JP2001085720A - Thin film photoelectric conversion module and method of manufacturing the same - Google Patents

Abstract

(57) Abstract: To provide a method of manufacturing a thin-film photoelectric conversion module that is effective in reducing manufacturing costs, or to provide a thin-film photoelectric conversion module having sufficient performance and a method of manufacturing the same. A method of manufacturing a thin film photoelectric conversion module according to the present invention has a structure in which a transparent front electrode layer, a thin film photoelectric conversion unit, and a metal back electrode layer are sequentially laminated on a transparent substrate. The method for manufacturing the conversion module 1 includes a step of irradiating the metal back electrode layer 5 with laser light having a wavelength of 400 nm or less from the back side to divide the metal back electrode layer 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thin-film photoelectric conversion module and a method of manufacturing the same, and more particularly, to a thin-film photoelectric conversion module for photoelectrically converting light incident on a thin-film photoelectric conversion unit from a transparent substrate side and a method of manufacturing the same. .

[0002]

2. Description of the Related Art A thin film photoelectric conversion module has a structure in which a plurality of thin film photoelectric conversion cells are integrated on a substrate. In a module that photoelectrically converts light incident from the transparent substrate side, these thin-film photoelectric conversion cells usually sequentially form and split a transparent front electrode layer, a thin-film photoelectric conversion unit, and a metal back electrode layer on a transparent substrate. It is formed by this.

[0003] The division of these thin films can be performed by several methods, but is generally performed by laser scribe. For example, the transparent front electrode layer absorbs the fundamental wave of the YAG laser, and the thin-film photoelectric conversion unit made of a silicon-based material or the like absorbs the second harmonic of the YAG laser with a sufficiently high efficiency. By doing so, it is possible to divide directly.

On the other hand, the metal back electrode layer has a low absorptivity with respect to the fundamental wave and the second harmonic of the YAG laser, and reflects most of it. Therefore, unlike the transparent front electrode layer and the thin film photoelectric conversion unit, they cannot be directly split by these laser beams. Therefore, conventionally, the division of the metal back electrode layer has been performed by utilizing sublimation generated by irradiating the thin film photoelectric conversion unit with laser light. That is,
The division of the metal back electrode layer has been performed by an indirect method by irradiating a laser beam from the transparent substrate side.

However, when the metal back electrode layer is divided by such a method, the division of the metal back electrode layer may be incomplete, and the film surface is easily damaged during the manufacturing process. Therefore, conventionally, there has been a problem that the performance of the module becomes insufficient or the manufacturing yield of the module is reduced.

[0006]

As described above, the division of the metal back electrode layer using the conventional technique has a problem in terms of both module performance and manufacturing cost.

The present invention has been made in view of the above problems, and has as its object to provide a method of manufacturing a thin-film photoelectric conversion module that is effective in reducing manufacturing costs.

Another object of the present invention is to provide a thin-film photoelectric conversion module having sufficient performance and a method for manufacturing the same.

[0009]

In order to solve the above-mentioned problems, the inventors of the present invention have found that the reason for the incomplete division of the metal back electrode layer by the method according to the prior art is that the irradiation of the laser beam is performed on the transparent substrate side. Therefore, it was considered that the defect in the transparent substrate hindered the division of the metal back electrode layer. Furthermore, the present inventors have found that the reason that the film surface is easily damaged by the method according to the related art is that the laser scribe device is designed to irradiate laser light from above to below for safety reasons. Therefore, in order to divide the metal back electrode layer, it is necessary to arrange the transparent substrate upside down so that the thin film photoelectric conversion unit is irradiated with laser light, that is, the film surface faces downward. I thought it was not going to be.

Therefore, the inventors of the present invention have conducted intensive studies on the belief that the above problem can be solved if it is possible to divide the metal back electrode layer by irradiating a laser beam from the film surface side. As a result, the laser light having a wavelength of 400 nm or less that can be absorbed by the metal back electrode layer with sufficiently high efficiency is used, or the laser light having a wavelength of 600 nm or less as compared with the metal back electrode layer has higher efficiency. By providing a light absorbing layer containing a sublimable material that absorbs in the metal back electrode layer, it is possible to divide the metal back electrode layer by laser light irradiation from the film surface side, and to solve all the above problems. I found it. Furthermore, the present inventors have found that when the metal back electrode layer is divided by irradiating laser light from the film surface side, a completely different characteristic structure is formed than when laser light is irradiated from the transparent substrate side. Was found.

That is, according to the present invention, there is provided a method of manufacturing a thin-film photoelectric conversion module having a structure in which a transparent front electrode layer, a thin-film photoelectric conversion unit, and a metal back electrode layer are sequentially laminated on a transparent substrate. A method for manufacturing a thin-film photoelectric conversion module, comprising: irradiating a laser beam having a wavelength of 400 nm or more from the side to the metal back electrode layer to divide the metal back electrode layer.

According to the present invention, there is also provided a method of manufacturing a thin film photoelectric conversion module having a structure in which a transparent front electrode layer, a thin film photoelectric conversion unit, and a metal back electrode layer are sequentially laminated on a transparent substrate. Forming, on the metal back electrode layer, a light absorbing layer containing a sublimable material that absorbs laser light having a wavelength of 600 nm or less with higher efficiency than the material of the metal back electrode layer, Irradiating the laser beam to the light absorbing layer to sublimate the sublimable material in the laser beam irradiating portion of the light absorbing layer and dividing the metal back electrode layer. A method for manufacturing a conversion module is provided.

Further, according to the present invention, there is provided a transparent substrate, and a plurality of thin film photoelectric conversion cells each having a transparent front electrode layer, a thin film photoelectric conversion unit, and a metal back electrode layer sequentially laminated on the transparent substrate. And in each of the plurality of thin-film photoelectric conversion cells, the metal back electrode layer,
There is provided a thin-film photoelectric conversion module provided so as to partially expose a peripheral portion of an upper surface of the thin-film photoelectric conversion unit.

In the present invention, a metal material having high reflectivity and conductivity, such as silver or aluminum, is used for the metal back electrode layer.

In the present invention, as the laser beam having a wavelength of 400 nm or less, for example, the third harmonic of a solid-state laser containing yttrium can be used. Also,
In the present invention, as the laser light having a wavelength of 600 nm or less, for example, a second harmonic of a solid-state laser containing yttrium can be used.

In the present invention, as the sublimable material, for example, titanium, chromium, tungsten, magnesium,
A material containing at least one material selected from the group consisting of silicon oxide, aluminum oxide, and zinc oxide can be used.

In the present invention, the thin-film photoelectric conversion unit can be made of, for example, a silicon-based material.

As described above, according to the present invention, since the metal back electrode layer can be divided from the film surface side, a device for turning the transparent substrate upside down is unnecessary. Therefore, according to the present invention, it is possible to reduce equipment costs and the like. Further, according to the present invention, since the metal back electrode layer can be divided from the film surface side, it is possible to use a transparent substrate which has been subjected to a surface treatment such as an anti-glare treatment on the light incident side in advance.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the drawings. In each of the drawings, similar members are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 is a top view schematically showing a thin-film photoelectric conversion module according to a first embodiment of the present invention. The thin-film photoelectric conversion module 1 shown in FIG. 1 has a structure in which a plurality of thin-film photoelectric conversion cells 10 are integrated on a transparent substrate 2. In FIG. 1, these thin-film photoelectric conversion cells 10
Forms a serial array 11 connected in series in the vertical direction, and a pair of electrode busbars 12 made of ribbon-like copper foil or the like are connected to both ends of the serial array 11, respectively.

The module 1 shown in FIG. 1 will be described in more detail with reference to FIG. FIG.
(C) is a sectional view schematically showing a manufacturing process of the thin-film photoelectric conversion module 1 shown in FIG. 1, and (c) is a sectional view taken along line AA of the module 1 shown in FIG. 1. is there. As shown in FIG. 2C, in the module 1 according to the present embodiment, the thin-film photoelectric conversion cell 10 includes a transparent substrate 2
It has a structure in which a transparent front electrode layer 3, a thin-film photoelectric conversion unit 4, and a metal back electrode layer 5 are sequentially laminated thereon.
That is, the module 1 photoelectrically converts light incident from the transparent substrate 2 side by the photoelectric conversion unit 4.

Module 1 shown in FIGS. 1 and 2 (c)
Can be produced, for example, by the following method. First, the transparent front electrode layer 3 is formed as a large-area thin film on one main surface of the transparent substrate 2. The transparent substrate 2 can be composed of a glass plate, a transparent resin film, or the like. The other main surface of the transparent substrate 2 may be subjected to a surface treatment such as an anti-glare treatment in advance.

The transparent front electrode layer 3 is made of an ITO film, S
It can be composed of a transparent conductive oxide layer such as an nO ₂ film or a ZnO film. The transparent front electrode layer 3 may have a single-layer structure or a multilayer structure. The transparent front electrode layer 3
It can be formed by a known vapor deposition method such as a vapor deposition method, a CVD method, or a sputtering method.

It is preferable to form a surface texture structure including fine irregularities on the surface of the transparent front electrode layer 3.
By forming such a texture structure on the surface of the transparent front electrode layer 3, the efficiency of light incidence on the photoelectric conversion unit 4 can be improved. The method for forming the surface texture structure is not particularly limited, and various known methods can be used.

Next, a groove 21 is formed in the transparent front electrode layer 3 formed as a large-area thin film by laser scribing, and the transparent front electrode layer 3 is divided corresponding to each cell 10. For the division of the transparent front electrode layer 3, a conventionally used laser beam such as a fundamental wave (wavelength 1060 nm) of a YAG laser can be used.

The laser scribe of the transparent front electrode layer 3 is as follows.
Although it can be performed from the substrate 2 side, it is preferably performed from the film surface side. In this case, damage to the transparent front electrode layer 3 can be prevented.

Next, a thin-film photoelectric conversion unit 4 is formed on the transparent front electrode layer 3. The groove 21 formed in the transparent front electrode layer 3 is thereby filled with the material constituting the thin-film photoelectric conversion unit 4.

The thin-film photoelectric conversion unit 4 includes, for example, a p-type non-single-crystal silicon-based semiconductor layer, a non-single-crystal silicon-based thin-film photoelectric conversion layer, and an n-type non-single-crystal silicon-based semiconductor layer on the transparent front electrode layer 3. It has a structure that is sequentially laminated. These p-type semiconductor layers, photoelectric conversion layers, and n-type semiconductor layers can all be formed by a plasma CVD method.

The p-type silicon-based semiconductor layer is formed by doping silicon or a silicon alloy such as silicon carbide or silicon germanium with a p-conductivity determining impurity atom such as boron or aluminum.

The photoelectric conversion layer formed on the p-type semiconductor layer is formed of a non-single-crystal silicon-based semiconductor material, such as an intrinsic semiconductor such as silicon (silicon hydride), silicon carbide and silicon. Silicon alloys such as germanium are included. In addition, if the photoelectric conversion function is sufficiently provided, weak p-type impurities containing a trace amount of impurities for determining the conductivity type are used.
Or weak n-type silicon-based semiconductor material can also be used.

The n-type silicon-based semiconductor layer formed on the photoelectric conversion layer is made of silicon or a silicon alloy such as silicon carbide or silicon germanium, or n-type silicon or the like.
It is formed by doping a conductivity type determining impurity atom.

As described above, the thin-film photoelectric conversion unit 4
Is formed, a groove 22 is formed in the photoelectric conversion unit 4 by laser scribing, as shown in FIG.
The groove portion 22 is provided for electrically connecting the transparent front electrode layer 3 of a certain cell 10 and the back metal electrode layer 5 of a cell 10 adjacent thereto.

In this embodiment, since the thin-film photoelectric conversion unit 4 is made of a silicon-based material, the thin-film photoelectric conversion unit 4 can be divided by a conventional method such as the second harmonic (wavelength 530 nm) of a YAG laser. The used laser light can be used. Further, the laser scribe of the thin film photoelectric conversion unit 4 is preferably performed from the film surface side similarly to the transparent front electrode layer 3. In this case, damage to the film surface can be prevented.

Next, as shown in FIG. 2B, a metal back electrode layer 5 is formed on the photoelectric conversion unit 4. The groove 22 formed in the photoelectric conversion unit 4 is thereby filled with a metal material, and the metal back electrode layer 5 and the transparent front electrode layer 3 are electrically connected.

The metal back electrode layer 5 not only has a function as an electrode, but also reflects light that enters the photoelectric conversion unit 4 from the transparent substrate 2 and reaches the back electrode layer 5 to be re-entered in the photoelectric conversion unit 4. It also has a function as a reflection layer to be incident. The metal back electrode layer 5 is formed of, for example, 2
It can be formed to a thickness of about 00 nm to 400 nm.

A transparent conductive thin film (not shown) made of a non-metallic material such as ZnO is provided between the metal back electrode layer 5 and the photoelectric conversion unit 4, for example, in order to improve the adhesion between them. ) Can be provided.

Next, as shown in FIG. 2C, a groove 23 is formed in the metal back electrode layer 5 by laser scribing, and the metal back electrode layer 5 is electrically insulated between the cells 10. Generally, the material constituting the metal back electrode layer 5 is 40
Laser light having a wavelength of 0 nm or less is absorbed with sufficiently high efficiency. In this embodiment, a laser beam having a wavelength of 400 nm or less is used to form the groove 23. Therefore, according to the present embodiment, the groove 23 can be formed by irradiating the laser beam from the film surface side.

The laser light source used for forming the groove 23 in the present embodiment is not particularly limited as long as it outputs laser light having a wavelength of 400 nm or less, and is a solid-state laser, a liquid laser, an excimer laser, a nitrogen laser, or the like. Or the like, but usually 250
One that outputs laser light having a wavelength of at least nm is used. Examples of such a laser beam include YAG and Y
The third and fourth harmonics of a solid-state laser containing yttrium, such as VO ₄ , may be mentioned.

The power and beam diameter of the laser beam used to form the groove 23, the relative speed between the substrate 2 and the optical axis of the laser beam, and the like depend on the material used for the metal back electrode layer 5, its thickness, and the groove to be formed. 23, depending on the width and the like. Generally, the power of the laser light is 0.2 W to 2 W, the frequency is 5 kHz to 50 kHz, and the beam diameter is 30 μm to
100 μm, and the relative speed between the substrate 2 and the optical axis of the laser beam is 100 mm / sec to 1000 mm / sec. In such a case, the groove portion 23 is set to, for example, 30 μm to 1 μm.
It can be formed to a width of 00 μm.

When the groove 23 is formed in the metal back electrode layer 5 as described above, the groove 24 as shown in FIGS. 2C and 3 is usually formed in the thin-film photoelectric conversion unit 4. 3A and 3B are photographs showing an example of the groove 23 formed by irradiating the metal back electrode layer 5 made of Ag with the third harmonic of the YAG laser from the film surface side. (Output 0.6 W, frequency 5 kHz,
The processing width of the metal back electrode layer 5 is 98 μm).

The width of the groove 24 depends on the material used for each layer,
The width varies depending on the laser power, the beam diameter, the relative speed between the substrate 2 and the optical axis of the laser light, and the like, but is smaller than the width of the groove 23 in any case. On the other hand, in the method according to the related art, the division of the metal back electrode layer 5 is performed by utilizing the sublimation of the thin film photoelectric conversion unit 4, so that the width of the groove formed in the thin film photoelectric conversion unit 4 is limited to the metal back electrode It is equal to or wider than the width of the groove formed in the layer 5. That is, the fact that the width of the groove 24 is smaller than the width of the groove 23 is a characteristic of the present method.

Although the width of the groove 24 varies as described above, it is generally 0% to 95% of the width of the groove 23. Further, in FIG. 2C, the bottom surface of the groove 24 is constituted by the upper surface of the transparent front electrode layer 3, but the bottom surface of the groove 24 does not have to reach the transparent front electrode layer 3.

After forming the groove 23 as described above,
Further, reactive ion etching or wet etching may be performed. As a result, the adjacent metal back electrode layer 5
An electrical short circuit between them can be more reliably prevented.

Module 1 formed by the method described above
, A pair of electrode busbars 1 is provided at both ends of the serial array 11.
After each of the two is connected, an organic protective film (not shown) is usually provided on the back surface thereof via a sealing resin layer (not shown). This sealing resin layer is for sealing each thin-film photoelectric conversion cell 10 formed on the transparent substrate 2, and is made of a resin capable of bonding an organic protective film to these cells 10. As such a resin,
Examples thereof include a thermoplastic resin, a thermosetting resin, and a photocurable resin, such as EVA (ethylene / vinyl acetate copolymer), PVB (polyvinyl butyral), PIB (polyisobutylene), and a silicone resin. Can be used.

As the organic protective film, a fluororesin film such as a polyvinyl fluoride film (for example, Tedlar film (registered trademark)) or an insulating film having excellent moisture resistance and water resistance such as a PET film can be used. Used. The organic protective film may have a single-layer structure,
A laminated structure in which these are laminated may be used. Further, the organic protective film may have a structure in which a metal foil made of aluminum or the like is sandwiched between these films. Since a metal foil such as an aluminum foil has a function of improving moisture resistance and water resistance, it is possible to more effectively protect the thin-film photoelectric conversion cell 10 from moisture by using an organic protective film having such a structure. it can.

The sealing resin / organic protective film can be simultaneously attached to the back surface of the thin-film photoelectric conversion module 1 by a vacuum lamination method.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 (a)
7A and 7B are cross-sectional views schematically illustrating a manufacturing method according to a second embodiment of the present invention.

First, in the first embodiment, FIG.
2B by performing the steps described with respect to FIGS.
The structure shown in (b) is obtained. Next, as shown in FIG. 4A, a light absorption layer 6 is formed on the metal back electrode layer 5. The light absorbing layer 6 is a sublimation that absorbs laser light having a wavelength of 600 nm or less, for example, a laser light widely used in the manufacture of the module 1 with higher efficiency than the material of the metal back electrode layer 5. Contains conductive materials. for that reason,
According to the present embodiment, even when a conventionally used laser beam is used, the reflection of the laser beam irradiated from the film surface side is suppressed, and the temperature is set to a temperature sufficient to divide the metal back electrode layer 5. Can be heated up to.

As a sublimable material constituting the light absorbing layer 6, for example, titanium, chromium, tungsten, magnesium, silicon oxide, aluminum oxide, zinc oxide and the like can be mentioned. The light absorption rate of the sublimable material constituting the light absorption layer 6 with respect to laser light having a wavelength of 400 nm to 600 nm is preferably 0.1 or more. In such a case, division of the metal back electrode layer 5 can be efficiently performed using existing equipment. Further, since the light absorbing layer 6 is formed on the back metal electrode layer 5, it is preferable that the light absorbing layer 6 is conductive.

The light absorbing layer 6 described above can be formed by a vapor deposition method, a sputtering method, or the like. The light absorption layer 6 is usually formed to a thickness of about 10 nm to 200 nm.

After forming the light absorption layer 6, as shown in FIG. 4B, a groove 23 is formed in the metal back electrode layer 5 by laser scribing, and the metal back electrode layer 5 is electrically connected between the cells 10. Insulation. As described above, in the present embodiment, the light absorbing layer 6 that absorbs laser light having a wavelength of 600 nm or less with higher efficiency than the metal back electrode layer 5 is provided on the metal back electrode layer 5. ing. Therefore, according to the present embodiment, the groove 23 is irradiated by irradiating a laser beam having a wavelength of 600 nm or less from the film surface side.
Can be formed.

The laser light source used to form the groove 23 in the present embodiment is not particularly limited as long as it outputs laser light having a wavelength of 600 nm or less, and is a solid-state laser, a liquid laser, an excimer laser, a nitrogen laser, or the like. Or the like, but it is usually 500
One that outputs laser light having a wavelength of at least nm is used. Examples of the laser light used for forming the groove 23 include a second harmonic of a solid-state laser containing yttrium such as YAG.

The power and beam diameter of the laser beam used to form the groove 23, the relative speed between the substrate 2 and the optical axis of the laser beam, and the like are determined by the material used for the metal back electrode layer 5 and the light absorbing layer 6,
The thickness varies depending on the thickness, the width of the groove 23 to be formed, and the like. Generally, the power of the laser light is 0.4 W to 4 W
The frequency is 5 kHz to 50 kHz, the beam diameter is 30 μm to 100 μm, and the relative speed between the substrate 2 and the optical axis of the laser beam is 100 mm / sec to 1000 mm.
/ Sec. In such a case, the groove 23 can be formed to have a width of, for example, 30 μm to 100 μm.

When the groove 23 is formed in the metal back electrode layer 5 as described above, a groove 24 as shown in FIG. 4B is usually formed in the thin-film photoelectric conversion unit 4. The width of the groove 24 is smaller than the width of the groove 23 in any case, as in the first embodiment. This groove 24
Is generally 0% to 95% of the width of the groove 23.
In FIG. 4B, the bottom of the groove 24 is formed by the upper surface of the transparent front electrode layer 3, but the bottom of the groove 24 does not have to reach the transparent front electrode layer 3.

FIGS. 5A and 5B show an example in which the light absorbing layer 6 is made of Ti, and the groove 23 formed by irradiating the third harmonic of the YAG laser from the film surface side.
The photograph (output: 0.4 W, frequency: 5 kHz, processing width of the metal back electrode layer 5 is 70 μm) is shown.

After forming the groove 23 as described above,
Reactive ion etching or wet etching may be performed. Thereby, an electrical short circuit between the adjacent metal back electrode layers 5 can be more reliably prevented.

In each of the above embodiments, the transparent substrate 2
The present invention relates to a structure in which a transparent electrode layer 3, a thin-film photoelectric conversion unit 4 having a pin junction, and a metal electrode layer 5 are sequentially stacked, but another structure can be adopted. For example, when the thin-film photoelectric conversion unit 4 is of a tandem type, the above-described method is more effectively applied because the metal back electrode layer 5 is formed thicker. Further, in each of the above-described embodiments, the cells 10 are connected in series, but they can be connected in parallel.

[0058]

Embodiments of the present invention will be described below.

Example 1 The thin-film photoelectric conversion module 1 shown in FIG. 1 was manufactured by the method shown in FIGS. This will be described below with reference to FIG. 1 and FIGS. 2 (a) to 2 (c).

First, as shown in FIG. 2A, laser scanning is performed from the film surface side of the substrate 1 in parallel with the long side using the first harmonic of the YAG laser, thereby forming one of the main substrates of the glass substrate 2. The SnO ₂ film 3 formed on the surface was scribed to form a plurality of grooves 21. The grooves 21 were formed by setting the power of the laser beam to 3 W, the frequency to 10 kHz, the beam diameter to 50 μm, and the relative speed between the substrate 2 and the optical axis of the laser beam to 200 mm / sec.

Next, SnO _{2 was formed} by plasma CVD.
On the film 3, a p-type hydrogen-containing amorphous silicon carbide layer having a thickness of 10 nm, an i-type hydrogen-containing amorphous silicon layer having a thickness of 300 nm, and an n-type hydrogen-containing microcrystalline silicon layer having a thickness of 10 nm are sequentially formed. Filmed. The p-type hydrogen-containing amorphous silicon carbide layer is doped with boron as an impurity,
The i-type hydrogen-containing amorphous silicon layer is undoped, and n
The hydrogen-containing microcrystalline silicon layer is doped with phosphorus.
As described above, the thin-film photoelectric conversion unit 4 having the pin junction was formed.

Thereafter, as shown in FIG.
The thin film photoelectric conversion unit 4 is scribed by laser scanning from the film surface side of the substrate 1 in parallel to the long side using the second harmonic of the laser, and a plurality of grooves 22 are formed in the thin film photoelectric conversion unit 4. did. These grooves 22 are formed by setting the laser beam power to 1 W and the frequency to 10 kHz.
The beam diameter was set to 80 μm, and the relative speed between the substrate 2 and the optical axis of the laser beam was set to 400 mm / sec.

Next, as shown in FIG. 2B, the thin film photoelectric conversion unit 4 is sputtered to a thickness of 100 nm.
A ZnO film (not shown) having a thickness of m and an Ag film 5 having a thickness of 300 nm were sequentially formed to form a back electrode layer. This Ag film 5
As shown in FIG. 2C, a laser scribe using the third harmonic of the YAG laser was performed from the film surface side to form a plurality of grooves 23 having a width of 80 μm. It should be noted that the formation of these grooves 22 is performed by setting the power of the laser beam to 0.5 W
The frequency is 5 kHz, the beam diameter is 70 μm, and the relative speed between the substrate 2 and the optical axis of the laser beam is 200 mm / sec.
I went to set. In addition, as the groove 23 is formed in the Ag film 5, the thin film photoelectric conversion unit 4 has a width of 60 μm.
The groove 24 was formed.

As described above, 10 mm long × 800 mm wide
A series array 11 was formed by serially connecting 50-mm thin film photoelectric conversion cells 10 in a vertical direction (parallel to the short side of the substrate 2). Further, by attaching a pair of electrode bus bars 12 to both ends of the serial array 11, respectively, the module 1 shown in FIGS. 1 and 2 (c) was obtained.

Ten modules 1 were manufactured by the above-described method, and the output characteristics of each module were examined using a solar simulator having an irradiance of 100 mW / cm ² and an AM of 1.5 using a xenon lamp as a light source. The measurement temperature was 25 ° C. As a result, the average output of the module 1 was 30 W. No damage was found on the film surface in any of the modules 1 manufactured by the above-described method.

(Comparative Example) Instead of laser scribing the Ag film 5 from the film surface side using the third harmonic of the YAG laser, the Ag film was laser scribed from the glass substrate side using the second harmonic of the YAG laser. Except for this, 10 modules were manufactured in the same manner as in Example 1. In addition, Ag
Laser scribing of the film, the power of the laser light to 1W,
The frequency was set to 10 kHz, the beam diameter was set to 80 μm, and the relative speed between the substrate and the optical axis of the laser beam was set to 400 mm / sec. In addition, the width of the Ag film is 100
A groove having a width of 100 μm was formed in the thin film photoelectric conversion unit 4.

Next, the output characteristics of each module were examined under the same conditions as in the first embodiment. As a result, in the module according to the comparative example, the output characteristics varied, and the average output was 27 W. Further, in two of the modules 1 manufactured by the above-described method, damage was found on the film surface.

Embodiment 2 FIGS. 2A, 2B, 4A and 4B show the thin film photoelectric conversion module 1 shown in FIG.
Was manufactured by the method shown in FIG. Hereinafter, FIGS. 1 and 2 (a),
This will be described with reference to (b), FIGS. 4 (a) and 4 (b).

First, the structure shown in FIG. 2B was obtained by the same method as that shown in Example 1. Next, FIG.
As shown in FIG. 5, a Ti film 6 having a thickness of 20 nm was formed on the Ag film 5 by a sputtering method.

Thereafter, as shown in FIG.
Laser scribing using the second harmonic of the laser was performed from the film surface side, and a plurality of grooves 23 having a width of 80 μm were formed in the Ag film 5. The grooves 22 are formed by setting the laser beam power to 1 W, the frequency to 10 kHz, and the beam diameter to 70
μm, the relative speed between the substrate 2 and the optical axis of the laser beam is set to 200
mm / sec. Along with the formation of the groove 23 in the Ag film 5, a groove 24 having a width of 70 μm was formed in the thin-film photoelectric conversion unit 4.

As described above, 10 mm long × 800 mm wide
A series array 11 was formed by serially connecting 50-mm thin film photoelectric conversion cells 10 in a vertical direction (parallel to the short side of the substrate 2). Further, by attaching a pair of electrode bus bars 12 to both ends of the serial array 11, module 1 shown in FIGS. 1 and 4B was obtained.

Ten modules 1 were manufactured by the above method, and the output characteristics of each module were examined under the same conditions as in Example 1. As a result, the average output of module 1 is 30
W. No damage was found on the film surface in any of the modules 1 manufactured by the above-described method.

[0073]

As described above, according to the present invention,
Laser scribing of the metal back electrode layer is performed by irradiating a laser beam from the film surface side. Therefore, even if a defect exists in the transparent substrate, the division of the metal back electrode layer is not hindered, and the metal back electrode is not hindered. When dividing the layers, it is not necessary to arrange the transparent substrate upside down so that the film surface faces downward. Therefore, it is possible to obtain sufficient module performance or to improve the production yield of the module.

That is, according to the present invention, there is provided a method of manufacturing a thin-film photoelectric conversion module which is effective in reducing the manufacturing cost. Further, according to the present invention, a thin-film photoelectric conversion module having sufficient performance and a method for manufacturing the same are provided.

[Brief description of the drawings]

FIG. 1 is a top view schematically showing a thin-film photoelectric conversion module according to a first embodiment of the present invention.

2 (a) to 2 (c) are cross-sectional views schematically showing manufacturing steps of the thin-film photoelectric conversion module 1 shown in FIG.

FIGS. 3A and 3B are photographs showing an example of a groove formed in a metal back electrode layer by the method according to the first embodiment of the present invention.

FIGS. 4 (a) and (b) respectively show a second embodiment of the present invention.
Sectional drawing which shows schematically the manufacturing method which concerns on 1st Embodiment.

FIGS. 5A and 5B are photographs showing an example of a groove formed in a metal back electrode layer by a method according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Thin film photoelectric conversion module 2 ... Transparent substrate 3 ... Transparent front electrode layer 4 ... Thin film photoelectric conversion unit 5 ... Backside metal electrode layer 6 ... Light absorption layer 10 ... Thin film photoelectric conversion cell 11 ... Series array 12 ... Electrode bus bar 21-24 … Groove

Claims (8)

[Claims] 1. A method of manufacturing a thin-film photoelectric conversion module having a structure in which a transparent front electrode layer, a thin-film photoelectric conversion unit, and a metal back electrode layer are sequentially laminated on a transparent substrate, wherein the metal back surface is arranged from the back side. A method of manufacturing a thin-film photoelectric conversion module, comprising: irradiating a laser beam having a wavelength of 400 nm or less to an electrode layer to divide the metal back electrode layer. 2. The laser beam according to claim 1, wherein the laser beam is a third harmonic of a solid-state laser containing yttrium.
3. The method for manufacturing a thin-film photoelectric conversion module according to item 1. 3. A method for manufacturing a thin-film photoelectric conversion module having a structure in which a transparent front electrode layer, a thin-film photoelectric conversion unit, and a metal back electrode layer are sequentially laminated on a transparent substrate, the method comprising: Forming a light absorbing layer containing a sublimable material that absorbs laser light having a wavelength of 600 nm or less with higher efficiency than the material of the metal back electrode layer; Irradiating the laser beam to sublimate the sublimable material in a laser beam irradiating portion of the light absorbing layer and dividing the metal back electrode layer. . 4. The sublimable material contains at least one material selected from the group consisting of titanium, chromium, tungsten, magnesium, silicon oxide, aluminum oxide, and zinc oxide. 3. The method for manufacturing a thin-film photoelectric conversion module according to item 1. 5. The laser light according to claim 3, wherein the laser light is a second harmonic of a solid-state laser containing yttrium.
Or the method for manufacturing a thin-film photoelectric conversion module according to 4. 6. The method for manufacturing a thin-film photoelectric conversion module according to claim 1, wherein the metal back electrode layer contains at least one of silver and aluminum. 7. A transparent substrate, and a plurality of thin-film photoelectric conversion cells each having a transparent front electrode layer, a thin-film photoelectric conversion unit, and a metal back electrode layer sequentially laminated on the transparent substrate; In each of the thin film photoelectric conversion cells, the metal back electrode layer is provided so as to partially expose a peripheral portion of an upper surface of the thin film photoelectric conversion unit. 8. The thin-film photoelectric conversion module according to claim 7, wherein said thin-film photoelectric conversion unit is made of a silicon-based material.