TWI737311B - Method of manufacturing solar cell with liquid phase deposition and solar cell thereof - Google Patents

Abstract

A method of manufacturing solar cell with liquid phase deposition and solar cell thereof are provided. The manufacturing method includes following steps: step S1, forming an emitter layer on the light facing face of a substrate; step S2, forming an anti-reflex layer on the surface of one side of the emitter layer away from the substrate through a liquid phase deposition method, such that the solar cell is provided with the substrate, the emitter layer, and the anti-reflex layer. Also, the anti-reflex layer and the emitter layer contact to form a boundary region therebetween. Thus, the liquid phase deposition method is applied for largely reducing the equipment cost and achieving a large area application and a batch-type production process, thereby optimizing the manufacturing efficiency.

Description

Method for manufacturing solar cell by liquid phase deposition and solar cell

The present invention relates to the technical field of solar cells, in particular to a method for manufacturing solar cells by liquid phase deposition and the solar cells.

Solar cells are clean and pollution-free renewable energy sources, and they have developed substantially after the world's oil crisis. However, due to factors such as power generation efficiency, manufacturing costs, and environmental constraints of solar cells, they have not yet reached considerable popularity. Among them, in terms of power generation efficiency and manufacturing cost, solar cells have always had difficulties that cannot be taken into account. Generally speaking, solar cells with good power generation efficiency have higher manufacturing costs; relatively, solar cells with lower manufacturing costs have power generation efficiency. It will be worse. Most of the production technologies use vacuum processes to fabricate solar cell structures. Such process technologies are not only time-consuming, but also higher machine costs.

In addition, the emergence of Passivated Emitter and Rear Cell (PERC) has also opened a new chapter for solar cells, which not only have high photoelectric conversion efficiency, but also cost different from ordinary solar cells. Not too big. It forms an emitter layer on the front surface of the silicon substrate, and uses a vacuum process technology to make an anti-reflection layer on the emitter layer to prevent light from being degraded by reflection before entering the emitter layer, thereby improving the photoelectric conversion. Efficiency, subsequent passivation treatment is performed on the back of the silicon substrate to form a passivation layer, and a protective layer is made on the passivation layer using vacuum process technology to protect the passivation layer from being damaged by subsequent electrode screen printing and sintering.

However, PERC solar cells are also manufactured by vacuum process technology, and the production cost cannot be greatly reduced, and because of the complicated process steps, the production speed and efficiency cannot be effectively improved.

The main purpose of this case is to solve the problem that conventional solar cells cannot be produced in large batches using vacuum process technology, resulting in the inability to reduce costs.

In order to achieve the above objective, the present invention provides a method for manufacturing a solar cell using liquid deposition, which includes step S1 and step S2. Step S1: forming an emitter layer on a light-facing surface of a substrate; Step S2: forming an anti-reflection layer on the surface of the emitter layer away from the substrate by liquid deposition.

Another embodiment of the present invention provides a solar cell, which includes a substrate, an emitter layer, and an anti-reflection layer. The substrate has a light-facing surface and a backlight surface which are arranged oppositely; the emitter layer is arranged on the light-facing surface of the substrate; The reflective layer is in contact with the emitter layer to form a boundary area.

Thereby, the solar cell of the present invention uses a liquid phase deposition method to form an anti-reflection layer on the surface of the emitter layer of the substrate, and can improve the uniformity of the anti-reflection layer molding, thereby enhancing the anti-reflection ability of the anti-reflection layer. Moreover, the present invention The process can greatly reduce equipment costs, and provide the effect of large area and batch mass production, thereby achieving the effect of optimizing process efficiency.

In order to facilitate the description of the central idea of the present invention expressed in the column of the above-mentioned summary of the invention, specific embodiments are used to express it. Various objects in the embodiments are drawn according to the proportions suitable for enumeration and description, rather than according to the proportions of actual elements, and are described first.

1 and 2, the present invention provides a solar cell 100. In this embodiment, a passivated emitter backside cell (PERC) is used as an illustration. The solar cell 100 includes a substrate 10, an emitter layer 20, and One anti-reflective layer 30.

The substrate 10, in this embodiment, a P-type semiconductor is used as an example. The substrate 10 has a light-facing surface 11 and a backlight surface 12 arranged oppositely. As shown in FIG. 1, the light-facing surface 11 and the backlight surface 12 have been cleaned and The etching process, in some embodiments, is to perform an etching process on at least the light-facing surface 11 of the substrate 10 to reduce the reflectivity of the light-facing surface 11.

The emitter layer 20 is an N-type semiconductor in this embodiment, and the emitter layer 20 is disposed on the light-facing surface 11 of the substrate 10.

The anti-reflection layer 30 is formed on the side surface of the emitter layer 20 away from the substrate 10 by a liquid-phase deposition process, and because the liquid-phase deposition method is adopted, the area where the anti-reflection layer 30 and the emitter layer 20 are in contact is formed A junction area 31, as shown in Figure 2. Wherein, the material of the anti-reflection layer 30 can be made of any one of titanium oxide (TiOx), silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiON), and aluminum oxide (AlOx). In an example, the material of the anti-reflection layer 30 is titanium dioxide; the material of the interface layer 31 includes the materials of the anti-reflection layer 20 and the emitter layer 20, and includes titanium dioxide, silicon dioxide and silicon atoms.

In a preferred embodiment, the present invention further includes a passivation layer 40 and a protective layer 50.

The passivation layer 40 is disposed on the backlight surface 12 of the substrate 10, and its material can be aluminum oxide (Al ₂ O ₃ ).

The protective layer 50 can also be formed on the side of the passivation layer 40 away from the substrate 10 by a liquid deposition process. The surface protective layer 50 can be made of the same material as the anti-reflection layer 30 and can be titanium oxide (TiO _x ) or silicon oxide. (SiO _x ), silicon nitride (SiN _x ), silicon oxynitride (SiON), and aluminum oxide (AlO _x ). In this embodiment, the material of the protective layer 50 is also titanium dioxide.

Referring to FIGS. 3 to 5, in addition to the above-mentioned structural embodiments, an embodiment of the present invention provides a method for manufacturing a solar cell 100 by liquid phase deposition, which includes the following steps:

Step S1: An emitter layer 20 is formed on the light-facing surface 11 of the substrate 10, where a pn junction region 21 is formed due to the emitter layer 20 being in contact with the substrate 10, and an oxide film (silicon dioxide) can be formed on the surface of the emitter layer 20. , SiO ₂ ).

Step S2: The anti-reflective layer 30 is formed on the surface of the emitter layer 20 away from the substrate 10 through the liquid-phase deposition method. It is worth noting that the liquid-phase deposition method uses a chemical reaction to deposit the anti-reflective layer 30 on the emitter layer. 20 surface, in this embodiment, the substrate 10 is immersed in a chemical solution. The chemical solution contains ammonium hexafluorotitanate (NH ₄ ) ₂ TiF ₆ and boric acid (H ₃ BO ₃ ), so that the chemical solution can penetrate The surface of the emitter layer 20 is deposited to form an anti-reflection layer 30. The reaction equation of the chemical solution of the present invention can be expressed as the following reaction equation: (NH ₄ ) ₂ TiF ₆ + 2H ₂ O → TiO ₂ + 2NH ₄ F + 4HF H _{3 BO 3 + 4HF → BF 4} - + H 3 O + + 2H 2 O TiF 6 2- + nH 2 O → TiF 6-n (OH) n 2- + nHF

According to the above reaction formula, ammonium hexafluorotitanate chemically reacts to form titanium dioxide, which is deposited on the surface of the emitter layer 20 to form the anti-reflective layer 30. Moreover, the titanium dioxide can react with the silicon dioxide on the surface of the emitter layer 20 to make it anti-reflective. The layer 30 is in contact with the emitter layer 20 to form a boundary area 31 to improve the anti-reflection effect of the anti-reflection layer 30, so that the anti-reflection layer 30 has better anti-reflection ability.

Thereby, the solar cell 100 of the present invention uses the liquid deposition method to form the anti-reflection layer 30 on the surface of the emitter layer 20 of the substrate 10, and can improve the uniformity of the anti-reflection layer 30, thereby enhancing the anti-reflection layer 30's anti-reflection. In addition, the manufacturing process of the present invention can greatly reduce equipment cost, and provide the utility of large area and batch mass production, thereby achieving the effect of optimizing the process efficiency.

In addition, the present invention further tests the reflection efficiency of solar cells 100 and flat panel solar cells using plasma chemical vapor deposition. Among them, the present invention uses solar cells 100 as the experimental group and plasma chemical vapor deposition of flat solar cells As an explanation of the control group, please refer to Figure 6. The test results show that the average reflectivity of the experimental group is 1.63%, and the average reflectivity of the control group is 1.02%, which means that the reflectivity of the solar cell 100 of the present invention is The reflectivity of the flat panel solar cells deposited by plasma chemical vapor deposition differs only by 0.61%. Obviously, the process of the present invention can provide the anti-reflection layer 30 with good anti-reflection ability, and can effectively reduce the light reflection benefit of the anti-reflection layer 30.

As shown in FIGS. 3 and 4, in a preferred embodiment, the present invention further includes a step P1 between step S1 and step S2.

Step P1: A passivation layer 40 is formed on the backlight surface 12 of the substrate 10, and the passivation layer 40 and the emitter layer 20 are respectively disposed on both sides of the substrate 10. In this embodiment, the passivation layer 40 is made of aluminum oxide (Al ₂ O ₃ ), and use non-vacuum atomic layer deposition technology to perform surface chemical passivation and field-effect passivation treatments on the backlight surface 12 of the substrate 10; then in step S2 of this embodiment, the passivation layer 40 is kept away from the substrate at the same time through the aforementioned liquid deposition method A protective layer 50 is formed on one side surface of 10, that is, the protective layer 50 and the anti-reflection layer 30 are deposited on the surface of the passivation layer 40 and the surface of the emitter layer 20 at the same time, thereby saving the separate manufacturing process of the protective layer 50 and the anti-reflection layer 30 Steps to achieve the effect of effectively optimizing process efficiency.

As shown in FIGS. 3 and 5, in a preferred embodiment, the present invention further includes a step P2 after step S2.

Step P2: The protective layer 50 and the passivation layer 40 are penetrated with a plurality of openings 51 that contact the backlight surface 12 of the substrate 10, which helps the back metal to form a back electric field during screen printing and sintering, and then protect the surface of the anti-reflection layer 30 A first electrode 60 and a second electrode 61 are respectively formed on the surface of the layer 50, and the second electrode 61 is filled in the opening 51 of the protective layer 50 and contacts the backlight surface 12 of the substrate 10. In a preferred embodiment, the first electrode 61 One electrode 60 is a silver electrode, and the second electrode 61 is an aluminum electrode, and they are respectively formed on the surface of the anti-reflection layer 30 and the surface of the protective layer 50 through screen printing, and then the solar cell 100 is placed in an environment of 200~900°C Perform annealing treatment.

Therefore, the present invention has the following effects:

1. The present invention uses the liquid deposition method to improve the uniformity of the anti-reflection layer 30, so as to provide the anti-reflection layer 30 with good anti-reflection ability and effectively reduce the light reflection benefit of the anti-reflection layer 30; in addition, , The liquid deposition method is a non-vacuum process, which can effectively reduce the requirements of the process environment, process time and machine cost.

2. The process method of the present invention enables the protective layer 50 and the anti-reflection layer 30 to be deposited on the surface of the passivation layer 40 and the surface of the emitter layer 20 at the same time, thereby reducing the process steps and achieving the effect of effectively optimizing process efficiency.

The above-mentioned embodiments are only used to illustrate the present invention, and are not used to limit the scope of the present invention. All modifications or changes made without violating the spirit of the present invention fall within the scope of the present invention's intended protection.

100: solar cell

50: protective layer

10: substrate

51: Hole

11: Glossy side

60: first electrode

12: Backlight

61: second electrode

20: Emitter layer

S1: Step

21: p-n junction area

S2: Step

30: Anti-reflective layer

P1: Step

31: Junction area

P2: Step

40: passivation layer

Fig. 1 is a schematic structural diagram of an embodiment of the present invention. Figure 2 is a partial enlarged view of Figure 1. Fig. 3 is a flow chart of an embodiment of the present invention. Fig. 4 is a schematic diagram (1) of the operation of the embodiment of the present invention. Fig. 5 is a schematic diagram (2) of the operation of the embodiment of the present invention. Fig. 6 is a comparison diagram of reflectance of an embodiment of the present invention.

S1: Step

S2: Step

P1: Step

P2: Step

Claims (8)

A method for manufacturing solar cells by liquid deposition, which includes the following steps: Step S1: forming an emitter layer on a light-facing surface of a substrate; Step P1: forming a passivation layer on a back light surface of the substrate to make The passivation layer is arranged opposite to the emitter layer, and the passivation layer is aluminum oxide; and step S2: simultaneously forming an anti-reflection layer on the side surface of the emitter layer away from the substrate through the liquid deposition method, and A protective layer is formed on the side surface of the passivation layer away from the substrate. The anti-reflection layer and the protective layer are made of the same material, and both are titanium dioxide. The method for manufacturing solar cells using liquid phase deposition as described in claim 1, wherein in step S2, the substrate is immersed in a chemical solution so that the chemical solution can penetrate the surface of the emitter layer and The anti-reflection layer is formed by deposition, and the anti-reflection layer is in contact with the emitter layer to form a boundary area. The method for manufacturing a solar cell by liquid phase deposition as described in claim 2, wherein the boundary area is composed of titanium dioxide, silicon dioxide and silicon atoms. The method for manufacturing a solar cell using liquid phase deposition as described in claim 1, wherein after the step S2, it further includes a step P2: the step P2: the protective layer and the passivation layer are penetrated with a plurality of contacts to the backlight A first electrode and a second electrode are respectively formed on the surface of the anti-reflection layer and the surface of the protective layer, and the second electrode is filled in the openings and contacts the backlight surface of the substrate. A solar cell includes: a substrate having a light-facing surface and a backlight surface arranged oppositely; An emitter layer, which is arranged on the light-facing surface of the substrate; a passivation layer, which is arranged on the backlight surface of the substrate, the passivation layer is aluminum oxide; and an anti-reflection layer, which is formed on the substrate by liquid deposition processing The emitter layer is away from a side surface of the substrate, and the anti-reflection layer is in contact with the emitter layer to form a boundary area; and a protective layer is formed on the passivation layer away from the substrate by a liquid deposition process One side surface, and the anti-reflection layer and the protective layer are simultaneously arranged on the surface of the emitter layer and the surface of the passivation layer. The solar cell according to claim 5, wherein the substrate is immersed in a chemical solution that can penetrate the surface of the emitter layer and deposit to form the anti-reflection layer, and the anti-reflection layer and the emitter The boundary area is formed between the layers. The solar cell according to claim 6, wherein the anti-reflection layer and the protective layer are made of the same material, and both are titanium dioxide. The solar cell according to claim 7, wherein the boundary area is composed of titanium dioxide, silicon dioxide and silicon atoms.

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