TWI483411B - Solar cell and its module - Google Patents

Description

Solar cell and its module

The invention relates to a battery and a module thereof, in particular to a solar battery and a module thereof.

Referring to FIGS. 1 and 2, a general solar cell mainly includes: a substrate 91 having a front surface 911 and a back surface 912, a positive electrode 92 on the front surface 911, and a plurality of back electric field structures on a portion of the back surface 912. a (Local Back Surface Field, LBSF for short), a passivation layer 94 on the back surface 912, a plurality of linear openings 95 on the passivation layer 94, and a first back electrode 96, and A plurality of second back electrodes 97 are arranged spaced apart from each other and connected to the first back electrode 96. In addition, a general solar cell can also be provided with an anti-reflection layer (not shown) on the front surface 911 to increase the absorption effect of light.

The first back electrode 96 includes a plurality of first conductive portions 961 respectively located in the plurality of linear openings 95 to contact the back surface 912, and a plurality of first conductive portions are disposed on the passivation layer 94 and connected to the plurality of first conductive portions The second conductive portion 962 of 961 is away from one side of the substrate 91. The first back electrode 96 is formed by applying a conductive paste on the passivation layer 94 by screen printing, and a part of the conductive paste flows into the plurality of linear openings 95 to contact. The substrate 91.

The material of the substrate 91 is usually bismuth (Si), and the material of the conductive paste is usually aluminum (Al). During the high-temperature sintering (Firing) process, the conductive paste is solidified to form the first back electrode 96. Where the conductive paste contacts the back surface 912 of the substrate 91, the aluminum of the conductive paste diffuses into the back surface 912, and further mixes with the crucible of the substrate 91 to form the plurality of back electric fields of the aluminum crucible mixture. Structure 93. At the same time, since the plurality of first conductive portions 961 are formed by fitting the plurality of linear openings 95, the plurality of back electric field structures 93 are also linear.

The carrier concentration of the plurality of back electric field structures 93 is greater than the carrier concentration of the substrate 91, which can help improve carrier collection efficiency and photoelectric conversion efficiency, and the carriers can enter the first back electrode 96 via the respective back electric field structures 93. Finally, the plurality of second back electrodes 97 are outwardly led out.

In general, in order to improve the carrier collection efficiency and the photoelectric conversion efficiency, the contact area between the plurality of first conductive portions 961 and the back surface 912 can be increased to enhance the opportunity for the carrier to derive the substrate 91. The back electric field structure 93 is also increased to enhance the back electric field effect. However, since the passivation layer 94 is used for repairing and reducing the surface defects at the back surface 912 of the substrate 91, the surface recombination Velocity (SRV) of the carrier at the back surface 912 is lowered to improve the photoelectric conversion efficiency. If the contact area between the plurality of first conductive portions 961 and the back surface 912 is increased, it is necessary to increase the ratio of the area of the plurality of linear openings 95 to the back surface 912 of the passivation layer 94. However, the passivation layer is lowered because the area ratio of the passivation layer 94 is reduced. Passivation quality and open circuit voltage of 94.

Therefore, how to balance the ratio of the area between the plurality of linear openings 95 and the passivation layer 94 to improve the carrier collection efficiency and photoelectric conversion efficiency of the battery is an important issue.

Therefore, the object of the present invention is to provide a solar cell and a module thereof which can improve carrier collection ability and photoelectric conversion efficiency, and can increase open circuit voltage and reduce series resistance.

Thus, the solar cell of the present invention comprises: a substrate, an emitter layer, a passivation layer, a plurality of annular openings, a first electrode, and a plurality of second electrodes.

The substrate includes a light-receiving front side and a back side opposite the front side. The emitter layer is disposed at the front surface, and the passivation layer is disposed at the back surface. The plurality of annular openings are respectively disposed on the passivation layer, and each of the annular openings includes a plurality of concave segments connected to each other, and any two of the plurality of annular openings are connected The concave segments are not perpendicular to each other. The first electrode is disposed on the emitter layer, and each of the second electrodes is located in the inner concave portion of each annular opening and contacts the back surface of the substrate.

Another solar cell of the present invention comprises: a substrate, an emitter layer, a passivation layer, a plurality of annular openings, a first electrode, and a plurality of second electrodes.

The substrate includes a light-receiving front side and a back side opposite the front side. The emitter layer is disposed at the front surface, and the passivation layer is disposed at the back surface. The plurality of annular openings are respectively along a first direction and a second side Arranging on the passivation layer, each annular opening includes two first concave segments respectively extending along the first direction and spaced apart from each other in the second direction, and two respectively along the second direction Second recessed sections extending and spaced apart from one another in the first direction. Each of the first concave segments and each of the second concave segments of each annular opening are connected to each other, and at least two adjacent rings of the plurality of annular openings in the first direction Openings, each of the first recessed sections being located on different straight lines extending along the first direction. The first electrode is disposed on the emitter layer, and each of the second electrodes is located in the two first recessed segments of each annular opening and the two second recessed segments and contacts the back of the substrate .

A solar cell of the present invention comprises: a substrate, an emitter layer, a passivation layer, a first opening, a second opening, a plurality of third openings, a first electrode, and a plurality of Two electrodes.

The substrate includes a light-receiving front side and a back side opposite the front side. The emitter layer is disposed at the front surface, and the passivation layer is disposed at the back surface. The first opening is disposed in the first direction and is disposed on the passivation layer, and the second opening is disposed in the second direction to the passivation layer, and the second opening intersects the first opening The passivation layer is separated into several regions. The plurality of third openings are spaced apart from each other and disposed on at least one of the plurality of regions of the passivation layer, and each of the third openings is not connected to the first opening and the second opening, or Each of the third openings connects only one of the first opening and the second opening. The first electrode is disposed on the emitter layer, and the plurality of second electrodes are located in the first opening, the second opening and the plurality of third openings and contact the back surface of the substrate.

A solar cell of the present invention comprises: a substrate, an emitter layer, a passivation layer, a first opening, a second opening, a plurality of third openings, a first electrode, and a plurality of Two electrodes.

The substrate includes a light-receiving front side and a back side opposite the front side. The emitter layer is disposed at the front surface, and the passivation layer is disposed at the back surface. The first opening is disposed in the first direction and is disposed on the passivation layer, the second opening is disposed in the second direction and disposed on the passivation layer, and the second opening intersects the first opening Dividing the passivation layer into a plurality of regions, wherein the plurality of third openings are spaced apart from each other and disposed on at least one of the plurality of regions of the passivation layer, and each of the third openings is simultaneously connected to the first region Opening the second opening. The first electrode is disposed on the emitter layer, and the plurality of second electrodes are located in the first opening, the second opening and the plurality of third openings and contact the back surface of the substrate.

A further solar cell of the present invention comprises: a substrate, an emitter layer, a passivation layer, a plurality of openings, a first electrode, and a plurality of second electrodes.

The substrate includes a light-receiving front side and a back side opposite the front side. The emitter layer is disposed at the front surface, and the passivation layer is disposed at the back surface. The plurality of openings are spaced apart from each other and disposed on the passivation layer, each of the openings includes a first concave section extending along a first direction, and a second concave section extending along a second direction, the number The first concave section of at least one of the openings is connected to the second concave section. The first electrode is disposed on the emitter layer, and each of the second electrodes is located in each of the openings and contacts the back surface of the substrate, wherein the substrate is a (100) crystal plane of the germanium substrate, and the first direction Is [001] parallel to the substrate or Direction, and the second direction is parallel to the substrate [010] or The direction.

The solar cell module of the present invention comprises: a first plate and a second plate spaced apart from each other, at least one solar cell disposed between the first plate and the second plate, and any one of the foregoing, and a The first plate and the second plate are in contact with the packaging material of the solar cell.

The effect of the present invention is that the plurality of openings have different along at least two conditions without increasing the ratio of the plurality of openings disposed on the passivation layer relative to the area of the passivation layer projected on the back surface. The direction extending and arranging structure enables the plurality of second electrodes located in the plurality of openings to be evenly and appropriately distributed to contact the back surface, thereby improving the carrier collection capability without reducing the area ratio of the passivation layer. The passivation layer can maintain a better quality, so that the open circuit voltage and the photoelectric conversion efficiency can be improved, and the series resistance can be lowered.

11‧‧‧ first plate

12‧‧‧Second plate

13‧‧‧Solar battery

14‧‧‧Package

21‧‧‧Substrate

211‧‧‧ first side

212‧‧‧Second side

213‧‧‧first diagonal

214‧‧‧second diagonal

22‧‧‧ positive

23‧‧‧Back

24‧‧ ‧ emitter layer

25‧‧‧ Passivation layer

250‧‧‧Area

251‧‧‧First area

252‧‧‧Second area

253‧‧‧ Third Area

254‧‧‧ fourth area

31‧‧‧Ring opening

310‧‧‧ concave section

311‧‧‧First concave section

312‧‧‧Second concave section

32‧‧‧Lineted opening

33‧‧‧Auxiliary opening

331‧‧‧Auxiliary concave section

332‧‧‧Connected concave section

34‧‧‧First opening

35‧‧‧Second opening

36‧‧‧ third opening

361‧‧‧First concave section

362‧‧‧Second concave section

363‧‧‧The third concave section

37‧‧‧Opening

371‧‧‧First concave section

372‧‧‧Second concave section

38‧‧‧fourth opening

4‧‧‧ Back electric field structure

51‧‧‧First electrode

52‧‧‧second electrode

53‧‧‧ third electrode

54‧‧‧fourth electrode

55‧‧‧ fifth electrode

81‧‧‧First direction

82‧‧‧second direction

D1~d8‧‧‧distance

Other features and effects of the present invention will be apparent from the following description of the drawings, wherein: FIG. 1 is a schematic view of a rear view of a general solar cell; FIG. 2 is a partial perspective cross-sectional view of the solar cell of FIG. 1; A schematic cross-sectional view of a first preferred embodiment of a solar cell module of the present invention; and FIG. 4 is a schematic rear view of a solar cell of the first preferred embodiment, in which one of the first preferred embodiments is omitted Fourth electrode 5 is a partial cross-sectional view of the solar cell; FIG. 6 is a schematic rear view of a solar cell according to a second preferred embodiment of the solar cell module of the present invention, and the second preferred embodiment is omitted FIG. 7 is a schematic rear view of a solar cell according to a third preferred embodiment of the solar cell module of the present invention, in which a fourth electrode of the third preferred embodiment is omitted; FIG. 8 is the solar cell FIG. 9 is a schematic rear view of a solar cell according to a fourth preferred embodiment of the solar cell module of the present invention, in which a fourth electrode of the fourth preferred embodiment is omitted; FIG. 10 is A rear view of a solar cell according to a fifth preferred embodiment of the present invention, in which the fourth electrode of the fifth preferred embodiment is omitted; FIG. 11 is a partial perspective cross-sectional view of the solar cell; Is a rear view of a solar cell according to a sixth preferred embodiment of the solar cell module of the present invention, in which the fourth electrode of the sixth preferred embodiment is omitted; FIG. 13 is the solar energy of the present invention. A rear view of a solar cell of one of the seventh preferred embodiments of the battery module, in which the fourth electrode of the seventh preferred embodiment is omitted; FIG. 14 is a partial perspective cross-sectional view of the solar cell; A schematic diagram of the back side of a solar cell according to an eighth preferred embodiment of the invention, in which the eighth comparison is omitted a fourth electrode of a preferred embodiment; FIG. 16 is a schematic rear view of a solar cell according to a ninth preferred embodiment of the solar cell module of the present invention, in which a fourth electrode of the ninth preferred embodiment is omitted; 17 is a schematic rear view of a solar cell according to a tenth preferred embodiment of the solar cell module of the present invention, in which a fourth electrode of the tenth preferred embodiment is omitted; FIG. 18 is a solar cell module of the present invention. A rear view of a solar cell according to one of the eleventh preferred embodiments, in which a fourth electrode of the eleventh preferred embodiment is omitted; and FIG. 19 is a twelfth preferred solar cell module of the present invention. A rear view of a solar cell of one embodiment, in which a fourth electrode of the twelfth preferred embodiment is omitted; FIG. 20 is a solar cell of a thirteenth preferred embodiment of the solar cell module of the present invention. A rear view of the fourth electrode of the thirteenth preferred embodiment is omitted; and FIG. 21 is a partial perspective cross-sectional view of the solar cell.

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 Figures 3, 4 and 5, a first preferred embodiment of the solar cell module of the present invention comprises: a first plate 11 and a second plate 12 spaced apart from each other, and a plurality of arrays arranged on the first plate a solar cell 13 between the second plate 12 and a first plate 11 and the same The package material 14 between the second sheets 12 and contacting the plurality of solar cells 13. Of course, in practice, the solar cell module may include only one solar cell 13.

In this embodiment, the first plate 11 is also referred to as a back sheet, and the second plate 12 is located on the side where the light is incident, and may be made of a light-transmitting material, such as a glass or plastic material. Special restrictions are required. The plurality of solar cells 13 are electrically connected to each other through a ribbon wire (not shown). The material of the package material 14 is ethylene-vinyl acetate copolymer (EVA) or other related materials that can be used for solar cell module packaging, and is not limited to the examples of the embodiment. Since the structure of the solar cell module is not an improvement of the present invention, it will not be described again, and is also simply illustrated in FIG. In addition, since the structures of the several 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.

The solar cell 13 of the present embodiment includes a substrate 21, an emitter layer 24, a passivation layer 25, a plurality of annular openings 31, a plurality of back electric field structures 4, a first electrode 51, and a plurality of second electrodes 52. A plurality of third electrodes 53, and a plurality of fourth electrodes 54.

The substrate 21 is a p-type wafer substrate 21, and may be a single crystal germanium substrate or a polycrystalline germanium substrate. The substrate 21 includes a light-receiving front surface 22 and a back surface 23 opposite the front surface 22. The emitter layer 24 is disposed within the front surface 22 and forms a pn junction with the substrate 21. An anti-reflection layer, not shown, may be disposed on the emitter layer 24, such as tantalum nitride (SiN _x ), for increasing the incident amount of light and reducing the surface recombination velocity (Surface Recombination Velocity, referred to as SRV). Since the improvement of the present invention is not here, it will not be described in detail.

The passivation layer 25 is disposed on the back surface 23, and the material thereof may be an oxide, a nitride or a combination of the above materials, and may be used for repairing, reducing the surface or internal defects of the substrate 21, thereby reducing the surface recombination rate of the carrier and improving Photoelectric conversion efficiency.

The plurality of annular openings 31 are respectively disposed on the passivation layer 25 and are respectively accommodated by the plurality of second electrodes 52. Hereinafter, for convenience of description, several annular openings 31 are arranged in the mesh in FIG. Mark.

Each annular opening 31 includes a plurality of concave sections 310 connected to each other, and any two adjacent annular openings 31 of the plurality of annular openings 31 share one of the concave sections adjacent to each other 310. In this embodiment, the distance d1 between the two parallel long sides of each of the concave segments 310 is 30 to 100 μm. The sum of the areas projected by the plurality of annular openings 31 on the back surface 23 is 4 to 13% of the area of the back surface 23.

In addition, any two connected concave segments 310 of each annular opening 31 of the present embodiment are not perpendicular to each other, and the four concave segments 310 are connected to each other to form a four-sided annular shape. Of course, in practice, any two adjacent concave segments 310 of the annular opening 31 may not be perpendicular to each other, and similarly, only one concave opening of the annular opening 31 may be used. The shape in which the 310s are connected to each other to form a four-sided ring shape, that is, the shape in which the concave portions 310 of each of the annular openings 31 are connected to each other is not limited to the example of the embodiment.

Further, although this embodiment defines the two The concave sections 310 adjacent to each other adjacent to each other are common to both, but in fact, it may be defined that the two adjacent annular openings 31 are adjacent to each other. The concave segments 310 are connected to each other and are not shared, and the distance d2 between the two parallel sides of each of the concave segments 310 is half of the aforementioned distance d1.

The plurality of back electric field structures 4 are respectively located within the back surface 23 of the substrate 21 corresponding to the plurality of annular openings 31, and are p-type semiconductors formed by an aluminum-bismuth (Al-Si) mixed material, and the carriers thereof The concentration is greater than the carrier concentration of the substrate 21. The electrons of the plurality of back electric field structures 4 block the movement of electrons toward the back surface 23, so that electrons are collected in the emitter layer 24 to improve carrier collection efficiency and photoelectric conversion efficiency.

The first electrode 51 is disposed on the emitter layer 24, and can be formed by applying a conductive paste containing silver to the front surface 22 of the substrate 21 by screen printing or the like, followed by sintering. In fact, the first electrode 51 may include at least one bus electrode, and a plurality of finger electrodes connected to the bus electrode. However, since the structure of the first electrode 51 is not the focus of improvement of the present invention, it will not be described, and its structure is not It is limited to the form disclosed in the embodiment.

Each of the second electrodes 52 is located in the inner concave portion 310 of each annular opening 31 and is connected to the back surface 23. The plurality of third electrodes 53 are located on the passivation layer 25 and connect the plurality of second electrodes 52. The plurality of fourth electrodes 54 are located on the passivation layer 25 and connect the plurality of second electrodes 52 and the plurality of third electrodes 53. Of course, in practice, the solar cell 13 may include only a third electrode 53.

The plurality of second electrodes 52 and the plurality of fourth electrodes 54 are available In the manner of screen printing or the like, a conductive paste containing aluminum (Al) is applied onto the passivation layer 25, and the aluminum-containing conductive paste flows into the plurality of annular openings 31, and is subsequently sintered through high temperature ( The conductive paste is solidified and formed, and the plurality of second electrodes 52 located in the plurality of annular openings 31 and the plurality of fourth electrodes 54 located on the passivation layer 25 are respectively formed. And during the sintering process, the aluminum of the conductive paste can be diffused into the back surface 23 of the substrate 21 through the plurality of annular openings 31, and mixed with the crucible of the substrate 21, thereby forming a material mainly composed of aluminum crucible. The plurality of back electric field structures 4 of the mixture. The plurality of third electrodes 53 are formed by applying a conductive paste containing silver to the passivation layer 25 by screen printing, followed by sintering.

It should be noted that the third electrode 53 of the present embodiment is made of a silver-containing conductive paste that does not penetrate the passivation layer 25, and thus the plurality of third electrodes 53 are located on the passivation layer 25; The plurality of second electrodes 52 located between the plurality of third electrodes 53 and the back surface 23 shown in FIG. 5 may be made of the same material as the plurality of third electrodes 53 and printed on the screen. Before the silver-containing conductive paste of the third electrode 53, the aluminum-containing conductive material that will become the plurality of second electrodes 52 does not exist in the plurality of annular openings 31 corresponding to the plurality of third electrodes 53 After the silver paste conductive paste is screen printed, the silver-containing conductive paste is filled into the plurality of annular openings 31, so the between the plurality of third electrodes 53 and the back surface 23 The plurality of second electrodes 52 of the plurality of annular openings 31 are made of the same material as the plurality of third electrodes 53. Of course, in practice, a penetrating silver-containing conductive paste can also be used according to requirements, and in the sintering process, the transparent conductive paste penetrates the passivation layer 25 to contact the back surface of the substrate 21. 23, thus making the several The third electrode 53 has a structure that penetrates the passivation layer 25 to contact the back surface 23. That is, the plurality of third electrodes 53 are completely in contact with the back surface 23.

Therefore, compared with a general solar cell, a linear opening extending only in a single direction is formed on the passivation layer, and correspondingly forming a linear electrode and a back electric field structure, the present embodiment will have two recessed sections 310. The distance d1 between the parallel sides is shortened, and the plurality of concave segments 310 extending in two different directions are increased, so that the proportion of the area projected by the plurality of annular openings 31 on the back surface 23 is not increased. Alternatively, the plurality of concave segments 310 are uniformly disposed on the passivation layer 25 without reducing the area ratio of the passivation layer 25.

Since the plurality of second electrodes 52 and the plurality of back electric field structures 4 match the shape and distribution position of the plurality of annular openings 31, the plurality of second electrodes located in the plurality of concave segments 310 The 52 can also be uniformly distributed in contact with the back surface 23 to enhance the chance of the carrier being led out of the substrate 21, which contributes to an improved current collecting effect.

Moreover, since the area ratio of the passivation layer 25 is not reduced, the total area of the plurality of second electrodes 52 contacting the back surface 23 is not excessively large, and the etching of the passivation layer 25 by the plurality of second electrodes 52 can be avoided. Destruction enables the passivation layer 25 to maintain a better quality, thereby increasing the open circuit voltage and short circuit current of the battery. At the same time, the plurality of back electric field structures 4 located at the back surface 23 of the substrate 21 corresponding to the positions of the plurality of annular openings 31 can also form an electric field effect close to the whole surface, thereby improving Carrier collection efficiency and photoelectric conversion efficiency.

In summary, the present embodiment transmits through the aforementioned innovative structure. The quality and performance of the passivation layer 25 and the plurality of back electric field structures 4 can be considered to improve the open circuit voltage and the photoelectric conversion efficiency, and reduce the series resistance.

Referring to FIG. 6, 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 plurality of annular openings 31 of the embodiment. The concave sections 310 are connected to each other to form a hexagonal ring shape. For convenience of explanation, several of the annular openings 31 are marked with dots in FIG.

In this embodiment, the distance d1 between the two parallel sides of each of the concave segments 310 is 30 to 100 μm. The sum of the areas of the plurality of annular openings 31 projected on the back surface (not shown) of the substrate 21 is 4 to 13% of the area of the back surface.

Referring to Figures 7 and 8, 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 that the plurality of annular openings of the embodiment The concave sections 310 of the 31 are connected to each other to form a circular ring. Of course, the concave sections 310 of the plurality of annular openings 31 can also be connected to each other to form an elliptical ring shape or other ring shape. Each of the solar cells 13 further includes a plurality of linear openings 32 respectively disposed on the passivation layer 25, and a plurality of fifth electrodes respectively located in the plurality of linear openings 32 and contacting the back surface 23 of the substrate 21. Electrode 55.

The linear openings 32 are all spaced apart along a first direction 81, and each of the linear openings 32 extends longitudinally along a second direction 82 perpendicular to the first direction 81 to communicate the plurality of rings. Opening 31.

The plurality of fourth electrodes 54 are located on the passivation layer 25 to connect the a plurality of second electrodes 52 and the plurality of fifth electrodes 55, and the plurality of second electrodes 52, the plurality of fifth electrodes 55, and the plurality of fourth electrodes 54 are all passed through the screen of the conductive paste containing aluminum Made by printing and sintering operations. The plurality of third electrodes 53 are located on the passivation layer 25 and connect the plurality of second electrodes 52, the plurality of fourth electrodes 54 and the plurality of fifth electrodes 55. The plurality of back electric field structures 4 are respectively located within the back surface 23 of the substrate 21 corresponding to the plurality of annular openings 31 and the plurality of linear openings 32.

In this embodiment, the distance d1 between the inner and outer sides of each of the annular openings 32 is 30 to 100 μm, and the distance d3 between the two parallel long sides of each of the linear openings 32 is 30~100μm.

Referring to FIG. 9, a fourth preferred embodiment of the solar cell module of the present invention is substantially the same as the first preferred embodiment. The difference between the two is that the plurality of annular openings 31 of the embodiment are The inner concave segments 310 are connected to each other to form an octagonal ring shape. For convenience of explanation, several of the annular openings 31 are marked with dots in Fig. 9.

Referring to FIGS. 10 and 11, a fifth 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 that each solar cell 13 of the embodiment further includes A plurality of auxiliary openings 33 respectively disposed on the passivation layer 25 and surrounded by the plurality of annular openings 31, and a plurality of back holes respectively located in the plurality of auxiliary openings 33 and contacting the substrate 21 The fifth electrode 55 of 23. For convenience of explanation, several of the annular openings 31 and a few of the auxiliary openings 33 are marked with dots in FIG.

Each of the auxiliary openings 33 has a ring shape and the same One of the spaced apart auxiliary concave segments 331 of the annular opening 31, and a plurality of connecting concave segments 332 that respectively connect the auxiliary concave segment 331 with the concave portion 310 of the annular opening 31. The plurality of fourth electrodes 54 are located on the passivation layer 25 to connect the plurality of second electrodes 52 and the plurality of fifth electrodes 55, and the plurality of second electrodes 52, the plurality of fifth electrodes 55, and the A plurality of fourth electrodes 54 are formed by screen printing and sintering operations of an aluminum-containing conductive paste. The plurality of third electrodes 53 are located on the passivation layer 25 and connect the plurality of second electrodes 52, the plurality of fourth electrodes 54 and the plurality of fifth electrodes 55. The plurality of back electric field structures 4 are respectively located within the back surface 23 of the substrate 21 corresponding to the plurality of annular openings 31 and the plurality of auxiliary openings 33.

In this embodiment, the distance d4 between the inner and outer sides of each auxiliary concave segment 331 is 30-100 μm, and the distance d5 between the two parallel sides of each connecting concave portion 332 is 30-100 μm. .

Referring to FIG. 12, a sixth preferred embodiment of the solar cell module of the present invention is substantially the same as the first preferred embodiment. The difference between the two is that the annular opening 31 of the embodiment is respectively along the first A direction 81 and a second direction 82 are arranged in an array on the passivation layer 25, wherein the first direction 81 is perpendicular to the second direction 82. For convenience of explanation, several of the annular openings 31 are marked with dots in FIG.

Each annular opening 31 includes two first concave sections 311 extending along the first direction 81 and spaced apart from each other along the second direction 82, and two extending along the second direction 82 and along each other The first direction 81 is spaced apart by a second concave section 312. Each of the first concave segments 311 of each annular opening 31 is perpendicular to each of the second concave segments 312 and is connected to each other A rectangular shape. At least two adjacent annular openings 31 of the plurality of annular openings 31 in the first direction 81, each of the first concave segments 311 are located along the first direction 81 On different lines. Each of the second electrodes 52 is located in the two first recessed sections 311 of each of the annular openings 31 and the two second recessed sections 312 and contacts the back surface of the substrate 21 (not shown).

In this embodiment, the distance d6 between each of the first concave segments 311 and the two parallel sides of each of the second concave segments 312 is 30 to 100 μm. The sum of the area of the plurality of annular openings 31 projected on the back surface accounts for 4 to 13% of the area of the back surface.

Referring to Figures 13 and 14, a seventh preferred embodiment of the solar cell module of the present invention is substantially the same as the first preferred embodiment. The difference between the two is that the solar cell 13 of the present embodiment includes a substrate 21. An emitter layer 24, a passivation layer 25, a first opening 34, a second opening 35, a plurality of third openings 36, a plurality of back electric field structures 4, a first electrode 51, and a plurality of Two electrodes 52, a plurality of third electrodes 53, and a plurality of fourth electrodes 54.

The substrate 21 further includes two first side edges 211 extending along a first direction 81 and spaced apart along a second direction 82 perpendicular to the first direction 81, and two extending along the second direction 82, respectively. And a second side 212 disposed along the first direction 81.

The first opening 34 is disposed in the passivation layer 25 along the first direction 81, and the second opening 35 is disposed in the passivation layer 25 along the second direction 82, and the second opening 35 The passivation layer 25 is separated from the first opening 34 to separate the plurality of regions 250.

The plurality of third openings 36 are spaced apart from each other in the plurality of regions 250 of the passivation layer 25, and one end of each of the third openings 36 is connected only to the first opening 34 and the second opening 35. One of them. In practice, the plurality of third openings 36 may also be disposed only on one of the plurality of regions 250 of the passivation layer 25.

The plurality of back electric field structures 4 are respectively located within the back surface 23 of the substrate 21 corresponding to the first opening 34, the second opening 35 and the plurality of third openings 36. The plurality of second electrodes 52 are disposed on the passivation layer 25, and respectively pass through the first opening 34, the second opening 35, and the plurality of third openings 36 to contact the back surface 23 of the substrate 21. The plurality of third electrodes 53 are located on the passivation layer 25 and are connected to the plurality of second electrodes 52. The plurality of fourth electrodes 54 are located on the passivation layer 25 and connect the plurality of second electrodes 52 and the plurality of The third electrode 53.

In this embodiment, the distance d8 between the two parallel long sides of the first opening 34, the second opening 35 and the plurality of third openings 36 is 30-100 μm. The total area of the first opening 34, the second opening 35, and the plurality of third openings 36 projected on the back surface 23 is 4 to 13% of the area of the back surface 23.

Referring to FIG. 15, an eighth preferred embodiment of the solar cell module of the present invention is substantially the same as the seventh preferred embodiment. The difference between the two is that the third openings 36 of the embodiment are not Connecting the first opening 34 and the second opening 35, and each of the third openings 36 has a first concave section 361 extending along the first direction 81, and a second along the second The direction 82 extends longitudinally and connects the second concave section 362 of the first concave section 361.

In this embodiment, the distance d8 between the first opening 34, the second opening 35, each of the first concave segments 361 and the two parallel long sides of each of the second concave segments 362 are 30~100μm.

In addition, the number of the third electrodes 53 of the embodiment is two, the two third electrodes 53 intersect each other to form an X shape, and the connection is located at the first opening 34, the second opening 35, and the plurality of The plurality of second electrodes 52 in the third opening 36.

Referring to FIG. 16, a ninth preferred embodiment of the solar cell module of the present invention is substantially the same as the seventh preferred embodiment. The difference between the two is that each third opening 36 of the embodiment is simultaneously connected. The first opening 34 and the second opening 35, and each of the third openings 36 has a first concave section 361 extending in the first direction 81 and connecting the second opening 35 a second concave section 362 extending along the second direction 82 and connected to the first opening 34, and a connection between the first concave section 361 and the second concave section 362 The third concave section 363.

In this embodiment, the first opening 34, the second opening 35, each of the first concave sections 361, each of the second concave sections 362 and the two parallel sections 363 are parallel to each other. The distance d8 between the sides is 30 to 100 μm.

Referring to FIG. 17, a tenth preferred embodiment of the solar cell module of the present invention is substantially the same as the seventh preferred embodiment. The difference between the two is that the substrate 21 of the embodiment is a (100) crystal plane. The substrate is further comprised, and further includes a first diagonal 213 parallel to a first direction 81 and a second diagonal 214 parallel to a second direction 82. Wherein the first direction 81 is parallel to the substrate 21 [001] or Direction, and the second direction 82 is parallel to the substrate 21 [010] or The direction.

The first opening 34 is disposed in the passivation layer 25 along the first direction 81 , and the second opening 35 is disposed in the passivation layer 25 along the second direction 82 . The second opening 35 intersects the first opening 34, thereby separating the passivation layer 25 into a plurality of regions, wherein the plurality of regions are a first region 251, a second region 252, and a third region 253. And a fourth region 254.

The plurality of third openings 36 are spaced apart from each other on the passivation layer 25, and the plurality of third openings 36 located in the first region 251 and the third region 253 extend along the second direction 82. The first opening 34 is connected, and the plurality of third openings 36 located in the second region 252 and the fourth region 254 extend along the first direction 81 to connect the second opening 35.

It should be noted that the substrate 21 is a (100) crystal plane germanium substrate, in [001] and Direction (ie the first direction 81), and [010] and The direction (ie, the second direction 82) has the highest carrier mobility (Carrier Mobility), and the first opening 34, the second opening 35, and the plurality of third openings 36 are respectively in this embodiment. Arranged along the foregoing direction, the plurality of second electrodes 52 and the plurality of back electric field structures (not shown) are also configured to be arranged along the aforementioned directions.

Therefore, although the embodiment does not change the path length (Travelling Length) of the carrier to the electrode, the foregoing innovative structural design can improve the carrier mobility, thereby increasing the carrier collection efficiency and the open circuit power. Press and lower the series resistance.

Referring to FIG. 18, an eleventh preferred embodiment of the solar cell module of the present invention is substantially the same as the tenth preferred embodiment. The difference between the two is that each of the third openings 36 of the embodiment is The first opening 34 and the second opening 35 are not connected, and each of the third openings 36 has a first concave section 361 extending along the first direction 81, and a first along the first The second direction 82 extends longitudinally and connects the second concave section 362 of the first concave section 361.

In addition, the number of the third electrodes 53 of the embodiment is two, and the two third electrodes 53 intersect each other to form a cross shape, and the connection is located at the first opening 34, the second opening 35, and the plurality of The plurality of second electrodes 52 in the third opening 36.

Referring to Fig. 19, a twelfth preferred embodiment of the solar cell module of the present invention is substantially the same as the tenth preferred embodiment. The following mainly describes the differences between the two. In FIG. 19, the first opening 34 and the second opening 35 are marked with dots. The plurality of third openings 36 of the embodiment are respectively disposed on the passivation layer 25 and are only connected to the second openings 35 and extend along the first direction 81 and are spaced apart along the second direction 82 respectively. The solar cell 13 further includes a plurality of fourth openings 38 respectively disposed on the passivation layer 25 and connected only to the first opening 34. The plurality of fourth openings 38 extend in the second direction 82 respectively. And spaced along the first direction 81.

The plurality of second electrodes 52 are disposed on the passivation layer 25 and pass through the first opening 34, the second opening 35, the plurality of third openings 36, and the plurality of fourth openings 38, respectively. And contacting the back surface of the substrate 21 (not shown) Show). In this embodiment, the distance d8 between the first parallel opening 34, the second opening 35, each of the third opening 36 and the two parallel long sides of each of the fourth openings 38 is 30~ 100 μm. The total area of the first opening 34, the second opening 35, the plurality of third openings 36, and the plurality of fourth openings 38 projected on the back surface is 4 to 13% of the area of the back surface.

Referring to Figures 20 and 21, a thirteenth preferred embodiment of the solar cell module of the present invention is substantially the same as the tenth preferred embodiment. The difference between the two is that the solar cell 13 of the present embodiment comprises a substrate. 21, an emitter layer 24, a passivation layer 25, a plurality of openings 37, a plurality of back electric field structures 4, a first electrode 51, a plurality of second electrodes 52, a plurality of third electrodes 53, and a plurality of Four electrodes 54.

The plurality of openings 37 are spaced apart from each other and disposed on the passivation layer 25. Each of the openings 37 includes a first concave section 371 extending along the first direction 81 and a second extending along the second direction 82. The concave portion 372, the first concave portion 371 of the at least one of the plurality of openings 37 is connected to the second concave portion 372.

The second electrode 52 is disposed on the passivation layer 25 and contacts the back surface 23 of the substrate 21 through the plurality of openings 37. The number of the third electrodes 53 is three, and is located on the passivation layer 25 and connects the plurality of second electrodes 52. The plurality of fourth electrodes 54 are located on the passivation layer 25 and connect the plurality of second electrodes 52 and the plurality of third electrodes 53.

In this embodiment, the distance d8 between the two parallel long sides of each of the first concave section 371 and each of the second concave sections 372 is 30-100 μm. The sum of the areas of the plurality of openings 37 projected on the back surface 23 The area of the back surface 23 is 4 to 13%.

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

21‧‧‧Substrate

25‧‧‧ Passivation layer

31‧‧‧Ring opening

310‧‧‧ concave section

52‧‧‧second electrode

53‧‧‧ third electrode

D1, d2‧‧‧ distance

Claims (12)

A solar cell comprising: a substrate comprising a light-receiving front surface and a back surface opposite to the front surface; an emitter layer disposed at the front surface; a passivation layer disposed at the back surface; and a plurality of annular openings And a hole, each of the plurality of annular openings Not perpendicular; a first electrode disposed on the emitter layer; and a plurality of second electrodes, each of the second electrodes being located in the recessed portion of each of the annular openings and contacting the back surface of the substrate. The solar cell of claim 1, wherein any two adjacent annular openings of the plurality of annular openings share one of the concave segments adjacent to each other. The solar cell according to claim 1, wherein the plurality of concave segments of at least one of the plurality of annular openings are connected to each other to form a polygonal ring shape, a circular ring shape or an elliptical ring shape. A solar cell comprising: a substrate comprising a light-receiving front surface and a back surface opposite to the front surface; an emitter layer disposed at the front surface; a passivation layer disposed at the back surface; and a plurality of annular openings Holes are respectively arranged along a first direction and a second direction Arranging on the passivation layer, each annular opening includes two first concave segments respectively extending along the first direction and spaced apart from each other in the second direction, and two extending respectively along the second direction And the second concave segments spaced apart from each other in the first direction, each of the first concave segments and each of the second concave segments of each annular opening are connected to each other, and in the first direction At least two adjacent annular openings of the plurality of annular openings, each of the first concave segments being located on different straight lines extending along the first direction; a first electrode disposed at the And a plurality of second electrodes, each of the second electrodes being located in the two first concave segments of each annular opening and the two second concave segments and contacting the back surface of the substrate . The solar cell of claim 4, wherein each of the first concave segments of each annular opening is perpendicular to each of the second concave segments. The solar cell according to claim 5, wherein the total area of the plurality of annular openings projected on the back surface accounts for 4 to 13% of the area of the back surface. A solar cell comprising: a substrate comprising a light-receiving front surface and a back surface opposite to the front surface; an emitter layer disposed at the front surface; a passivation layer disposed at the back surface; a first opening And extending in a first direction to the passivation layer; a second opening extending along the second direction to the passivation layer And the second opening intersects the first opening to separate the passivation layer into a plurality of regions; and the plurality of third openings are disposed at least one of the plurality of regions of the passivation layer spaced apart from each other And the third opening is not connected to the first opening and the second opening, or each of the third opening is only connected to one of the first opening and the second opening; The first electrode is disposed on the emitter layer; and the plurality of second electrodes are located in the first opening, the second opening and the plurality of third openings and are in contact with the back surface of the substrate. The solar cell of claim 7, further comprising two third electrodes on the passivation layer, the two third electrodes intersecting each other and connecting the plurality of second electrodes. The solar cell of claim 7 or 8, wherein the substrate further comprises a first diagonal line parallel to the first direction, and a second diagonal line parallel to the second direction, and the substrate is ( 100) a germanium substrate of the crystal face, and the first direction is parallel to the substrate [001] or Direction, and the second direction is parallel to the substrate [010] or The direction. A solar cell comprising: a substrate comprising a light-receiving front surface and a back surface opposite to the front surface; an emitter layer disposed at the front surface; a passivation layer disposed at the back surface; a first opening And extending in a first direction to the passivation layer; a second opening extending along the second direction to the passivation layer, and the second opening intersecting the first opening to separate the passivation layer into a plurality of regions; and the plurality of third openings Arranging at least one of the plurality of regions of the passivation layer, and each of the third openings simultaneously connects the first opening and the second opening; a first electrode disposed on the first opening And a plurality of second electrodes located in the first opening, the second opening and the plurality of third openings and contacting the back surface of the substrate. A solar cell comprising: a substrate comprising a light-receiving front surface and a back surface opposite to the front surface; an emitter layer disposed at the front surface; a passivation layer disposed at the back surface; and a plurality of openings Intersected from each other and disposed in the passivation layer, each opening includes a first concave section extending along a first direction, and a second concave section extending along a second direction, the plurality of openings The first concave section of the at least one opening is connected to the second concave section; a first electrode is disposed on the emitter layer; and a plurality of second electrodes, each second electrode is located in each opening And contacting the back surface of the substrate; wherein the substrate is a (100) crystal plane of the germanium substrate, and the first direction is parallel to the substrate [001] or Direction, and the second direction is parallel to the substrate [010] or The direction. A solar cell module comprising: a first plate and a second plate spaced apart; at least one solar cell according to any one of claims 1, 4, 7, 10, 11 disposed at the first Between the sheet and the second sheet; and a packaging material between the first sheet and the second sheet and contacting the solar cell.