TWI476940B - Solar cell and solar cell module - Google Patents

Description

Solar cell and solar cell module

The present invention relates to a photoelectric conversion device, and more particularly to a solar cell.

Since the interdigitated back contact solar cell (IBC) has high battery efficiency, it has become a trend in the development of solar cells. Please refer to FIG. 1 , which is a partial cross-sectional view showing a solar cell with a fork-shaped back contact. The solar cell 100 with the interdigitated back contact mainly comprises an N-type substrate 102, an N ⁺ -type conductive layer 108, an anti-reflection layer 110, an N ⁺⁺ -type doped layer 114, a P ⁺ -type doped layer 116 , a passivation layer 118 , N The type electrode 120 and the P type electrode 122.

In the solar cell 100, the opposite sides of the N-type substrate 102 have a light receiving surface 104 and a back surface 106, respectively. A rough structure 112 is provided on the light receiving surface 104 to increase the amount of light incident. The N ⁺ -type conductive layer 108 is entirely provided on the light-receiving surface 104 as a front surface electric field (FSF) layer of the solar cell 100. The anti-reflective layer 110 is overlaid on the N ⁺ -type conductive layer 108 to avoid reflection of incident light. The N ⁺⁺ type doped layer 114 and the P ⁺ -type doped layer 116 are respectively disposed in a partial region of the back surface 106 of the N-type substrate 102, and are separated from each other and have an elongated spacer shape. A passivation layer 118 overlies the back side 106. The passivation layer 118 has a plurality of openings 128 and 130 exposing portions of the N ⁺⁺ type doped layer 114 and a portion of the P ⁺ -type doped layer 116, respectively. The N-type electrode 120 and the P-type electrode 122 are disposed on the passivation layer 118 and are respectively in contact with the N ⁺⁺ -type doped layer 114 and the P ⁺ -type doped layer 116 via the openings 128 and 130 of the passivation layer 118, respectively.

In this solar cell 100, since the N ⁺⁺ -type doping layer 114 and the P ⁺ -type doping layer 116 are both disposed in the back surface 106 of the N-type substrate 102, and are in close proximity to each other. Moreover, since the N ⁺⁺ -type doped layer 114 and the P ⁺ -type doped layer 116 are doped regions, in order to enable the N ⁺⁺ -type doped layer 114 and the P ⁺ -type doped layer 116 to be more effectively separated, a technique A bi-level structure 124 is formed on the back side 106 of the N-type substrate 102 between any two adjacent N ⁺⁺ -type doped layers 114 and P ⁺ -type doped layers 116.

Since the solar cell 100 has an electrode structure of a finger-shaped back contact, that is, the N-type electrode 120 and the P-type electrode 122 are arranged in a fork-like arrangement, N ^{++ which is in} contact with the N-type electrode 120 and the P-type electrode 122, respectively. The doped layer 114 and the P ⁺ doped layer 116 are also generally arranged in the shape of a finger. Thus, these double-order structures 124 between the N ⁺⁺ -type doped layer 114 and the P ⁺ -type doped layer 116 are all extended in the same direction. However, if the thickness of the N-type substrate 102 is relatively thin (for example, about 200 um, or even less), or if the trench 126 excavated in the back surface 106 of the N-type substrate 102 where the double-order structure 124 is formed is too deep, the trench The structure of the bottom side of the 126 is relatively weak, and the N-type substrate 102 is easily broken along the side of the bottom surface of the trench 126, resulting in poor process yield.

In addition, the finger portions of the N-type electrode 120 and the P-type electrode 122 are disposed in parallel with each other, and the openings 128 and 130 are linear linear openings and are respectively disposed at intervals of the N-type electrode 120 and the P-type electrode. In the passivation layer 118 below 122. However, when the carrier is formed at the light-receiving surface 104 of the N-type substrate 102 corresponding to the other-side double-order structure 124, the lead-out path of the carrier here can only have the linear opening 128 on both sides thereof, 130 moves, so that the distance between the N-type electrode 120 and the P-type electrode 122 in which the carrier moves into the openings 128 and 130 is long, which will result in a decrease in the efficiency of carrier collection. Further, the current density of the solar cell 100 cannot be effectively increased, and the problem that the overall battery efficiency cannot be improved is derived.

Therefore, an aspect of the present invention provides a solar cell and a solar cell module in which a plurality of second conductive type layers are arranged in a two-dimensional array and are independently connected to each other in a second conductive type substrate and close to each other. At the back side, the periphery of the second conductive type layer is surrounded by a plurality of first conductive type layers, and is respectively matched with the design corresponding to the first opening and the second opening. Therefore, the moving distance of the carrier can be shortened, thereby effectively increasing the current density of the solar cell and the module, and improving the efficiency of the overall battery.

Another aspect of the present invention provides a solar cell and a solar cell module, wherein the first conductive type layer and the second conductive type layer are arranged in a two-dimensional array and are independently connected to each other in a second conductivity type. The interior of the substrate is adjacent to the back surface and corresponds to the design of the first recessed portion and the second recessed portion which are individually arranged in a two-dimensional array, that is, a non-conventional continuous double-stage structure design. Therefore, the bending or cracking of the substrate caused by the double-stage structure of the conventional solar cell can be avoided, thereby improving the process yield of the solar cell and the module to which it is applied.

According to still another aspect of the present invention, a solar cell and a solar cell module are provided, wherein an opening of the first conductive type layer surrounds an opening of the second conductive type layer. Therefore, the collection efficiency of the carrier from the light receiving surface of the solar cell can be improved, thereby increasing the current density and improving the efficiency of the overall battery.

According to the above object of the present invention, a solar cell is proposed. The solar cell comprises a second conductive type substrate, a plurality of first conductive type layers, a plurality of second conductive type layers, a passivation layer, a plurality of first openings, and a plurality a second opening, a first electrode and a second electrode. The second conductive type substrate includes one light receiving surface and a back surface opposite to each other. The plurality of first conductive type layers are disposed inside the second conductive type substrate and near the back surface. The plurality of second conductive type layers are arranged in a two-dimensional array inside the second conductive type substrate and near the back side. The periphery of each of the second conductive type layers is surrounded by a plurality of first conductive type layers, wherein the plurality of second conductive type layers are independent of each other without being connected. The passivation layer is disposed on the outer side of the second conductive type substrate and covers the back surface. The plurality of first openings are disposed in the passivation layer, wherein the first openings respectively correspond to the plurality of first conductive type layers. A plurality of second openings are disposed in the passivation layer, wherein the second openings respectively correspond to the plurality of second conductivity type layers. The first electrode is disposed on a side of the passivation layer away from the back surface, and is in contact with the plurality of first conductive type layers via the plurality of first openings. The second electrode is disposed on a side of the passivation layer away from the back surface, and is in contact with the plurality of second conductive type layers via the plurality of second openings.

According to an embodiment of the present invention, each of the second conductive type layers is surrounded by the plurality of first conductive type layers in a direction parallel to one of the normal lines of the back surface.

According to another embodiment of the present invention, the periphery of each of the second conductive type layers is completely surrounded by the first conductive type layers.

According to still another embodiment of the present invention, the plurality of first conductivity type layers are directly connected to each other.

According to still another embodiment of the present invention, each of the first conductive type layer and each of the second conductive type layers is respectively provided with an isolation region, and the isolation region completely surrounds each second in a direction parallel to one of the normal lines of the back surface. Conductive layer.

According to still another embodiment of the present invention, the line connecting the plurality of first openings or the plurality of second openings may form a honeycomb shape.

According to still another embodiment of the present invention, the plurality of first conductive type layers are arranged in a two-dimensional array and are not in contact with each other.

According to still another embodiment of the present invention, at least one of the plurality of first openings may extend along the corresponding first conductivity type layer.

According to still another embodiment of the present invention, at least one of the plurality of first openings is formed by a plurality of holes, and the holes are arranged around the surrounding second conductivity type layer.

According to still another embodiment of the present invention, the back surface includes at least one first recessed portion, and at least one of the plurality of first conductive type layers is disposed on an inner side surface of the at least one first recessed portion.

According to still another embodiment of the present invention, the back surface includes at least one second recessed portion, and at least one of the plurality of second conductive type layers is disposed on an inner side surface of the at least one second recessed portion. And the bottom surface of the at least one first inner concave portion is closer to the light receiving surface than the bottom surface of the at least one second inner concave portion.

According to the above object of the present invention, a solar battery module is further proposed. The solar cell module comprises an upper plate, a lower plate, a solar cell as described above, and at least one layer of encapsulating material. The solar cell is disposed between the upper plate and the lower plate. At least one layer of encapsulating material is positioned between the upper and lower plates to bond the solar cells to the upper and lower plates.

Please refer to FIG. 2, which illustrates an embodiment of the present invention. A schematic cross-sectional view of a solar cell module. In the present embodiment, the solar cell module 200 mainly comprises an upper plate 204, a lower plate 206, a solar cell 202, and one or more layers of encapsulating material, such as encapsulating material layers 208 and 210, such as ethylene vinyl acetate copolymerization. Material (EVA) material.

As shown in FIG. 2, in the solar cell module 200, the solar cell 202 is disposed on the lower plate 206 and disposed under the upper plate 204. Therefore, the upper plate 204 is disposed above the lower plate 206, and the solar cell 202 is disposed between the lower plate 206 and the upper plate 204. In addition, the two layers of encapsulation material layers 208 and 210 are disposed between the upper plate 204 and the solar cell 202, and the lower plate 206 and the solar cell 202, respectively. The solar cell 202 can be bonded to the lower plate 206 and the upper plate 204 when the encapsulating material layers 208 and 210 are in the molten state by a high temperature press-fitting procedure.

Please refer to FIG. 3 to FIG. 5 , which are respectively a rear view of a solar cell not provided with an electrode according to an embodiment of the present invention, a partial enlarged cross-sectional view of the solar cell of FIG. 3 , and a solar cell Set a partial rear view of the electrode. In the present embodiment, the solar cell 202 can be a prismatic back-contact solar cell. Therefore, as shown in FIG. 5, the first electrode 232 and the second electrode 238 are in the shape of a fork, and the first electrode 232 and the second electrode 238 are both disposed on the same surface of the second conductive substrate 244.

In an embodiment, as shown in FIGS. 3 to 5, the solar cell 202 can mainly include a second conductive type substrate 244, a plurality of first conductive type layers 216, a plurality of second conductive type layers 218, and a passivation layer. 222. The first electrode 232 and the second electrode 238. One of the first conductivity type and the second conductivity type may be a P type, and the other may be an N type. In a preferred embodiment, the first conductivity type It is a P type, and the second conductivity type is an N type.

Referring to a partial region 230 of the solar cell 202 (as shown in FIG. 3 ) illustrated in FIG. 4 , the second conductive substrate 244 includes a light receiving surface 246 and a back surface 248 . The light receiving surface 246 and the back surface 248 are located on opposite sides of the second conductive substrate 244 . The material of the second conductive type substrate 244 may be, for example, a semiconductor material such as germanium. In one embodiment, the light-receiving surface 246 of the second conductive substrate 244 may be roughened to have a roughness 250 to enhance the absorption efficiency of the solar cell 202 for incident light.

The plurality of first conductive type layers 216 may be disposed at a position inside the second conductive type substrate 244 near the back surface 248. The plurality of second conductive type layers 218 may also be disposed at a position inside the second conductive type substrate 244 near the back surface 248. In an embodiment, as shown in FIG. 3, each of the second conductive type layers 218 is completely surrounded by a first conductive type layer 216. In an exemplary example, the second conductivity type substrate 244 is electrically N-type, and the first conductivity type layer 216 can be a P-type doped layer, such as a boron doped layer. Moreover, the second conductive type layer 218 can be an N-type doped layer, such as a phosphorus doped layer.

In the present embodiment, as shown in FIG. 3, these second conductive type layers 218 may be arranged in a two-dimensional array at a position inside the second conductive type substrate 244 near the back surface 248. In addition, the first conductive type layers 216 may also be arranged in a two-dimensional array at a position inside the second conductive type substrate 244 near the back surface 248 and not in contact with each other, for example, the first conductive type layers 216 are respectively separated from each other. Intervals are separated by 256 zones. Moreover, as shown in FIGS. 3 and 4, each of the second conductive type layers 218 and the first conductive type layer 216 correspondingly surrounding the second conductive type layer 218 may be provided. An isolation region 228 is formed to separate the corresponding second conductive type layer 218 from the first conductive type layer 216.

In an embodiment, the back surface 248 of the second conductive substrate 244 is further recessed with at least one first recess 220. At least one of the first conductive type layers 216 may be disposed on an inner side surface of the at least one first inner recessed portion 220, for example, a bottom surface and a side wall surface of the at least one first inner recessed portion 220. In an embodiment, as shown in FIG. 4, the back surface 248 may be recessed with a plurality of first recesses 220, and all of the first conductive layers 216 may be disposed on the inner sides of the first recesses 220. In this way, each of the second conductive type layers 218 can be completely surrounded by a first conductive type layer 216 in the direction of the normal to the parallel back surface 248.

In the embodiment shown in FIG. 4, the second conductive type layer 218 is disposed at a position inside the second conductive type substrate near the back surface 248, but is not disposed at any recess of the back surface 248. However, please refer to FIG. 6 , which is a partial rear view showing a solar cell in which an electrode has not been disposed in accordance with another embodiment of the present invention. In this embodiment, the structure of the solar cell 202a is substantially the same as that of the solar cell 202 of the above embodiment, and the difference between the two structures is that the back surface 248a of the second conductive type substrate 244a of the solar cell 202a is more recessed. There is at least one second recess 258. At least one of the second conductive type layers 218 may be disposed on an inner side surface of the at least one second inner recessed portion 258, for example, a bottom surface and a side wall surface of the at least one second inner recessed portion 258.

In one embodiment, the back surface 248a of the solar cell 202a may be recessed with a plurality of second recesses 258, and all of the second conductive layers 218 may be disposed on the inner sides of the second recesses 258. Therefore, each number The second conductive layer 218 can also be completely surrounded by a first conductive type layer 216 in the direction of the normal to the parallel back surface 248a. In an exemplary example, when the second conductivity type is N-type, since the movement rate of the hole is slower than that of the electron, the movement time of the hole and the electron to the first conductivity type layer 216 and the second conductivity type layer 218, respectively. The bottom surface of the first inner recessed portion 220 is closer to the light receiving surface 246 than the bottom surface of the second inner recessed portion 258, so that the formed first conductive type layer 216 is closer to the light receiving surface 246 than the second conductive type layer 218. Thereby, the efficiency of the solar cell 202a can be improved.

As shown in FIG. 3, in the solar cell 202, the periphery of each of the second conductive type layers 218 is completely surrounded by a first conductive type layer 216. However, referring to FIG. 7, a partial rear view of a solar cell in which an electrode has not been disposed in accordance with still another embodiment of the present invention is shown. In this embodiment, the structure of the solar cell 202b is substantially the same as that of the solar cell 202 of the above embodiment, and the difference between the two structures is that the solar cell 202b surrounds each of the second conductive type layers 218. A conductive layer 216a can include at least two portions 212 and 214 that are separated from one another.

Referring to Fig. 7, in the solar cell 202b, the first conductive type layer 216a is disposed on the inner side surface of the first inner concave portion 220a of the back surface 248b inside the second conductive type substrate 244a. In addition, the two portions 212 and 214 are separated by the ribs 260 between the two portions 212 and 214 of the first conductive type layer 216a. That is, between the two portions 212 and 214 of each of the first conductive type layers 216a, the ribs 260 are not recessed in the back surface 248b, thereby protruding the two portions 212 provided on the inner side surface of the first inner recess 220a. Between 214 and 214. With such a structural design, the structural strength of the solar cell 202b can be made stronger. The solar cell 202 is large.

Referring again to FIG. 4, in the solar cell 202, the passivation layer 222 is located outside the second conductive type substrate 244 and covers the back surface 248. Moreover, since the first conductive type layer 216 and the second conductive type layer 218 are located inside the second conductive type substrate 244 near the back surface, the passivation layer 222 is viewed from the outside of the back surface 248 of the second conductive type substrate 244. It is like covering the first conductive type layer 216 and the second conductive type layer 218. The passivation layer 222 is provided with a plurality of first openings 224 and a plurality of second openings 226. The first opening 224 and the second opening 226 are disposed in the passivation layer 222 in a two-dimensional array arrangement. In addition, the first openings 224 respectively expose a portion of each of the first conductive type layers 216, and the second openings 226 respectively expose a portion of each of the second conductive type layers 218.

In an embodiment, as shown in FIG. 3, each of the first conductive type layers 216 corresponds to the plurality of first openings 224. The first openings 224 may be arranged along the first conductive type layer 216 , and the first openings 224 may surround the second opening of the second conductive type layer 218 surrounded by the first conductive type layer 216 . Around the hole 226. In another embodiment, as shown in FIG. 7, each of the first conductive type layers 216a also corresponds to the plurality of first openings 224. The first openings 224 may be arranged along portions 212 and 214 of the first conductive type layer 216a, and may be respectively disposed in the second openings of the second conductive type layer 218 surrounded by the first conductive type layer 216a. The two sides of the 226 are peripheral. In another embodiment, only a single first opening 224 may be respectively disposed above portions 212 and 214 of at least one first conductive type layer 216a of the solar cell 202b, and the two first openings 224 may be respectively along Portions 212 and 214 of first conductivity type layer 216a extend, such as L-shaped apertures.

Referring to FIG. 4 and FIG. 5 simultaneously, the first electrode 232 and the second electrode 238 are both disposed on a side of the passivation layer 222 away from the back surface. The first electrode 232 can include a plurality of finger electrodes 236 and one bus electrode 234, wherein one end of each of the finger electrodes 236 is connected to the bus electrode 234. The finger electrodes 236 of the first electrode 232 cover a portion of the passivation layer 222 and are in contact with the first conductive type layer 216 via the first opening 224, thereby electrically connecting with the first conductive type layers 216. These finger electrodes 236 can transfer the current collected from the first conductive type layer 216 to the bus electrode 234 for output.

Similarly, the second electrode 238 may also include a plurality of finger electrodes 242 and one bus electrode 240, wherein one end of each of the finger electrodes 242 is connected to the bus electrode 240. The finger electrodes 242 of the second electrode 238 cover a portion of the passivation layer 222 and are in contact with the second conductive type layer 218 via the second opening 226, thereby forming an electrical connection with the second conductive type layers 218. Similarly, the finger electrodes 242 can transfer the current collected from the second conductivity type layer 218 to the bus electrode 240 for output.

Referring again to FIG. 4, in the present embodiment, the solar cell 202 further includes a second conductive type electric field layer 252. The second conductive type electric field layer 252 is located inside the second conductive type substrate 244 at a position close to the light receiving surface 246. The potential energy provided by the second conductive type electric field layer 252 can drive the holes and electrons formed in the vicinity of the light receiving surface 246 of the second conductive type substrate 244 to the first conductive type layer 216 and the second side of the back surface 248, respectively. The conductive layer 218 moves. In addition, the solar cell 202 can further include an anti-reflective layer 254 according to product requirements. The anti-reflective layer 254 is overlaid on the second conductive type electric field layer 252 to enhance the light incidence of the solar cell 202. rate.

The plurality of first conductive type layers of the present invention may also be designed to be connected to each other. Please refer to FIG. 8 , which is a partial rear view showing a solar cell in which an electrode has not been disposed in accordance with still another embodiment of the present invention. In this embodiment, the structure of the solar cell 202c can be substantially the same as that of the solar cell 202 of the above embodiment. The main difference between the two structures is that the plurality of first conductive type layers 216b of the solar cell 202c are connected to each other. Directly connected. That is, in the solar cell 202c, the single-layer first conductivity type structure can be divided into a plurality of first conductivity type layers 216b directly connected to each other, that is, without any interval therebetween.

In addition, all of the first conductive type layer 216b and the second conductive type layer 218 of the solar cell 202c are coplanar with the isolation region 228a, that is, the positions of the first conductive type layer 216b and the second conductive type layer 218 are not located. Concave on the back side 248c, as shown in Fig. 9. In an embodiment, each of the second conductive type layers 218 may have a circular shape, and the isolation region 228a may have a circular shape. In the passivation layer 222, the periphery of each of the second openings 226 is surrounded by a plurality of first openings 224. The electrode of the back surface 248c of the solar cell 202c can be contacted by the circular second opening 226, the annular isolation region 228a, and the plurality of first openings 224 encircling the design of the corresponding second opening 226. Points have a good spatial position match. Therefore, the collection efficiency of the carrier from the front side of the solar cell 202c can be improved, and the current density of the solar cell 202c can be improved, and the overall battery efficiency can be improved. In addition, such a design can also avoid bending or cracking of the substrate caused by the arrangement of the long double-order structure of the conventional solar cell, thereby improving the process yield of the solar cell and the module to which it is applied.

In an embodiment, the lines connecting the second conductive type layers 218 of the solar cell 202c may form a hexagon. In another embodiment, the wires of the second conductive type layers 218 of the solar cells 202c may form a honeycomb shape. In a preferred embodiment, the first opening 224 and the second opening 226 of the solar cell 202c can be arranged in the closest packing manner to more effectively reduce the moving distance of the carrier and improve the carrier collection efficiency.

Please refer to FIGS. 8 and 9. FIG. 9 is a partial rear elevational view showing the electrode of the solar cell according to still another embodiment of the present invention. The line connecting the plurality of first openings 224 or the plurality of second openings 226 to each other may form a honeycomb shape. Among them, the configuration of the honeycomb shape enables the collection of carriers to achieve the highest efficiency. Of course, if the openings of other embodiments of the present invention are arranged in a honeycomb shape, the same optimum carrier collection efficiency can be produced.

Referring again to FIG. 9, in the solar cell 202c, with the arrangement of the first opening 224 and each of the second openings 226, each of the finger electrodes 236a of the first electrode 232a is curved, and the second electrode 238a The finger electrode 242a has a shape in which a plurality of dumbbells are connected in series.

It can be seen from the above embodiments that one of the advantages of the present invention is that the plurality of second conductive type layers of the solar cell and the solar cell module are arranged in a two-dimensional array and are not connected to each other independently in the second conductive type substrate. The position of the second conductive type layer is surrounded by a plurality of first conductive type layers, and is respectively matched with the design corresponding to the first opening and the second opening. Therefore, the moving distance of the carrier can be shortened, thereby effectively increasing the current density of the solar cell and the module, and improving the overall battery efficiency.

It can be seen from the above embodiments that another advantage of the present invention is that the first conductive type layer and the second conductive type layer of the solar cell and the solar cell module are arranged in a two-dimensional array and are not connected to each other independently. The inside of the two-conductivity type substrate is located close to the back surface, and corresponds to the design of the first inner concave portion and the second inner concave portion which are individually arranged in a two-dimensional array, that is, a non-conventional continuous double-step structural design. Therefore, the bending or cracking of the substrate caused by the double-stage structure of the conventional solar cell can be avoided, thereby improving the process yield of the solar cell and the module to which it is applied.

According to the above embodiments, another advantage of the present invention is that the first opening of the first conductive type layer of the solar cell and the solar cell module surrounds the second opening of the second conductive type layer. Therefore, the collection efficiency of the carrier from the light receiving surface of the solar cell can be improved, thereby increasing the current density and improving the efficiency of the overall battery.

While the present invention has been described above by way of example, it is not intended to be construed as a limitation of the scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

100‧‧‧ solar cells

102‧‧‧N type substrate

104‧‧‧Stained surface

106‧‧‧Back

108‧‧‧N ⁺ type conductive layer

110‧‧‧Anti-reflective layer

112‧‧‧Rough structure

114‧‧‧N ⁺⁺ doped layer

116‧‧‧P ⁺ doped layer

118‧‧‧ Passivation layer

120‧‧‧N type electrode

122‧‧‧P type electrode

124‧‧‧ double-order structure

126‧‧‧ trench

128‧‧‧ openings

130‧‧‧Opening

200‧‧‧Solar battery module

202‧‧‧ solar cells

202a‧‧‧Solar battery

202b‧‧‧Solar battery

202c‧‧‧Solar battery

204‧‧‧Upper board

206‧‧‧ Lower board

208‧‧‧Package material layer

210‧‧‧Package material layer

Section 212‧‧‧

Section 214‧‧‧

216‧‧‧First Conductive Layer

216a‧‧‧First Conductive Layer

216b‧‧‧First Conductive Layer

218‧‧‧Second conductive layer

220‧‧‧First recess

220a‧‧‧First recess

222‧‧‧ Passivation layer

224‧‧‧ first opening

226‧‧‧Second opening

228‧‧‧Isolated Area

228a‧‧‧Isolated Area

230‧‧‧Local area

232‧‧‧first electrode

232a‧‧‧first electrode

234‧‧‧Concurrent electrode

236‧‧‧ finger electrode

236a‧‧‧ finger electrode

238‧‧‧second electrode

238a‧‧‧second electrode

240‧‧‧Concurrent electrode

242‧‧‧ finger electrodes

242a‧‧‧ finger electrode

244‧‧‧Second conductive substrate

244a‧‧‧Second conductive substrate

246‧‧‧Stained surface

248‧‧‧ back

248a‧‧‧Back

248b‧‧‧Back

248c‧‧‧back

250‧‧‧Rough structure

252‧‧‧Second conductive electric field layer

254‧‧‧Anti-reflective layer

256‧‧‧ interval

258‧‧‧Second recess

260‧‧‧ rib

The above and other objects, features, advantages and embodiments of the present invention will become more apparent and understood.

Figure 1 is a partial cross-sectional view showing a solar cell with a forked back contact.

2 is a diagram showing a solar energy according to an embodiment of the present invention. A schematic cross-sectional view of a battery module.

3 is a partial rear elevational view showing a solar cell in which an electrode has not been disposed in accordance with an embodiment of the present invention.

Fig. 4 is a partially enlarged cross-sectional view showing the solar cell of Fig. 3.

Figure 5 is a partial rear elevational view of an electrode of a solar cell in accordance with an embodiment of the present invention.

Figure 6 is a partial rear elevational view showing a solar cell in which an electrode has not been disposed in accordance with another embodiment of the present invention.

Figure 7 is a partial rear elevational view showing a solar cell in which an electrode has not been disposed in accordance with still another embodiment of the present invention.

Figure 8 is a partial rear elevational view showing a solar cell in which an electrode has not been disposed in accordance with still another embodiment of the present invention.

Figure 9 is a partial rear elevational view showing an electrode of a solar cell according to still another embodiment of the present invention.

202‧‧‧ solar cells

216‧‧‧First Conductive Layer

218‧‧‧Second conductive layer

220‧‧‧First recess

222‧‧‧ Passivation layer

224‧‧‧ first opening

226‧‧‧Second opening

228‧‧‧Isolated Area

230‧‧‧Local area

248‧‧‧ back

256‧‧‧ interval

Claims (12)

A solar cell comprising: a second conductive type substrate comprising a light receiving surface opposite to each other and a back surface; a plurality of first conductive type layers disposed at a position inside the second conductive type substrate and adjacent to the back surface; The second conductive type layer is arranged in a two-dimensional array at a position inside the second conductive type substrate and close to the back surface, wherein each of the second conductive type layers is surrounded by the plurality of first conductive type layers The plurality of second conductive type layers are mutually independent and not connected to each other; a passivation layer is disposed on the outer side of the second conductive type substrate and covering the back surface, the passivation layer comprising a plurality of first openings and plural numbers a second opening, wherein the plurality of first openings respectively correspond to the plurality of first conductive type layers, wherein the plurality of second openings respectively correspond to the plurality of second conductive type layers; a first electrode is disposed on The passivation layer is away from the side of the back surface, and is respectively in contact with the plurality of first conductive type layers via the plurality of first openings; and a second electrode is disposed on a side of the passivation layer away from the back surface, And divide Contact with the plurality of second conductivity type through the plurality of second layer apertures. The solar cell according to claim 1, wherein each of the second conductive type layers is surrounded by the plurality of first conductive type layers in a direction parallel to one of the normals of the back surface. The solar cell of claim 1, wherein the periphery of each of the second conductive type layers is completely surrounded by each of the first conductive type layers. The solar cell of claim 3, wherein the plurality of solar cells The conductive layers are directly connected to each other. The solar cell of claim 1, wherein an isolation region is disposed between each of the first conductive type layer and each of the second conductive type layers, and the isolation region is completely surrounded by a direction parallel to a normal of the back surface. Each of the second conductive type layers. The solar cell according to claim 1, wherein the connection between the plurality of first openings or the connection of the plurality of second openings to each other constitutes a honeycomb shape. The solar cell of claim 1, wherein the plurality of first conductivity type layers are arranged in a two-dimensional array and are not in contact with each other. The solar cell of claim 7, wherein at least one of the plurality of first openings extends along the corresponding first conductivity type layer. The solar cell of claim 8, wherein the at least one of the plurality of first openings is composed of a plurality of holes, and the plurality of holes are arranged to surround the surrounded second conductivity type layer around. The solar cell of claim 1, wherein the back surface comprises at least one first recessed portion, and at least one of the plurality of first conductive type layers is disposed on an inner side surface of the at least one first recessed portion. The solar cell of claim 10, wherein the back surface comprises at least one second recessed portion, and at least one of the plurality of second conductive type layers is disposed on an inner side surface of the at least one second recessed portion, The bottom surface of the at least one first recessed portion is closer to the light receiving surface than the bottom surface of the at least one second recessed portion. A solar cell module comprising: an upper plate; a solar cell according to any one of claims 1 to 11, disposed between the upper plate and the lower plate; and at least one layer of encapsulating material between the upper plate and the lower plate, The solar cell is combined with the upper plate and the lower plate.