CN118380481B

CN118380481B - Solar cell

Info

Publication number: CN118380481B
Application number: CN202410804760.1A
Authority: CN
Inventors: 刘生璞; 陈军; 杨天子; 丁森; 宋帮浩; 王永谦
Original assignee: Zhuhai Fushan Aixu Solar Energy Technology Co Ltd
Current assignee: Zhuhai Fushan Aixu Solar Energy Technology Co Ltd
Priority date: 2024-06-21
Filing date: 2024-06-21
Publication date: 2024-09-17
Anticipated expiration: 2044-06-21
Also published as: CN118380481A

Abstract

The invention is applicable to the technical field of photovoltaics, and provides a solar cell, wherein at least one surface of the solar cell comprises a plurality of repeated areas, each repeated area comprises a plurality of PNG units, each PNG unit comprises an N area, a P area and a G area, at least any two PNG units are respectively a first unit and a second unit, and the first unit and the second unit meet at least one of the following conditions: the widths of the P areas are different; the widths of the N areas are different; the width of the G region is not the same. The width difference of the N area and the P area is adjusted, so that the light absorption range and the photoelectric conversion efficiency of the solar cell can be improved, the light energy resource is utilized to the greatest extent, and the collection probability of the photo-generated current is greatly increased while the productivity is not influenced; and the efficiency change ratio of the battery to the component and the yield of the battery piece and the component are improved.

Description

Solar cell

Technical Field

The invention belongs to the technical field of photovoltaics, and particularly relates to a solar cell.

Background

The back junction cell utilizes photoetching technology to respectively carry out phosphorus and boron local diffusion on the back of the cell, and a P region and an N region which are arranged in an interdigitated manner, and a P+ region and an n+ region which are positioned above the P region and the N region are formed. The P+ and N+ regions formed by re-expansion can effectively eliminate the voltage saturation effect under the high concentration condition. In addition, the coverage area of the contact electrodes of the P+ and N+ regions almost reaches 1/2 of the back surface, and the series resistance is greatly reduced. And a G region is arranged between the P region and the N region to form a gap, so that the separation efficiency of photo-generated charge carriers is improved, and the recombination loss is reduced.

At present, a single PNG structure is generally used in a thin gate region of a back junction battery, and different regions (such as edges and the like) of a battery piece have different carrier collecting capacities, so that the current battery piece structure cannot realize the maximization of carrier collection and has low collecting efficiency.

Disclosure of Invention

The invention provides a solar cell, which aims to solve the problems that the cell structure can not realize the maximization of carrier collection and the collection efficiency is low.

The invention is realized in such a way that at least one side of the solar cell comprises a plurality of repeated areas, the repeated areas comprise a plurality of PNG units, the PNG units comprise an N area, a P area and a G area, at least any two PNG units are respectively a first unit and a second unit, and the first unit and the second unit meet at least one of the following:

the widths of the P areas are different;

the widths of the N areas are different;

The G region width is different.

Optionally, the P-region width and/or the N-region width of the first cell and the second cell are different, and the G-region width of the first cell and the second cell are the same.

Optionally, each of the repeating areas includes one first unit and at least three second units.

Optionally, the total width of the first unit is 1 to 3 times the total width of the second unit.

Optionally, the width of the P region in the first unit is 0.3 to 3 times the width of the P region in the second unit; the width of the N region in the first cell is 0.3 to 3 times the width of the N region in the second cell.

Optionally, the width ratio of the N region and the P region in each PNG unit is 2:8 to 8:2.

Optionally, the two adjacent sides of the N region are respectively provided with a G region.

Optionally, metal gate lines are respectively arranged in the P region and the N region in each PNG unit, and the distance between each metal gate line and the adjacent G region is greater than 0.

Optionally, the width of the metal gate line of the P region in the first cell and the width of the metal gate line of the P region in the second cell are in a ratio of 0.05:20; the ratio of the width of the metal gate line of the N region in the first cell to the width of the metal gate line of the N region in the second cell is 0.05:20.

Optionally, the distance between the metal gate line and the adjacent G region is not less than 25 μm.

The invention has the beneficial effects that as at least one solar cell comprises a plurality of repeated areas, each repeated area comprises at least two PNG units, and each PNG unit comprises an N area, a P area and a G area. In this design, any two PNG units are defined as a first unit and a second unit, respectively, and there may be a difference in at least any one of the P-region width, the N-region width, and the G-region width of the first unit and the second unit. The width difference of the N area, the P area and the G area is adjusted, so that the light absorption range and the photoelectric conversion efficiency of the solar cell can be improved, the light energy resource is utilized to the greatest extent, and the collection probability of the photo-generated current is greatly increased while the productivity is not influenced; and the efficiency change ratio of the battery to the component and the yield of the battery piece and the component are improved.

Drawings

Fig. 1 is a schematic structural view of a repeating region of a first solar cell provided in the present invention;

FIG. 2 is a schematic view of the structure of the repeating area of a second solar cell according to the present invention;

FIG. 3 is a schematic view of the structure of a repeating area of a third solar cell provided by the present invention;

FIG. 4 is a schematic view of the structure of a repeating area of a fourth solar cell provided by the present invention;

Fig. 5 is a schematic structural view of a repeating region of a fifth solar cell according to the present invention.

Reference numerals illustrate:

100. a repeat region; 101. a first unit; 102. and a second unit.

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. Examples of the embodiments are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements throughout or elements having like or similar functionality. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the invention. Furthermore, it should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the present invention.

In the description of the present invention, it should be understood that the terms "length," "width," "upper," "lower," "left," "right," "horizontal," "top," "bottom," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically connected, electrically connected or can be communicated with each other; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present invention, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

The following disclosure provides many different embodiments, or examples, for implementing different structures of the invention. In order to simplify the present disclosure, components and arrangements of specific examples are described below. They are, of course, merely examples and are not intended to limit the invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples, which are for the purpose of brevity and clarity, and which do not themselves indicate the relationship between the various embodiments and/or arrangements discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

The invention is characterized in that at least one solar cell comprises a plurality of repeated areas, each repeated area comprises at least two PNG units, and each PNG unit comprises an N area, a P area and a G area. In this design, any two PNG units are defined as a first unit and a second unit, respectively, and there may be a difference in at least any one of the P-region width, the N-region width, and the G-region width of the first unit and the second unit. The width difference of the N area, the P area and the G area is adjusted, so that the light absorption range and the photoelectric conversion efficiency of the solar cell can be improved, the light energy resource is utilized to the greatest extent, and the collection probability of the photo-generated current is greatly increased while the productivity is not influenced; and the efficiency change ratio of the battery to the component and the yield of the battery piece and the component are improved.

Example 1

The present embodiment provides a solar cell, where at least one side of the solar cell includes a plurality of repeating areas 100, where the repeating areas 100 include a plurality of PNG units, where the PNG units include an N area, a P area, and a G area, at least any two PNG units are a first unit 101 and a second unit 102, respectively, and the first unit 101 and the second unit 102 satisfy at least one of the following:

the widths of the P areas are different;

the widths of the N areas are different;

The G region width is different.

A plurality of repeating areas 100 are provided on one or both sides of the solar cell panel, each repeating area 100 includes two or more PNG units, each of the repeating areas 100 includes PNG units identical to PNG units included in other repeating areas 100, and a plurality of identical repeating areas 100 are repeatedly provided. It will be appreciated that the repeat region 100 need not be fully populated with cells, and that a portion of the cells may not be comprised of the repeat region 100.

Each PNG unit comprises an N region, a P region and a G region, wherein the N region is called N-type semiconductor region, can be an N-type doped region formed by diffusion doping, can be an N-type silicon substrate, and can be an N+ region formed by ion implantation or other modes; the English of the P region is called as P-type semiconductor, which can be a P-type doped region formed by diffusion doping, a P-type silicon substrate, a P+ aluminum back surface field formed by aluminum paste sintering, and a P+ region formed by ion implantation or other modes; the G region, namely the GAP region, is also called a photo-generated charge separation layer, can be an undoped silicon base region, a shallow doped region and other electrical poor conductor structures, and is positioned between the P region and the N region, so that the separation of PN junctions in space is realized, and the problem of electric leakage of P, N contact regions is effectively solved.

Any two PNG units are a first unit 101 and a second unit 102, respectively, and the first unit 101 and the second unit 102 are disposed adjacently. Specifically, the widths of the P regions of the first unit 101 and the second unit 102 are different but the widths of the N regions are the same, as shown in fig. 1; it is also possible that the widths of the N regions of the first cell 101 and the second cell 102 are different but the widths of the P regions are the same, as shown in fig. 2; it is also possible that the widths of the P region and the N region of the first unit 101 and the second unit 102 are different, but the widths of the P region and the N region in the first unit 101 are the same, and the widths of the P region and the N region in the second unit 102 are different, as shown in fig. 3; it is also possible that the widths of the P region and the N region of the first unit 101 and the second unit 102 are different, but the widths of the P region and the N region in the second unit 102 are the same, and the widths of the P region and the N region in the first unit 101 are different, as shown in fig. 4; it is also possible that the widths of the P region and the N region of the first unit 101 and the second unit 102 are different, and the widths of the P region and the N region in the first unit 101 are the same, and the widths of the P region and the N region in the second unit 102 are the same, as shown in fig. 5. The above examples include two cases when the widths of the P regions of the first cell 101 and the second cell 102 are the same or different, respectively.

Specifically, the N region, the P region and the G region in the PNG unit may be tiled on the same plane, or may be partially overlapped.

In the embodiment, the solar cell can be realized by adopting different materials and processes, and the charge separation efficiency and the electric energy output performance of the solar cell under different illumination conditions can be adjusted by precisely controlling the widths of the N region, the P region and the G region. For example, the charge transport and current collection effects may be optimized by controlling the width of the P region to improve the photoelectric conversion efficiency of the battery. In addition, by adjusting the width differences of the N region, the P region, and the G region, the light absorption range and the photoelectric conversion efficiency of the solar cell can be improved, and the light energy resources can be utilized to the maximum extent. The collection probability of the photo-generated current is greatly increased while the productivity is not influenced; and the efficiency change ratio of the battery to the component and the yield of the battery piece and the component are improved.

The structural dimensions of the N, P and G regions can be precisely defined and controlled during fabrication by advanced process techniques, such as photolithography and chemical deposition. Meanwhile, the material selection is also important, and high-efficiency photovoltaic materials such as silicon, cadmium selenide or gallium arsenide can be adopted to realize higher photoelectric conversion efficiency.

It will be appreciated that such a design may optimize the performance of the solar cell, improving its stability and flexibility in light conditions. By adjusting the widths of the N area, the P area and the G area to be different, the fine adjustment of the battery characteristics can be realized, so that the requirements of different application scenes can be met. In the photovoltaic field, the design can provide new ideas and possibilities for research and development of solar cells, and is helpful for promoting progress and application of solar photovoltaic technology.

Example two

On the basis of the first embodiment, the P-region width and/or the N-region width of the first unit 101 and the second unit 102 are different, and the G-region width of the first unit 101 and the second unit 102 are the same.

The width of the G region is an important parameter in the solar cell, and the narrower G region can promote the rapid separation of photo-generated charge carriers and prevent charge recombination, so that the smaller G region width is beneficial to improving the photoelectric conversion efficiency of the cell, but can increase the resistance and influence the current collecting effect of the current.

Maintaining the same width for each G-zone ensures uniformity and consistency of cell structure, helps control and optimize cell performance during production, and reduces non-uniformity effects that occur in different zones. The G region with the same width can simplify the manufacturing process, does not need extra process steps to adjust the sizes of different regions, is more convenient for arranging the battery pieces, is favorable for improving the production efficiency and reduces the production cost.

Example III

On the basis of the first embodiment, each of the repetition areas 100 includes one first unit 101 and at least three second units 102.

In the simulation experiment of the photovoltaic cell, the theoretical efficiency of the PNG unit with the width of 1.2mm is 26.914%, the theoretical efficiency of the PNG unit with the width of 0.8mm is 27.132%, and the efficiency of the PNG unit is 27.088% by matching 3 modes of 0.8mm and 1 mode of 1.2mm, so that the efficiency is reduced by less than 0.05%, the efficiency loss is small, and the electrical yield of the cell can be greatly improved.

The actual efficiency of the PNG unit can be estimated by:

Assuming that two PNG elements are pitch1 and pitch2, respectively, the PNG unit theoretical photoelectric conversion efficiency of pitch1 width w ₁ is: eta ₁;

The theoretical photoelectric conversion efficiency of the PNG unit with the width of Pitch2 of w ₂ is as follows: eta ₂;

When the minimum repetitive region 100 contains n ₁ Pitch1 and n ₂ Pitch2, the efficiency can be estimated to be the arithmetic average Eta=(n₁×w₁×Eta₁+n₂×w₂×Eta₁)/(n₁×w₁+n₂×w₂),, the process suitable for production can be calculated according to the calculated efficiency value and yield value, if the expected efficiency value is Eta ₁, the structure of (Eta-Eta ₁) <0.05% is selected as the design.

According to experimental data, when the number ratio of the first unit 101 to the second unit 102 in the repetition area 100 is greater than 1:3, the effect on efficiency is small, and the improvement effect on the electrical yield of the battery piece is obvious. Specifically, the number proportion can be calculated according to the actual requirement through the calculation formula.

Example IV

On the basis of the first embodiment, the total width of the first unit 101 is 1 to 3 times the total width of the second unit 102.

In the simulation experiment of the photovoltaic cell, the theoretical efficiency of the PNG unit with the width of 0.4mm is found to be 27.23%, if a combination of 1 PNG unit with the width of 0.4mm and 1 PNG unit with the width of 1.3mm is used, the efficiency is 27.01%, the efficiency reduction value reaches 0.22%, the efficiency loss is excessive, and the requirement of improving the efficiency of the cell design cannot be met.

Specifically, the total width of the first unit 101 may be greater than the total width of the second unit 102, and when the total width of the first unit 101 is not greater than three times the total width of the second unit 102 through laboratory verification, the influence on the battery cell efficiency is small.

The total width of the first unit 101 and the total width of the second unit 102 may be the same, specifically, the width of the N region of the first unit 101 and the width of the P region of the second unit 102 coincide, and the width of the N region of the second unit 102 and the width of the P region of the first unit 101 coincide. The width in particular may be set according to the actual use requirements.

Example five

On the basis of the first embodiment, the width of the P region in the first unit 101 is 0.3 to 3 times the width of the P region in the second unit 102; the width of the N region in the first cell 101 is 0.3 to 3 times the width of the N region in the second cell 102.

The width of the P region in the first cell 101 may be smaller than the width of the P region in the second cell 102, for example, the width of the P region in the first cell 101 is 0.3 times the width of the P region in the second cell 102; the width of the P region in the first cell 101 may be greater than the width of the P region in the second cell 102, for example, the width of the P region in the first cell 101 is 3 times the width of the P region in the second cell 102. According to laboratory data, when the width of the P region in the first unit 101 is 0.3 to 3 times that of the P region in the second unit 102, the effect on the battery efficiency is small, and the battery appearance is also more attractive.

The width of the N region in the first cell 101 may be smaller than the width of the N region in the second cell 102, for example, the width of the N region in the first cell 101 is 0.3 times the width of the N region in the second cell 102; the width of the N region in the first cell 101 may be greater than the width of the N region in the second cell 102, for example, the width of the N region in the first cell 101 is 3 times the width of the N region in the second cell 102. According to laboratory data, when the width of the N region in the first unit 101 is 0.3 to 3 times that of the N region in the second unit 102, the influence on the battery efficiency is small, and the battery appearance is also more attractive.

The ratio of the width of the P region in the first unit 101 to the width of the P region in the second unit 102, and the ratio of the width of the N region in the first unit 101 to the width of the N region in the second unit 102 may be set according to actual use requirements.

Example six

On the basis of the first embodiment, the width ratio of the N region and the P region in each PNG unit is 2:8 to 8:2.

In simulation experiments of photovoltaic cells, it was found that a pitch cell with a width of 1.2mm, where the ratio of width of the P region to the N region was 1:1, had an efficiency of 26.95%; when the width ratio of the P area to the N area is 1:5, the efficiency is 26.63%, the efficiency reduction value is 0.32%, the efficiency loss is overlarge, and the requirement of improving the efficiency of the battery design cannot be met; when the width ratio of the P area to the N area is 5:1, the efficiency is 26.71%, the efficiency reduction value is 0.24%, the efficiency loss is overlarge, and the requirement of improving the efficiency of the battery design cannot be met.

According to laboratory data, when the width ratio of the N area to the P area in each pitch unit is 2:8-8:2, the influence on the battery efficiency is small, and the appearance of the battery is attractive.

Specifically, in a PNG unit, the width of the N region may be greater than the width of the P region, e.g., the ratio of the width of the N region to the width of the P region may be 6:4; the width of the N region may also be equal to the width of the P region, e.g., the ratio of the width of the N region to the width of the P region may be 1:1; the width of the N region may also be smaller than the width of the P region, e.g., the ratio of the width of the N region to the width of the P region may be 4:6.

Example seven

On the basis of the first embodiment, the adjacent two sides of the N region are respectively provided with a G region.

The G region is arranged to form a gap between the P region and the N region, and in the same PNG unit, the G region is arranged between the P region and the N region, and in the adjacent PNG units, the N region of the previous unit is adjacent to the P region of the next unit. G areas are respectively arranged on two adjacent sides of the N area, so that any adjacent P area and N area can be ensured to be separated by the G area.

Example eight

On the basis of the first embodiment, metal gate lines are respectively arranged in the P region and the N region in each PNG unit, and the distance between each metal gate line and the adjacent G region is greater than 0.

The metal grid line is arranged in the P area and the N area, is a conducting wire used for carrying current and conducts the current through contact with the P area or the N area.

In particular embodiments, the design details of the solar cell structure are of paramount importance. For the P region and the N region in each PNG unit, the arrangement of the metal grid line not only can improve the electric conduction performance of the electric joint, but also can effectively collect and conduct photo-generated charges. The metal grid line material can be selected from metals with excellent conductivity and strong oxidation resistance, such as silver, aluminum, copper and the like, so as to ensure long-term stable electrical performance and environmental corrosion resistance.

Further, the metal gate lines are respectively disposed at intermediate positions of the P region and the N region and are kept at a certain distance, not only to maintain independence of electrical properties but also to prevent occurrence of electrical faults such as short circuits. It should be appreciated that such layout design may be implemented by sophisticated photolithography and deposition techniques to ensure that the location and distance of each metal gate line meets the design requirements. These processes can be implemented by a high-precision PLC control device to ensure the manufacturing precision of each PNG unit.

In addition, in practical application, the metal grid lines corresponding to the P region and the N region respectively have good conductivity, and also need to have certain mechanical strength and flexibility so as to adapt to various operations of the solar cell in the production and installation processes. It will be appreciated that the choice of suitable metallic materials and structural design is particularly critical, as well as a requirement to improve overall performance and reliability of the battery.

In actual operation, the distance between the metal grid line of the P region and the adjacent G region is kept to be larger than 0, so that the recombination loss of the photo-generated carriers in the battery structure can be effectively avoided, the current collection efficiency is improved, the internal stress concentration can be reduced, and the mechanical stability of the battery is improved.

Through the detailed design of the embodiment, the solar cell can be optimized in various aspects such as photoelectric conversion efficiency, long-term reliability, environmental adaptability and the like. The structural design not only improves the working stability and the current collection efficiency of the solar cell, but also provides reliable technical reference and design theory for the solar cell research and development with higher efficiency in the future.

In one embodiment, the metal gate line is spaced from the adjacent G-region by a distance greater than or equal to 25 μm.25 μm is a safe distance, avoiding the metal wire being set in the G region, and being unable to conduct current.

Example nine

Based on the eighth embodiment, the width of the metal gate line of the P region in the first cell 101 and the width of the metal gate line of the P region in the second cell 102 are in a ratio of 0.05:20; the ratio of the width of the metal gate line in the N region of the first cell 101 to the width of the metal gate line in the N region of the second cell 102 is 0.05:20.

In this embodiment, the proportional relationship of the metal gate line width between different cells in the solar cell is further described. Specifically, the ratio of the width of the P-region metal gate line in the first cell 101 to the width of the P-region metal gate line in the second cell 102 is 0.05:20; similarly, the ratio of the N-region metal gate line width in the first cell 101 to the N-region metal gate line width in the second cell 102 is also 0.05:20. This design detail can be understood to optimize the overall performance of the solar cell by varying the width of the different cell metal grids.

The advantage is that by designing metal gate lines of different widths between the first cell 101 and the second cell 102, the collection path of the current can be optimized, improving the collection efficiency of the charge carriers.

The metal grid lines with narrower width have higher density in specific areas, and the current collection capability of small areas is improved. The arrangement of metal gate lines with different widths can help to reduce the overall circuit resistance, thereby reducing power loss and improving output power. The metal grid lines with different widths can help disperse heat generated in the battery, avoid overheat areas, and improve stability and service life. High-precision photoetching technology and metal deposition technology are adopted to accurately control and manufacture metal grid lines with different widths so as to meet specific proportion requirements. A metal material (such as silver, aluminum or copper) with high conductivity, corrosion resistance and proper mechanical properties is selected to manufacture the metal grid line.

Specifically, the width of the P-region and N-region metal gate lines in the first cell 101: for example, the metal gate lines of the P region and the N region of the first cell 101 may be set to a minimum width, e.g., 10 μm. The P-region and N-region metal gate line width of the second cell 102 is 20 times, i.e., 200 μm, compared to the first cell 101.

Through the design, the overall performance of the solar cell can be more balanced, efficient and stable. This design helps to accommodate electrical performance requirements for different illumination intensities and different installation conditions. This will create a significant width difference between the different cells, affecting the current collection efficiency and the resistive characteristics.

In summary, by controlling the metal gate width ratio design of the solar cell in the first and second units 102, the overall photoelectric conversion efficiency can be significantly improved, and the thermal management and current collection routes are optimized, providing a powerful technical advantage for commercial applications.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention.

Claims

1. The solar cell is characterized in that at least one surface of the solar cell comprises a plurality of repeated areas, the repeated areas comprise a plurality of PNG units, each PNG unit comprises an N area, a P area and a G area, and the G areas are respectively arranged on two adjacent sides of the N area; at least any two PNG units are a first unit and a second unit respectively, and the first unit and the second unit meet at least one of the following:

the widths of the P areas are different;

the widths of the N areas are different;

The widths of the G areas are different;

wherein the total width of the first cells is greater than the total width of the second cells, and each of the repeating areas includes one of the first cells and at least three of the second cells.

2. The solar cell of claim 1, wherein the first cell and the second cell differ in P-region width and/or N-region width, and the first cell and the second cell differ in G-region width.

3. The solar cell of claim 1, wherein the total width of the first cells is 1 to 3 times the total width of the second cells.

4. The solar cell of claim 1, wherein the width of the P-region in the first cell is 0.3 to 3 times the width of the P-region in the second cell; the width of the N region in the first cell is 0.3 to 3 times the width of the N region in the second cell.

5. The solar cell of claim 1, wherein the ratio of the width of the N region to the P region in each PNG unit is 2:8 to 8:2.

6. The solar cell of claim 1, wherein metal gate lines are disposed in each of the PNG units in the P region and the N region, respectively, and the metal gate lines are spaced apart from adjacent G regions by a distance greater than 0.

7. The solar cell of claim 6, wherein a ratio of a width of the metal gate line of the P-region in the first cell to a width of the metal gate line of the P-region in the second cell is 0.05:20; the ratio of the width of the metal gate line of the N region in the first cell to the width of the metal gate line of the N region in the second cell is 0.05:20.

8. The solar cell of claim 6, wherein the metal grid line is at a distance of not less than 25 μm from adjacent the G-region.