Solar cell and photovoltaic module

The solar cell includes: a substrate; a tunneling dielectric layer located on the first surface of the substrate; multiple doped conductive layers, where the multiple doped conductive layers are located on a surface of the tunneling dielectric layer away from the substrate, and are disposed at intervals; multiple first electrodes, where the multiple first electrodes are disposed at intervals, extend along a first direction, are arranged on a side of the multiple doped conductive layers away from the substrate, and are electrically connected to the multiple doped conductive layers; at least one conductive transport layer, where the at least one conductive transport layer is located between every two adjacent doped conductive layers in the multiple doped conductive layers, and is in contact with a side surface of the multiple doped conductive layers.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of priority under the Paris Convention to Chinese Patent Application No. 202210940296.X filed on Aug. 5, 2022 and Chinese Patent Application No. 202222078085.8 filed on Aug. 5, 2022, each of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

Embodiments of the present disclosure relate to the field of solar cells, and in particular to a solar cell and a photovoltaic module.

BACKGROUND

A solar cell has desirable photoelectric conversion capability. Generally, a tunneling dielectric layer and a doped conductive layer are prepared on a surface of a substrate to suppress the carrier recombination on the surface of the substrate in the solar cell and enhance the passivation effect on the substrate. The tunneling dielectric layer has better chemical passivation effect, and the doped conductive layer has better field passivation effect. In addition, in order to transport and collect photogenerated carriers generated by the solar cell, electrodes are also prepared on a part of the surface of the substrate.

However, currently, the solar cell has the problem of low photoelectric conversion efficiency.

SUMMARY

Embodiments of the present disclosure provide a solar cell and a photovoltaic module, which are at least beneficial for improving the photoelectric conversion efficiency of the solar cell.

A solar cell is provided according to an embodiment of the present disclosure, the solar cell includes: a substrate; a tunneling dielectric layer disposed over a first surface of the substrate; multiple doped conductive layers arranged at intervals over the tunneling dielectric layer; multiple first electrodes each extending in a first direction, where the multiple first electrodes respectively correspond to the multiple doped conductive layers and are arranged at intervals along a second direction perpendicular to the first direction, and each of the multiple first electrodes is disposed on and electrically connected to a corresponding one of the multiple doped conductive layers; at least one conductive transport layer located between every two adjacent doped conductive layers in the multiple doped conductive layers, and in contact with a side surface of each of the two adjacent doped conductive layers.

In some embodiments, there are multiple conductive transport layers, and the multiple conductive transport layers are disposed at intervals along the first direction.

In some embodiments, the multiple conductive transport layers are disposed in a form of an array, the array includes multiple columns of conductive transport layers disposed at intervals along the first direction, conductive transport layers in each column of the multiple columns of conductive transport layers are disposed at intervals along the second direction, there is at least one first electrode between two adjacent conductive transport layers in a same column of conductive transport layers along the second direction, and the second direction is perpendicular to the first direction.

In some embodiments, there are multiple conductive transport layers between every two adjacent first electrodes.

In some embodiments, a column of the conductive transport layers and an adjacent column of the conductive transport layers in the multiple columns of the conductive transport layers are disposed in a stagger manner along the first direction.

In some embodiments, each of a column of conductive transport layers is in one-to-one correspondence to each of an adjacent column of conductive transport layers, and every two adjacent conductive transport layers corresponding to each other are disposed in the spaced manner along the second direction.

In some embodiments, the solar cell includes: multiple second electrodes disposed at intervals, where the multiple second electrodes extend along the second direction and electrically connected to the multiple first electrodes disposed at intervals along the second direction.

In some embodiments, in a column of the conductive transport layers, there is at least one second electrode between two adjacent conductive transport layers.

In some embodiments, in the column of the conductive transport layers, there are two second electrodes between two adjacent conductive transport layers.

In some embodiments, a column of the conductive transport layers and an adjacent column of the conductive transport layers in the multiple columns of the conductive transport layers are disposed in a stagger manner along the first direction, and two conductive transport layers belong to different columns of the conductive layers and disposed in a stagger manner are located on opposite sides of the second electrode, respectively.

In some embodiments, the substrate includes a peripheral area and a central area, the peripheral area is defined as a periphery of the second electrode located at an outermost side, the central area is defined as an area of the substrate apart from the peripheral area, and a distance between every two adjacent conductive transport layers located in the peripheral area in the first direction is smaller than a distance between every two adjacent conductive transport layers located in the central area in the first direction.

In some embodiments, in each column of the conductive transport layers located in the central area, a distance between every two adjacent conductive transport layers in the first direction is constant.

In some embodiments, in each column of the conductive transport layers located in the central area, the distance between every two adjacent conductive transport layers ranges from 0.01 mm to 20 mm, in each column of the conductive transport layers located in the peripheral area, a distance between every two adjacent conductive transport layers ranges from 0.005 mm to 18 mm.

In some embodiments, the solar cell further includes: a first connecting portion, where the first connecting portion is located between two adjacent conductive transport layers disposed at intervals along the first direction, and is electrically connected to side surfaces of the two adjacent conductive transport layers.

In some embodiments, a top surface of the at least one conductive transport layer is lower than or flush with top surfaces of the multiple doped conductive layers.

In some embodiments, the top surface of the at least one conductive transport layer has a light trapping structure.

In some embodiments, the at least conductive transport layer is made of a same material as the multiple doped conductive layers.

In some embodiments, the multiple doped conductive layers are made of at least one of doped amorphous silicon, doped polysilicon, or doped microcrystalline silicon.

In some embodiments, the solar cell further includes: a first passivation layer, one part of the first passivation layer covers the first surface of the substrate, and the other part of the first passivation layer covers top surfaces of the multiple doped conductive layers and a top surface of the at least one conductive transport layer.

Correspondingly, a photovoltaic module is further provided according to an embodiment of the present disclosure, the photovoltaic module includes at least one cell string, where the at least one cell string is formed by connecting multiple solar cells, each of the multiple solar cells being a solar cell according to any one above; at least one package layer configured to cover a surface of the at least one cell string; at least one cover plate configured to cover a surface of the at least one package layer away from the at least one cell string.

DETAILED DESCRIPTION

It is known from the background technology that the photoelectric conversion efficiency of a solar cells in the prior art is low.

It is found in the analysis that one of the reasons for the low photoelectric conversion efficiency of the solar cell in the prior art is that, at present, in order to prevent light from being absorbed by a doped conductive layer, the doped conductive layer is generally disposed in a metallized area, and the doped conductive layer in a non-metallized area will be thinned or removed. However, this will lead to the lack of lateral transport channels for carriers in a substrate, that is, the carriers in the substrate are more transported to the area covered by the doped conductive layer, while the area without the doped conductive layer lacks the transport of the carriers, so that the filling factor of the solar cell is greatly reduced, resulting in a problem that the overall power generation efficiency of the solar cell is low.

A solar cell is provided according to the embodiments of the present disclosure, in which multiple doped conductive layers are disposed at intervals, so that in response to incident light irradiating an area between two adjacent doped conductive layers, since the area has no doped conductive layers, the incident light in the area will not be absorbed by the multiple doped conductive layers, thereby reducing the parasitic absorption of the incident light by the multiple doped conductive layers and improving the utilization rate of the incident light by the substrate. In addition, the conductive transport layer is arranged between two adjacent doped conductive layers and in contact with the doped conductive layer, so that the majority carriers in the substrate can be transported into the multiple doped conductive layers through the conductive transport layer, so that the lateral transport of the majority carriers in the substrate is improved, the filling factor of the solar cell is improved, so as to improve the transport capability of the majority carriers in the substrate while improving the utilization rate of incident light, thereby generally improving the photoelectric conversion efficiency of the solar cell.

The embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. However, those skilled in the art may appreciate that, in the various embodiments of the present disclosure, numerous technical details are set forth in order to provide the reader with a better understanding of the present disclosure. However, the technical solutions claimed in the present disclosure may be implemented without these technical details and various changes and modifications based on the following embodiments.

FIG.1is a schematic structural view of a top view of a solar cell provided according to an embodiment of the present disclosure.FIG.2is a partial enlarged view of1shown inFIG.1.FIG.3is another partial enlarged view of1shown inFIG.1.FIG.4is a schematic view of carrier transport in the solar cell provided according to an embodiment of the present disclosure.

Referring toFIG.1,FIG.2andFIG.4, a solar cell110includes: a substrate100; a tunneling dielectric layer101disposed over a first surface of the substrate100; multiple doped conductive layers102arranged at intervals over the tunneling dielectric layer101; multiple first electrodes103each extending in a first direction, where the multiple first electrodes103respectively correspond to the multiple doped conductive layers102and are arranged at intervals along a second direction perpendicular to the first direction, and each of the multiple first electrodes103is disposed on and electrically connected to a corresponding one of the multiple doped conductive layers102; at least one conductive transport layer104located between every two adjacent doped conductive layers102in the multiple doped conductive layers102, and in contact with a side surface of each of the two adjacent doped conductive layers102.

The conductive transport layer104is arranged between every two adjacent doped conductive layers102in the multiple doped conductive layers102and in contact with the doped conductive layer102, so that the majority carriers in the substrate100can be transported to the multiple doped conductive layer102through the conductive transport layer104. In this way, the lateral transport of majority carriers in the substrate100is improved, the filling factor of the solar cell110is improved, the utilization rate of incident light is improved, and the transport capability of the majority carriers in the substrate100is improved, thereby improving the overall photoelectric conversion efficiency of solar cell110. For details, referring toFIG.4, which is a schematic view of carrier transport in the solar cell provided according to an embodiment of the present disclosure. With the arrangement of the conductive transport layer104, the carriers in the substrate100can move laterally into a lateral transport layer, and is transported into the multiple doped conductive layers102through the lateral transport layer104, thereby increasing the transport capability of carriers in the substrate100and increasing the carrier concentration in the multiple doped conductive layers102.

In other embodiments, each of the doped conductive layers102includes multiple main body portions10disposed at intervals, and the multiple main body portions10are electrically connected to the first electrode103, that is, the thickness of the doped conductive layer102in the metallized area is relatively thicker, so that the multiple main body portions10can play a role of reducing metal contact recombination. In response to incident light irradiating the area between the adjacent main body portions10, the incident light is not absorbed by the multiple main body portions10, so that the absorption and utilization rate of the incident light by the substrate100can be improved.

In addition, each of the doped conductive layers102further includes a first connecting portion11, the first connecting portion11is located between every two adjacent main body portions10, which forms a lateral transport channel for the carriers, so that the majority carriers in the substrate100can be transported into the main body portion10through the first connecting portion11, thereby improving the lateral transport capability of the carriers in the substrate100in the multiple doped conductive layers102. In addition, since the main body portion10and the first connecting portion11are integrally formed, it is beneficial to reduce the loss of carrier transport at the contact interface between the main body portion10and the first connecting portion11and further improve the carrier transport efficiency.

The substrate100is configured to receive incident light and generate photo-generated carriers. In some embodiments, the substrate100may be embodied as a silicon substrate, and the silicon substrate may be made of at least one of monocrystalline silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon. In other embodiments, the substrate100may also be made of at least one of silicon carbide, organic material, or multicomponent compound, where the multicomponent compound includes perovskite, gallium arsenide, cadmium telluride, copper indium selenide, and the like.

In some embodiments, the substrate100is doped with N-type or P-type doping ions, where the N-type doping ions may be any one of phosphorus (P) element, bismuth (Bi) element, antimony (Sb) element, arsenic (As) element, or other group V elements, the P-type element may be any one of boron (B) element, aluminum (Al) element, gallium (Ga) element, indium (In) element, or other group III elements. For example, in response to the substrate100being P-type substrate100, the substrate100has P-type doping elements. Or, in response to the substrate100being N-type substrate100, the substrate100has N-type doping elements, such as anyone of phosphorus element, bismuth element, antimony element, arsenic element.

In some embodiments, the solar cell110is a tunnel oxide passivated contact (TOPCON) cell, the substrate100further includes a second surface opposite to the first surface, the first surface and the second surface of the substrate100are both configured to receive incident light or reflected light. In some embodiments, the first surface may be a backside surface of the substrate100, and the second surface may be a frontside surface of the substrate100. In other embodiments, the first surface may also be the frontside surface of the substrate100, and the second surface may be the backside surface of the substrate100.

In some embodiments, the first surface of the substrate100may be embodied as a non-pyramid textured surface, such as a stacked step topography, so that the tunneling dielectric layer101on the first surface of the substrate100has high density and uniformity, which causes the tunneling dielectric layer101has a desirable passivation effect on the first surface of the substrate100. The second surface of the substrate100may be embodied as a pyramid textured surface, so that the reflectivity of the second surface of the substrate100to incident light is lower, resulting in a higher absorption and utilization rate of light.

In some embodiments, the tunneling dielectric layer101and the doped conductive layer102are configured to form a passivation contact structure on surfaces of the substrate100, so as to reduce the recombination of carriers in the surfaces of the substrate100, thereby increasing the open circuit voltage and improving the photoelectric conversion efficiency of the solar cell110. Specifically, the tunneling dielectric layer101can reduce the concentration of defect states on the first surface of the substrate100, so that the number of recombination centers on the first surface of the substrate100is reduced, thereby reducing the recombination rate of carriers.

The doped conductive layer102is configured to form a field passivation layer, so that minority carriers escape from the interface, thereby reducing the concentration of minority carriers. Since the carrier recombination rate at the interface of the substrate100is lower, the open circuit voltage of the solar cell110is reduced, the short-circuit current and the filling factor are relatively large, which improves the photoelectric conversion performance of the solar cell110. In some embodiments, the doped conductive layer102and the substrate100have doping elements of the same conductivity type.

In some embodiments, the multiple doped conductive layers102extend along the first direction X, and the multiple doped conductive layers102are disposed at intervals along the second direction Y, where the second direction Y is perpendicular to the first direction X. In some embodiments, the first electrodes103and the doped conductive layers102are in a one-to-one correspondence, that is, one first electrode103is electrically connected to one doped conductive layer102. That is to say, the doped conductive layer102is only provided in the area corresponding to the first electrode103, so that the parasitic light absorption effect of the area without the first electrode103can be reduced, and the utilization rate of light by the substrate100can be improved. In some embodiments, the first electrodes103may be made of at least one of silver, aluminum, copper, tin, gold, lead, or nickel.

In other embodiments, the multiple main body portions10extend along the first direction X, and the multiple main body portions10are disposed at intervals along the second direction Y, where the second direction Y is perpendicular to the first direction X. In some embodiments, the first electrodes103and the main body portions10are in a one-to-one correspondence, that is, one first electrode103is electrically connected to one main body portion10. That is to say, the main body portion10is only provided in the area corresponding to the first electrode103, so that the parasitic light absorption of incident light done by the doped conductive layer102is reduced while improving the contact recombination of the first electrode103. In some embodiments, the first electrodes103may be made of at least one of silver, aluminum, copper, tin, gold, lead, or nickel.

The tunneling dielectric layer101and the multiple doped conductive layers102are stacked. Specifically, in some embodiments, the tunneling dielectric layer101covers the entire first surface of the substrate100, and the multiple doped conductive layers102are disposed at intervals on the top surface of the tunneling dielectric layer101. In other embodiments, the tunneling dielectric layer101is disposed corresponding to the doped conductive layers102, that is, the tunneling dielectric layer101is disposed between the doped conductive layer102and the substrate100, and the tunneling dielectric layer101is also located between the conductive transport layer104and the substrate100, so that a part of the tunneling dielectric layer101reduces the recombination of carriers on the first surface of the substrate100, thereby increasing the concentration of carriers transported to the conductive transport layer104.

In some embodiments, the tunneling dielectric layer101may be made of, but is not limited to, aluminum oxide, silicon oxide, silicon nitride, silicon oxynitride, intrinsic amorphous silicon, intrinsic polysilicon, and other dielectric materials with tunneling function. Specifically, the tunneling dielectric layer101may be formed of a silicon oxide layer including silicon oxide (SiOx). The silicon oxide has desirable passivation properties, and the carriers can easily tunnel through the silicon oxide layer.

In some embodiments, the conductive transport layer104is made of the same material as the doped conductive layer102. By making the conductive transport layer104of the same material as the doped conductive layer102, on the one hand, types of materials in the entire production process can be reduced to facilitate management. on the other hand, the contact between the conductive transport layer104and the doped conductive layer102is desirable, so that the transport of carriers at an interface between the doped conductive layer102and the conductive transport layer104is desirable, thereby reducing transport loss. In addition, the transport rates of carriers in the conductive transport layer104and the doped conductive layer102can be made similar or the same, thereby improving the transport efficiency of carriers from the conductive transport layer104to the doped conductive layer102. It is worth noting that the same material here means that the conductive transport layer104has the same doping ion type and doping ion concentration as those in the doped conductive layer102.

In other embodiments, the main body portion10and the first connecting portion11are integrally formed, on the one hand, the types of materials in the whole production process can be reduced, so as to facilitate management. On the other hand, the first connecting portion11and the main body portion10are made to have the same carrier type and carrier concentration, so that the transport of carriers at an interface between the main body portion10and the first connecting portion11, thereby reducing transport loss. In addition, the transport rate of carriers in the main body portion10and the first connecting portion11can be made the same, thereby improving the transport efficiency of carriers from the first connecting portion11to the main body portion10.

Specifically, in some embodiments, the doped conductive layer102is made of at least one of doped amorphous silicon, doped polysilicon or doped microcrystalline silicon. Correspondingly, the conductive transport layer104may also be made of one of doped amorphous silicon, doped polysilicon or doped microcrystalline silicon material.

It can be understood that, in other embodiments, the conductive transport layer104may also be made of different material from the doped conductive layer102, for example, the conductive transport layer104may be made of one of doped amorphous silicon, doped polysilicon or doped microcrystalline silicon, the doped conductive layer102may be made of another one of doped amorphous silicon, doped polysilicon, or doped microcrystalline silicon.

In some embodiments, in response to the conductive transport layer104being made of different material from the doped conductive layer102, the absorption coefficient of the conductive transport layer104to the incident light can be set to be smaller than the absorption coefficient of the incident light of the conductive transport layer104, so that the absorption capability of the conductive transport layer104for incident light can be reduced while improving the lateral transport capability of carriers, thereby improving the utilization rate of the incident light by the solar cell110.

In some embodiments, since the conductive transport layer104is made of the same material as the doped conductive layer102, the actual process method for preparing the doped conductive layer102and the conductive transport layer104is as follows.

An initial tunneling dielectric layer101and an initial doped conductive layer102are formed on the first surface of the substrate100by a deposition process, where the initial tunneling dielectric layer101covers the entire first surface of the substrate100, and the initial doped conductive layer102covers the entire first surface of the tunneling dielectric layer101.

A patterning process is performed on the top surface of the initial doped conductive layer102to define the shape of the doped conductive layer102disposed at intervals and the shape of the conductive transport layer104.

The patterned initial doped conductive layer102is subjected to an etching process to remove a part of the initial doped conductive layer102to form the doped conductive layers102disposed at intervals and the conductive transport layers104located between adjacent doped conductive layers102.

In some embodiments, a laser process is used to perform laser etching on the initial doped conductive layer102, so that the etching process is relatively simple, and the patterning process for the initial doped conductive layer102may be omitted, which is beneficial to simplify the preparation process.

In some embodiments, in response to the tunneling dielectric layer101being arranged to cover the entire first surface of the substrate100, and the multiple doped conductive layers102being arranged on the top surface of the tunneling dielectric layer101at intervals, in the etching process, only the initial doped conductive layer102is etched, and the initial tunneling dielectric layer101is served as the tunneling dielectric layer101.

In other embodiments, the tunneling dielectric layer101is disposed corresponding to the doped conductive layer102, that is, the tunneling dielectric layer101is disposed between the doped conductive layer102and the substrate100, and the tunneling dielectric layer101is also located between the conductive transport layer104and the substrate100, the initial tunneling dielectric layer101is etched simultaneously during the process of etching the initial doped conductive layer102to form the doped conductive layer102and the conductive transport layer104corresponds to the tunneling dielectric layer101.

In some embodiments, there are multiple conductive transport layers104, and the multiple conductive transport layers104are disposed along the first direction X at intervals. By disposing multiple conductive transport layers104between two adjacent doped conductive layers102, the majority carriers in the substrate100can be transported into the doped conductive layers102through the multiple conductive transport layers104, thereby enhancing the lateral transport capability of majority carriers in the substrate100. In addition, the multiple conductive transport layers104are disposed in a space manner, that is, the multiple conductive transport layers104do not cover all areas between two adjacent doped conductive layers102, but are disposed on a partial area between two adjacent doped conductive layers102. In this way, in response to the conductive transport layer104being made of the same material as the doped conductive layer102, the overall area of the conductive transport layer104will not be excessive, thereby preventing the incident light from being excessively absorbed by the conductive transport layer104, resulting in a low utilization rate of the incident light by the substrate100.

In some embodiments, the multiple conductive transport layers104are disposed in an array, the array includes multiple columns of conductive transport layers104disposed at intervals along the second direction Y, multiple conductive transport layers104in each column of the multiple columns of conductive transport layers104are disposed at intervals along the first direction X, there is at least one first electrode103between two adjacent columns of conductive transport layers104along the second direction Y, and the second direction Y is perpendicular to the first direction X. That is, in some embodiments, in response to only one first electrode103being arranged between adjacent conductive transport layers104, there is at least one conductive transport layer104between every two adjacent first electrodes103. In other embodiments, there may also be multiple first electrodes103between two adjacent columns of conductive transport layers104, so that there is at least one conductive transport layer104between some of the two adjacent first electrodes103, and there is no conductive transport layer104between other adjacent first electrodes. For example, along the first direction X, there is at least one conductive transport layer104between a No. 1 first electrode103and a No. 2 first electrode103, and there is no conductive transport layer104between the No. 2 first electrode103and a No. 3 first electrode103. It can be understood that, in response to the conductive transport layer104being made of the same material as the doped conductive layer102, the greater the number of the conductive transport layer104, the stronger the absorbing capability to incident light while enhancing the lateral capability of carriers. Therefore, connecting relationship between the conductive transport layer104and the doped conductive layer102can be flexibly set based on the total number of the first electrodes103and the demand for the current collecting capability of the first electrodes103, so as to prevent the incident light from being excessively absorbed by the conductive transport layer104while improving the transport capability of carriers.

Referring toFIG.1, in some embodiments, at least one conductive transport layer104is disposed between all adjacent first electrodes103, which improves the lateral transport capability between adjacent first electrodes103, thereby improving the current collecting capability of each first electrode103.

Referring toFIG.2, in some embodiments, the top surface of the conductive transport layer104is lower than or flush with the top surface of the doped conductive layer102. In response to the top surface of the conductive transport layer104being arranged no higher than the top surface of the doped conductive layer102, the top surface of the conductive transport layer104is prevented from extending over the top surface of the doped conductive layer102, so that the side surface of the conductive transport layer104is prevented from absorbing the incident light, thereby reducing the parasitic absorption capability of the conductive transport layer104to incident light. It can be understood that in response to the top surface of the conductive transport layer104being lower than the top surface of the doped conductive layer102, the top surface of the doped conductive layer102will play a certain role of sheltering on the incident light incident obliquely to the top surface of the conductive transport layer104. Therefore, the transport capability of the conductive transport layer104to incident light can be further reduced. In response to the top surface of the conductive transport layer104being flush with the top surface of the doped conductive layer102, the production process of the solar cell110can be simplified, and the conductive transport layer104and the doped conductive layer102can be formed in the same step by laser ablation.

In some embodiments, along the direction perpendicular to the surface of the substrate100, the height of the conductive transport layer104may be 0.5 to 1.2 times the height of the doped conductive layer102, and the specific value may be 0.5, 0.6, 0.7, 0.8, 0.9, 1 or 1.2. Within this range, on the one hand, the thickness of the conductive transport layer104will not be excessively small, so that the lateral transport capability of the conductive transport layer104to carriers will not be too poor. On the other hand, the thickness of the conductive transport layer104is not excessive, so as to prevent the incident light from being excessively absorbed due to excessive thickness of the conductive transport layer104. Referring toFIG.3, in other embodiments, the top surface of the first connecting portion11is lower than or flush with the top surface of the doped conductive layer102. In response to the top surface of the first connecting portion11being lower than the top surface of the doped conductive layer102, the top surface of the doped conductive layer102will block the incident light obliquely incident on the top surface of the first connecting portion11to a certain extent, so that the transport capability of the first connecting portion11to incident light can be further reduced. In response to the top surface of the first connecting portion11being flush with the top surface of the doped conductive layer102, the production process of the solar cell110can be simplified, and the first connecting portion11and the doped conductive layer102can be formed in the same step by laser ablation. In some embodiments, in the direction perpendicular to the surface of the substrate100, the height of the first connecting portion11may be 0.5 to 1.2 times the height of the doped conductive layer102, and the specific value may be 0.5, 0.6, 0.7, 0.8, 0.9, 1 or 1.2.

Referring toFIG.5andFIG.6,FIG.5is a schematic structural view of a top view of another solar cell provided according to an embodiment of the present disclosure, andFIG.6is a schematic structural view of a top view of yet another solar cell provided according to an embodiment of the present disclosure. In some embodiments, a column of conductive transport layers104and an adjacent column of conductive transport layers104are arranged in a stagger manner along the first direction X.

Specifically, in some embodiments, each conductive transport layer104in the first column of conductive transport layers104and each conductive transport layer104in the second column of conductive transport layers104are not aligned in the second direction Y, That is, each conductive transport layer104in the first column of conductive transport layers104and each conductive transport layer104in the second column of conductive transport layers104are staggered in the first direction X. Multiple conductive transport layers104are arranged in a stagger manner, on the one hand, the number of conductive transport layers104is prevented from being excessive, thereby preventing the conductive transport layers104from absorbing more incident light. On the other hand, the conductive transport layers104can be uniformly distributed on the first surface of the substrate100, while the number of the conductive transport layers104is relatively small, so that the lateral transport capability of carriers at different positions in the substrate100can be enhanced.

Referring toFIG.1, in other embodiments, each conductive transport layer104in a column of conductive transport layers104is in one-to-one correspondence with each conductive transport layer104in an adjacent column of conductive transport layers104, and corresponding two conductive transport layers104are arranged at intervals along the second direction Y. For example, each conductive transport layer104in the first column of conductive transport layers104and the corresponding conductive transport layer104in the second column of conductive transport layers104are aligned and arranged in the second direction Y, and each column of conductive transport layers104are aligned and arranged, so that the number of conductive transport layers104is increased, thereby forming more lateral transport channels to laterally transport carriers in the substrate100. In addition, since the conductive transport layers104in each column are aligned and arranged, in the actual process of preparing the conductive transport layers104, the process of forming the conductive transport layers104can be simplified.

Referring toFIG.1,FIG.5andFIG.6, in some embodiments, the solar cell110further includes multiple second electrodes106arranged at intervals, where the multiple second electrodes106extend along the second direction Y, and are electrically connected to the multiple first electrodes arranged at intervals along the second direction Y. The multiple second electrodes106are arranged at intervals along the first direction X, and the multiple second electrodes106are electrically connected to the multiple first electrodes103, so as to collect current in the multiple first electrodes103, and the current is lead out of the solar cell110. It can be understood that the second electrode106is not only in electrical contact with the first electrode103, but also in electrical contact with a part of the doped conductive layer102, so that the carriers in the doped conductive layer102can be directly transported to the multiple second electrodes106without passing through the multiple first electrodes103, thereby improving the capability of the second electrode106to collect current.

In some embodiments, in a column of conductive transport layers104, at least one second electrode106is disposed between two adjacent conductive transport layers104. That is to say, the second electrode106is spaced apart from the conductive transport layer104. In this way, the second electrode106can be position-limited by the conductive transport layer104, so that position of the second electrode106can be determined without performing additional positioning during the process of preparing the second electrode106, which facilitates the printing of the second electrode106and simplifies the process procedure.

Referring toFIG.5toFIG.6, specifically, in some embodiments, in a column of conductive transport layers104, two second electrodes106are disposed between two adjacent conductive transport layers104. That is to say, the conductive transport layers104are sparsely disposed, so that the incident light is prevented from being excessively absorbed by the conductive transport layers104due to excessive quantity of the conductive transport layers104.

It can be understood that since the conductive transport layers104serve as lateral transport channels for carriers, the carrier concentration in the doped conductive layer102adjacent to the conductive transport layers104is relatively high, so that a part of the first electrode103electrically connected to the doped conductive layer102adjacent to the conductive transport layers104has a higher carrier concentration. Based on this, in some embodiments, a column of conductive transport layers104and an adjacent column of conductive transport layers104are disposed in a stagger manner along the first direction X, and two conductive transport layers104belong to different columns of the conductive transport layers104and disposed in a stagger manner are located on opposite sides of the second electrode106, respectively. The conductive transport layers104located on two sides of the second electrode106are not aligned in the first direction X. In this way, in response to the number of the conductive transport layers104being limited, the conductive transport layers104are uniformly distributed on two sides of the second electrode106. The conductive transport layers104are arranged on two sides of the second electrode106, that is, the second electrode106is electrically connected to the part of the first electrode103with higher carrier concentration, so that the collection capability of the second electrode106on current in the first electrode103can be integrally improved. In addition, due to the small number of conductive transport layers104, the incident light is prevented from being excessively absorbed by the conductive transport layers104, thereby improving the overall photoelectric conversion performance of the solar cell110.

It can be understood that, in other embodiments, a projection of a part of the second electrode106on the first surface of the substrate100may also overlap a part of the conductive transport layer104. In this way, the second electrode106can cover a part of the top surface of the conductive transport layer104to partially shield the conductive transport layer104, thereby reducing the parasitic light absorption capability of the conductive transport layer104to incident light, and further improving the photoelectric conversion efficiency of the solar cell110. In some embodiments, the solar cell110further includes a second connecting portion105, the second electrode106is also in direct electrical contact with the second connecting portion105being covered, and the second connecting portion105is configured to be a lateral transport channel between adjacent second electrodes106, so that the carriers in the second connecting portion105and the conductive transport layer104are also directly transported to the second electrode106, which further improves the current collecting capability of the second electrode106.

It can be understood that, in a step of laminating the solar cell110, in order to prevent solar cell pieces from being crushed, the second electrode106is generally disposed far from edges of the solar cell pieces, that is, edges of the substrate100are spaced from the second electrode106, which causes the number of second electrodes106at the edges of the substrate100to be less, so that the second electrode106located at the outermost of the edges has a weaker capability to collect carriers at the edges of the substrate100. Based on this, in some embodiments, the substrate100includes a peripheral area and a central area, the peripheral area is defined as a periphery of the second electrode106located at an outermost side, the central area is defined as an area of the substrate100apart from the peripheral area, and a distance between every two adjacent conductive transport layers104located in the peripheral area in the first direction X is smaller than a distance between every two adjacent conductive transport layers104located in the central area in the first direction X. In this way, the density of the conductive transport layer104on the first surface of the substrate100in the peripheral area is greater than that in the central area, that is, the lateral transport capability of carriers in the substrate100corresponding to the peripheral area is stronger, so that the carrier concentration in the first electrode103in the peripheral area is relatively higher, so as to compensate the number of carriers collected by the outermost second electrode106and improve the current collecting capability of the outermost second electrode106.

In some embodiments, among the conductive transport layers104in each column, there are multiple conductive transport layers104in the peripheral area, and there is one conductive transport layer104or no conductive transport layer104between two adjacent second electrodes106in the central area. That is to say, the conductive transport layer104is sparsely distributed in the central area, thereby reducing the parasitic light absorption capability of the conductive transport layer104to incident light. In the peripheral area, the conductive transport layer104is densely distributed, so as to improve the current collecting capability of the outermost second electrode106, thereby further integrally improving the photoelectric conversion performance of the solar cell110.

Specifically, referring toFIG.5, in some embodiments, among the first column of conductive transport layers104in the peripheral area, the number of the conductive transport layers104on the outermost second electrode106side may be 2, and among the second column of conductive transport layers104in the peripheral area, the number of the conductive transport layers104on the outermost second electrode106side may be 1, and the first column of conductive transport layers104are disposed in a stagger manner with the second column of conductive transport layers104. Only the arrangement of first column and the second column of the conductive transport layers104is shown here, and reference may be made to the first column and the second column for the arrangement of the conductive transport layers104in the remaining third, fourth, fifth and sixth columns.

Referring toFIG.7, in other embodiments, among the first column of conductive transport layers104in the peripheral area, the number of the conductive transport layers104on the outermost second electrode106side may be one, among the second column of conductive transport layers104in the peripheral area, the number of the conductive transport layers104on the outermost second electrode106side may be one, and among the third column of conductive transport layers104in the peripheral area, the number of the conductive transport layers104on the outermost second electrode106side may be one. The adjacent three columns of the conductive transport layers104are disposed in a stagger manner along the first direction X. Only the arrangement of the conductive transport layers104in the first, second and third columns is shown here, and reference may be made to the first column, the second column and the third column of conductive transport layers104for the arrangement of the conductive transport layers104in the remaining columns.

In some embodiments, in each column of the conductive transport layers104located in the central area, a distance between every two adjacent conductive transport layers104in the first direction X is constant. In each column of the conductive transport layers104, the distance between every two adjacent conductive transport layers104is constant, which facilitates the laser ablation process during the formation process, that is, it is not necessary to adjust the distance between every two adjacent conductive transport layers104, thereby facilitating the production. In addition, the distance between every two adjacent conductive transport layers104in the central area are constant, so that the conductive transport layers104in the central area are evenly distributed, thereby uniformly improving the carrier collecting capability of the second electrode106at different positions.

In some embodiments, in each column of the conductive transport layers104located in the central area, the distance between every two adjacent conductive transport layers104ranges from 0.01 mm to 20 mm, for example, the distance may range from 0.01 mm to 0.1 mm, from 0.1 mm to 0.5 mm, from 0.5 mm to 2 mm, from 2 mm to 5 mm, from 5 mm to 10 mm, from 10 mm to 15 mm, or from 15 mm to 20 mm. in each column of the conductive transport layers located in the peripheral area, the distance between every two adjacent conductive transport layers104ranges from 0.005 mm to 18 mm, for example, the distance may range from 0.005 mm to 0.01 mm, from 0.01 mm to 0.1 mm, from 0.1 mm to 0.5 mm, from 0.5 mm to 2 mm, from 2 mm to 5 mm, from 5 mm to 10 mm, from 10 mm to 15 mm, or from 15 mm to 18 mm. Within this range, on the one hand, the distance between adjacent conductive transport layers104is not too small, so as to prevent the conductive transport layers104from absorbing too much incident light due to excessively dense arrangement of the conductive transport layers104; on the other hand, within this range, the distance between every two adjacent conductive transport layers104is not too small, so that more lateral transport channels are formed, which can greatly improve the lateral transport capability of carriers in the substrate100.

Referring toFIG.6,FIG.6is a schematic structural view of a top view of yet another solar cell provided according to an embodiment of the present disclosure. In some embodiments, the solar cell110further includes: a second connecting portion105, the second connecting portion105is located between adjacent conductive transport layers104arranged at intervals along the first direction X, and is electrically connected to side surfaces of the two adjacent conductive transport layers104. It can be understood that the width of the second connecting portion105in the second direction Y is smaller than the distance between two adjacent doped conductive layers102in the second direction Y, that is, a side surface of the second connecting portion105is not in contact with the side surfaces of the two adjacent doped conductive layers102. In this way, in response to incident light irradiating the gap between the doped conductive layer102and the second connecting portion105, the incident light will not be absorbed by the second connecting portion105or the doped conductive layer102. In some embodiments, the second connecting portion105may be made of the same material as the conductive transport layer104, so that the second connecting portion105may also serve as a lateral transport channel for carriers in the substrate100. Specifically, the carriers in the substrate100corresponding to the second connecting portion105can be transported to the second connecting portion105, the carriers in the second connecting portion105are then transported to the conductive transport layer104, and the carriers are transported to the doped conductive layer102through the conductive transport layer104. It is not difficult to find that due to the second connecting portion105, more carriers in the substrate100can be transported to the conductive transport layer104and finally reach the doped conductive layer102, thereby improving the lateral transport capability of the carriers in the substrate100. Therefore, the carrier concentration in the doped conductive layer102is bigger, thereby increasing the current collecting capability of the first electrode103.

Referring toFIG.3andFIG.4, in some other embodiments, the doped conductive layer102further includes: a bottom connecting portion20, and the bottom connecting portion20is located between two adjacent main body portions10and is connected to side surfaces of two adjacent main body portions10. The top surface of the bottom connecting portion20is lower than the top surface of the main body portion10, and the first connecting portion11is located on a part of the top surface of the bottom connecting portion20. That is to say, the thickness of the doped conductive layer102on the surface of the substrate100corresponding to the non-metallized area is thinner than that of the doped conductive layer102on the surface of the substrate100corresponding to the metallized area, so that the parasitic absorption of incident light done by the doped conductive layer102corresponding to the non-metallized area can be reduced. In addition, the bottom connecting portion20located in the non-metallized area is further configured to provide a transport channel for majority carriers between adjacent main body portions10.

It can be seen from the above analysis that for the solution in which the doped conductive layer102only includes the main body portion10, the doped conductive layer102corresponding to the non-metallized area is removed, and for the solution in which the doped conductive layer102further includes the bottom connecting portion20, the doped conductive layer102corresponding to the non-metallized area is thinned, so that the carrier transport capability of the substrate100corresponding to the non-metallized area is relatively weak. Based on this, the first connecting portion11is arranged between the two adjacent main body portions10to provide a lateral transport channel between the two adjacent main body portions10for majority carriers, so that the transport efficiency of carriers in the substrate100and between the doped conductive layers102is increased, thereby improving the filling factor of the solar cell110and the photoelectric conversion efficiency of the solar cell110.

The tunneling dielectric layer101and the main body portions10are stacked. Specifically, in some embodiments, the tunneling dielectric layer101covers the entire first surface of the substrate100, and the multiple main body portions10are disposed at intervals on the top surface of the tunneling dielectric layer101. In other embodiments, the tunneling dielectric layer101is disposed corresponding to the main body portions10, that is, the tunneling dielectric layer101is disposed between the main body portions10and the substrate100, and the tunneling dielectric layer101is also located between the conductive transport layer104and the substrate100, so that a part of the tunneling dielectric layer101reduces the recombination of carriers on the first surface of the substrate100, thereby increasing the concentration of carriers transported to the conductive transport layer104.

The main body portion10and the first connecting portion11are integrally formed, on the one hand, the types of materials in the whole production process can be reduced, so as to facilitate management. On the other hand, the first connecting portion11and the main body portion10are made to have the same carrier type and carrier concentration, so that the transport of carriers at an interface between the main body portion10and the first connecting portion11, thereby reducing transport loss. In addition, the transport rate of carriers in the main body portion10and the first connecting portion11can be made the same, thereby improving the transport efficiency of carriers from the first connecting portion11to the main body portion10.

Referring toFIG.5andFIG.7, in some embodiments, a column of the first connecting portions11and an adjacent column of the first connecting portions11are disposed in a stagger manner along the first direction X. Specifically, in some embodiments, each first connecting portions11in the first column of first connecting portions11and each first connecting portions11in the second column of first connecting portions11are not aligned in the second direction Y, that is each first connecting portions11in the first column of first connecting portions11and each first connecting portions11in the second column of first connecting portions11are arranged in a stagger manner in the first direction X. By arranging multiple first connecting portions11in a stagger manner, on the one hand, the number of first connecting portions11is prevented from being excessive, thereby preventing the first connecting portions11from absorbing too much incident light. On the other hand, the first connecting portions11can be uniformly distributed on the first surface of the substrate100, while the number of the conductive transport layers104is relatively small, so that the lateral transport capability of carriers at different positions in the substrate100can be enhanced.

In some embodiments, each first connecting portion11in a column of first connecting portions11is in one-to-one correspondence with each first connecting portion11in an adjacent column of first connecting portions11, and two corresponding first connecting portions11are arranged at intervals along the second direction Y. That is, each first connecting portion11in the first column of first connecting portions11and the corresponding first connecting portion11in the second column of first connecting portions11are aligned and arranged in the second direction Y, and each column of first connecting portions11are aligned and arranged, so that the number of conductive transport layers104is increased, thereby forming more lateral transport channels to laterally transport carriers in the substrate100. In addition, since the first connecting portions11in each column are aligned and arranged, in the actual process of preparing the first connecting portions11, the process of forming the first connecting portions11can be simplified.

Referring back toFIG.1,FIG.5andFIG.6, in some embodiments, the solar cell110further includes multiple second electrodes106arranged at intervals, where the multiple second electrodes106extend along the second direction Y, and are electrically connected to the multiple first electrodes arranged at intervals along the second direction Y. The multiple second electrodes106are arranged at intervals along the first direction X, and the multiple second electrodes106are electrically connected to the multiple first electrodes103, so as to collect current in the multiple first electrodes103, and the current is lead out of the solar cell110. It can be understood that the second electrode106is not only in electrical contact with the first electrode103, but also in electrical contact with a part of the doped conductive layer102, so that the carriers in the doped conductive layer102can be directly transported to the multiple second electrodes106without passing through the multiple first electrodes103, thereby improving the capability of the second electrode106to collect current.

In some embodiments, the second electrodes106and the first connecting portions11are arranged at intervals, or a projection of the first connecting portion11on the substrate100at least partially overlaps a projection of the second electrode106on the substrate100. By arranging the second electrodes106and the first connecting portions11at intervals, the second electrode106can be position-limited by the first connecting portion11, so that position of the second electrode106can be determined without performing additional positioning during the process of preparing the second electrode106, which facilitates the printing of the second electrode106and simplifies the process flow.

The projection of the first connecting portion11on the substrate100at least partially overlaps the projection of the second electrode106on the substrate100, that is to say, a part of the second electrodes106can cover a part of the top surface of the first connecting portion11to shield a part of the first connecting portion11, so as to reduce the parasitic light absorption capability of the first connecting portion11to incident light, thereby further improving the photoelectric conversion efficiency of the solar cell110. In some embodiments, the second electrode106is also in direct electrical contact with the covered first connecting portion11, since the first connecting portion11and the main body portion10are integrally formed, and the first connecting portion11and the main body portion10are both in electrical contact with the second electrodes106, so that a lateral transport channel is also formed between the adjacent second electrodes106, the carriers in the first connecting portion11can also be directly transported to the second electrodes106, and thereby further improving the current collecting capability of the second electrodes106.

It can be understood that since the first connecting portions11serve as lateral transport channels for carriers, the carrier concentration in the main body portions10adjacent to the first connecting portions11is relatively high, so that a part of the first electrode103electrically connected to the main body portions10adjacent to the first connecting portions11has a higher carrier concentration. Based on this, in some embodiments, a column of first connecting portions11and an adjacent column of first connecting portions11are disposed in a stagger manner along the first direction X, and two first connecting portions11belong to different columns of the first connecting portions11and disposed in a stagger manner are located on opposite sides of the second electrode106, respectively. The first connecting portions11located on two sides of the second electrode106are not aligned in the first direction X. In this way, in response to the number of the first connecting portions11being limited, the first connecting portions11are uniformly distributed on two sides of the second electrode106. The first connecting portions11are arranged on two sides of the second electrode106, that is, the second electrode106is electrically connected to the part of the first electrode103with higher carrier concentration, so that the collection capability of the second electrode106on current in the first electrode103can be integrally improved. In addition, due to the small number of first connecting portions11, the incident light is prevented from being excessively absorbed by the first connecting portions11, thereby improving the overall photoelectric conversion performance of the solar cell110.

It can be understood that, in a step of laminating the solar cell110, in order to prevent solar cell pieces from being crushed, the second electrode106is generally disposed far from edges of the solar cell pieces, that is, edges of the substrate100are spaced from the second electrode106, which causes the number of second electrodes106at the edges of the substrate100to be less, so that the second electrode106located at the outermost of the edges has a weaker capability to collect carriers at the edges of the substrate100. Based on this, in some embodiments, the substrate100includes a peripheral area and a central area, the peripheral area is defined as a periphery of the second electrode106located at an outermost side, the central area is defined as an area of the substrate100apart from the peripheral area, and a distance between every two adjacent first connecting portions11located in the peripheral area in the first direction X is smaller than a distance between every two adjacent first connecting portions11located in the central area in the first direction X. In this way, the density of the first connecting portions11on the first surface of the substrate100in the peripheral area is greater than that in the central area, that is, the lateral transport capability of carriers in the substrate100corresponding to the peripheral area is stronger, so that the carrier concentration in the first electrode103in the peripheral area is relatively higher, so as to compensate the number of carriers collected by the outermost second electrode106and improve the current collecting capability of the outermost second electrode106.

In some embodiments, in the first connecting portions11of each column, the number of the first connecting portions11located in the peripheral area is multiple, and in the central area, the first connection between two adjacent second electrodes106The number of the parts11is one or zero.

Specifically, referring toFIG.8, in some embodiments, among the first column of first connecting portions11in the peripheral area, the number of the first connecting portions11on the outermost second electrode106side may be 2, and among the second column of first connecting portions11in the peripheral area, the number of the first connecting portions11on the outermost second electrode106side may be 1, and the first column of first connecting portions11are disposed in a stagger manner with the second column of first connecting portions11. Only the arrangement of first column and the second column of the first connecting portions11is shown here, and reference may be made to the first column and the second column for the arrangement of the first connecting portions11in the remaining third, fourth, fifth and sixth columns.

Referring toFIG.10, in other embodiments, among the first column of first connecting portions11in the peripheral area, the number of the first connecting portions11on the outermost second electrode106side may be one, among the second column of first connecting portions11in the peripheral area, the number of the first connecting portions11on the outermost second electrode106side may be one, and among the third column of first connecting portions11in the peripheral area, the number of the first connecting portions11on the outermost second electrode106side may be one. The adjacent three columns of the first connecting portions11are disposed in a stagger manner along the first direction X. Only the arrangement of the first connecting portions11in the first, second and third columns is shown here, and reference may be made to the first column, the second column and the third column of first connecting portions11for the arrangement of the first connecting portions11in the remaining columns.

In some embodiments, in each column of the first connecting portions11located in the central area, the distance between every two adjacent first connecting portions11ranges from 0.01 mm to 20 mm, for example, the distance may range from 0.01 mm to 0.1 mm, from 0.1 mm to 0.5 mm, from 0.5 mm to 2 mm, from 2 mm to 5 mm, from 5 mm to 10 mm, from 10 mm to 15 mm, or from 15 mm to 20 mm. in each column of the first connecting portions11located in the peripheral area, the distance between every two adjacent first connecting portions11ranges from 0.005 mm to 18 mm, for example, the distance may range from 0.005 mm to 0.01 mm, from 0.01 mm to 0.1 mm, from 0.1 mm to 0.5 mm, from 0.5 mm to 2 mm, from 2 mm to 5 mm, from 5 mm to 10 mm, from 10 mm to 15 mm, or from 15 mm to 18 mm. Within this range, on the one hand, the distance between adjacent first connecting portions11is not too small, so as to prevent the first connecting portions11from absorbing too much incident light due to excessively dense arrangement of the first connecting portions11; on the other hand, within this range, the distance between every two adjacent first connecting portions11is not too small, so that more lateral transport channels are formed, which can greatly improve the lateral transport capability of carriers in the substrate100.

Referring toFIG.12toFIG.13, in some embodiments, the top surface of the conductive transport layer104has a light trapping structure108. The light trapping structure108is configured to enhance the reflection capability of the top surface of the conductive transport layer104to the incident light, so that the incident light irradiating on the top surface of the conductive transport layer104can be reflected and prevented from being absorbed by the conductive transport layer104. This part of the reflected incident light can continue to be reflected back, for example, this part of the reflected incident light can be reflected to the area not covered by the doped conductive layer102and the conductive transport layer104, so as to be absorbed and utilized by the substrate100. In this way, the absorption and utilization rate of the substrate100to the incident light can be enhanced.

Specifically, referring toFIG.12, in some embodiments, the light trapping structure108includes multiple pyramid structures, each of the multiple pyramid structures has a bottom surface and a side surface connected to the bottom surface. Incident light may be repeatedly reflected between side surfaces of two adjacent pyramid structures, so as to reflect the incident light irradiating on the top surface of the conductive transport layer104to out of the conductive transport layer104, thereby reducing the absorption of the incident light done by the conductive transport layer104. Moreover, since each of the pyramid structures has multiple side surfaces, reflection probability of the incident light is further increased, the absorption of the incident light done by the conductive transport layer104is further reduced. The reflected incident light can be re-reflected to a part of the first surface of the substrate100not covered by the doped conductive layer102and the conductive transport layer104, which increases the utilization rate of incident light by the substrate100, increases the open circuit voltage and short circuit current, thereby improving the photoelectric conversion efficiency of the solar cell110.

In other embodiments, the light trapping structure108further includes a recessed structure that is recessed toward the substrate100, and the recessed structure is provided, on the one hand, the top surface of the conductive transport layer104is lower than the top surface of the doped conductive layer102, the doped conductive layer102has a certain shielding effect on the incident light irradiating on the top surface of the conductive transport layer104. On the other hand, the incident light is enabled to be repeatedly reflected on sidewalls of the recessed structure, thereby reducing the parasitic absorption of the incident light by the top surface of the doped conductive layer102.

Specifically, in some embodiments, along a direction in which the doped conductive layer102points to the center of the recessed structure, the height of the recessed structure gradually decreases. Referring specifically toFIG.12, the recessed structure has two opposite sidewalls, the tops of the two opposite sidewalls are spaced apart from each other, and the bottoms are connected, that is, the two sidewalls of the recessed structure are inclined relative to the first surface of the substrate100. In this way, in response to the incident light irradiating one of two sidewall surfaces, one part of the incident light will be reflected from a first sidewall surface to a second sidewall surface, and after that, in the incident light reflected to the second sidewall surface, one part of the incident light will be reflected to the outside, and the other part of the incident light will be re-reflected from the second sidewall surface to the first sidewall surface. In this way, after the incident light is reflected multiple times, the incident light is substantially emitted to the outside, so that the incident light emitted to the outside has a high probability of being re-reflected to a part of the first surface the substrate100that is not covered by the doped conductive layer102and the conductive transport layer104.

In other embodiments, referring toFIG.13, in the direction in which the doped conductive layer102points to the substrate100, the cross-sectional shape of the recessed structure may also be a rectangle. That is, the recessed structure has two opposite side walls and a bottom wall, the two opposite side walls are perpendicular to the first surface of the substrate100, and the bottom wall can be arranged parallel to the first surface of the substrate100.

It can be understood that, in other embodiments, the recessed structure may also be in other shapes, as long as the recessed structure recesses toward the substrate100.

Referring toFIG.2, in some embodiments, the solar cell110further includes: a first passivation layer107, a part of the first passivation layer107covers the first surface of the substrate100, and the remaining part of the first passivation layer107covers the doped conductive layer102and the top surface of the conductive transport layer104. That is to say, the tunneling dielectric layer101is disposed correspondingly to the doped conductive layer102. The tunneling dielectric layer101is disposed between the doped conductive layer102and the substrate100, and between the conductive transport layer104and the substrate100, so that the tunneling dielectric layer101only covers a part of the surface of the substrate100, and a part of the first passivation layer107can directly in contact with the first surface of the substrate100. Since the conductive transport layer104is disposed between every two adjacent doped conductive layers102, multiple lateral transport channels are formed in the substrate100in direct contact with the first passivation layer107, and the carriers in the substrate100can move laterally into the doped conductive layer102, thereby reducing the consumption of carriers in the transport process and increasing the transport rate. Moreover, since the doped conductive layers102are arranged at intervals and are only arranged in the metallized area (the area corresponding to the first electrode103), in response to incident light irradiating the area between the adjacent doped conductive layers102, the probability of incident light being absorbed is greatly reduced, and the parasitic absorption of incident light by the doped conductive layer102is integrally reduced. It can be seen from this that the solar cell110provided according to the embodiments of the present disclosure not only improve the utilization rate of the incident light by the solar cell110, but also maintain a relatively high transport efficiency of carriers in the solar cell110.

In some embodiments, the first passivation layer107may be a single-layer or multi-layer structure, and the first passivation layer107may be made of at least one of magnesium fluoride, silicon oxide, aluminum oxide, silicon oxynitride, silicon nitride, titanium oxide.

In other embodiments, a front surface of the tunneling dielectric layer101may also be disposed on the first surface of the substrate100. Based on this, the first passivation layer107is disposed to partially cover the top surface of the doped conductive layer102and the top surface of the conductive transport layer104. The remaining part of the first passivation layer107covers the first surface of the substrate100.

In some embodiments, the first passivation layer107may be formed by using a plasma enhanced chemical vapor deposition (PECVD) method after the doped conductive layer102and the conductive transport layer104are formed.

The first electrode103penetrates through the first passivation layer107to be electrically connected to the doped conductive layer102. The first passivation layer107is configured to reduce the reflection of the incident light by the substrate100. In some embodiments, after the first passivation layer107is formed, multiple first electrodes103disposed at intervals are formed on a side of the doped conductive layer102away from the substrate100, the first electrode103extends along the first direction X, and is electrically connected to the doped conductive layer102.

In some embodiments, the second surface of the substrate100has an emitter with a type of doping ions in the emitter that is different from the type of doping ions in the doped conductive layer102. In some embodiments, a surface of the emitter away from the substrate100further has an anti-reflection layer, and the anti-reflection layer is configured to anti-reflect incident light. In some embodiments, the anti-reflection layer may be a silicon nitride layer, and the silicon nitride layer is made of silicon nitride material. In other embodiments, the anti-reflection layer may also be provided in a multi-layer structure, for example, may be a stacked-layer structure composed of one or more materials selected from silicon nitride, silicon oxide, or silicon oxynitride.

In other embodiments, the second surface of the substrate100also has a structure similar to structures formed on the first surface of the substrate100, for example, the second surface of the substrate100may have a second tunneling dielectric layer and a second doped conductive layer stacked in sequence along a direction away from the second surface of the substrate100. The type of doping ions in the second doped conductive layer is different from the type of doping ions in the doped conductive layer102.

In some embodiments, the solar cell110further includes a third electrode (not shown). The third electrode is located on the second surface of the substrate100. In response to the second surface of the substrate100having an emitter, the third electrode penetrates through the anti-reflection layer to be electrically connected to the emitter. In response to the second surface of the substrate100being formed with structures similar to that of the first surface of the substrate100, the third electrode is electrically connected to the second doped conductive layer.

In the solar cell110provided according to the above embodiments, the conductive transport layer104is arranged between every two adjacent doped conductive layers102in the multiple doped conductive layers102and in contact with the doped conductive layer102, so that the majority carriers in the substrate100can be transported to the multiple doped conductive layer102through the conductive transport layer104. In this way, the lateral transport of majority carriers in the substrate100is improved, the filling factor of the solar cell110is improved, the utilization rate of incident light is improved, and the transport capability of the majority carriers in the substrate100is improved, thereby improving the overall photoelectric conversion efficiency of solar cell.

Correspondingly, a photovoltaic module is further provided according to an embodiment of the present disclosure. Referring toFIG.14, the photovoltaic module includes at least one cell string, where the at least one cell string is formed by connecting multiple solar cells110, each of the multiple solar cells110being a solar cell110according to any one above; at least one package layer120configured to cover a surface of the at least one cell string; at least one cover plate130configured to cover a surface of the at least one package layer120away from the at least one cell string. The solar cells110are electrically connected in the form of a whole piece or multiple pieces to form multiple cell strings, and the multiple cell strings are electrically connected in series and/or parallel.

Specifically, in some embodiments, the multiple cell strings are electrically connected by conductive strips140. The package layer120covers the front surface and the back surface of the solar cell110. Specifically, the package layer120may be embodied as an ethylene-vinyl acetate copolymer (EVA) adhesive film, a polyethylene octene co-elastomer (POE) adhesive film, a polyethylene terephthalate (PET) film, or other organic package films. In some embodiments, the cover plate130may be embodied as a cover plate130with a light-transmitting function, such as a glass cover plate, a plastic cover plate, or the like. Specifically, a surface of the cover plate130facing the package layer120may be a surface with protrusions and recess, thereby increasing the utilization rate of incident light.

Although the present disclosure is disclosed above with preferred embodiments, it is not used to limit the claims. Any person skilled in the art can make some possible changes and modifications without departing from the concept of the present disclosure. The scope of protection shall be subject to the scope defined by the claims of the present disclosure.

Those of ordinary skill in the art can understand that the above embodiments are specific examples for realizing the present disclosure, and in actual disclosures, various changes may be made in form and details without departing from the spirit and range of the present disclosure. Any person skilled in the art can make their own changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the scope defined by the claims.