TWI517419B - Solar cell device - Google Patents

Description

Solar cell component

The present invention relates to a solar cell element, and more particularly to an electrode structure of a back contact type solar cell element.

In the conventional solar cell structure, the upper electrode is disposed on the upper surface of the tantalum substrate, and the lower electrode is disposed on the lower surface of the tantalum substrate. However, the upper surface of the ruthenium substrate is used to receive the illumination of sunlight, so that the upper electrode on the upper surface shields part of the incident light, thereby reducing the photoelectric conversion efficiency of the solar cell. Therefore, the current technology has developed to move the upper electrode to the lower surface of the ruthenium substrate, so that the upper and lower electrodes (or p-type electrodes and n-type electrodes) are disposed together on the lower surface of the ruthenium substrate, and the solar cell having such a structure is called It is a Back Contact Solar Cell. Back contact solar cells can be roughly classified into four types of structures: Interdigitated Back Contact (IBC), Emitter Wrap Through (EWT), and metal wear. A Metallization Wrap Through (MWT) and Metallization Wrap Around (MWA), in which an interdigitated back electrode solar cell is more common.

Please refer to the top view of the conventional interdigital back electrode solar cell 100 illustrated in FIG. 1. As shown in FIG. 1, the conventional solar cell 100 includes an N-type diffusion region 111, a P-type diffusion region 121, an N-type bus electrode 112, a P-type bus electrode 122, a plurality of N-type finger electrodes 113, and a plurality of P-type fingers. Electrode 123. The above-mentioned N-type diffusion region 111 is arranged in a comb shape, P The type diffusion region 121 surrounds the N-type diffusion region 111. In addition, the P-type bus electrode 122 and the plurality of P-type finger electrodes 123 are disposed on the P-type diffusion region 121 and the three are electrically connected to each other. The N-type bus electrode 112 and the plurality of N-type finger electrodes 113 are disposed on the N-type diffusion region 111 and the three are electrically connected to each other.

In addition, in the interdigitated back electrode solar cell 100, after the light is irradiated onto the upper surface of the substrate and an electron hole pair is generated, the electrons are concentrated toward the N-type diffusion region 111, and the hole is directed to the P-type diffusion region 121. Gather. However, for the pair of electron holes generated on the surface of the germanium substrate above the center of the N-type diffusion region 111, if the hole is to be moved to the distance of the P-type diffusion region 121, the electron is moved to the lower side N The distance of the type diffusion region 111 is relatively far. Further, for the electron hole generated on the surface of the ruthenium substrate above the center of the P-type diffusion region 121, if the electrons are moved to the distance of the N-type diffusion region 111, the P is moved to the lower side than the hole. The distance of the type diffusion region 121 is relatively far. It is worth noting that in the N-type germanium substrate, the holes generated by the light irradiation of the substrate surface belong to a minority carrier, and the electrons belong to the majority carrier. Therefore, if the area of the N-type diffusion region 111 is too large, the distance between the hole and the P-type diffusion region 121 is likely to be too long, and the minority carrier (hole) is easily lost during the movement, so that the short circuit (short circuit) Current, referred to as Isc) is reduced, which in turn affects the efficiency of solar cells. However, if the area of the N-type diffusion region 111 is reduced, the conduction resistance of most carriers will be affected. In addition, the area of the larger P-type diffusion region 121 facilitates collecting more minority carriers to enhance the Isc, thereby improving the photoelectric conversion efficiency of the solar cell. However, the larger P-type diffusion region 121 causes the distance of electrons to move to the N-type diffusion region 111 to become longer. When the resistance of the electron movement becomes larger, the fill factor (Fill Factor, FF for short) is reduced, thereby reducing the photoelectricity. Conversion efficiency.

Therefore, some manufacturers have proposed a technical solution to solve the problem caused by an excessive N-type diffusion region or an excessive P-type diffusion region under the bus electrode. 2A is a schematic structural view of a solar cell element proposed by SunPower. 2B is a schematic view of a series of welded structures of two sets of solar cell elements. Please refer to Figure 2A first. SunPower Corporation The proposed solar cell element 200 includes a bus electrode 202 and a finger electrode 204. Compared to a conventional rectangular large-area bus electrode, SunPower proposes to reduce the bus electrode 202 into a plurality of square patterns and disposed in an edge region of the solar cell element 200. In other words, when the area of the bus electrode 202 is reduced, it means that the area of the diffusion region under the bus electrode 202 can be simultaneously reduced, so that an excessive N-type diffusion region or an excessively large P-type diffusion region under the bus electrode 202 can be solved. The problem caused. However, there is no bus electrode 202 in the intermediate portion of the above solar cell element 200. Therefore, for electrons or holes, the distance from the finger electrodes 204 to the bus electrodes 202 becomes longer. This is not conducive to the transmission of electrons or holes. In addition, since the reduced bus electrode 202 of the solar cell element 200 is disposed at the edge of the element, the finger electrodes 204 located at the edge regions of the solar cell element 200 need to be rearranged so that the finger electrodes 204 can be directly connected to the reduced Square bus electrode 202.

Furthermore, please refer to FIG. 2B at the same time. Because of the special design of the above-mentioned bus electrode 202, the battery piece having the solar cell element 200a and the cell piece having the solar cell element 200b cannot be connected to each other by the conventional string welding technology, so a special design is required. The solder strip 206 can realize the serial connection of the two cells.

Therefore, it is an important spirit to develop the present invention to provide an improved electrode structure of a solar cell and to obtain an optimized design of the ratio of the area of the N-type diffusion region to the area of the P-type diffusion region to improve the photoelectric conversion efficiency of the solar cell.

The invention proposes a solar cell element to improve the photoelectric conversion efficiency of the solar cell.

In order to achieve the above advantages or other advantages, an embodiment of the present invention provides a solar cell component, including a substrate, a first finger electrode, a second finger electrode, a first patterned insulating layer, a second patterned insulating layer, and A bus electrode and a second bus electrode. The substrate has a first diffusion region and at least a second diffusion region, wherein the first diffusion region is surrounded by Around the second diffusion zone. The first finger electrode is disposed on the first diffusion region and electrically connected to the first diffusion region. The second finger electrode is disposed on the second diffusion region and electrically connected to the second diffusion region. The first patterned insulating layer is disposed above a portion of the second diffusion region and a portion of the second finger electrodes. The second patterned insulating layer is disposed above a portion of the first diffusion region and on a portion of the first finger electrodes. The first bus electrode is disposed on the first patterned insulating layer, on the portion of the first finger electrode and above the portion of the first diffusion region, and electrically connected to the first finger electrode. The second bus electrode is disposed on the second patterned insulating layer, above the second portion of the second diffusion region and on the portion of the second finger electrode, and electrically connected to the second finger electrode.

The invention further provides a solar cell component, comprising a substrate, a patterned passivation layer, a first finger electrode, a second finger electrode, a first patterned insulating layer, a second patterned insulating layer, a first bus electrode and a second Confluence electrode. The substrate has a first diffusion region and at least a second diffusion region, wherein the first diffusion region surrounds the second diffusion region. The patterned passivation layer is disposed on the first diffusion region and the second diffusion region. The first finger electrode is disposed on the first diffusion region and electrically connected to the first diffusion region. The second finger electrode portion is disposed on the second diffusion region and partially disposed above the first diffusion region, wherein a portion of the second finger electrode disposed on the second diffusion region is electrically connected to the second diffusion region, and is disposed on the second diffusion region A portion of the second finger electrode above the first diffusion region and the first diffusion region further comprise a patterned passivation layer. The first patterned insulating layer is disposed above a portion of the second diffusion region and a portion of the second finger electrodes. The second patterned insulating layer is disposed above a portion of the first diffusion region and on a portion of the first finger electrodes. The first bus electrode is disposed on the first patterned insulating layer, on the portion of the first finger electrode and above the portion of the first diffusion region, and electrically connected to the first finger electrode. And the second bus electrode is disposed on the second patterned insulating layer, above the second portion of the second diffusion region, on the portion of the second finger electrode and over the patterned passivation layer, and the second bus electrode is electrically connected to the second finger electrode.

In summary, the present invention extends the N-type finger electrode and the N-type diffusion region below the P-type bus electrode, and extends the P-type finger electrode and the P-type diffusion region below the N-type bus electrode. Solve only the N-type diffusion region under the traditional N-type bus electrode and The problems caused by the large N-type diffusion region and the problems caused by the P-type diffusion region and the excessive P-type diffusion region under the conventional P-type bus electrode. Moreover, the present invention can also reduce the moving distance and transmission impedance of the holes or electrons under the N-type bus electrode or the P-type bus electrode, thereby improving the photoelectric conversion efficiency of the solar cell. Further, the welding method between the two cells having the solar cell element of the present invention is compatible with the conventional string welding technique.

100, 200, 200a, 200b‧‧‧ solar cell components

111‧‧‧N type diffusion zone

121‧‧‧P type diffusion zone

112‧‧‧N type bus electrode

122‧‧‧P type bus electrode

113‧‧‧N type finger electrode

123‧‧‧P type finger electrode

202‧‧‧Concurrent electrode

204‧‧‧ finger electrodes

206‧‧‧ soldering tape

300, 400‧‧‧ solar cell components

310‧‧‧Substrate

312, 412‧‧‧ first diffusion zone

313, 413‧‧‧Second diffusion zone

3132‧‧‧The first long district

3133‧‧‧second short zone

342, 442‧‧‧ first finger electrode

343, 443‧‧‧ second finger electrode

352, 452‧‧‧ first patterned insulation

353, 453‧‧‧Second patterned insulation

362, 462‧‧‧ first bus electrode

363, 463‧‧‧ second bus electrode

320, 420‧‧‧ patterned passivation layer

413c‧‧‧round area

413s‧‧‧ Strips

W1‧‧‧ first width

W2‧‧‧ second width

S1‧‧‧Stained surface

S2‧‧‧Backlit surface

S3‧‧‧ surface

L1‧‧‧ first length

L2‧‧‧ second length

A-a’, b-b’, c-c’, d-d’‧‧‧ tangent

1 is a top view of a conventional interdigitated back electrode solar cell 100.

2A is a schematic structural view of a solar cell element proposed by SunPower.

2B is a schematic view of a series of welded structures of two sets of solar cell elements.

3A is a structural top view of a solar cell element according to an embodiment of the invention.

Figure 3B is a cross-sectional view taken along line a-a' of Figure 3A.

Figure 3C is a cross-sectional view taken along line b-b' of Figure 3A.

4A is a top view of a solar cell structure in accordance with an embodiment of the present invention.

Figure 4B is a cross-sectional view taken along line c-c' of Figure 4A.

Figure 4C is a cross-sectional view taken along line d-d' of Figure 4A.

3A is a structural top view of a solar cell element according to an embodiment of the invention. Figure 3B is a cross-sectional view taken along line a-a' of Figure 3A. Figure 3C is a cross-sectional view taken along line b-b' of Figure 3A. Please also refer to FIG. 3A and FIG. 3B. The solar cell element 300 of the present invention includes a substrate 310 having a first diffusion region 312 and at least a second diffusion region 313, a first finger electrode 342, a second finger electrode 343, a first patterned insulating layer 352, The second patterned insulating layer 353, the first bus electrode 362 and the second bus electrode 363. In FIG. 3A, a plurality of second diffusion regions 313, a plurality of second finger electrodes 343, and a plurality of first finger electrodes 342 are illustrated, but the invention is not limited thereto. Further, the solar cell element 300 described above is, for example, a back contact type solar cell. Therefore, the substrate 310 further includes, for example, a light receiving surface S1 and a backlight surface S2. The light receiving surface S1 is for receiving the irradiation of sunlight, and the light receiving surface S1 is a rough surface to enhance the light absorption rate of the light receiving surface S1. In addition, the first diffusion region 312 and the second diffusion region 313 are disposed in the substrate 310 away from the light receiving surface S1. The substrate 310 is, for example, an N-type germanium substrate.

Please refer to Figure 3A first. The first diffusion region 312 is surrounded by the plurality of second diffusion regions 313, and each of the second diffusion regions 313 includes a first long region 3132 and a second short region 3133, wherein the first long region 3132 and the first The two short areas 3133 are connected. The first diffusion region 312 is an emitter diffusion region for collecting a small number of charge carriers (for example, holes) generated after the sunlight is irradiated onto the light receiving surface S1. The second diffusion region 313 is a base diffusion region for collecting a plurality of charge carriers (for example, electrons) generated after the sunlight is irradiated onto the light receiving surface S1 of the substrate 310. In addition, the above-mentioned emitter diffusion region is, for example, a P-type doped region or a P-type diffusion region, and the base diffusion region is, for example, an N-type doped region or an N-type diffusion region. In addition, the first length L1 of the first long area 3132 is greater than the second length L2 of the second short area 3133, and the widths of the first long area 3132 and the second short area 3133 are different.

Please continue to refer to Figure 3A. The first finger electrode 342 is disposed on the first diffusion region 312 and electrically connected to the first diffusion region 312. The first finger electrode 342 is a P-type finger electrode. The second finger electrode 343 is disposed on the second diffusion region 313 and electrically connected to the second diffusion region 313, wherein the second finger electrode 343 is an N-type finger electrode. In addition, the first patterned insulating layer 352 is disposed above the portion of the second diffusion region 313 and the portion of the second finger electrodes 343 and directly contacts the second finger electrodes 343. Moreover, the second patterned insulating layer 353 is disposed above the portion of the first diffusion region 312 and the portion of the first finger electrodes 342 and directly contacts the first finger electrodes 342. In more detail, the first pattern is absolutely The edge layer 352 is disposed above a portion of the first long region 3132 of the second diffusion region 313 and disposed on a portion of the second finger electrodes 343 located in the first long region 3132. Moreover, the second patterned insulating layer 353 is disposed on a portion of the first finger electrode 342 adjacent to the portion of the first diffusion region 312 of the second short region 3133 and adjacent to the second short region 3133.

It is worth mentioning that the first diffusion region 312 is disposed adjacent to the second diffusion region 313, and the width of the second diffusion region 313 is narrow. Moreover, during the process of forming the second patterned insulating layer 353 over a portion of the first diffusion region 312 adjacent to the second short region 3133 and adjacent to the portion of the first finger electrode 342 of the second short region 3133, The width of the second patterned insulating layer 353 on the single first finger electrode 342 may be equal to or slightly larger than the width of the first diffusion region 312 between the two adjacent second diffusion regions 312. Therefore, in order to avoid the alignment error in the process, the second patterned insulating layer 353 covers the second finger electrode due to the error offset, the present invention proposes that the first width W1 of the first long region 3132 can be, for example, less than or It is equal to the second width W2 of the second short zone 3133. This improves component yield. In a preferred embodiment, the first width W1 is, for example, between 200 and 500 microns. In other embodiments of the present invention, the second width W2 may be between 300 and 600 micrometers, for example, but the range of the second width W2 may be finely adjusted under different process conditions and process environments, so the present invention does not The above is limited.

Please continue to refer to Figure 3A. Furthermore, the first bus electrode 362 is disposed on the first patterned insulating layer 352, on the portion of the first finger electrode 342 and above the portion of the first diffusion region 312. Further, the second bus electrode 363 is disposed on the second patterned insulating layer 353, above the portion of the second diffusion region 313, and on the portion of the second finger electrodes 343. In addition, the first bus electrode 362 is electrically connected to the plurality of first finger electrodes 342 for collecting current from the plurality of first finger electrodes 342, wherein the first bus electrode 362 is a P-type bus electrode. The second bus electrode 363 is electrically connected to the plurality of second finger electrodes 343 for collecting current from the plurality of second finger electrodes 343, wherein the second bus electrode 363 is an N-type bus electrode.

It should be noted that the first bus electrode 362 is disposed with a first diffusion region 312 and a second diffusion region 313 under the first patterned insulating layer 352. Further, the first bus electrode 362 further includes a plurality of first finger electrodes 342 and a plurality of second finger electrodes 343 located under the first patterned insulating layer 352. The first patterned insulating layer 352 is used to electrically isolate the second finger electrode 343 from the first bus electrode 362. In addition, the second diffusion region 313 is disposed under the second diffusion region 313 and the first diffusion region 312 under the second patterned insulating layer 353, and the second bus electrode 363 is further disposed with a plurality of second layers. The finger electrode 343 and the plurality of first finger electrodes 342 located under the second patterned insulating layer 353. The second patterned insulating layer 353 is used to electrically isolate the first finger electrode 342 from the second bus electrode 363. Therefore, the second bus electrode 363 of the present invention is disposed with a second diffusion region 313, and further includes a first diffusion region 312. This can solve the problem that only the N-type diffusion region is below the conventional N-type bus electrode and is too large. Problems caused by the N-type diffusion zone. In addition, the first bus electrode 362 of the present invention includes a second diffusion region 313 in addition to the first diffusion region 312, so that only the P-type diffusion region under the conventional P-type bus electrode can be solved. Problems caused by excessive P-type diffusion zones.

In addition, it is to be noted that the first bus electrode 362 and the second bus electrode 363 of the solar cell element 300 of the present invention have a conventional pattern design, and thus the two cell sheets having the solar cell element 300 of the present invention can be Traditional tandem welding techniques are used to connect the sink electrodes to each other without the need for specially designed solder ribbons.

Please refer to Figure 3B. Figure 3B is a cross-sectional view taken along line a-a' of Figure 3A. The solar cell element 300 of the present invention includes, for example, a patterned passivation layer 320 in addition to the above-described elements. The patterned passivation layer 320 is disposed on the surface S3 of the first diffusion region 312 and the second diffusion region 313 away from the light receiving surface S1 for protecting the first diffusion region 312 and the second diffusion region 313. The first finger electrode 342 and the second finger electrode 343 penetrate the patterned passivation layer 320 and directly contact the first diffusion region 312 and the second diffusion region 313, respectively. worth taking note of In FIG. 3B, the first finger electrode 342 and the second finger electrode 343 having the same width are used as an illustrative example, but the width ratio between the different finger electrodes may be adjusted according to the requirements of the process conditions, and the present invention does not limit.

Please continue to refer to Figure 3B. In addition, the second bus electrode 363 is directly in contact with and electrically connected to the plurality of second finger electrodes 343. Moreover, as can be seen from FIG. 3B, the second diffusion electrode 363 (ie, the N-type bus electrode) is disposed under the second diffusion region 313 and the first diffusion region 312 under the second patterned insulating layer 353. In this way, the problem caused by only the N-type diffusion region and the excessive N-type diffusion region under the conventional N-type bus electrode can be solved. Further, the second bus electrode 363 of the present invention further includes a plurality of second finger electrodes 343 and a plurality of first finger electrodes 342 located under the second patterned insulating layer 353.

It is worth noting that please refer to FIG. 3A and FIG. 3B at the same time. If only the first diffusion region 312 extends below the second bus electrode 363, but does not extend the first finger electrode 342 to the first diffusion region 312 below the second bus electrode 363, then the second bus electrode A minority of charge carriers (eg, holes) generated in the first diffusion region 312 below 363 must be moved a distance in the first diffusion region 312 to be connected to the first finger electrode, thus being disadvantageous to a few charge carriers. Pass. The present invention therefore proposes to extend the first finger electrode 342 to the first diffusion region 312 under the second bus electrode 363 in order to allow a small number of charges generated in the first diffusion region 312 below the second bus electrode 363. The sub-ports (for example, holes) can flow directly to the first finger electrodes 342 below the second bus electrodes 363, so that the moving distance and the transmission impedance of the holes can be relatively reduced to improve the photoelectric conversion efficiency.

Please refer to Figure 3C. Figure 3C is a cross-sectional view taken along line b-b' of Figure 3A. As can be seen in FIG. 3C, the first bus electrode 362 is in direct contact with the plurality of first finger electrodes 342. Moreover, the first bus electrode 362 (ie, the P-type bus electrode) of the present invention is disposed with a first diffusion region 312 (ie, a P-type diffusion region) and a second diffusion region 313 under the first patterned insulating layer 352. (ie N-type diffusion zone). This can solve the traditional P-type bus electrode The problem is only caused by the P-type diffusion region and the excessive P-type diffusion region. In addition, the first bus electrode 362 of the present invention further includes a plurality of first finger electrodes 342 and a plurality of second finger electrodes 343 located under the first patterned insulating layer 352. With such a configuration, most of the charge carriers (for example, electrons) generated in the second diffusion region 313 under the first bus electrode 362 can be directly transmitted to the second finger electrodes 343 below the first bus electrode 362. In this way, the moving distance and the transmission impedance of the electrons can be relatively reduced to improve the photoelectric conversion efficiency.

4A is a top view of a solar cell structure in accordance with an embodiment of the present invention. Figure 4B is a cross-sectional view taken along line c-c' of Figure 4A. Figure 4C is a cross-sectional view taken along line d-d' of Figure 4A. Please refer to Figure 4A first. Compared with the second diffusion region 313 of the solar cell element 300 of FIG. 3A having the first long region 3132 and the first short region 3133, the biggest difference is that the second diffusion region 413 of the solar cell 400 of the present invention has a plurality of A continuous area (for example, a circle, a quadrangle, etc.) and a strip area 413s. In FIG. 4A, a plurality of discontinuous circular regions 413c are taken as examples of the plurality of discontinuous regions, but the invention is not limited thereto.

Please refer to FIG. 4A and FIG. 4B at the same time. The solar cell 400 of the present invention includes a substrate 410 having a first diffusion region 412 and a second diffusion region 413, a patterned passivation layer 420, a first finger electrode 442, a second finger electrode 443, and a first patterned insulating layer 452. a second patterned insulating layer 453, a first bus electrode 462, and a second bus electrode 463. In FIG. 4A, a plurality of second diffusion regions 413, a plurality of second finger electrodes 443, and a plurality of first finger electrodes 442 are illustrated, but the invention is not limited thereto. Further, the solar cell 400 described above is, for example, a back contact type solar cell. Therefore, the substrate 410 further includes, for example, a light receiving surface S1 and a backlight surface S2. In addition, the first diffusion region 412 and the second diffusion region 413 are disposed in the substrate 410 away from the light receiving surface S1. The substrate 410 is, for example, an N-type germanium substrate.

Please refer to Figure 4A first. The first diffusion region 412 surrounds the plurality of second diffusion regions 413, and each of the second diffusion regions 413 includes, for example, a plurality of discontinuous circular regions 413c and strip regions 413s. And the circular regions 413c of the adjacent second diffusion regions 413 can mutually Parallel juxtaposition or staggered arrangement is illustrated in FIG. 4A in a staggered arrangement as an illustrative example, but the invention is not limited thereto. It is worth mentioning that if the circular regions 413c of the adjacent second diffusion regions 413 are staggered with each other, the respective strip regions 413s respectively have a long and short configuration, as shown in FIG. 4A.

Please refer to FIG. 4A and FIG. 4B at the same time. The patterned passivation layer 420 is disposed on the first diffusion region 412 and the second diffusion region 413. In more detail, the patterned passivation layer 420 is disposed on the surface S3 of the first diffusion region 412 and the second diffusion region 413 that is away from the light-receiving surface S1. In addition, the first diffusion region 412 is a P-type doped region, and the second diffusion region 413 is an N-type doped region. In addition, the first finger electrode 442 is disposed on the first diffusion region 412 and electrically connected to the first diffusion region 412, wherein the first finger electrode 442 is a P-type finger electrode. The second finger electrode 443 is disposed on the second diffusion region 413 and electrically connected to the second diffusion region 413. The second finger electrode 443 is an N-type finger electrode. It is to be noted that each of the second finger electrodes 443 is partially disposed on the second diffusion region 413 and partially disposed above the first diffusion region 412, wherein a portion of the second finger electrodes disposed on the second diffusion region 413 is disposed. 443 is electrically connected to the second diffusion region 413, and a portion of the second finger electrode 443 disposed above the first diffusion region 412 and the first diffusion region 412 further includes a patterned passivation layer 420 for the second finger shape. The electrode 443 is electrically insulated from the first diffusion region 412.

Please continue to refer to FIG. 4A and FIG. 4B simultaneously. The first patterned insulating layer 452 is disposed above the portion of the second diffusion region 413 and the portion of the second finger electrode 443, and the second patterned insulating layer 453 is disposed above the portion of the first diffusion region 412 and partially first. Finger electrode 442. In addition, the first bus electrode 462 is disposed on the first patterned insulating layer 452, on the portion of the first finger electrode 442 and above the portion of the first diffusion region 412. The first bus electrode 462 is electrically connected to the first finger electrode 442. The first bus electrode 462 is a P-type bus electrode. The second bus electrode 463 is disposed on the second patterned insulating layer 453, above the portion of the second diffusion region 413, on the portion of the second finger electrode 443, and above the patterned passivation layer 420. The second bus electrode 463 is electrically connected to the second finger electrode 443. The second bus electrode 463 is an N-type bus electrode. More detailed The first patterned insulating layer 452 is disposed above the strip region 413s of the second diffusion region 413, for example, and the second bus electrode 463 is disposed above the plurality of circular regions 413c of the second diffusion region 413, for example.

Please refer to Figure 4B. Figure 4B is a cross-sectional view taken along line c-c' of Figure 4A. The cross-sectional view of Fig. 4B is substantially the same as the cross-sectional view of Fig. 3B. The difference is that, as shown in FIG. 4B, the second finger electrodes 443 partially disposed above the first diffusion region 412 and not disposed on the second diffusion region 413 do not directly contact the first diffusion region 412. The patterned passivation layer 420 disposed on the first diffusion region 412 is directly contacted.

Please refer to Figure 4C. Figure 4C is a cross-sectional view taken along line d-d' of Figure 4A. The cross-sectional view of Fig. 4C is the same as the cross-sectional view of Fig. 3C, and therefore the same portions will not be described again.

In summary, the present invention extends the N-type finger electrode and the N-type diffusion region below the P-type bus electrode, and extends the P-type finger electrode and the P-type diffusion region below the N-type bus electrode. Solving the problems caused by only the N-type diffusion region and the excessive N-type diffusion region under the conventional N-type bus electrode, and the P-type diffusion region and the excessive P-type diffusion region under the conventional P-type bus electrode problem. Moreover, the present invention can also reduce the moving distance and transmission impedance of the holes or electrons under the N-type bus electrode or the P-type bus electrode, thereby improving the photoelectric conversion efficiency of the solar cell. Further, the welding method between the two cells having the solar cell element of the present invention is compatible with the conventional string welding technique.

300‧‧‧Solar battery components

312‧‧‧First Diffusion Zone

313‧‧‧Second diffusion zone

3132‧‧‧The first long district

3133‧‧‧second short zone

342‧‧‧First finger electrode

343‧‧‧second finger electrode

352‧‧‧First patterned insulation

353‧‧‧Second patterned insulation

362‧‧‧First bus electrode

363‧‧‧Second bus electrode

W1‧‧‧ first width

W2‧‧‧ second width

L1‧‧‧ first length

L2‧‧‧ second length

A-a’, b-b’‧‧‧ tangent

Claims (10)

A solar cell component comprising: a substrate having a first diffusion region and at least a second diffusion region, wherein the first diffusion region surrounds the second diffusion region; a first finger electrode disposed at the first a first diffusion electrode is electrically connected to the first diffusion region; a second finger electrode is disposed on the second diffusion region and electrically connected to the second diffusion region; a first patterned insulating layer is disposed And a portion of the second finger electrode is disposed on a portion of the second finger electrode; a second patterned insulating layer disposed on a portion of the first diffusion region and a portion of the first finger electrode; a first bus electrode And disposed on the first patterned insulating layer, on the portion of the first finger electrode and above the first diffusion region, and electrically connected to the first finger electrode; and a second bus electrode disposed on the first The second patterned insulating layer is partially over the second diffusion region and partially on the second finger electrode, and electrically connected to the second finger electrode. The solar cell component of claim 1, wherein the second diffusion region has a first long region and a second short region, wherein the first long region is connected to the second short region. The solar cell component of claim 2, wherein the first patterned insulating layer is disposed over a portion of the first long region of the second diffusion region and disposed in a portion of the first long region. The second patterned insulating layer is disposed above a portion of the first diffusion region adjacent to the second short region and disposed on a portion of the first finger electrode adjacent to the second short region. The solar cell component of claim 2, wherein a first length of one of the first long zones is greater than a second length of the second short zone, and a first width of the first long zone is less than or It is equal to one second width of the second short zone. The solar cell component of claim 4, wherein the first width is between 200 and 500 microns. The solar cell component of claim 1, wherein the first diffusion region is an emitter diffusion region for collecting a small number of charge carriers generated by sunlight after the substrate is irradiated, and the second diffusion The fauna is a base diffusion region for collecting most of the charge carriers generated by sunlight after illuminating the substrate. The solar cell component of claim 1, wherein the emitter diffusion region is a P-type doped region, and the base diffusion region is an N-type doped region. A solar cell component comprising: a substrate having a first diffusion region and at least a second diffusion region, wherein the first diffusion region surrounds the second diffusion region; a patterned passivation layer disposed on the first a first finger electrode disposed on the first diffusion region and electrically connected to the first diffusion region; a second finger electrode partially disposed on the second diffusion region And a portion of the second diffusion electrode is electrically connected to the second diffusion region, and is disposed above the first diffusion region. The portion of the second finger electrode and the first diffusion region further includes the patterned passivation layer for electrically insulating the second finger electrode from the first diffusion region; a first patterned insulating layer And disposed on a portion of the second diffusion region and a portion of the second finger electrode; a second patterned insulating layer disposed on a portion of the first diffusion region and a portion of the first finger electrode; a bus electrode disposed in the first patterning The first finger electrode is electrically connected to the first finger electrode and the second bus electrode is disposed on the second patterned insulating layer. Part of the second diffusion Above the region, a portion of the second finger electrode is over the patterned passivation layer, and the second bus electrode is electrically connected to the second finger electrode. The solar cell component of claim 8, wherein the second diffusion region has a plurality of discontinuous regions and a strip region. The solar cell component of claim 9, wherein the first patterned insulating layer is disposed above the strip region of the second diffusion region, and the second bus electrode layer is disposed in the second diffusion region Above the discontinuous areas.