JP2009283549A - Method for manufacturing solar cell, and method for manufacturing solar cell module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a solar cell for manufacturing a solar cell for increasing a short-circuiting current and photoelectric conversion efficiency by reducing light reflection by an antireflection film formed from a liquid phase and having a high light reflection reduction effect while preventing deterioration of a curvilinear factor, and allowing evaluation of an electric characteristic of the solar cell and soldering onto an electrode even after formation of the antireflection film; and a method for manufacturing a solar cell module. <P>SOLUTION: This method for manufacturing a solar cell having an antireflection film on a semiconductor substrate includes: a first process of forming an electrode on one principal surface side of the semiconductor substrate having a PN junction part; a second process of selectively forming, in a region covering the electrode on the one principal surface side of the semiconductor substrate, a protective layer repelling a coating liquid for forming the antireflection film; and a third process of forming the antireflection film by applying the coating liquid for forming the antireflection film on the semiconductor substrate with the protective layer formed thereon. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a solar battery cell and a method for manufacturing a solar battery module.

  As a method for producing a crystalline silicon solar cell, the following process is common. First, the surface of the silicon substrate is etched and etched to a depth of several μm to several tens of μm using an ant potassium solution. Next, minute irregularities or grooves having a height difference of several μm to several tens of μm are formed. As a method for forming the irregularities and grooves, for example, texture etching or dicing is performed in which a micro pyramid shape with a height of several μm is formed on the substrate surface by etching using a mixed solution of several wt% sodium hydroxide aqueous solution and alcohol. There are a method of forming a large number of grooves having a depth of several tens of μm on the substrate surface by using an apparatus or a laser, a method by dry etching, and the like. These irregularities and grooves are for reducing the surface reflection during the operation of the completed solar cell and improving the short-circuit current.

Next, in a state where the silicon substrate is placed in a quartz tube heated to about 800 ° C. to 1100 ° C., a liquid impurity source such as phosphorus oxychloride (POCl ₃ ) contained in a bubbler container is put into nitrogen in the quartz tube. It introduces by carrier gas. At this time, a phosphor oxide layer is formed on the substrate surface. At the same time, the phosphorus oxide layer serves as a diffusion source to diffuse phosphorus in the silicon substrate, and a pn junction is formed on the substrate surface side portion. After this diffusion step, a hygroscopic oxide film containing phosphorus as a main component remains on the substrate surface, and this film is removed with hydrofluoric acid.

Thereafter, in order to further reduce surface reflection, an antireflection film is formed on the substrate surface. As an antireflection film at this time, a silicon nitride film (SiN film) formed using a low pressure plasma CVD (chemical vapor deposition) method, or a titanium dioxide film (TiO2) formed using an atmospheric pressure CVD method. ₂ films) and the like are used. For example, when a SiN film is formed by a low pressure plasma CVD method, a carrier gas such as silane, ammonia, or nitrogen is sent, decomposed by plasma, then transported to the substrate surface, and a SiN film is deposited on the substrate surface.

Next, the light-receiving surface side of the substrate is protected with an acid-resistant tape or resist, and an unnecessary joint formed on the back surface side of the substrate in the diffusion step is mixed with nitric acid (HNO ₃ ) -hydrogen fluoride (HF). To remove. Next, an aluminum paste is printed on the back side of the substrate and baked at about 700 ° C. to 800 ° C. to form a back electrode and a P ⁺ layer. Thereafter, a silver paste is printed in a fishbone shape on the substrate surface (light receiving surface) side and fired to form a light receiving surface electrode.

  As a method for producing the antireflection film, there is a simple method as disclosed in JP-A-58-23486 (Patent Document 1). This is made by mixing one volume of tantalum alkoxide, such as tantalum ethylate, and one volume of carboxylic acid, such as glacial acetic acid, or less in a suitable solvent, such as one volume or more of alcohol, and the dielectric tantalate and solvent. Is applied onto the substrate, and the tantalum oxide thin film is obtained by heating at 200 ° C. to 800 ° C.

  Japanese Patent Laid-Open No. 2004-158843 (Patent Document 2) discloses a method of selectively depositing a material on a semiconductor device using an electrophoretic volume process. Specifically, a hydrophobic mask is selectively formed in a region where the deposited film on the surface of the semiconductor device is not desired to be formed, and the region where the mask is formed contacts the chemical solution in the bath for performing the electrophoresis volume process. This is a method of selectively forming a deposited film by avoiding this.

  Furthermore, Japanese Patent Application Laid-Open No. 2005-249882 (Patent Document 3) discloses a method of forming a single-layer antireflection film by applying inorganic oxide fine particles and an organic material of a binder to the surface of a solar cell and thermosetting them. .

JP 58-23486 A JP 2004-158843 A JP 2005-249982 A

  By the way, when producing an antireflection film on a solar cell as described above, particularly when an antireflection film is formed by applying a porous film made of a solution or dispersion as a raw material after forming an electrode on the surface of the substrate. The inventor of the present application has found that the electrical characteristics are lowered by application of a solution or the like on the solar cell substrate when the antireflection film is produced.

  Therefore, the inventor of the present application, as a result of earnest research to investigate the cause, the long-term reliability of the solar cell by the entry of fine particles, dispersion medium, raw material sol, etc. between the electrode and the solar cell substrate, The existence of the problem that the electrical characteristics deteriorate is clarified by the study of the present inventor. Here, the curve factor is a value obtained by dividing the maximum output power of the solar cell by the product of the short-circuit current and the open-circuit voltage. On the other hand, no method has been proposed for preventing the deterioration of electrical characteristics, particularly the deterioration of the fill factor, and the present invention has been reached in order to prevent such deterioration.

  In addition, if an antireflection film is applied to the entire surface of the solar cell substrate, an antireflection film is also formed on the electrode on the surface. After the antireflection film is formed, the electrical characteristics of the solar cell are evaluated. become unable. Furthermore, when an antireflection film is also formed on the electrodes, there is a problem that tabs cannot be attached because it is difficult for solder to adhere to the electrodes of the solar battery cells in the modularization process of the solar battery. To do.

  The present invention has been made in view of the above, and by reducing light reflection by an antireflection film having a high light reflection reduction effect formed from a liquid phase while preventing deterioration of a fill factor, a short circuit current and Solar cell manufacturing method and solar battery capable of increasing the photoelectric conversion efficiency and manufacturing a solar cell capable of evaluating the electrical characteristics of the solar cell and soldering onto the electrode even after the formation of the antireflection film It aims at obtaining the manufacturing method of a module.

  In order to solve the above-described problems and achieve the object, a method for manufacturing a solar cell according to the present invention is a method for manufacturing a solar cell including an antireflection film on a semiconductor substrate, and a PN junction portion is provided. A first step of forming an electrode on one main surface side of the semiconductor substrate, and a region covering the electrode on the one main surface side of the semiconductor substrate with a protective layer for repelling the coating liquid for forming the antireflection film A second step of selectively forming the anti-reflection film, and a third step of applying the anti-reflection film on the semiconductor substrate on which the protective layer has been formed. It is characterized by including.

  According to the present invention, the short circuit current and the photoelectric conversion efficiency can be increased by reducing the light reflection by the antireflection film having a high light reflection reducing effect formed from the liquid phase while preventing the deterioration of the fill factor. In addition, it is possible to obtain a solar cell capable of evaluating the electrical characteristics of the solar cell and soldering on the electrode even after the antireflection film is formed.

  EMBODIMENT OF THE INVENTION Below, embodiment of the manufacturing method of the photovoltaic cell concerning this invention and the manufacturing method of a solar cell module is described in detail based on drawing. In addition, this invention is not limited to the following description, In the range which does not deviate from the summary of this invention, it can change suitably. In the drawings shown below, the scale of each member may be different from the actual scale for easy understanding. The same applies between the drawings.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view showing a schematic configuration of the solar battery cell according to the first embodiment of the present invention. The solar cell according to the first embodiment includes a semiconductor substrate 1 that is a solar battery substrate and has a pn junction, and a first antireflection film 2 formed on a surface (front surface) on the light receiving surface side of the semiconductor substrate 1. The back surface electrode 3 formed on the surface (back surface) opposite to the light receiving surface of the semiconductor substrate 1 and the surface (front surface) on the light receiving surface side of the semiconductor substrate 1 are surrounded by the first antireflection film 2. A light receiving surface side electrode 4 and a second antireflection film 6 formed on the first antireflection film 2. As the light-receiving surface side electrode 4, the bus electrode and grid electrode of a photovoltaic cell are included, In FIG. 1, sectional drawing in the direction substantially orthogonal to the longitudinal direction of a bus electrode is shown.

  According to the solar cell according to the first embodiment formed as described above, the second antireflection film 6 formed of the antireflection film material made of the liquid phase is provided, and the antireflection film made of the liquid phase is provided. Formation of defect levels due to the penetration of the material and the dispersion liquid to the semiconductor substrate 1 is prevented, and the short circuit current and the photoelectric conversion efficiency are reduced without reducing the fill factor which is one of the output electric characteristics of the solar cell. Excellent solar cells have been realized.

  Further, according to the solar cell according to the first embodiment, since the second antireflection film 6 is not formed on the light receiving surface side electrode 4 on the light receiving surface side, after the second antireflection film 6 is formed. The solar cell which can take an output directly from the light-receiving surface side electrode 4 and can evaluate the characteristics even after the formation of the second antireflection film 6 is realized.

  Moreover, according to the formed photovoltaic cell according to the first embodiment, since the second antireflection film 6 is not formed on the light receiving surface side electrode 4 on the light receiving surface side, the second antireflection film 6 is formed. Even after the formation of the solar cell, a solar battery cell capable of easily and reliably soldering the tab electrode to the light receiving surface side electrode 4 is realized. Thereby, a solar cell module can be manufactured by electrically connecting solar cells easily and reliably.

  Below, the manufacturing method of the photovoltaic cell concerning Embodiment 1 comprised as mentioned above is demonstrated with reference to FIGS. 2-1-FIGS. 2-6. FIGS. 2-1 to 2-6 are cross-sectional views for explaining the method for manufacturing the solar battery cell according to the first embodiment. First, a p-type polycrystalline silicon substrate having a volume resistivity of 1 to 5 Ω · cm is immersed in a heated alkali solution, for example, about 10 wt% sodium hydroxide aqueous solution to etch the surface, thereby cutting out the silicon substrate. The substrate surface cleaning is performed at the same time as removing the damaged region that is sometimes generated and exists near the surface of the p-type polycrystalline silicon substrate.

Next, the p-type polycrystalline silicon substrate is etched in a solution heated by adding about 1 wt% of an alkali solution such as an aqueous solution of sodium hydroxide of about 10 wt% as described above and an alcohol solution such as isopropyl alcohol. To form a texture shape on the surface of the p-type polycrystalline silicon substrate. Then, after the surface is thinned using etching with an alkaline solution in this way, the p-type polycrystalline silicon substrate is heated at about 800 to 900 ° C. in a phosphorus oxychloride (POCl ₃ ) gas atmosphere. As a result, a semiconductor pn junction is formed on the surface of the p-type polycrystalline silicon substrate.

  Next, this p-type polycrystalline silicon substrate is immersed in a hydrofluoric acid aqueous solution of about 5 wt%, and the phosphorous glass formed on the surface of the p-type polycrystalline silicon substrate is removed, so that the semiconductor substrate 1 having a pn junction is obtained. Is obtained (FIG. 2-1). A silicon nitride film is formed on the semiconductor substrate 1 with silane, ammonia and nitrogen gas by a plasma enhanced chemical vapor deposition (PECVD) method to obtain a first antireflection film 2 (FIG. 2-2).

  Next, a paste containing aluminum powder and silver is printed on the back surface and the light receiving surface of the semiconductor substrate 1, respectively, and then baked to form the back electrode 3 and the light receiving surface side electrode 4, thereby producing a solar cell. (FIGS. 2-3).

  Next, a dilute solution containing a water repellent for repelling the antireflection film coating solution is selectively applied only on the light receiving surface side electrode 4 on the light receiving surface side of the solar battery cell using an ink jet coating apparatus. At this time, the diluted solution is applied so as to cover the light receiving surface side electrode 4 and seal the light receiving surface side electrode 4. Then, by heating the semiconductor substrate 1 on a hot plate heated to about 100 ° C., the water repellent solution is dried and at the same time a water repellent film having a water repellent effect is formed. Thereby, the electrode part protective layer 5a which consists of a water repellent film is formed so that the light-receiving surface side electrode 4 may be covered and the light-receiving surface side electrode 4 may be sealed (FIGS. 2-4).

  Next, an aqueous solution in which 2 parts by weight of titanium oxide particles are dispersed is diluted 10-fold with isopropyl alcohol to prepare a coating solution in which titanium oxide particles are dispersed, and this is used as a first antireflection film on the light receiving surface side. The second antireflection film 6 is formed on the light receiving surface side electrode of the silicon nitride film 2 by spray application using a two-fluid nozzle (FIG. 2-5). At this time, since the coating solution in which the titanium oxide particles are dispersed is not deposited on the light receiving surface side electrode 4 on which the electrode portion protective layer 5a made of the water repellent film is formed, the second surface is formed on the light receiving surface side electrode 4. The antireflection film 6 is not formed.

  Next, by heating the substrate on a hot plate heated to about 300 ° C., the electrode portion protective layer 5a made of the water repellent film formed on the light receiving surface side electrode 4 is removed, and the first embodiment is applied. A solar battery cell is completed (FIGS. 2-6).

  According to the manufacturing method of the solar cell according to the first embodiment as described above, the electrode portion protective layer 5a made of a water repellent film is formed on the light receiving surface side electrode 4 to seal the light receiving surface side electrode 4. As a result, in the subsequent manufacturing process of the solar battery cell, the antireflection film material or dispersion made of a liquid phase enters and penetrates between the light receiving surface side electrode 4 and the semiconductor substrate 1 in the semiconductor substrate 1. A coating-type antireflection film can be formed while preventing formation of defect levels. Thereby, it can be said that the short circuit current density and the photoelectric conversion efficiency can be improved before and after the application of the second antireflection film 6 without reducing the fill factor which is one of the output electrical characteristics of the solar cell. Producing a solar cell having a solar cell characteristic with an increased short-circuit current by reducing light reflection while preventing deterioration of the solar cell characteristic, in particular, deterioration of the fill factor, which has a remarkable effect that has not existed before. Can do.

  That is, according to the manufacturing method of the photovoltaic cell concerning Embodiment 1, while providing the 2nd antireflection film 6 formed from the antireflection film material which consists of a liquid phase, antireflection film material which consists of a liquid phase, Formation of defect levels due to penetration of the dispersion into the semiconductor substrate 1 is prevented, and the short circuit current and photoelectric conversion efficiency are excellent without lowering the fill factor which is one of the output electric characteristics of the solar cell. A solar battery cell can be produced.

  Moreover, according to the manufacturing method of the photovoltaic cell concerning Embodiment 1, since the 2nd antireflection film 6 is not formed on the light reception surface side electrode 4 by the side of a light reception surface, formation of the 2nd antireflection film 6 is carried out. A solar cell that can take an output directly from the light-receiving surface side electrode 4 and can be evaluated even after the second antireflection film 6 is formed can be manufactured.

  Moreover, according to the manufacturing method of the photovoltaic cell concerning Embodiment 1, since the 2nd antireflection film 6 is not formed on the light reception surface side electrode 4 by the side of a light reception surface, formation of the 2nd antireflection film 6 is carried out. Even later, it is possible to manufacture a solar battery cell in which the tab electrode can be easily and surely soldered to the light-receiving surface side electrode 4. That is, it is possible to produce a solar battery cell that can easily and reliably electrically connect solar battery cells to manufacture a solar battery module.

Embodiment 2. FIG.
Embodiment 2 demonstrates the other manufacturing method of the photovoltaic cell shown in FIG. 1 with reference to FIGS. 3-1-FIGS. 3-5. FIGS. 3-1 to 3-5 are cross-sectional views for explaining the method for manufacturing the solar battery cell according to the second embodiment. First, the solar battery cell shown in FIG. 3-1 (corresponding to FIG. 2-3 in Embodiment 1) is obtained by carrying out the steps described with reference to FIGS. 2-1 to 2-3 in Embodiment 1. Make it.

Next, a dilute solution containing a water repellent for repelling the antireflection film coating solution is applied to the entire light receiving surface side of the solar cell using a spin coating device, and the water repellent coating film is applied to the entire light receiving surface side. 5b is formed (FIG. 3-2). Next, in the water repellent coating film 5b on the light receiving surface side of the solar battery cell, the electrode portion protective layer 5a made of the water repellent film is formed by selectively irradiating the laser only on the light receiving surface side electrode 4. For example, a water repellent film is formed by irradiating the light receiving surface side electrode 4 with YCO ₄ laser light having a wavelength of about 1064 nm and heating the water repellent-containing solution applied to the light receiving surface side electrode 4 to dry and solidify. At this time, if the laser power is too high, the water repellent component is sublimated before the water repellent film is formed. Therefore, it is necessary to select the laser power so that the substrate temperature is about 100 ° C.

  Next, the water repellent-containing solution applied to the semiconductor substrate 1 other than on the light receiving surface side electrode 4 is removed. For example, an unnecessary water repellent-containing solution is removed by cleaning the semiconductor substrate 1 with a toluene solution. Thereby, the electrode portion protective layer 5a made of a water repellent film is formed so as to cover the light receiving surface side electrode 4 and seal the light receiving surface side electrode 4 (FIG. 3-3, FIG. 2 in the first embodiment). -4).

  Next, an aqueous solution in which 2 parts by weight of titanium oxide particles are dispersed is diluted 10-fold with isopropyl alcohol to prepare a coating solution in which titanium oxide particles are dispersed, and this is used as a first antireflection film on the light receiving surface side. The second antireflection film 6 is formed on the light receiving surface side electrode of the silicon nitride film 2 by spray application using a two-fluid nozzle (FIG. 3-4). At this time, since the coating solution in which the titanium oxide particles are dispersed is not deposited on the light receiving surface side electrode 4 on which the electrode portion protective layer 5a made of the water repellent film is formed, the second surface is formed on the light receiving surface side electrode 4. The antireflection film 6 is not formed.

  Next, by heating the substrate on a hot plate heated to about 300 ° C., the electrode portion protective layer 5a made of the water repellent film formed on the light receiving surface side electrode 4 is removed, and the first embodiment is applied. A solar battery cell is completed (FIGS. 3-5).

  According to the method for manufacturing a solar battery cell according to the second embodiment as described above, the electrode part protective layer 5a made of a water repellent film is formed on the light receiving surface side electrode 4 as in the case of the first embodiment. By sealing the light-receiving surface side electrode 4, a liquid-phase antireflection film material or dispersion enters and penetrates between the light-receiving surface side electrode 4 and the semiconductor substrate 1 in the subsequent manufacturing process of the solar battery cell. Thus, it is possible to prevent the formation of defect levels in the semiconductor substrate 1 and to form a coating type antireflection film. Thereby, it can be said that the short circuit current density and the photoelectric conversion efficiency can be improved before and after the application of the second antireflection film 6 without reducing the fill factor which is one of the output electrical characteristics of the solar cell. Producing a solar cell having a solar cell characteristic with an increased short-circuit current by reducing light reflection while preventing deterioration of the solar cell characteristic, in particular, deterioration of the fill factor, which has a remarkable effect that has not existed before. Can do.

  That is, according to the manufacturing method of the solar cell according to the second embodiment, the second antireflection film 6 formed of the liquid phase antireflection film material is provided, and the liquid layer antireflection film material or Formation of defect levels due to penetration of the dispersion into the semiconductor substrate 1 is prevented, and the short circuit current and photoelectric conversion efficiency are excellent without lowering the fill factor which is one of the output electric characteristics of the solar cell. A solar battery cell can be produced.

  Moreover, according to the manufacturing method of the photovoltaic cell concerning Embodiment 2, since the 2nd antireflection film 6 is not formed on the light reception surface side electrode 4 by the side of a light reception surface, formation of the 2nd antireflection film 6 is carried out. A solar cell that can take an output directly from the light-receiving surface side electrode 4 and can be evaluated even after the second antireflection film 6 is formed can be manufactured.

  Moreover, according to the manufacturing method of the photovoltaic cell concerning Embodiment 2, since the 2nd antireflection film 6 is not formed on the light reception surface side electrode 4 by the side of a light reception surface, formation of the 2nd antireflection film 6 is carried out. Even later, it is possible to manufacture a solar battery cell in which the tab electrode can be easily and surely soldered to the light-receiving surface side electrode 4. That is, it is possible to produce a solar battery cell that can easily and reliably electrically connect solar battery cells to manufacture a solar battery module.

Embodiment 3 FIG.
FIG. 4 is a cross-sectional view showing a schematic configuration of the solar battery cell according to the third embodiment of the present invention. The solar battery cell according to the third embodiment includes a semiconductor substrate 1 that is a solar battery substrate and has a pn junction, and a first antireflection film 2 formed on the light receiving surface side (surface) of the semiconductor substrate 1. The back surface electrode 3 formed on the surface (back surface) opposite to the light receiving surface of the semiconductor substrate 1 and the surface (front surface) on the light receiving surface side of the semiconductor substrate 1 are surrounded by the first antireflection film 2. A light receiving surface side electrode 4 and a second antireflection film 6 formed on the first antireflection film 2. As the light-receiving surface side electrode 4, the bus electrode and grid electrode of a photovoltaic cell are included, In FIG. 1, sectional drawing in the direction substantially orthogonal to the longitudinal direction of a bus electrode is shown. Further, on the light receiving surface side electrode 4 and on a partial region of the first antireflection film 2 adjacent to the light receiving surface side electrode 4, the light receiving surface side electrode portion 4a made of silver (Ag) nanoparticles. Is provided.

  According to the solar cell according to the third embodiment formed as described above, the second antireflection film 6 formed of the antireflection film material made of the liquid phase is provided, and the antireflection film made of the liquid phase is provided. Formation of defect levels due to the penetration of the material and the dispersion liquid to the semiconductor substrate 1 is prevented, and the short circuit current and the photoelectric conversion efficiency are reduced without reducing the fill factor which is one of the output electric characteristics of the solar cell. Excellent solar cells have been realized.

  Further, according to the solar cell according to the third embodiment, the second antireflection film 6 is not formed on the light receiving surface side electrode 4 on the light receiving surface side, and is formed of silver (Ag) nanoparticles. Since the light receiving surface side electrode portion 4a is formed, an output can be directly taken from the light receiving surface side electrode portion 4a even after the formation of the second antireflection film 6, and after the second antireflection film 6 is formed. A solar battery cell capable of evaluating characteristics is realized.

  Further, according to the solar cell according to the third embodiment, the second antireflection film 6 is not formed on the light receiving surface side electrode 4 on the light receiving surface side, and is formed of silver (Ag) nanoparticles. Since the light receiving surface side electrode portion 4a is formed, the tab electrode is easily and reliably soldered to the light receiving surface side electrode 4 (light receiving surface side electrode portion 4a) even after the second antireflection film 6 is formed. A solar cell that can be used has been realized. Thereby, a solar cell module can be manufactured by electrically connecting solar cells easily and reliably.

  Furthermore, according to the solar cell according to the third embodiment, by providing the light receiving surface side electrode portion 4a on the light receiving surface side electrode 4, the electrode thickness on the light receiving surface side is increased, thereby reducing the resistance of the electrode. The illustrated solar cell is realized.

  Below, the manufacturing method of the photovoltaic cell concerning Embodiment 3 comprised as mentioned above is demonstrated with reference to FIGS. 5-1-FIGS. 5-4. 5A to 5D are cross-sectional views for explaining the method for manufacturing the solar battery cell according to the third embodiment. First, the solar cell shown in FIG. 5A (corresponding to FIG. 2-3 in Embodiment 1) is obtained by carrying out the steps described with reference to FIGS. 2-1 to 2-3 in Embodiment 1. Make it.

  Next, a solution obtained by dispersing nanoparticle metal, for example, silver (Ag) nanoparticle powder, in a diluted solution containing a water repellent that repels the antireflection film coating solution is received by a solar battery cell using an inkjet coating apparatus. It is selectively applied only on the light receiving surface side electrode 4 on the surface side. At this time, the diluted solution is applied so as to cover the light receiving surface side electrode 4 and seal the light receiving surface side electrode 4. Then, by heating the semiconductor substrate 1 on a hot plate heated to about 100 ° C., the water repellent solution is dried and at the same time a water repellent film having a water repellent effect is formed. Thereby, the electrode part protective layer 5c made of a water repellent film containing silver (Ag) nanoparticle powder is formed so as to cover the light receiving surface side electrode 4 and seal the light receiving surface side electrode 4 (FIG. 5). -2).

  Next, an aqueous solution in which 2 parts by weight of titanium oxide particles are dispersed is diluted 10-fold with isopropyl alcohol to prepare a coating solution in which titanium oxide particles are dispersed, and this is used as a first antireflection film on the light receiving surface side. The second antireflection film 6 is formed on the light receiving surface side electrode of the silicon nitride film 2 by spray application using a two-fluid nozzle (FIG. 5-3). At this time, since the coating solution in which the titanium oxide particles are dispersed is not deposited on the light receiving surface side electrode 4 on which the electrode part protective layer 5c made of a water repellent film containing silver (Ag) nanoparticle powder is formed, The second antireflection film 6 is not formed on the light receiving surface side electrode 4 (bus electrode and grid electrode).

  Next, from the water repellent film containing silver (Ag) nanoparticle powder formed on the light-receiving surface side electrode 4 (bus electrode and grid electrode) by heating the substrate on a hot plate heated to about 400 ° C. At the same time as removing the electrode part protective layer 5c, Ag nanoparticles are deposited on the electrode. Thereby, the light receiving surface side electrode portion 4a composed of Ag nanoparticles is formed on the light receiving surface side electrode 4, and the electrode thickness on the light receiving surface side is increased to reduce the resistance of the electrode on the light receiving surface side. Can do. The solar cell concerning Embodiment 3 is completed by the above (FIG. 5-4).

  When the electrode on the light receiving surface side of the solar battery cell is formed by screen printing, the electrode thickness that can be printed in one printing process is about several μm to several tens μm. The area that the electrode on the light receiving surface occupies on the light receiving surface of the solar cell greatly affects the conversion efficiency of the solar cell. Therefore, in order to reduce the area occupied by this electrode, it is preferable to make the electrode width as thin as possible. .

  Here, it may occur that the electrode cross-sectional area sufficient to allow a desired current to flow cannot be secured by simply reducing the electrode width, so the electrode height (thickness) is increased (thickened) to reduce the resistance of the electrode. It is necessary to plan. That is, it is necessary to increase the electrode height (thickness) by performing screen printing several times. However, if screen printing is performed several times and the number of times of printing is increased, the number of work steps is increased, and at the same time, there is a problem that a printing position shift occurs at the time of each printing. For this reason, a screen printing process can be shortened by substituting the electrode height (thickness) for one screen printing process with the light-receiving surface side electrode part 4a comprised by Ag nanoparticle.

  According to the method for manufacturing a solar cell according to the third embodiment as described above, the electrode part protective layer 5c made of a water-repellent film containing silver (Ag) nanoparticle powder is formed on the light-receiving surface side electrode 4. By sealing the light-receiving surface side electrode 4, an antireflection film material or dispersion made of a liquid phase enters and penetrates between the light-receiving surface side electrode 4 and the semiconductor substrate 1 in the subsequent manufacturing process of the solar battery cell. It is possible to form a coating type antireflection film while preventing the formation of defect levels in the semiconductor substrate 1 due to the above. Thereby, it can be said that the short circuit current density and the photoelectric conversion efficiency can be improved before and after the application of the second antireflection film 6 without reducing the fill factor which is one of the output electrical characteristics of the solar cell. Producing a solar cell having a solar cell characteristic with an increased short-circuit current by reducing light reflection while preventing deterioration of the solar cell characteristic, in particular, deterioration of the fill factor, which has a remarkable effect that has not existed before. Can do.

  That is, according to the method of manufacturing a solar battery cell according to the third embodiment, the second antireflection film 6 formed of the liquid phase antireflection film material is provided, and the liquid layer antireflection film material or Formation of defect levels due to penetration of the dispersion into the semiconductor substrate 1 is prevented, and the short circuit current and photoelectric conversion efficiency are excellent without lowering the fill factor which is one of the output electric characteristics of the solar cell. A solar battery cell can be produced.

  Moreover, according to the manufacturing method of the photovoltaic cell concerning Embodiment 3, without forming the second antireflection film 6 on the light receiving surface side electrode 4 on the light receiving surface side, the silver (Ag) nanoparticles are used. Since the configured light receiving surface side electrode portion 4a is formed, an output can be directly taken from the light receiving surface side electrode portion 4a even after the second antireflection film 6 is formed. It is possible to produce a solar battery cell whose characteristics can be evaluated even after the formation.

  Moreover, according to the manufacturing method of the photovoltaic cell concerning Embodiment 3, without forming the second antireflection film 6 on the light receiving surface side electrode 4 on the light receiving surface side, the silver (Ag) nanoparticles are used. Since the configured light receiving surface side electrode portion 4a is formed, the tab electrode can be easily and reliably attached to the light receiving surface side electrode 4 (light receiving surface side electrode portion 4a) even after the second antireflection film 6 is formed. A solar battery cell that can be soldered can be manufactured. That is, it is possible to produce a solar battery cell that can easily and reliably electrically connect solar battery cells to manufacture a solar battery module.

  Furthermore, according to the method for manufacturing a solar cell according to the third embodiment, the light receiving surface side electrode portion 4a is formed on the light receiving surface side electrode 4 to ensure the thickness of the electrode. There is no increase in the number of screen printings, and there are no problems such as an increase in work man-hours and a shift in printing position due to multilayer printing. Therefore, it is possible to manufacture a solar battery cell in which the resistance of the electrode on the light receiving surface side is reduced while shortening the work process.

Embodiment 4 FIG.
In the fourth embodiment, another method for manufacturing the solar battery cell described in the first embodiment shown in FIG. 1 will be described. This embodiment will be described with reference to FIGS. 3-1 to 3-5 used in the description of the second embodiment. First, by performing the steps described with reference to FIGS. 2-1 to 2-3 in Embodiment 1, the solar cell shown in FIG. (Corresponding to FIG. 2-3).

Next, a dilute solution containing a water repellent for repelling the antireflection film coating solution is applied to the entire light receiving surface side of the solar battery cell using a spin coating device, and the water repellent agent is applied to the entire light receiving surface side. A film 5b is formed (FIG. 3-2). Next, the substrate temperature is heated to about 100 ° C., and the water repellent coating film 5b on the light receiving surface side of the solar battery cell is dried and solidified to form a function as a water repellent film. Next, by selectively irradiating only the portion other than the light receiving surface side electrode 4 of the solar battery cell and sublimating the water repellent film, the electrode portion protective layer is selectively formed only on the light receiving surface side electrode 4. 5a is formed. For example, the water repellent film is sublimated and removed by selectively irradiating only a portion other than the light receiving surface side electrode 4 with YCO ₄ laser light having a wavelength of about 1064 nm. When carbide is deposited during sublimation of the water repellent film, it can be removed by washing with water. Thereby, the electrode portion protective layer 5a made of a water repellent film is formed so as to cover the light receiving surface side electrode 4 and seal the light receiving surface side electrode 4 (FIG. 3-3, FIG. 2 in the first embodiment). -4).

  Next, an aqueous solution in which 2 parts by weight of titanium oxide particles are dispersed is diluted 10-fold with isopropyl alcohol to prepare a coating solution in which titanium oxide particles are dispersed, and this is used as a first antireflection film on the light receiving surface side. The second antireflection film 6 is formed on the light receiving surface side electrode of the silicon nitride film 2 by spray application using a two-fluid nozzle (FIG. 3-4). At this time, since the coating solution in which the titanium oxide particles are dispersed is not deposited on the light receiving surface side electrode 4 on which the electrode portion protective layer 5a made of the water repellent film is formed, the second surface is formed on the light receiving surface side electrode 4. The antireflection film 6 is not formed.

  Next, by heating the substrate on a hot plate heated to about 300 ° C., the electrode portion protective layer 5a made of the water repellent film formed on the light receiving surface side electrode 4 is removed, and the first embodiment is applied. A solar battery cell is completed (FIGS. 3-5).

  As described above, according to the method for manufacturing a solar battery cell according to the fourth embodiment, the electrode part protective layer 5a made of the water-repellent film is selected only on the light-receiving surface side electrode 4 as in the first embodiment. In other words, by sealing the light receiving surface side electrode 4, the antireflection film material or dispersion composed of a liquid phase is transferred from the light receiving surface side electrode 4 and the semiconductor substrate 1 in the subsequent manufacturing process of the solar battery cell. It is possible to form a coating-type antireflection film by preventing the formation of defect levels in the semiconductor substrate 1 due to penetration and penetration between the two. Thereby, it can be said that the short circuit current density and the photoelectric conversion efficiency can be improved before and after the application of the second antireflection film 6 without reducing the fill factor which is one of the output electrical characteristics of the solar cell. Producing a solar cell having a solar cell characteristic with an increased short-circuit current by reducing light reflection while preventing deterioration of the solar cell characteristic, in particular, deterioration of the fill factor, which has a remarkable effect that has not existed before. Can do.

  That is, according to the method for manufacturing a solar battery cell according to the fourth embodiment, the second antireflection film 6 formed of the liquid phase antireflection film material is provided, and the liquid layer antireflection film material or Formation of defect levels due to penetration of the dispersion into the semiconductor substrate 1 is prevented, and the short circuit current and photoelectric conversion efficiency are excellent without lowering the fill factor which is one of the output electric characteristics of the solar cell. A solar battery cell can be produced.

  Moreover, according to the manufacturing method of the photovoltaic cell concerning Embodiment 4, since the 2nd antireflection film 6 is not formed on the light reception surface side electrode 4 of the light reception surface side, formation of the 2nd antireflection film 6 is carried out. A solar cell that can take an output directly from the light-receiving surface side electrode 4 and can be evaluated even after the second antireflection film 6 is formed can be manufactured.

  Moreover, according to the manufacturing method of the photovoltaic cell concerning Embodiment 4, since the 2nd antireflection film 6 is not formed on the light reception surface side electrode 4 of the light reception surface side, formation of the 2nd antireflection film 6 is carried out. Even later, it is possible to manufacture a solar battery cell in which the tab electrode can be easily and surely soldered to the light-receiving surface side electrode 4. That is, it is possible to produce a solar battery cell that can easily and reliably electrically connect solar battery cells to manufacture a solar battery module.

Embodiment 5 FIG.
A tab electrode is soldered to the light receiving surface side electrode 4 (light receiving surface side electrode portion 4a) of the solar cell according to the first to fourth embodiments described above, and a plurality of solar cells are electrically connected using the tab electrode. A solar cell module can be manufactured by connecting, sealing with sealing materials, such as glass and a resin sheet, and arrange | positioning a board | substrate on a sealing material. Accordingly, the second antireflection film 6 formed of the liquid phase antireflection film material is provided, and the defect level caused by the penetration of the liquid phase antireflection film material or the dispersion liquid to the semiconductor substrate 1 is obtained. Formation is prevented, and a solar cell module excellent in short-circuit current and photoelectric conversion efficiency can be produced without reducing the fill factor that is one of the output electrical characteristics of the solar cell.

  FIG. 6 is a cross-sectional view illustrating an example of a solar battery module manufactured using the solar battery cell according to the first embodiment, and includes a semiconductor substrate 1, a first antireflection film 2, a back electrode 3, and light reception. A surface-side electrode 4, a second antireflection film 6 formed on the first antireflection film 2, a sealing material 7, a transparent substrate 8, and a protective substrate 9 are provided.

  Such a solar cell module has an ethylene vinyl acetate resin film as the sealing material 7 and a transparent substrate 8 on the formation surface of the second antireflection film 6 after the solar cell according to the first embodiment is completed. A glass substrate is laminated in this order, and an ethylene vinyl acetate resin film as a sealing material 7 and a polyethylene terephthalate resin as a protective substrate 9 are laminated in this order on the back side, and pressure is applied from both sides. It can be produced by heating at 100 ° C. to 200 ° C. under vacuum while adding.

  As described above, the method for manufacturing a solar cell according to the present invention increases the short-circuit current by reducing the light reflection by the antireflection film formed from the antireflection film material made of a liquid phase. This is useful when forming excellent solar cells.

It is sectional drawing which shows schematic structure of the photovoltaic cell concerning Embodiment 1 of this invention. It is sectional drawing for demonstrating the manufacturing method of the photovoltaic cell concerning Embodiment 1 of this invention. It is sectional drawing for demonstrating the manufacturing method of the photovoltaic cell concerning Embodiment 1 of this invention. It is sectional drawing for demonstrating the manufacturing method of the photovoltaic cell concerning Embodiment 1 of this invention. It is sectional drawing for demonstrating the manufacturing method of the photovoltaic cell concerning Embodiment 1 of this invention. It is sectional drawing for demonstrating the manufacturing method of the photovoltaic cell concerning Embodiment 1 of this invention. It is sectional drawing for demonstrating the manufacturing method of the photovoltaic cell concerning Embodiment 1 of this invention. It is sectional drawing for demonstrating the manufacturing method of the photovoltaic cell concerning Embodiment 2 of this invention. It is sectional drawing for demonstrating the manufacturing method of the photovoltaic cell concerning Embodiment 2 of this invention. It is sectional drawing for demonstrating the manufacturing method of the photovoltaic cell concerning Embodiment 2 of this invention. It is sectional drawing for demonstrating the manufacturing method of the photovoltaic cell concerning Embodiment 2 of this invention. It is sectional drawing for demonstrating the manufacturing method of the photovoltaic cell concerning Embodiment 2 of this invention. It is sectional drawing which shows schematic structure of the photovoltaic cell concerning Embodiment 3 of this invention. It is sectional drawing for demonstrating the manufacturing method of the photovoltaic cell concerning Embodiment 3 of this invention. It is sectional drawing for demonstrating the manufacturing method of the photovoltaic cell concerning Embodiment 3 of this invention. It is sectional drawing for demonstrating the manufacturing method of the photovoltaic cell concerning Embodiment 3 of this invention. It is sectional drawing for demonstrating the manufacturing method of the photovoltaic cell concerning Embodiment 3 of this invention. It is sectional drawing which shows an example of the solar cell module produced using the photovoltaic cell concerning Embodiment 1 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor substrate 2 Antireflection film 3 Back surface electrode 4 Light reception surface side electrode 4a Light reception surface side electrode part 5a Electrode part protective layer 5b Water repellent coating film 5c Electrode part protective layer 6 Antireflection film 7 Sealant 8 Transparent substrate 9 Protection substrate

Claims (7)

A method for producing a solar battery cell comprising an antireflection film on a semiconductor substrate,
A first step of forming an electrode on one main surface side of the semiconductor substrate having a PN junction;
A second step of selectively forming a protective layer for repelling the coating liquid for forming the antireflection film in a region covering the electrode on one main surface side of the semiconductor substrate;
A third step of coating the antireflection film by applying a coating liquid for forming the antireflection film on the semiconductor substrate on which the protective layer is formed;
The manufacturing method of the photovoltaic cell characterized by including. The second step includes
A step of selectively applying, by an inkjet method, a coating solution for forming the protective film containing a material that repels the coating solution to a region covering the electrode on one main surface side of the semiconductor substrate;
Forming the protective layer by drying a coating solution for forming the protective film applied to one main surface side of the semiconductor substrate;
The manufacturing method of the photovoltaic cell of Claim 1 characterized by the above-mentioned. The second step includes
Applying a coating solution for forming the protective film containing a material that repels the coating solution over the entire main surface of the semiconductor substrate;
Selectively forming the protective layer by selectively irradiating a laser on only the region covering the electrode on the one main surface side of the semiconductor substrate to dry and solidify the coating liquid for forming the protective film; ,
The manufacturing method of the photovoltaic cell of Claim 1 characterized by the above-mentioned. The second step includes
Applying a coating solution for forming the protective film containing a material that repels the coating solution over the entire main surface of the semiconductor substrate;
Heat-treating the semiconductor substrate to dry and solidify the protective film containing a water-repellent material applied to the entire main surface of the semiconductor substrate;
By selectively irradiating a portion of the semiconductor substrate other than the region covering the electrode on the one main surface side with a laser to sublimate the coating liquid for forming the protective film, on the one main surface side of the semiconductor substrate Selectively forming the protective layer on a region covering the electrode;
The manufacturing method of the photovoltaic cell of Claim 1 characterized by the above-mentioned. The protective layer for repelling the coating liquid for forming the antireflection film contains metal nanoparticles,
After the third step,
Having a step of depositing only the metal nanoparticles on the electrode by heat-treating the protective layer;
The manufacturing method of the photovoltaic cell of Claim 1 characterized by these. Before the first step,
Forming another antireflection film in a light receiving region excluding a region where the electrode is formed on one main surface side of the semiconductor substrate;
The manufacturing method of the photovoltaic cell of Claim 1 characterized by these.   The manufacturing method of the solar cell module characterized by including the manufacturing method of the photovoltaic cell as described in any one of Claims 1 thru | or 6.

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