneously contacting the first surface 201 of the substrate 2 and the first metal layer. 5. In practice, the first region 31 may only contact the first metal layer 5 without contacting the first surface 201. At this time, the first region 31 extends inwardly from the outer side surface 392 but does not extend to the inner side surface 391. .

The first region 31 has a plurality of first finger regions 32 extending along a first direction 71 and a plurality of first bus bars 33 extending in a second direction 72 different from the first direction 71. The plurality of first bustling regions 33 are spaced apart along the first direction 71, and the plurality of first finger regions 32 are connected to the plurality of first confluence regions 33. The plurality of first finger regions 32 located on opposite sides of each of the first busbar regions 33 may be aligned in two or two as shown in FIG. 4, and may of course be staggered in pairs. In practice, the first area 31 may have only one first bus area 33, and thus the number of the first bus area 33 is not limited to the example of the embodiment. Further, in the present embodiment, the first direction 71 is perpendicular to the second direction 72.

Referring to FIGS. 5 and 6, the second transparent conductive layer 4 is disposed on the second surface 202 to contact the n ⁺ -type amorphous germanium layer 24 of the substrate 2, and has anti-reflection and conductive effects. The average impedance value of the second transparent conductive layer 4 is smaller than the average impedance value of the first transparent conductive layer 3. The second transparent conductive layer 4 includes a second region 41, a second base material region 40, an inner side surface 491 contacting the second surface 202, and opposite the inner side surface 492 for the second metal layer 6 to be disposed. An outer side 492. The impedance value of the second region 41 is smaller than the impedance value of the second base material region 40.

The second region 41 extends inwardly from the outer side surface 492 of the second transparent conductive layer 4 to the inner side surface 491 of the second transparent conductive layer 4, thereby simultaneously contacting the second surface 202 of the substrate 2 and the second metal layer 6. . In practice, the second region 41 can only contact the second metal layer 6 without contacting the second surface 202. At this time, the second region 41 extends inwardly from the outer side surface 492 but does not extend to the inner side surface 491. . The second region 41 has a plurality of second island regions 44 spaced apart from one another.

Referring to FIGS. 3, 4, and 5, the first metal layer 5 is disposed on the first region 31 of the first transparent conductive layer 3, and includes a plurality of first finger-shaped metal portions 51 extending along the first direction 71. And a plurality of first bus bar metal portions 52 extending in the second direction 72. The plurality of first bus bar metal portions 52 are spaced apart along the first direction 71 , and the plurality of first finger metal portions 51 are connected to the plurality of first bus bar metal portions 52 . In practice, the first metal layer 5 may have only one first bus bar metal portion 52, and thus the number of the first bus bar metal portions 52 is not limited to the example of the embodiment.

Each of the plurality of first finger regions 32 is in contact with one of the plurality of first finger metal portions 51. In the embodiment, the number of the plurality of first finger metal portions 51 and the plurality of The number of the first finger regions 32 is the same. Therefore, as shown in FIG. 3, the plurality of first finger-shaped metal portions 51 are in one-to-one contact with the plurality of first finger regions 32, respectively. Of course, in practice, the number of the plurality of first finger-shaped metal portions 51 may be greater than the number of the plurality of first finger-shaped regions 32. At this time, several of the plurality of first finger-shaped metal portions 51 are The plurality of first finger regions 32 are respectively contacted, and the other of the plurality of first finger metal portions 51 do not contact the plurality of first finger regions 32.

The width d1 of each of the first finger regions 32 is greater than the width d2 of the first finger metal portions 51 in contact therewith, and the width d3 of the plurality of first bus bar regions 33 is greater than the width d4 of the first bus bar metal portion 52 in contact therewith. . In addition, a projected area of the first metal layer 5 on the first surface 201 is smaller than a projected area of the first area 31 on the first surface 201.

Referring to FIGS. 5 and 6, it should be noted that the solar cell 13 of the present embodiment is in the form of single-sided light receiving, so that the first surface 201 is the main light receiving surface of the solar cell 13, and the second surface 202 is the solar cell. 13 backlit surface. The second metal layer 6 is disposed on the second transparent conductive layer 4 in a planar manner and contacts the second base material region 40 and the plurality of second island regions 44 of the second region 41.

It is to be noted that the solar cell 13 can also be in the form of double-sided light receiving as shown in FIG. 7. At this time, the first surface 201 is the main light receiving surface of the solar cell 13, and the second surface 202 is the solar energy. The secondary light receiving surface of the battery 13. Correspondingly, the secondary light receiving surface of the solar cell 13 can be identical to the structure at the main light receiving surface.

Specifically, the second region 41 of the second transparent conductive layer 4 may have the same structure as the first region 31 of the first transparent conductive layer 3, and has a plurality of second busbar regions 43 and a plurality of strips. The second finger area (not shown). The second metal layer 6 may have the same structure as the first metal layer 5, and has a plurality of second bus bar metal portions 62 and a plurality of second finger bus bar metal portions 61.

Referring to Figures 4, 5, 8, and 9, a preferred embodiment of the method of fabricating the solar cell 13 of the present invention comprises: Step 81: Prepare the substrate 2 having a p-n junction structure to produce a photovoltaic effect.

Step 82: Form the first transparent conductive layer 3 and the second transparent conductive layer 4 on the first surface 201 and the second surface 202 of the substrate 2, respectively. The material of the first transparent conductive layer 3 and the second transparent conductive layer 4 may specifically be indium tin oxide (ITO). In practice, the first transparent conductive layer 3 and the second transparent conductive layer 4 may be formed by vacuum coating or spraying.

Step 83: Treat the first region 31 of the first transparent conductive layer 3 by laser to reduce the impedance value of the first region 31.

Specifically, since the first transparent conductive layer 3 obtained in the step 82 generally has a plurality of island-like crystal structures separated from each other and an amorphous structure located between the island-like crystal structures, the laser is irradiated in the first The outer side surface 392 of the transparent conductive layer 3 crystallizes the amorphous structure in the portion of the first transparent conductive layer 3 where the first region 31 is expected to be formed, thereby increasing the degree of crystallization of the first region 31, thereby reducing The impedance value of the first region 31, and the region where the first transparent conductive layer 3 is not processed by the laser is the first base material region 30.

Step 84: The second region 41 of the second transparent conductive layer 4 is processed by laser to reduce the impedance value of the second region 41, and the region where the second transparent conductive layer 4 is not processed by the laser is the second Base material area 40. The specific method of this step is the same as step 83, and will not be described in detail. In implementation, The order of steps 83, 84 can be interchanged or performed simultaneously.

It is further explained that the average impedance value of the second transparent conductive layer 4 is smaller than the average impedance value of the first transparent conductive layer 3, because the second surface 202 of the substrate 2 is more conductive than the transmittance. Therefore, the conductivity at the second surface 202 can be made better than the conductivity of the first surface 201. In order to achieve the foregoing effects, in practice, the length of time that the laser processing can be transmitted is different, so that the impedance value of the second region 41 is smaller than the impedance value of the first region 31; or the range of the range that can be processed through the laser is different. The projection area of the second region 41 on the second surface 202 is larger than the projected area of the first region 31 on the first surface 201. The average impedance value of the second transparent conductive layer 4 is smaller than the first method. The average impedance value of a transparent conductive layer 3.

In addition, in this embodiment, in steps 83 and 84, specifically, the first transparent conductive layer 3 and the second transparent conductive layer 4 are processed by using a femtosecond laser, because the action area of the femtosecond laser is shallow. Therefore, the laser processing process does not pass through the first transparent conductive layer 3 and the second transparent conductive layer 4, thereby affecting the amorphous of the p-type amorphous germanium layer 23 and the n ⁺ -type amorphous germanium layer 24. organization. In practice, the first transparent conductive layer 3 and the second transparent conductive layer 4 may also be treated by ultraviolet light. It should be noted that because the energy density of the ultraviolet light is lower than that of the laser, the ultraviolet light is used. The process time is longer.

Step 85: forming the first metal layer 5 and the second metal layer 6 on the first transparent conductive layer 3 and the second transparent conductive layer 4, respectively. In this embodiment, the conductive paste is separately screen printed on the first transparent conductive layer. 3 and the second transparent conductive layer 4, and further, the conductive paste is sintered into the first metal layer 5 and the second metal layer 6 by heat treatment.

In this embodiment, the width d1 of each of the first finger regions 32 is greater than the width d2 of the first finger metal portions 51 in contact therewith, and the width d3 of the plurality of first bus bar regions 33 is greater than the first confluence with the contact The width d4 of the metal portion 52 facilitates screen printing and alignment in step 85.

Further, since the solar cell 13 of the present embodiment is in the one-sided light receiving form, in step 85, the conductive paste is overprinted over the second metal layer 6 in a full-face manner. If the solar cell 13 is in the double-sided light receiving form, the conductive paste can be screen printed on the second metal layer 6 in step 85, and after sintering, the solar cell 13 as shown in FIG. 7 can be obtained. The structure.

Referring to FIGS. 3, 4, 5, and 8, it can be seen from the above description that the first region 31 of the first transparent conductive layer 3 and the second region 41 of the second transparent conductive layer 4 are treated by laser or ultraviolet light. Thereby, the degree of crystallization of the first region 31 and the second region 41 is increased, thereby reducing the impedance values of the first region 31 and the second region 41, and improving the first transparent conductive layer 3 and the second transparent conductive layer. Conductivity of layer 4 and carrier collection efficiency. Therefore, when the first metal layer 5 is disposed on the first transparent conductive layer 3 and the second metal layer 6 is disposed on the second transparent conductive layer 4, the first metal layer 5 and the first The contact impedance of the region 31 and the contact resistance of the second metal layer 6 and the second region 41, so that the photocurrent generated by the substrate 2 due to the photovoltaic effect can pass through the first region 31 with a lower impedance value and the The second region 41 is conducted to the first metal layer 5 and the second metal layer 6 and then outward It is derived to increase the photoelectric flow rate that the solar cell 13 can produce.

It should be noted that, in this embodiment, only the local region of the first transparent conductive layer 3 is subjected to laser or ultraviolet light treatment because the first region 31 obtained by the treatment has a higher degree of crystallization and lower resistance. However, the transmittance with respect to the first region 31 may become lower. After measuring the incident amount of the light of the substrate 2 and reducing the impedance value, the embodiment only performs laser or ultraviolet light treatment on the first transparent conductive layer 3 to cover the first metal layer 5, since the substrate 2 receives the The cover of the first metal layer 5 is inevitably exposed to light, so that the low transmittance characteristic of the first region 31 has little effect on the amount of light incident on the entire solar cell 13, but the first region 31 has a low impedance. The value of the value is favorable for the outward transmission of the photoelectric flow generated by the substrate 2. In addition, the first transparent conductive layer 3 is subjected to laser or ultraviolet light treatment with respect to the entire surface. The means for performing processing only in a partial area in this embodiment can save time and improve manufacturing efficiency and cost.

2, 3, and 9, in addition, since the first finger-shaped metal portion 51 of the first metal layer 5 is mainly used to collect the photocurrent generated by the substrate 2, the first metal layer 5 is A bus bar metal portion 52 is mainly used for collecting the photocurrents transmitted by the plurality of first finger metal portions 51 and feeding them to the plurality of ribbon wires 15 for outward conduction. That is to say, since the portions of the plurality of first finger-shaped metal portions 51 are to collect photocurrent, better electrical conductivity is generally required with respect to the plurality of first bus bar metal portions 52.

In addition, in order to reduce the time of laser or ultraviolet light treatment to improve manufacturing efficiency, the first region 31 may be formed only in step 83. The plurality of first finger regions 32 are not required to be formed, and when the first metal layer 5 is formed in step 85, the plurality of first finger metal portions 51 are respectively located at the first The first finger region 32 of a region 31 is located, and the plurality of first bus bar metal portions 52 are respectively located on the first base material region 30. In this way, the manufacturing efficiency can be improved, and the plurality of first finger-shaped metal portions 51 can also pass through the plurality of first finger regions 32 to have good current collecting performance.

Referring to FIG. 10, a second preferred embodiment of the solar cell module of the present invention is substantially the same as the first preferred embodiment, and the difference between the two is: the structure of the first region 31.

In this embodiment, each of the first confluence regions 33 of the first region 31 has two confluence strips 331 spaced along the first direction 71 and extending along the second direction 72. The first region 31 Each of the finger regions 32 has two finger-shaped strips 321 extending along the first direction 71 and spaced along the second direction 72. The first bus bar metal portion 52 of each first metal layer 5 has two confluent long edges 521 respectively contacting the two bus bar strips 331; and the first finger metal contacting the first finger regions 32 The portions 51 each have two finger-shaped long edges 511 that are in contact with the two finger-shaped strip portions 321 , respectively.

Since the photocurrent generated by the substrate 2 not covered by the first metal layer 5 is substantially transmitted from both sides of each first bus bar metal portion 52 or both sides of each first finger metal portion 51, As long as the photocurrent generated by the substrate 2 can enter the first bus bar metal portion 52 from the bus bar portion 331 of each first bus bar region 33, or by each of the first finger regions 32 The finger-shaped strip portion 321 enters the first finger-shaped metal portion 51, thereby achieving the purpose of reducing the contact resistance and increasing the photoelectric flow rate that can be produced by the solar cell 13.

In this embodiment, each of the first busbars 33 is divided into two bus bar strips 331 spaced apart from each other, and the projected area of each of the first busbars 33 on the first surface 201 (see FIG. 5) is reduced. In the process, the time and range of processing the first transparent conductive layer 3 by laser or ultraviolet light is reduced, thereby improving manufacturing efficiency. The effect of separating each of the first finger regions 32 into the two finger-shaped strip portions 321 spaced apart from each other is also the same and will not be described again.

Referring to FIG. 11, a third preferred embodiment of the solar cell module of the present invention is substantially the same as the first preferred embodiment, and the difference between the two is: the structure of the first region 31.

In addition to the plurality of first finger regions 32, the first region 31 of the embodiment further has a plurality of first island regions 34 separated from each other, and each of the first island regions 34 and The first bus bar metal portion 52 is in contact. In this embodiment, by reducing the projected area of the first region 31 on the first surface 201 (see FIG. 5), the time and range of laser or ultraviolet light processing can be reduced in the process, thereby improving manufacturing efficiency.

In summary, the present invention processes the first region of the first transparent conductive layer by laser or ultraviolet light, thereby increasing the degree of crystallization of the first region to reduce the impedance value of the first region, and improving the first Conductivity of the transparent conductive layer and carrier collection efficiency. Through the foregoing innovative design, the contact resistance of the first metal layer disposed on the first transparent conductive layer can be reduced, so that the photocurrent generated by the photovoltaic effect of the substrate can pass the lower impedance value. An area is conducted to the first metal layer and then outwardly, thereby enhancing the photoelectric flow rate that the solar cell can produce, so that the object of the present invention can be achieved.

The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications made by the patent application scope and patent specification content of the present invention, All remain within the scope of the invention patent.

13‧‧‧Solar battery

2‧‧‧Substrate

201‧‧‧ first surface

202‧‧‧ second surface

21‧‧‧矽 substrate

22‧‧‧ Essential amorphous layer

23‧‧‧p-type amorphous germanium layer

24‧‧‧n ⁺ type amorphous layer

3‧‧‧First transparent conductive layer

30‧‧‧First base metal area

31‧‧‧First area

33‧‧‧First Confluence Area

391‧‧‧ inside

392‧‧‧Outside

4‧‧‧Second transparent conductive layer

40‧‧‧Second base metal area

41‧‧‧Second area

44‧‧‧Second island

491‧‧‧ inside

492‧‧‧ outside side

5‧‧‧First metal layer

51‧‧‧First finger metal

52‧‧‧First Confluence Metals Division

6‧‧‧Second metal layer

Claims (18)

A method for manufacturing a solar cell, comprising: preparing a substrate having a pn junction structure to generate a photovoltaic effect; forming a first transparent conductive layer on a first surface of the substrate; treating the first surface by laser or ultraviolet light a first region of a transparent conductive layer to reduce an impedance value of the first region, and the first region has a plurality of first finger regions extending along a first direction; and forming a first metal layer at the first a transparent conductive layer, and the first metal layer includes a first bus bar metal portion extending in a second direction different from the first direction, and extending along the first direction and connecting the first bus bar metal portion a plurality of first finger-shaped metal portions; each of the plurality of first finger regions is in contact with one of the plurality of first finger-shaped metal portions. The method of manufacturing a solar cell according to claim 1, wherein each of the first finger regions has a width greater than a width of the first finger metal portion in contact therewith. The method of manufacturing a solar cell according to claim 1 or 2, wherein the first region further has a first confluence region extending in the second direction and contacting the first confluence metal portion, the first confluence region Connecting the plurality of first finger regions. The method of manufacturing a solar cell according to claim 3, wherein the first bus bar has two bus bar strips; the first bus bar metal portion has two bus bar lengths respectively contacting the two bus bar strips edge. The method of manufacturing a solar cell according to claim 3, wherein each of the first finger regions has two finger-shaped strip portions; and the first bus bar metal portions that are in contact with the first finger regions have respectively The two finger-shaped long edges that the two finger-shaped strips contact. The method for manufacturing a solar cell according to claim 1, further comprising forming a second transparent conductive layer on a second surface of the substrate, wherein the second transparent conductive layer has an average impedance value smaller than the first transparent conductive layer The average impedance value, the first surface is the main light receiving surface of the solar cell. The method for manufacturing a solar cell according to claim 6, further comprising treating a second region of the second transparent conductive layer with laser or ultraviolet light to reduce an impedance value of the second region; The projected area of the first surface is smaller than the projected area of the second area at the second surface. The method for manufacturing a solar cell according to claim 6, further comprising treating a second region of the second transparent conductive layer with laser or ultraviolet light to reduce an impedance value of the second region; and impedance of the second region The value is less than the impedance value of the first region. The method of manufacturing a solar cell according to claim 1, wherein the first region contacts the first surface of the substrate and the first metal layer. A solar cell comprising: a substrate having a pn junction structure to produce a photovoltaic effect, and comprising a first surface and a second surface opposite to the first surface, the first surface being the main light receiving of the solar cell a first transparent conductive layer disposed on the first surface and including a first region and a first base material region, the impedance value of the first region is smaller than an impedance value of the first base material region, and the first region has a plurality of first finger regions extending along a first direction a second transparent conductive layer disposed on the second surface, the average impedance value of the second transparent conductive layer is smaller than an average impedance value of the first transparent conductive layer; and a first metal layer disposed on the first a transparent conductive layer, and includes a first bus bar metal portion extending in a second direction different from the first direction, and a plurality of first finger shapes extending along the first direction and connecting the first bus bar metal portion The metal portion, each of the plurality of first finger regions is in contact with one of the plurality of first finger metal portions. The solar cell of claim 10, wherein the second transparent conductive layer comprises a second region and a second base material region, and the impedance value of the second region is smaller than the impedance value of the second base material region. The solar cell of claim 11, wherein a projected area of the first area on the first surface is smaller than a projected area of the second area on the second surface. The solar cell of claim 11, wherein the impedance value of the second region is less than the impedance value of the first region. A solar cell comprising: a substrate having a pn junction structure to generate a photovoltaic effect and comprising a first surface; a first transparent conductive layer disposed on the first surface and including a first region and a First base material region, impedance value of the first region An impedance value smaller than the first base material region, and the first region has a plurality of first finger regions extending along a first direction, and a first portion extending in a second direction different from the first direction a first bus bar connecting the plurality of first finger regions, the first bus bar having two bus bar strips; and a first metal layer disposed on the first transparent conductive layer and including a first bus bar metal portion extending along the second direction, and a plurality of first finger metal portions extending along the first direction and connecting the first bus bar metal portion, the first bus bar metal portion having the two Two converging long edges contacting the bus bar strips, each of the plurality of first finger regions respectively contacting one of the plurality of first finger metal portions. The solar cell of claim 14, wherein the width of each of the first finger regions is greater than the width of the first finger metal portion in contact therewith. The solar cell of claim 14, wherein each of the first finger regions has two finger-shaped strip portions; and the first bus bar fingers that are in contact with the first finger regions have respectively Two finger-shaped long edges that are in contact with the finger strips. The solar cell of claim 14, wherein the first region contacts the first surface of the substrate and the first metal layer. A solar cell module comprising: a first plate and a second plate disposed oppositely; and a plurality of solar cells according to any one of claims 10 to 17, arranged on the first plate and the second plate And a package material between the first plate and the second plate, and Covered around the several solar cells.