阅读说明：本技术 晶体硅太阳能电池扩散层及其制备方法、电池、组件 (Crystalline silicon solar cell diffusion layer and preparation method thereof, cell and assembly ) 是由 冯雪 蒋晔 陈颖 付浩然 张柏诚 刘兰兰 王志建 邰艳龙 彭祖军 于 2018-09-10 设计创作，主要内容包括：本发明涉及一种晶体硅太阳能电池扩散层及其制备方法,所述制备方法包括：(1)提供硅片以及扩散源,其中扩散源包括扩散元素；(2)采用打印方法将扩散源置于硅片一表面上而形成第一预制层；(3)对带有第一预制层的硅片进行退火处理,使扩散元素扩散进入硅片中,以形成预制扩散层；(4)采用打印方法将扩散源置于预制扩散层上而形成间隔的第二预制结构；(5)对带有第二预制结构的硅片再次进行退火处理,使扩散元素扩散进入预制扩散层中,得到扩散层；其中,扩散层包括多个连续的单元,每一单元包括相邻的第一扩散结构和第二扩散结构,第一扩散结构的方阻大于第二扩散结构的方阻。本发明在第二扩散结构对应的区域制备电极,可提升接触性能。(The invention relates to a crystalline silicon solar cell diffusion layer and a preparation method thereof, wherein the preparation method comprises the following steps: (1) providing a silicon wafer and a diffusion source, wherein the diffusion source comprises a diffusion element; (2) placing a diffusion source on one surface of a silicon wafer by a printing method to form a first prefabricated layer; (3) annealing the silicon wafer with the first prefabricated layer to enable diffusion elements to diffuse into the silicon wafer so as to form a prefabricated diffusion layer; (4) placing the diffusion source on the prefabricated diffusion layer by adopting a printing method to form a second prefabricated structure at intervals; (5) annealing the silicon wafer with the second prefabricated structure again to enable the diffusion elements to diffuse into the prefabricated diffusion layer to obtain a diffusion layer; the diffusion layer comprises a plurality of continuous units, each unit comprises a first diffusion structure and a second diffusion structure which are adjacent, and the sheet resistance of the first diffusion structure is larger than that of the second diffusion structure. According to the invention, the electrode is prepared in the area corresponding to the second diffusion structure, so that the contact performance can be improved.)

1. A preparation method of a crystalline silicon solar cell diffusion layer is characterized by comprising the following steps:

(1) providing a silicon wafer and a diffusion source, wherein the diffusion source comprises a diffusion element;

(2) placing the diffusion source on one surface of the silicon wafer by adopting a printing method to form a first prefabricated layer;

(3) annealing the silicon wafer with the first prefabricated layer to enable the diffusion elements to diffuse into the silicon wafer so as to form a prefabricated diffusion layer;

(4) placing the diffusion source on the prefabricated diffusion layer by a printing method to form a second prefabricated structure;

(5) annealing the silicon wafer with the second prefabricated structure again to enable the diffusion elements to diffuse into the prefabricated diffusion layer to obtain a diffusion layer; the diffusion layer comprises a first diffusion structure and a second diffusion structure, and the sheet resistance of the first diffusion structure is larger than that of the second diffusion structure.

2. The method for preparing the crystalline silicon solar cell diffusion layer according to claim 1, wherein in the step (1), the thickness of the silicon wafer is 5 μm to 100 μm.

3. The method for preparing the crystalline silicon solar cell diffusion layer according to claim 1, wherein in the step (1), the diffusion element comprises a B element or a P element.

4. The method for preparing the crystalline silicon solar cell diffusion layer according to claim 1, wherein the diffusion source in the step (2) has the same diffusion element as the diffusion source in the step (4).

5. The method of preparing a crystalline silicon solar cell diffusion layer as claimed in claim 1, wherein the thickness of the first pre-fabricated structure is greater than the thickness of the second pre-fabricated structure.

6. The method for preparing the crystalline silicon solar cell diffusion layer according to claim 1, wherein in the step (2) and the step (4), the printing method comprises one of ink direct writing and ink jet printing.

7. The method for preparing the crystalline silicon solar cell diffusion layer according to claim 1, wherein the annealing treatment processes in the step (3) and the step (5) are identical, the annealing treatment temperature is 600-1000 ℃, and the annealing treatment time is 20-120 minutes.

8. The method for preparing the crystalline silicon solar cell diffusion layer as claimed in claim 7, wherein a protective gas is introduced during the annealing treatment, and the protective gas comprises at least one of nitrogen and argon.

9. The method for preparing the crystalline silicon solar cell diffusion layer according to claim 8, wherein the protective gas further comprises oxygen, and the introduction amount of the oxygen is less than or equal to 50%.

10. The method for preparing the crystalline silicon solar cell diffusion layer according to claim 1, further comprising removing the first prefabricated layer remaining on the silicon wafer by using an etching solution after the annealing treatment in the step (3) and before the step (4); and/or

And (5) after the annealing treatment, removing the residual second prefabricated structure on the silicon wafer by using etching solution.

11. The crystalline silicon solar cell diffusion layer obtained by the preparation method according to any one of claims 1 to 10, wherein the diffusion layer comprises a first diffusion structure and a second diffusion structure, the sheet resistance of the first diffusion structure and the sheet resistance of the second diffusion structure are both 20 Ω/□ -110 Ω/□, and the sheet resistance of the first diffusion structure is greater than that of the second diffusion structure.

12. A crystalline silicon solar cell comprising an electrode and the diffusion layer of claim 11, the electrode being disposed on a surface of the second diffusion structure.

13. A solar cell module comprising the crystalline silicon solar cell of claim 12.

Technical Field

The invention relates to the field of solar cells, in particular to a crystalline silicon solar cell diffusion layer, a preparation method thereof, a cell and a component.

Background

The process for manufacturing the crystalline silicon solar cell in a large-scale mode comprises diffusion, and a PN junction obtained after a diffusion layer is formed by diffusion is the heart of the crystalline silicon solar cell and directly influences the electrical property of the crystalline silicon solar cell.

Currently, the crystalline silicon solar cell generally adopts (100) p-type silicon as a base material, and is vertically inserted into a quartz boat back to use liquid phosphorus oxychloride (POCl)₃) As a diffusion source, a phosphorus source is carried into a reaction system by protective gas, and then a diffusion layer is formed in the silicon wafer through thermal diffusion treatment. Wherein, the thermal diffusion treatment is to decompose the phosphorus source at about 1000 ℃ and deposit the phosphorus source on the surface of the silicon wafer, and then carry out knot pushing for a period of time at 800-900 ℃ to form a diffusion layer.

However, with the decreasing thickness of silicon wafers, the ultra-thin silicon wafers cannot be inserted into the quartz boat back-to-back vertically, which causes a great compatibility problem in the above process. In addition, in the thermal diffusion treatment, diffusion layers are formed on both sides and edges of the silicon wafer, and the diffusion layers at the edges can conduct the upper and lower surfaces, so that the battery cannot work normally. In order to ensure the performance of the solar cell, the silicon wafer is generally floated on an acid solution in industrial production to remove the diffusion layer on the back surface and the edge. However, the existing post-cleaning equipment mainly adopts a roller assembly line to remove the diffusion layer on the back and the edge, and the minimum thickness of the silicon wafer is generally required to be 140-160 μm. If the process is adopted to directly etch the ultrathin silicon wafer, the corrosive solution at the bottom of the silicon wafer bypasses the edge of the silicon wafer and reaches the front side of the silicon wafer, so that the diffusion layer on the front side is damaged. Meanwhile, the ultrathin silicon wafer has certain flexibility, so that the ultrathin silicon wafer can be bent to a certain degree between the rollers, and the stability of the etching process is greatly reduced. Therefore, in the prior art, a method for directly growing a diffusion layer exists, but the method has higher equipment cost; the preparation of the diffusion layer can be realized by a method of spin coating the diffusion source or a method of diffusion after coating the diffusion source in a photoetching technology area, but the controllability of the diffusion layer is not high, the diffusion can only be realized in the whole area, and the photoetching technology cost of the diffusion layer is higher and the production efficiency is lower.

Disclosure of Invention

Therefore, the preparation method is not limited by the thickness of the silicon wafer, the controllable preparation of the diffusion layer can be realized, the integrity of the silicon wafer can be ensured, and the sheet resistance of the prepared diffusion layer is controllable.

A preparation method of a crystalline silicon solar cell diffusion layer comprises the following steps:

(1) providing a silicon wafer and a diffusion source, wherein the diffusion source comprises a diffusion element;

(2) placing the diffusion source on one surface of the silicon wafer by adopting a printing method to form a first prefabricated layer;

(3) annealing the silicon wafer with the first prefabricated layer to enable the diffusion elements to diffuse into the silicon wafer so as to form a prefabricated diffusion layer;

(4) placing the diffusion source on the prefabricated diffusion layer by a printing method to form a second prefabricated structure;

(5) annealing the silicon wafer with the second prefabricated structure again to enable the diffusion elements to diffuse into the prefabricated diffusion layer to obtain a diffusion layer; the diffusion layer comprises a first diffusion structure and a second diffusion structure, and the sheet resistance of the first diffusion structure is larger than that of the second diffusion structure.

In one embodiment, in the step (1), the thickness of the silicon wafer is 5 μm to 100 μm.

In one embodiment, in step (1), the diffusion element includes a B element or a P element.

In one embodiment, the diffusion source in step (2) has the same diffusion element as the diffusion source in step (4).

In one embodiment, the first preform layer has a thickness greater than a thickness of the second preform structure.

In one embodiment, in step (2) and step (4), the printing method includes one of direct ink writing and ink jet printing.

In one embodiment, the annealing treatment processes in the step (3) and the step (5) are consistent, the annealing treatment temperature is 600-1000 ℃, and the annealing treatment time is 20-120 minutes.

In one embodiment, a protective gas is introduced during the annealing process, and the protective gas includes at least one of nitrogen and argon.

In one embodiment, the protective gas further comprises oxygen, and the introduction amount of the oxygen is less than or equal to 50%.

In one embodiment, after the annealing treatment in the step (3) and before the step (4), an etching solution is used to remove the first prefabricated layer remaining on the silicon wafer; and/or

And (5) after the annealing treatment, removing the residual second prefabricated structure on the silicon wafer by using etching solution.

The invention realizes the uniform and controllable preparation of the prefabricated layer on the silicon wafer by the printing method without the limitation of the thickness of the silicon wafer. Particularly, when the silicon wafer is an ultrathin silicon wafer, a printing probe of the printing method is not in contact with the silicon wafer, the method for preparing the prefabricated layer in a non-pressure non-contact mode cannot damage the ultrathin silicon wafer, the integrity of the ultrathin silicon wafer is protected, and the reliability of the solar cell diffusion process of the ultrathin silicon wafer is improved.

In the annealing treatment process, the first prefabricated layer and the second prefabricated layer are kept in the printing area and do not deviate, the solvent of the first prefabricated layer and the second prefabricated layer is volatilized, then the diffusion elements are diffused into the silicon wafer, the solid diffusion is realized, the diffusion layer can not be formed on the other surface and the side surface of the silicon wafer, the subsequent complicated cleaning process of the diffusion layer is not needed, the process is simple, the cost is low, the integrity and the process stability of the silicon wafer can be ensured, the repeatability is good, and the practical application value is good.

The crystalline silicon solar cell diffusion layer obtained by the preparation method comprises a first diffusion structure and a second diffusion structure, the sheet resistance of the first diffusion structure and the sheet resistance of the second diffusion structure are both 20 omega/□ -110 omega/□, and the sheet resistance of the first diffusion structure is larger than that of the second diffusion structure.

The diffusion layer comprises the first diffusion structure and the second diffusion structure, and the square resistance of the first diffusion structure is larger than that of the second diffusion structure, so that the open-circuit voltage of the crystalline silicon solar cell can be improved. Moreover, the electrode is prepared on the surface of the second diffusion structure, so that the contact performance with the electrode can be improved, the contact resistance is reduced, the capacity of collecting photoproduction current of the battery is improved, and the electrode is suitable for being applied to high-sensitivity devices, thin film batteries in the aviation field and the like.

A crystalline silicon solar cell comprises an electrode and the diffusion layer, wherein the electrode is arranged on the surface of the second diffusion structure.

The conversion efficiency of the crystalline silicon solar cell is far higher than that of other solar cells, and the crystalline silicon solar cell can be produced in batch, and is high in production efficiency and low in cost.

A solar cell module comprises the crystalline silicon solar cell.

The solar cell module has high electric energy conversion efficiency. In addition, the cost of the crystalline silicon solar cell is reduced, so that the overall cost of the solar cell module is reduced, the power generation cost of the solar cell module is reduced, and the solar cell module has great market competitiveness.

Drawings

FIG. 1 is a flow chart of a process for preparing a crystalline silicon solar cell diffusion layer according to an embodiment of the present invention;

fig. 2 is a flow chart of a preparation process of another embodiment of the crystalline silicon solar cell diffusion layer of the invention.

In the figure: 1. a silicon wafer; 2. a first pre-fabricated layer; 3. prefabricating a diffusion layer; 4. a second prefabricated structure; 5. a diffusion layer; 51. a first diffusion structure; 52. a second diffusion structure.

Detailed Description

The crystalline silicon solar cell diffusion layer provided by the invention, and the preparation method, the cell and the module thereof are further explained below.

As shown in fig. 1, the method for preparing the crystalline silicon solar cell diffusion layer of the embodiment includes:

(1) providing a silicon wafer 1 and a diffusion source, wherein the diffusion source comprises a diffusion element;

(2) placing the diffusion source on one surface of the silicon wafer 1 by adopting a printing method to form a first prefabricated layer 2;

(3) annealing the silicon wafer 1 with the first prefabricated layer 2 to diffuse the diffusion elements into the silicon wafer 1 to form a prefabricated diffusion layer 3;

(4) placing the diffusion source on the prefabricated diffusion layer 3 by a printing method to form a second prefabricated structure 4;

(5) annealing the silicon wafer 1 with the second prefabricated structure 4 again to enable the diffusion elements to diffuse into the prefabricated diffusion layer 4 to obtain a diffusion layer 5; the diffusion layer 5 includes a first diffusion structure 51 and a second diffusion structure 52, and the sheet resistance of the first diffusion structure 51 is greater than that of the second diffusion structure 52.

In the step (1), the thickness of the silicon wafer 1 is not limited, and the preparation method is suitable for mainstream silicon wafers and ultrathin silicon wafers with the thickness of about 160-180 μm at present. Considering that the silicon wafer with the thickness of 5-100 microns has flexibility, the printing method belongs to a non-pressure non-contact additive manufacturing method, and cannot damage the silicon wafer, so that the silicon wafer 1 is preferably an ultrathin silicon wafer with the thickness of 5-100 microns, the controllable preparation of a diffusion layer on the ultrathin silicon wafer can be realized, the cost is low, and the efficiency is high.

The diffusion source is prepared by mixing an organic vehicle with various functional powders, such as phosphorus doped (POCl)₃、P₂O₅) Or boron doping (BBr)₃、BCl₃、B₂H₆Boron powder), or boron-aluminum doped slurry obtained by doping a certain proportion of boron element in aluminum slurry, or a mixture containing phosphorus and silicon and using ethanol/ester as a solvent.

In the diffusion source, the diffusion element includes a B element or a P element. Preferably, when a P-type silicon wafer is used, the diffusion element is a P element to form n⁺A/p-type crystalline silicon solar cell; when an n-type silicon wafer is used, the diffusion element is B element to form p⁺An/n-type crystalline silicon solar cell. The two types of crystalline silicon solar cells have equivalent performances, but n⁺The irradiation resistance of the p-type crystalline silicon solar cell is superior to that of p⁺The/n type crystalline silicon solar cell is more suitable for space application.

In the step (2), the printing method belongs to a non-pressure non-contact additive manufacturing method, and compared with pressure contact type coating methods such as a spin coating method, a screen printing method, an ink jet printing method, a slit coating method, a spraying method, a relief printing method, a gravure printing method and the like, a printing probe of the printing method is not in contact with the silicon wafer, the silicon wafer 1 is not damaged, the uniform first prefabricated layer 2 can be formed on the silicon wafer 1, the method is particularly suitable for ultrathin flexible silicon wafers, and the effect is remarkable. The printing method is not limited, and may be preferably one of direct ink writing and inkjet printing which are easy to handle.

It will be appreciated that the first pre-form layer 2 may be formed by a single pass through the modification of the printing apparatus. On the basis of the existing printing equipment, the first prefabricated layer 2 can be formed by back and forth printing through the printing probe. Under the condition of the same printing speed, the cross-sectional volume of single printing is the same, and at the moment, the distance between the printing probe and the silicon wafer needs to be adjusted to control the aspect ratio (the ratio of the height to the width) of the single printing, so as to control the thickness of the first prefabricated layer 2. Considering that if the aspect ratio is too large during single printing, the diffusion source is easy to spread unevenly and is not beneficial to fully entering the silicon wafer 1 by diffusion elements during diffusion; if the aspect ratio is too small, surface holes are easy to appear in the printing process, so that the diffusion of the diffusion elements in the silicon wafer 1 is not uniform. Therefore, the aspect ratio during single printing is preferably 2:1 to 1:10, the thickness of the formed first prefabricated layer 2 can be controlled, and the uniformity of the formed first prefabricated layer 2 is relatively guaranteed.

In the step (3), the diffusion elements in the first prefabricated layer 2 are diffused into the silicon wafer 1 through annealing treatment, and a prefabricated diffusion layer 3 is formed in the silicon wafer 1. The diffusion process belongs to solid state diffusion, and a diffusion layer is not formed on the other surface and the side surface of the silicon wafer 1, so that the controllable preparation of the prefabricated diffusion layer 3 can be realized.

Specifically, in the annealing process, with the increase of the temperature, the organic carriers in the first prefabricated layer 2 begin to volatilize, then the functional powder begins to melt and keeps good contact with the surface of the silicon wafer 1, and when the silicon wafer 1 reaches a thermal equilibrium state after being melted for a period of time, the diffusion element boron or phosphorus begins to diffuse into the silicon wafer 1. After the annealing treatment is completed, the temperature starts to decrease, and the diffusion elements in the silicon wafer 1 start to precipitate due to saturation, and part of the diffusion elements move in the direction of the original first preform layer 2, thereby forming a concentration gradient. The pre-formed diffusion layer 3 reaches a steady state when the temperature is lowered below the active temperature of the diffusion element.

Preferably, the annealing treatment temperature is 600-1000 ℃ and the time is 20-120 minutes, so as to obtain the prefabricated diffusion layer 3 with proper sheet resistance.

Preferably, a protective gas is introduced during the annealing treatment, and the protective gas comprises at least one of nitrogen and argon.

Preferably, when the diffusion source is phosphorus doped (POCl)₃、P₂O₅) Or boron doping (BBr)₃、BCl₃、B₂H₆Boron powder), oxygen can be introduced into the protective gas, and a thin silicon oxide layer is formed on the surface of the silicon wafer by a thermal oxidation method, so that the solid solubility of the first prefabricated layer 2 in the silicon oxide layer is higher, and the diffusion element can conveniently diffuse into the silicon wafer 1 to form a prefabricated diffusion layer 3 with higher concentration. And the silicon oxide layer can be removed by etching solution such as HF solution after the diffusion is finished. Of course, when the oxygen concentration is too high, it is difficult to control the thickness and the quality of the silicon oxide layer, and therefore, the amount of the introduced oxygen is 50% or less, and more preferably 5% to 50%.

Preferably, the thickness of the first prefabricated layer 2 is greater than or equal to 2 μm, and a more ideal concentration gradient can be formed through annealing treatment, so that the sheet resistance of the prefabricated diffusion layer 3 can be accurately controlled. After the annealing treatment in step (3), the first preform layer 2 may remain on the surface of the silicon wafer 1. The remaining first pre-fabricated layer 2 may be removed using an etching solution, preferably an HF solution. Compared with the violent reaction generated by the traditional cleaning equipment, the integrity of the silicon wafer 1 can be ensured by removing the residual first prefabricated layer 2 by using the etching solution. Moreover, when the silicon wafer 1 belongs to an ultrathin flexible silicon wafer, the stability of the process can be ensured.

In the step (4), when the second preform structure 4 is formed, the diffusion element of the diffusion source is the same as the diffusion element of the diffusion source in the step (2), but the concentration of the diffusion element in the diffusion source in the step (4) is greater than or equal to the concentration of the diffusion element in the diffusion source in the step (2).

Preferably, the thickness of the second preform structure 4 is greater than or equal to 2 μm, and preferably greater than 2 μm, so that a more desirable concentration gradient can be formed by annealing treatment, and the sheet resistance of the second diffusion structure 52 can be accurately controlled. Further, the thickness of the first preformed layer 2 is greater than the thickness of the second preformed structure 4, preventing the second preformed structure 4 from destroying the structure of the preformed diffusion layer 3 during diffusion.

In this embodiment, the second preformed structure 4 is a complete laminated structure.

The temperature for annealing again in the step (5) is 600-1000 ℃, and the time is 20-120 minutes.

It will be appreciated that when the annealing process is performed again in step (5), the pre-formed diffusion layer 3 will continue to diffuse, increasing its diffusion depth in the wafer.

Specifically, the second preform structure 4 may remain on the surface of the silicon wafer 1 after the annealing treatment in the step (5). The remaining second preform 4 can also be removed using an etching solution, preferably an HF solution.

In this embodiment, the diffusion layer 5 obtained by two full-area diffusions includes a first diffusion structure 51 and a second diffusion structure 52, the second diffusion structure 52 constitutes an integral contact surface of the crystalline silicon solar cell, and an electrode can be disposed on the surface of the second diffusion structure 52 according to the requirements of the cell.

It is understood that in other embodiments, the second diffusion structures 52 may be spaced according to the electrode position design of the crystalline silicon solar cell.

Specifically, as shown in fig. 2, in step (4), after forming the spaced second pre-structures 4 on the pre-diffusion layer 3 and annealing again, the resulting diffusion layer 5 includes the first diffusion structures 51 and the second diffusion structures 52, and the second diffusion structures 52 are formed at intervals on the portions of the diffusion layer 5 constituting a contact surface of the crystalline silicon solar cell. Then, an electrode is provided on the surface of the second diffusion structure 52.

In short, the sheet resistance of the second diffusion structure 52 obtained by the embodiment shown in fig. 1 or fig. 2 is low, and the electrodes are arranged on the second diffusion structure 52, so that the contact performance with the electrodes can be improved, the contact resistance can be reduced, the capacity of collecting the photo-generated current of the battery can be improved, and the effect of arranging the electrodes on the contact surface with low sheet resistance formed by one-time diffusion is obviously superior to that of arranging the electrodes on the contact surface with low sheet resistance formed by one-time diffusion.

The invention realizes the uniform and controllable preparation of the prefabricated layer on the silicon wafer by the printing method without the limitation of the thickness of the silicon wafer. Particularly, when the silicon wafer is an ultrathin silicon wafer, a printing probe of the printing method is not in contact with the silicon wafer, the method for preparing the prefabricated layer in a non-pressure non-contact mode cannot damage the ultrathin silicon wafer, the integrity of the ultrathin silicon wafer is protected, and the reliability of the solar cell diffusion process of the ultrathin silicon wafer is improved.

In the annealing treatment process, the first prefabricated layer and the second prefabricated layer are kept in the printing area and do not deviate, the solvent of the first prefabricated layer and the second prefabricated layer is volatilized, then the diffusion elements are diffused into the silicon wafer, the solid diffusion is realized, the diffusion layer can not be formed on the other surface and the side surface of the silicon wafer, the subsequent complicated cleaning process of the diffusion layer is not needed, the process is simple, the cost is low, the integrity and the process stability of the silicon wafer can be ensured, the repeatability is good, and the practical application value is good.

The invention also provides a crystalline silicon solar cell diffusion layer obtained by the preparation method, the diffusion layer comprises a first diffusion structure and a second diffusion structure, the sheet resistance of the first diffusion structure and the sheet resistance of the second diffusion structure are both 20 omega/□ -110 omega/□, and the sheet resistance of the first diffusion structure is larger than that of the second diffusion structure.

Specifically, according to different processes, the second diffusion structures 52 in the obtained diffusion layer constitute a contact surface of the crystalline silicon solar cell, or the second diffusion structures 52 are formed at intervals in the diffusion layer 5 to constitute a contact surface of a part of the crystalline silicon solar cell.

Preferably, when the silicon wafer is an ultra-thin silicon wafer of 5 μm to 100 μm, the diffusion layer is formed. The flexible crystalline silicon solar cell can be prepared on the basis of the ultrathin silicon wafer, and further, the flexible solar cell module can be prepared on the basis of the flexible crystalline silicon solar cell.

The diffusion layer comprises the first diffusion structure and the second diffusion structure, and the square resistance of the first diffusion structure is larger than that of the second diffusion structure, so that the open-circuit voltage of the crystalline silicon solar cell can be improved. Moreover, the electrode is prepared on the surface of the second diffusion structure, so that the contact performance with the electrode can be improved, the contact resistance is reduced, the capacity of collecting photoproduction current of the battery is improved, and the electrode is suitable for being applied to high-sensitivity devices, thin film batteries in the aviation field and the like.

The invention also provides a crystalline silicon solar cell which comprises an electrode and the diffusion layer, wherein the electrode is arranged on the surface of the second diffusion structure.

Preferably, when the silicon wafer is an ultrathin silicon wafer with the thickness of 5-100 μm, the prepared flexible crystalline silicon solar cell is.

The conversion efficiency of the crystalline silicon solar cell is far higher than that of other solar cells, and the crystalline silicon solar cell can be produced in batch, and is high in production efficiency and low in cost.

The invention also provides a solar cell module which comprises the crystalline silicon solar cell.

Specifically, the solar cell module further comprises a substrate, an encapsulating material and the like.

Preferably, when the crystalline silicon solar cell is a flexible crystalline silicon solar cell, a flexible solar cell module can be prepared.

The solar cell module has high electric energy conversion efficiency. In addition, the cost of the crystalline silicon solar cell is reduced, so that the overall cost of the solar cell module is reduced, the power generation cost of the solar cell module is reduced, and the solar cell module has great market competitiveness.

Hereinafter, the crystalline silicon solar cell diffusion layer and the method for preparing the same will be further described by the following specific examples.