CN112951928A

CN112951928A - Electrode structure and solar cell structure

Info

Publication number: CN112951928A
Application number: CN202010072891.7A
Authority: CN
Inventors: 廖士霆; 罗俊杰; 张瀚丞; 黄建福; 陈建勋
Original assignee: Industrial Technology Research Institute ITRI
Current assignee: Industrial Technology Research Institute ITRI
Priority date: 2019-12-09
Filing date: 2020-01-21
Publication date: 2021-06-11
Anticipated expiration: 2040-01-21
Also published as: TWI718803B; TW202123480A; CN112951928B

Abstract

The invention discloses an electrode structure, which comprises a multi-layer doped polycrystalline structure and an electrode. The multi-layer doped polycrystalline structure comprises a first doped polycrystalline layer, a second doped polycrystalline layer and a first doped dielectric layer. The second doped polycrystalline layer is located on the first doped polycrystalline layer. The first doped polycrystalline layer and the second doped polycrystalline layer are of the same doping type. The doping concentration of the second doping polycrystalline layer is larger than that of the first doping polycrystalline layer. The first doped dielectric layer is located between the first doped polycrystalline layer and the second doped polycrystalline layer. The electrode is positioned on one side of the second doped polycrystalline layer far away from the first doped dielectric layer. The electrode is electrically connected to the multi-layer doped polycrystalline structure. The electrode structure can optimize the field effect, improve the hidden open-circuit voltage and reduce the sheet resistance.

Description

Electrode structure and solar cell structure

Technical Field

The present invention relates to an electrode structure and a solar cell structure, and more particularly, to an electrode structure and a solar cell structure having a multi-layer doped polycrystalline structure.

Background

Solar energy is a pollution-free energy source, and thus has become the most spotlighted green energy source when petrochemical energy is in short supply. Among them, solar cells (solar cells) are the focus of solar energy development at present because they can directly convert solar energy into electric energy. However, the development of solar cells is still going to be further broken through due to the poor efficiency of solar cells.

Disclosure of Invention

The invention provides an electrode structure which can optimize a field effect, increase an implicit open circuit voltage (iVoc) and reduce sheet resistance (sheet resistance).

The invention provides a solar cell structure which can have better solar cell efficiency.

The invention provides an electrode structure, which comprises a multi-layer doped polycrystalline structure and an electrode. The multi-layer doped polycrystalline structure comprises a first doped polycrystalline layer, a second doped polycrystalline layer and a first doped dielectric layer. The second doped polycrystalline layer is located on the first doped polycrystalline layer. The first doped polycrystalline layer and the second doped polycrystalline layer are of the same doping type. The doping concentration of the second doping polycrystalline layer is larger than that of the first doping polycrystalline layer. The first doped dielectric layer is located between the first doped polycrystalline layer and the second doped polycrystalline layer. The electrode is positioned on one side of the second doped polycrystalline layer far away from the first doped dielectric layer. The electrode is electrically connected to the multi-layer doped polycrystalline structure.

According to an embodiment of the present invention, in the electrode structure, the first doped poly layer, the first doped dielectric layer and the second doped poly layer may be of the same doping type. The doping concentration of the first doped polysilicon layer, the doping concentration of the first doped dielectric layer and the doping concentration of the second doped polysilicon layer are in a gradient relationship in a sequentially increasing order.

According to an embodiment of the present invention, in the electrode structure, the material of the first doped polycrystalline layer and the material of the second doped polycrystalline layer are, for example, polycrystalline silicon, silicon carbide (SiC), aluminum gallium nitride (A1GaN), or a combination thereof.

According to an embodiment of the present invention, in the electrode structure, a doping concentration of the first doped poly layer is, for example, 5 × 10¹⁸Atom/cm³To 5X 10²⁰Atom/cm³。

According to an embodiment of the present invention, in the electrode structure, the doping concentration of the second doped polycrystalline layer is, for example, 1 × 10¹⁹Atom/cm³To 1X 10²¹Atom/cm³。

According to an embodiment of the present invention, the electrode structure may further include a second doped dielectric layer. The second doped dielectric layer is located on one side of the first doped polycrystalline layer far away from the first doped dielectric layer.

According to an embodiment of the present invention, in the electrode structure, the second doped dielectric layer, the first doped polysilicon layer, the first doped dielectric layer and the second doped polysilicon layer may be of the same doping type. The doping concentration of the second doped dielectric layer, the doping concentration of the first doped polycrystalline layer, the doping concentration of the first doped dielectric layer and the doping concentration of the second doped polycrystalline layer can be in a gradient relationship which is increased in sequence.

According to an embodiment of the present invention, a third doped dielectric layer may be further included in the electrode structure. The third doped dielectric layer is located between the second doped dielectric layer and the first doped polycrystalline layer.

According to an embodiment of the present invention, in the electrode structure, the second doped dielectric layer, the third doped dielectric layer, the first doped polysilicon layer, the first doped dielectric layer and the second doped polysilicon layer may be of the same doping type. The doping concentration of the second doped dielectric layer, the doping concentration of the third doped dielectric layer, the doping concentration of the first doped polycrystalline layer, the doping concentration of the first doped dielectric layer and the doping concentration of the second doped polycrystalline layer can be in a gradient relation which is increased in sequence.

According to an embodiment of the present invention, in the electrode structure, the material of the first doped dielectric layer, the material of the second doped dielectric layer, the material of the third doped dielectric layer, and the material of the third doped dielectric layer are, for example, silicon oxide, silicon nitride, or a combination thereof.

According to an embodiment of the present invention, in the electrode structure, a thickness of the first doped poly layer is, for example, 5nm to 20 nm. The thickness of the second doped poly layer is, for example, 5nm to 15 nm. The thickness of the first doped dielectric layer is, for example, 70nm to 200 nm. The thickness of the second doped dielectric layer is, for example, 1nm to 2 nm. The thickness of the third doped dielectric layer is, for example, 1nm to 10 nm.

According to an embodiment of the invention, a passivation layer may be further included in the electrode structure. The passivation layer is located between the electrode and the second doped polycrystalline layer. The electrode is electrically connected to the multi-layer doped polycrystalline structure through the passivation layer.

According to an embodiment of the present invention, in the electrode structure, the passivation layer may have at least one opening therein. The electrode fills the opening.

According to an embodiment of the present invention, in the electrode structure, an opening ratio of the passivation layer is, for example, lower than 3%.

According to an embodiment of the present invention, in the electrode structure, an aperture of the opening is, for example, 1 μm to 15 μm.

According to an embodiment of the present invention, in the electrode structure, the number of the openings may be multiple. The pitch of the openings is, for example, 50 μm to 100 μm.

According to an embodiment of the present invention, in the electrode structure, the connection position of the electrode and the multi-layer doped polycrystalline structure may range from a surface of the second doped polycrystalline layer on a side away from the first doped dielectric layer to a surface of the first doped polycrystalline layer on a side adjacent to the first doped dielectric layer.

The invention provides a solar cell structure, which comprises a substrate, a first electrode structure and a second electrode structure. The substrate has a first side and a second side. The substrate includes a first region and a second region on a second side. The first electrode structure is located in the first region. The first electrode structure includes a first multi-layer doped polycrystalline structure and a first electrode. The first multi-layer doped polycrystalline structure comprises a first doped polycrystalline layer, a second doped polycrystalline layer and a first doped dielectric layer. The first doped polycrystalline layer is positioned on the substrate on the second side. The second doped polycrystalline layer is located on the first doped polycrystalline layer. The first doped polycrystalline layer and the second doped polycrystalline layer are of the same doping type. The doping concentration of the second doping polycrystalline layer is larger than that of the first doping polycrystalline layer. The first doped dielectric layer is located between the first doped polycrystalline layer and the second doped polycrystalline layer. The first electrode is located on one side of the second doped polycrystalline layer far away from the first doped dielectric layer. The first electrode is electrically connected to the first multi-layer doped polycrystalline structure. The second electrode structure is located in the second region. The first electrode structure and the second electrode structure are of different doping types.

According to an embodiment of the present invention, in the solar cell structure, the first electrode structure and the substrate may be of different doping types. The second electrode structure and the substrate may be of the same doping type.

According to an embodiment of the present invention, in the solar cell structure, the first electrode structure and the substrate may be of the same doping type. The second electrode structure and the substrate may be of different doping types.

According to an embodiment of the present invention, in the solar cell structure, the second electrode structure may include a doped region and a second electrode. The doped region is located in the substrate at the second side. The second electrode is electrically connected to the doped region.

According to an embodiment of the present invention, in the solar cell structure, the second electrode structure may include a second multi-layer doped polycrystalline structure and a second electrode. The second multi-layer doped polycrystalline structure comprises a third doped polycrystalline layer, a fourth doped polycrystalline layer and a fourth doped dielectric layer. The third doped polycrystalline layer is positioned on the substrate on the second side. The fourth doped polycrystalline layer is located on the third doped polycrystalline layer. The third doped polycrystalline layer and the fourth doped polycrystalline layer are of the same doping type. The doping concentration of the fourth doping polycrystalline layer is larger than that of the third doping polycrystalline layer. The fourth doped dielectric layer is located between the third doped polycrystalline layer and the fourth doped polycrystalline layer. The second electrode is located on one side of the fourth doped polycrystalline layer far away from the fourth doped dielectric layer. The second electrode is electrically connected to the second multi-layer doped polycrystalline structure.

According to an embodiment of the invention, in the solar cell structure, an antireflection layer may be further included. The anti-reflection layer is positioned on the substrate on the first side.

According to an embodiment of the invention, the solar cell structure may further include a doped region. The doped region is located in the substrate at the first side. The doped region and the substrate may be of the same doping type.

Based on the above, the electrode structure provided by the present invention has a multi-layer doped polycrystalline structure, wherein the first doped polycrystalline layer and the second doped polycrystalline layer in the multi-layer doped polycrystalline structure are of the same doping type, and the doping concentration of the second doped polycrystalline layer is greater than the doping concentration of the first doped polycrystalline layer, so that the electrode structure can optimize the field effect, increase the hidden open circuit voltage, and reduce the sheet resistance. In addition, in the solar cell structure provided by the invention, the field effect can be optimized, the hidden open-circuit voltage can be increased, and the sheet resistance can be reduced due to the first electrode structure, so that the efficiency of the solar cell can be effectively improved.

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

FIG. 1 is a cross-sectional view of an electrode structure according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of a solar cell structure according to an embodiment of the invention;

FIG. 3 is a cross-sectional view of a solar cell structure according to another embodiment of the present invention;

fig. 4 is a cross-sectional view of a solar cell structure according to another embodiment of the invention.

Description of the symbols:

10. 20, 30: solar cell structure

100. 100a, 100b, 122, 132: electrode structure

102. 102a, 102 b: multi-layer doped polycrystalline structure

104. 104a, 104b, 126, 136: electrode for electrochemical cell

106. 106a, 106b, 108a, 108 b: doped polycrystalline layer

110. 110a, 110b, 112a, 112b, 114a, 114 b: doped dielectric layer

116. 116 a: passivation layer

118. 118 a: opening of the container

120: substrate

124. 130, 134: doped region

128: anti-reflection layer

R1: first region

R2: second region

S1: first side

S2: second side

Detailed Description

Fig. 1 is a cross-sectional view of an electrode structure according to an embodiment of the invention.

Referring to fig. 1, an electrode structure 100 includes a multi-layer doped poly structure 102 and an electrode 104. In some embodiments, the electrode structure 100 can be applied to a solar cell, but the invention is not limited thereto. For example, the electrode structure 100 may be disposed on a substrate of a solar cell.

The multi-layered doped poly structure 102 comprises a doped poly layer 106, a doped poly layer 108 and a doped dielectric layer 110. The multi-layer doped poly structure 102 has good passivation characteristics, thereby reducing carrier recombination (recombination) problems. Thus, the electrode structure 100 can optimize the field effect, increase the hidden open circuit voltage, and reduce the sheet resistance. The doped poly layer 106 may be P-type or N-type. In the case where the doped polycrystalline layer 106 is P-type, the dopant in the doped polycrystalline layer 106 is, for example, boron (B). In the case where the doping type of the doped polycrystalline layer 106 is N type, the doping in the doped polycrystalline layer 106 is, for example, phosphorus (P). The doping concentration of the doped poly layer 106 is, for example, 5 × 10¹⁸Atom/cm³To 5X 10²⁰Atom/cm³. The thickness of the doped poly layer 106 is, for example, 5nm to 20 nm. The material of the doped poly layer 106 is, for example, polysilicon, SiC, AlGaN, or a combination thereof. The doped poly layer 106 may be formed by Chemical Vapor Deposition (CVD), such as Plasma Enhanced Chemical Vapor Deposition (PECVD). In addition, the doped poly layer 106 may be deposited by in-situ doping.

A doped poly layer 108 is located on doped poly layer 106. The doped poly layer 108 may be P-type or N-type. In the case where the doping type of the doped polycrystalline layer 108 is P-type, the doping in the doped polycrystalline layer 108 is, for example, boron (B). In the case where the doping type of the doped polycrystalline layer 108 is N type, the doping in the doped polycrystalline layer 108 is, for example, phosphorus (P). The thickness of the doped poly layer 108 is, for example, 5nm to 15 nm. The material of the doped poly layer 108 is, for example, polysilicon, SiC, AlGaN, or a combination thereof. The doped polysilicon layer 108 is formed by chemical vapor deposition, such as PECVD. In addition, the doped poly layer 108 may be deposited by in-situ doping (in-situ doping).

In addition, the doped poly layer 106 and the doped poly layer 108 are of the same doping type. In some embodiments, the doped poly layer 106 and the doped poly layer 108 may be both P-type. In some embodiments, the doped poly layer 106 and the doped poly layer 108 may be both N-type. In addition, the doping concentration of the doped poly layer 108 is greater than the doping concentration of the doped poly layer 106. The doping concentration of the doped poly layer 108 is, for example, 1 × 10¹⁹Atom/cm³To 1X 10²¹Atom/cm³。

A doped dielectric layer 110 is located between the doped poly layer 106 and the doped poly layer 108. In the case where the doping type of the doped dielectric layer 110 is P-type, the doping in the doped dielectric layer 110 is, for example, boron (B). In the case where the doping type of the doped dielectric layer 110 is N type, the doping in the doped dielectric layer 110 is, for example, phosphorus (P). The doped poly layer 106, the doped dielectric layer 110 and the doped poly layer 108 may be of the same doping type, such as P-type or N-type. The doping concentration of the doped poly layer 106, the doping concentration of the doped dielectric layer 110 and the doping concentration of the doped poly layer 108 may be in a sequentially increasing gradient relationship. The thickness of the doped dielectric layer 110 is, for example, 70nm to 200 nm. The material of the doped dielectric layer 110 is, for example, silicon oxide, silicon nitride, or a combination thereof. The doped dielectric layer 110 is formed by a chemical vapor deposition method, such as a plasma enhanced chemical vapor deposition method. In addition, the doped dielectric layer 110 may be deposited by in-situ doping (in-situ doping).

The electrode 104 is located on a side of the doped poly layer 108 away from the doped dielectric layer 110. The electrode 104 is electrically connected to the multi-layered doped poly structure 102. The connection location of the electrode 104 to the multi-layered doped polycrystalline structure 102 may range from a surface of the doped polycrystalline layer 108 on a side away from the doped dielectric layer 110 to a surface of the doped polycrystalline layer 106 on a side adjacent to the doped dielectric layer 110. That is, the electrode 104 is electrically connected to the doped poly layer 108. In the present embodiment, the electrode 104 is electrically connected to the doped poly layer 106 and the doped poly layer 108 at the same time, but the invention is not limited thereto. The material of the electrode 104 is, for example, silver or aluminum. In some embodiments, the electrode 104 may be formed by screen printing conductive paste and then sintering at a high temperature. In some embodiments, the electrode 104 may be formed by using a combination of deposition processes, photolithography processes, and etching processes.

The electrode structure 100 may also optionally include at least one of a doped dielectric layer 112, a doped dielectric layer 114, and a passivation layer 116. The doped dielectric layer 112 is located on a side of the doped poly layer 106 away from the doped dielectric layer 110. In the case where the doping type of the doped dielectric layer 112 is P-type, the doping in the doped dielectric layer 112 is, for example, boron (B). In the case where the doping type of the doped dielectric layer 112 is N type, the doping in the doped dielectric layer 112 is, for example, phosphorus (P). The doped dielectric layer 112, the doped poly layer 106, the doped dielectric layer 110 and the doped poly layer 108 may be of the same doping type, such as P-type or N-type. The doping concentration of the doped dielectric layer 112, the doping concentration of the doped polysilicon layer 106, the doping concentration of the doped dielectric layer 110 and the doping concentration of the doped polysilicon layer 108 may be in a sequentially increasing gradient relationship. The thickness of the doped dielectric layer 112 is, for example, 1nm to 2 nm. The material of the doped dielectric layer 112 is, for example, silicon oxide, silicon nitride, or a combination thereof. In the case where the material of the doped dielectric layer 112 is silicon oxide, the doped dielectric layer 112 is formed by a thermal oxidation method or a chemical vapor deposition method. In the case where the material of the doped dielectric layer 112 is silicon nitride, the doped dielectric layer 112 is formed by a chemical vapor deposition method, for example.

In the present embodiment, the electrode structure 100 includes the doped dielectric layer 114, so that the dopant in the doped dielectric layer 112 can be obtained by diffusing the dopant in the doped dielectric layer 114. In other embodiments, in the case that the electrode structure 100 does not include the doped dielectric layer 114, the dopant in the doped dielectric layer 112 may be diffused by the dopant in the doped poly layer 106.

The doped dielectric layer 114 is located between the doped dielectric layer 112 and the doped poly layer 106. The doped dielectric layer 114 can further optimize field effect, increase hidden open circuit voltage, and reduce sheet resistance. Thereby, in the case of applying the electrode structure 100 in a solar cell structure, the doping of the dielectric layer 114 can further improve the solar cell efficiency. In addition, the doped dielectric layer 114 prevents plasma damage to the doped dielectric layer 112 during subsequent processing. In the case where the doping type of the doped dielectric layer 114 is P-type, the doping in the doped dielectric layer 114 is, for example, boron (B). In the case where the doping type of the doped dielectric layer 114 is N-type, the doping in the doped dielectric layer 114 is, for example, phosphorus (P). The doped dielectric layer 112, the doped dielectric layer 114, the doped poly layer 106, the doped dielectric layer 110 and the doped poly layer 108 may be of the same doping type, such as P-type or N-type. The doping concentration of the doped dielectric layer 112, the doping concentration of the doped dielectric layer 114, the doping concentration of the doped poly layer 106, the doping concentration of the doped dielectric layer 110 and the doping concentration of the doped poly layer 108 may be in a sequentially increasing gradient relationship. The thickness of the doped dielectric layer 114 is, for example, 1nm to 10 nm. The material of the doped dielectric layer 114 is, for example, silicon oxide, silicon nitride, or a combination thereof. The doped dielectric layer 114 is formed by a chemical vapor deposition method, such as a plasma enhanced chemical vapor deposition method. In addition, the doped dielectric layer 114 may be deposited by in-situ doping (in-situ doping).

A passivation layer 116 is located between the electrode 104 and the doped poly layer 108. The electrode 104 is electrically connected to the multi-layered doped poly structure 102 through the passivation layer 116. The passivation layer 116 is made of, for example, silicon nitride, silicon oxide, silicon oxynitride, aluminum oxide, or a combination thereof. The passivation layer 116 is formed by a chemical vapor deposition method, such as a plasma enhanced chemical vapor deposition method.

In addition, there may be at least one opening 118 in the passivation layer 116. In the present embodiment, the opening 118 may also extend to the surface of the doped poly layer 106 through the doped poly layer 108 and the doped dielectric layer 110, but the invention is not limited thereto. In other embodiments, the opening 118 may extend only to the surface of the doped poly layer 108 on the side away from the doped dielectric layer 110. The electrode 104 fills the opening 118, and thus the depth of the electrode 104 can be determined by the depth of the opening 118. In addition, the electrode 104 is filled into the opening 118 to form a dot-shaped electrode structure, so that the surface damage ratio can be reduced, and the device efficiency performance can be improved. The opening 118 is formed by, for example, performing a laser drilling process or a photolithography process.

The aperture ratio of the passivation layer 116 is, for example, less than 3%. In the present embodiment, the aperture ratio of the passivation layer 116 is defined as: the upper viewing area of opening 118 accounts for the proportion of the upper viewing area of passivation layer 116 within the range of the upper viewing area of multi-layered doped polycrystalline structure 102. In some embodiments, the aperture ratio of the passivation layer 116 may be 1% to 2%. The aperture of the opening 118 is, for example, 1 μm to 15 μm. In the present embodiment, the number of the openings 118 may be plural, but the invention is not limited thereto. In the case where the number of the openings 118 is plural, the pitch of the openings 118 is, for example, 50 μm to 100 μm. In some embodiments, the pitch of the openings 118 is, for example, 70 μm to 80 μm. In some embodiments, the pitch of the openings 118 is, for example, 50 μm, 70 μm, 80 μm, 100 μm, or a combination thereof. In addition, the absolute efficiency of the device can be improved by the above-mentioned design of the spacing of the openings 118.

Based on the above embodiments, the electrode structure 100 has the multi-layered doped poly structure 102, the doped poly layer 106 and the doped poly layer 108 in the multi-layered doped poly structure 102 are of the same doping type, and the doping concentration of the doped poly layer 108 is greater than the doping concentration of the doped poly layer 106, so the electrode structure 100 can optimize the field effect, increase the hidden open circuit voltage, and reduce the sheet resistance. Thereby, in the case of applying the electrode structure 100 to a solar cell structure, the multi-layer doped polycrystalline structure 102 may further improve the solar cell efficiency.

Fig. 2 is a cross-sectional view of a solar cell structure according to an embodiment of the invention.

Referring to fig. 2, the solar cell structure 10 includes a substrate 120, an electrode structure 100a and an electrode structure 122. The substrate 120 has a first side S1 and a second side S2. The substrate 120 includes a first region R1 and a second region R2 at the second side S2. The substrate 100 may be a semiconductor substrate, such as a silicon substrate. In addition, the substrate 100 may have a first doping type. Hereinafter, the first doping type and the second doping type may be one and the other of N-type and P-type, respectively. In the present embodiment, the first doping type is an N type, and the second doping type is a P type, but the invention is not limited thereto. In other embodiments, the first doping type may be P-type and the second doping type may be N-type. In addition, in order to increase the amount of light, a roughening (roughened) process may be selectively performed on the first side S1 of the substrate 120 to further improve the photoelectric conversion efficiency, but the invention is not limited thereto.

The electrode structure 100a is located in the first region R1. The electrode structure 100a includes a multi-layer doped poly structure 102a and an electrode 104 a. The multi-layered doped poly structure 102a includes a doped poly layer 106a, a doped poly layer 108a and a doped dielectric layer 110 a. The doped poly layer 106a is on the substrate 120 at the second side S2. A doped poly layer 108a is located on the doped poly layer 106 a. The doped poly layer 106a and the doped poly layer 108a are of the same doping type. The doping concentration of the doped poly layer 108a is greater than the doping concentration of the doped poly layer 106 a. The doped dielectric layer 110a is located between the doped poly layer 106a and the doped poly layer 108 a. The electrode 104a is located on a side of the doped poly layer 108a away from the doped dielectric layer 110 a. The electrode 104a is electrically connected to the multi-layered doped poly structure 102 a.

In addition, the electrode structure 100a may further optionally include at least one of a doped dielectric layer 112a, a doped dielectric layer 114a and a passivation layer 116 a. The doped dielectric layer 112a is located between the substrate 120 and the doped poly layer 106 a. The doped dielectric layer 114a is located between the doped dielectric layer 112a and the doped poly layer 106 a. The passivation layer 116a is located between the electrode 104a and the doped poly layer 108 a. The electrode 104a is electrically connected to the multi-layered doped poly structure 102a through the passivation layer 116 a. The electrode 104a fills the opening 118a of the passivation layer 116a, thereby forming a dot-shaped electrode structure.

In addition, the electrode structure 100a may be one of an emitter electrode structure and a back surface field electrode structure. In the present embodiment, the electrode structure 100a is an emitter electrode structure, and the poly-doped poly structure 102a can be used as a poly-doped thin film emitter, but the invention is not limited thereto. The electrode structure 100a and the substrate 120 may be of different doping types. For example, the electrode structure 100a may be of a second doping type (e.g., P-type). The doping type (e.g., P-type) of the electrode structure 100a is determined by the doping types (e.g., P-type) of the doped poly layer 106a, the doped poly layer 108a and the doped dielectric layer 110 a. In the electrode structure 100a of fig. 2 and the electrode structure 100 of fig. 1, similar components are denoted by similar symbols, and the details of each component in the electrode structure 100a of fig. 2 can be referred to the description of the electrode structure 100 of fig. 1, and will not be described again here.

Electrode structure 122 is located in second region R2. The electrode structure 122 may include a doped region 124 and an electrode 126. The doped region 124 is located in the substrate 120 at the second side S2. The doping concentration of the doped region 124 is, for example, greater than the doping concentration of the substrate 120. The electrode 126 is electrically connected to the doped region 124. In addition, the electrode structure 122 may further include a passivation layer 116 a. The electrode 126 is electrically connected to the doped region 124 through the passivation layer 116 a.

In addition, the electrode structure 122 may be the other of the emitter electrode structure and the back surface field electrode structure. In the embodiment, the electrode structure 122 is exemplified by a Back Surface Field (BSF) electrode structure, and the doped region 124 can be used as a BSF, but the invention is not limited thereto.

The electrode structure 100a and the electrode structure 122 are doped differently. The electrode structure 122 and the substrate 120 may be of the same doping type. For example, the electrode structure 122 may be a first doping type (e.g., N-type). The doping type (e.g., N-type) of the electrode structure 122 may be determined by the doping type (e.g., N-type) of the doped region 124.

The solar cell structure 10 may also optionally include an anti-reflective layer 128. The anti-reflection layer 128 is on the substrate 120 of the first side S1. The antireflective layer 128 may be a single layer or a multi-layer structure. The material of the anti-reflection layer 128 is, for example, silicon nitride, silicon oxide, silicon oxynitride, zinc oxide, titanium oxide, Indium Tin Oxide (ITO), indium oxide, bismuth oxide (bismuth oxide), tin oxide (stannic oxide), zirconium oxide (zirconia oxide), hafnium oxide (hafnium oxide), antimony oxide (antimony oxide), gadolinium oxide (gadolinium oxide), or a combination thereof.

The doped region 130 is located in the substrate 120 at the first side S1. The doped region 130 may be used as a Front Side Field (FSF). The doped region 130 and the substrate 120 may be the same doping type. For example, the doped region 130 may be a first doping type (e.g., N-type). The doping concentration of the doped region 130 is, for example, greater than the doping concentration of the substrate 120. In addition, the doping concentration of the doped region 130 is, for example, less than that of the doped region 124.

Based on the above embodiments, in the solar cell structure 10, since the electrode structure 100a can optimize the field effect, increase the hidden open circuit voltage, and reduce the sheet resistance, the solar cell efficiency can be effectively improved.

Fig. 3 is a cross-sectional view of a solar cell structure according to another embodiment of the invention.

Referring to fig. 2 and 3, the solar cell structure 20 of fig. 3 is different from the solar cell structure 10 of fig. 2 as follows. The solar cell structure 20 of fig. 3 is obtained by replacing the electrode structure 122 of the solar cell structure 10 of fig. 2 with the electrode structure 100 b. The electrode structure 100b is located in the second region R2. The electrode structure 100b may include a multi-layered doped poly structure 102b and an electrode 104 b. The doped poly layer 106b is on the substrate 120 at the second side S2. A doped poly layer 108b is located on the doped poly layer 106 b. The doped poly layer 106b and the doped poly layer 108b are of the same doping type. The doping concentration of the doped poly layer 108b is greater than the doping concentration of the doped poly layer 106 b. The doped dielectric layer 110b is located between the doped poly layer 106b and the doped poly layer 108 b. The electrode 104b is located on a side of the doped poly layer 108b away from the doped dielectric layer 110 b. The electrode 104b is electrically connected to the multi-layered doped poly structure 102 b.

In addition, the electrode structure 100b may further optionally include at least one of a doped dielectric layer 112b, a doped dielectric layer 114b and a passivation layer 116 a. The doped dielectric layer 112b is located between the substrate 120 and the doped poly layer 106 b. The doped dielectric layer 114b is located between the doped dielectric layer 112b and the doped poly layer 106 b. The passivation layer 116a is located between the electrode 104b and the doped poly layer 108 b. The electrode 104b is electrically connected to the multi-layered doped polycrystalline structure 102b through the passivation layer 116 a. The electrode 104b fills the opening 118a of the passivation layer 116a, thereby forming a dot-shaped electrode structure.

In addition, the electrode structure 100b may be one of an emitter electrode structure and a back surface field electrode structure. In the present embodiment, the electrode structure 100b is a back surface field electrode structure, and the multi-layer doped poly structure 102b can be used as a back surface field of a multi-layer doped thin film, but the invention is not limited thereto.

The electrode structure 100a and the electrode structure 100b are doped differently. The electrode structure 100a and the substrate 120 may be of different doping types. The electrode structure 100b and the substrate 120 may be of the same doping type. The doping type (e.g., N-type) of the electrode structure 100b is determined by the doping types (e.g., N-type) of the doped poly layer 106b, the doped poly layer 108b and the doped dielectric layer 110 b. In the electrode structure 100b of fig. 3 and the electrode structure 100 of fig. 1, similar components are denoted by similar symbols, and the details of the components in the electrode structure 100b of fig. 3 can be referred to the description of the electrode structure 100 of fig. 1, and are not described again here. In the solar cell structure 20 of fig. 3 and the solar cell structure 10 of fig. 2, the same members are denoted by the same reference numerals, and descriptions thereof are omitted.

Based on the above embodiments, in the solar cell structure 20, since the electrode structures 100a and 100b can optimize the field effect, increase the hidden open circuit voltage, and reduce the sheet resistance, the solar cell efficiency can be effectively improved.

Referring to fig. 3 and 4, the solar cell structure 30 of fig. 4 is different from the solar cell structure 20 of fig. 3 as follows. The solar cell structure 30 of fig. 4 is obtained by replacing the electrode structure 100a in the solar cell structure 20 of fig. 3 with the electrode structure 132. The electrode structure 132 is located in the first region R1. The electrode structure 132 may include a doped region 134 and an electrode 136. The doped region 134 is located in the substrate 120 at the second side S2. The electrode 136 is electrically connected to the doped region 134. In addition, the electrode structure 122 may further include a passivation layer 116 a. The electrode 136 is electrically connected to the doped region 134 through the passivation layer 116 a.

In addition, the electrode structure 132 may be one of an emitter electrode structure and a back surface field electrode structure. In the present embodiment, the electrode structure 132 is an emitter electrode structure, and the doped region 134 can be used as an emitter, but the invention is not limited thereto.

The electrode structure 132 and the electrode structure 100b are doped differently. The electrode structure 100b and the substrate 120 may be of the same doping type. The electrode structure 132 and the substrate 120 may be of different doping types. The doping type (e.g., P-type) of the electrode structure 132 is determined by the doping type (e.g., P-type) of the doped region 134. In the solar cell structure 30 of fig. 4 and the solar cell structure 20 of fig. 3, the same members are denoted by the same reference numerals, and descriptions thereof are omitted.

Based on the above embodiments, in the solar cell structure 30, since the electrode structure 100b can optimize the field effect, increase the hidden open circuit voltage, and reduce the sheet resistance, the solar cell efficiency can be effectively improved.

In summary, since the electrode structure of the above embodiments has a multi-layer doped polycrystalline structure, the electrode structure can optimize the field effect, increase the hidden open circuit voltage, and reduce the sheet resistance. In addition, since the solar cell structure of the above embodiment has the above electrode structure, the solar cell efficiency can be effectively improved.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. An electrode structure comprising:

a multi-layered doped polycrystalline structure comprising:

a first doped polycrystalline layer;

a second doped polycrystalline layer located on the first doped polycrystalline layer, wherein the first doped polycrystalline layer and the second doped polycrystalline layer are of the same doping type, and the doping concentration of the second doped polycrystalline layer is greater than that of the first doped polycrystalline layer; and

a first doped dielectric layer between the first doped poly layer and the second doped poly layer; and

and the electrode is positioned on one side of the second doped polycrystalline layer far away from the first doped dielectric layer and is electrically connected to the multi-layer doped polycrystalline structure.

2. The electrode structure of claim 1, wherein the first doped polysilicon layer, the first doped dielectric layer and the second doped polysilicon layer are of the same doping type, and the doping concentration of the first doped polysilicon layer, the doping concentration of the first doped dielectric layer and the doping concentration of the second doped polysilicon layer are in a sequentially increasing gradient relationship.

3. The electrode structure of claim 1, wherein the material of the first and second doped poly layers respectively comprises polysilicon, silicon carbide, aluminum gallium nitride, or a combination thereof.

4. The electrode structure of claim 1, wherein the first doped polycrystalline layer has a doping concentration of 5 x 10¹⁸Atom/cm³To 5X 10²⁰Atom/cm³。

5. The electrode structure of claim 1, wherein the second doped polycrystalline layer has a doping concentration of 1 x 10¹⁹Atom/cm³To 1X 10²¹Atom/cm³。

6. The electrode structure of claim 1, further comprising:

and the second doped dielectric layer is positioned on one side of the first doped polycrystalline layer far away from the first doped dielectric layer.

7. The electrode structure of claim 6, wherein the second doped dielectric layer, the first doped polycrystalline layer, the first doped dielectric layer and the second doped polycrystalline layer are of the same doping type, and the doping concentration of the second doped dielectric layer, the doping concentration of the first doped polycrystalline layer, the doping concentration of the first doped dielectric layer and the doping concentration of the second doped polycrystalline layer are in a sequentially increasing gradient relationship.

8. The electrode structure of claim 6, further comprising:

a third doped dielectric layer between the second doped dielectric layer and the first doped poly layer.

9. The electrode structure of claim 8, wherein the second doped dielectric layer, the third doped dielectric layer, the first doped polycrystalline layer, the first doped dielectric layer and the second doped polycrystalline layer are of the same doping type, and the doping concentration of the second doped dielectric layer, the doping concentration of the third doped dielectric layer, the doping concentration of the first doped polycrystalline layer, the doping concentration of the first doped dielectric layer and the doping concentration of the second doped polycrystalline layer are in a sequentially increasing gradient relationship.

10. The electrode structure of claim 8, wherein the material of the first, second and third doped dielectric layers respectively comprises silicon oxide, silicon nitride or a combination thereof.

11. The electrode structure of claim 8, wherein the first doped poly layer has a thickness of 5nm to 20nm, the second doped poly layer has a thickness of 5nm to 15nm, the first doped dielectric layer has a thickness of 70nm to 200nm, the second doped dielectric layer has a thickness of 1nm to 2nm, and the third doped dielectric layer has a thickness of 1nm to 10 nm.

12. The electrode structure of claim 1, further comprising:

a passivation layer between the electrode and the second doped polycrystalline layer, wherein the electrode is electrically connected to the multi-layered doped polycrystalline structure through the passivation layer.

13. The electrode structure of claim 12, wherein the passivation layer has at least one opening therein, and the electrode fills the at least one opening.

14. The electrode structure of claim 13, wherein the passivation layer has an aperture ratio of less than 3%.

15. The electrode structure of claim 13, wherein the at least one opening has a pore size of 1 μ ι η to 15 μ ι η.

16. The electrode structure of claim 13, wherein the at least one opening is plural in number, and the pitch of the plural openings is 50 μm to 100 μm.

17. The electrode structure of claim 1, wherein the connection location of the electrode to the multi-layered doped polycrystalline structure ranges from a surface of a side of the second doped polycrystalline layer distal from the first doped dielectric layer to a surface of a side of the first doped polycrystalline layer adjacent to the first doped dielectric layer.

18. A solar cell structure comprising:

a substrate having a first side and a second side, wherein the substrate comprises a first region and a second region on the second side;

a first electrode structure located in the first region and comprising:

a first multi-layered doped polycrystalline structure comprising:

a first doped poly layer on the substrate of the second side;

a first electrode located on a side of the second doped polycrystalline layer away from the first doped dielectric layer and electrically connected to the first multi-layered doped polycrystalline structure; and

and the second electrode structure is positioned in the second area, wherein the first electrode structure and the second electrode structure are of different doping types.

19. The solar cell structure of claim 18, wherein the first electrode structure and the substrate are of different doping types and the second electrode structure and the substrate are of the same doping type.

20. The solar cell structure of claim 18, wherein the first electrode structure is the same doping type as the substrate and the second electrode structure is a different doping type than the substrate.

21. The solar cell structure of claim 18, wherein the second electrode structure comprises:

a doped region in the substrate at the second side; and

the second electrode is electrically connected to the doped region.

22. The solar cell structure of claim 18, wherein the second electrode structure comprises:

a second multi-layered doped polycrystalline structure comprising:

a third doped poly layer on the substrate of the second side;

a fourth doped polycrystalline layer located on the third doped polycrystalline layer, wherein the third doped polycrystalline layer and the fourth doped polycrystalline layer are of the same doping type, and the doping concentration of the fourth doped polycrystalline layer is greater than that of the third doped polycrystalline layer; and

a fourth doped dielectric layer between the third doped poly layer and the fourth doped poly layer; and

and the second electrode is positioned on one side of the fourth doped polycrystalline layer far away from the fourth doped dielectric layer and is electrically connected to the second multi-layer doped polycrystalline structure.

23. The solar cell structure of claim 18, further comprising:

an anti-reflection layer on the substrate of the first side.

24. The solar cell structure of claim 18, further comprising:

a doped region in the substrate at the first side, wherein the doped region is of the same doping type as the substrate.