JP3042130B2 - Method for manufacturing thin-film solar cell device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the manufacture of a thin-film solar battery device in which solar battery unit cells each using a thin-film semiconductor mainly composed of amorphous silicon or the like formed on a flexible substrate are connected in series. About the method.

[0002]

2. Description of the Related Art An amorphous semiconductor thin film formed by glow discharge decomposition of a source gas or photo-CVD can be easily formed on a flexible substrate such as a polymer material because the film is formed at a low temperature. . For this reason, it is expected as a solar cell material to be installed on a curved material such as a house building material or a car sunroof. In order to efficiently extract the power generated from such amorphous solar cells,
The solar cell device is shaped, for example, as shown in FIG.
A structure in which unit cells are connected in series is desirable.
In this structure, a first electrode having a light-transmitting property and a conductive property with respect to a power generation wavelength region of a solar cell made of SnO ₂ , ZnO, or the like is formed on a flexible insulating substrate 1 such as a polymer material having a light-transmitting property. Tier 2
1, 22, 23 are formed in the shape of a strip, on which the amorphous semiconductor layers 31, 32, 33 which are photovoltaic power generation sections, and then the second electrode layer 41 made of a light-transmitting / conductive thin film or a metal thin film, 42, 43
Are sequentially laminated. Then, the patterns of the two electrode layers and the amorphous semiconductor layer are configured so that the first electrode layer of one unit cell is in partial contact with the second electrode layer of an adjacent unit cell. Such a pattern of each layer is formed by patterning a thin film formed on the entire surface by a laser patterning method.

[0003]

In order to manufacture a series-connected thin-film solar cell device as shown in FIG. 2, three patterning operations are required. It divides the light-transmitting and conductive thin film into strips and forms a plurality of electrically separated first electrode layers. The first electrode patterning forms a gap that can be connected between the first and second electrode layers. In order to achieve this, the amorphous semiconductor thin film is divided into an amorphous semiconductor thin film and the second electrode layer is divided into unit electrodes to electrically separate the unit cells. However, when a flexible substrate is used, the flatness of the flexible substrate deteriorates due to stress of each layer generated by forming the first and second electrode layers or the amorphous semiconductor thin film thereon. As shown in FIG. 3, the laser energy density on the film surface to be processed increases when the processing point by the laser deviates from the reference point in the lens direction, and decreases when the processing point deviates toward the XY stage supporting the substrate. Become. Therefore, when the flatness of the flexible substrate is deteriorated, the processing uniformity of the laser patterning is reduced, and the dimensional accuracy of each unit cell is reduced, or the electrical separation between the unit cells or the incomplete electrical connection is caused. there were.

An object of the present invention is to solve the above-mentioned problems and to manufacture a thin-film solar cell device for uniformly processing a thin film on a flexible substrate, which has lost its flatness due to stress at the time of forming each layer, with a laser. It is to provide a method.

[0005]

In order to achieve the above object, the present invention provides a first and a second electrode layer formed by dividing a thin film formed on a flexible insulating substrate, respectively. In a method for manufacturing a thin-film solar cell in which unit cells having an amorphous semiconductor layer are connected in series,
After forming the thin film, at least one surface is a smooth surface, and at least one is fixed with a flexible insulating substrate sandwiched between the smooth surfaces of two correction plates having a light-transmitting property, and laser light is transmitted through the light-correcting plate. Irradiate and divide. Alternatively, unit cells formed by dividing a thin film formed on a light-transmitting flexible insulating substrate and having an amorphous semiconductor layer between first and second electrode layers are connected in series. In the method for manufacturing a thin-film solar cell, at least one surface is a smooth surface after the thin film is formed, and at least one is fixed with a flexible insulating substrate between the smooth surfaces of two correction plates having a light-transmitting property. A laser beam is irradiated through a light-correcting plate and a light-transmitting flexible insulating substrate to be divided. At that time, it is effective that the wavelength of the laser beam projected to process the amorphous semiconductor layer and the second electrode layer is shorter than the wavelength of the laser beam projected to process the first electrode layer. Further, it is effective to place the flexible substrate and the correction plate on a XY stage that can be moved in a plane perpendicular to the laser light projection direction by computer control during processing by laser light projection.

[0006]

The flexible substrate is fixed by sandwiching and fixing the flexible substrate from both sides with a translucent correcting plate such as glass having a smooth surface on a surface in contact with the flexible substrate and a correcting plate having a smooth surface. The flatness of the substrate is improved, thereby improving the processing uniformity of laser patterning by the laser light projected through the correction plate.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to the drawings in which the same parts as those in FIG. FIG.
X for laser patterning of thin film on flexible substrate
It shows a method of attaching to a Y stage. In the previous process, a ZnO film having a thickness of 1 μm is formed as the first electrode layers 21, 22, and 23 on the flexible insulating substrate 1 such as a polymer material, and then an amorphous semiconductor (amorphous silicon) is formed.
The layers 31, 32, 33 are formed with a thickness of 0.4 μm. The first electrode layer and the amorphous semiconductor layer were patterned by the same laser scribe method as in the related art. As a laser light source for patterning the first electrode layers 21, 22, and 23, a YAG: Na laser having a wavelength of 1.06 μm is used. As a light source for patterning the amorphous semiconductor layers 31, 32, and 33, YAG: Nd having a wavelength of 0.53 μm is used. Using each laser,
The projection was performed from the side of the flexible substrate 1. Next, a silver thin film 40 for the second electrode layer was formed thereon to a thickness of 0.2 μm. Then, as shown in the figure, the flexible substrate 1, which had been poor in flatness by being sandwiched between the correction glass plates 51 and 52 from both sides, was fixed so as to be flat, and was set on the XY stage 6. In patterning, the XY stage 6 takes arbitrary coordinates under computer control.

YA having a wavelength of 0.53 μm is used as a laser light source.
G: An Nd laser is used, and a laser beam 7 is also incident from the flexible substrate 1 side. In this case, the laser beam 7 is transmitted through the transparent correcting glass plate 51 and the flexible substrate 1, and is not absorbed by the first electrode layers 21, 22, and 23 because of its short wavelength, but is absorbed by the silver thin film 40. Since the material of this film is evaporated, XY
The part 8 indicated by a dotted line in the figure by controlling the movement of the stage 6
Is removed.

By using the straightening glass plates 51 and 52 as described above, the flatness which is a problem of the flexible substrate can be reduced as shown in FIG.
Was controlled within ± 500 μm indicated by A. As a result, variations in laser energy density during processing can be made within ± 0.1, and laser patterning with good uniformity can be performed. As a result, a high-performance series-connected thin-film solar cell having flexibility was obtained.

In the above embodiment, the correction glass plate is used only when the second electrode layer is patterned. However, depending on the degree of flatness of the flexible substrate after the formation of the first electrode layer or the amorphous semiconductor layer. Also, it is effective to sandwich the first electrode layer or the amorphous semiconductor layer between the correction glass plates at the time of patterning.

[0011]

According to the present invention, as a result of employing the above method, the processing uniformity of the laser patterning is improved, and accurate patterning can be performed. This makes it possible to manufacture a thin-film solar cell device that can be installed on a curved surface with high performance.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view during a second electrode layer patterning step according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the thin-film solar cell device manufactured through the process shown in FIG.

FIG. 3 is a relationship curve diagram of a deviation of a processing point from a reference point during laser processing and a laser energy density at the processing point.

[Explanation of symbols]

 REFERENCE SIGNS 1 flexible insulating substrate 21 first electrode layer 22 second electrode layer 23 third electrode layer 31 amorphous semiconductor layer 32 amorphous semiconductor layer 33 amorphous semiconductor layer 40 silver thin film 41 second electrode layer 42 second electrode layer 43 second electrode Layer 51 Glass plate for correction 52 Glass plate for correction 6 XY stage 7 Laser beam 8 Laser processing part

Claims (4)

(57) [Claims] A thin film formed by dividing a thin film formed on a flexible insulating substrate and formed by serially connecting unit cells each having an amorphous semiconductor layer between first and second electrode layers. In the method of manufacturing a solar cell, at least one surface is a smooth surface after the thin film is formed, and at least one is fixed with a flexible insulating substrate sandwiched between the smooth surfaces of two correction plates having a light-transmitting property. A method for manufacturing a thin-film solar cell device, comprising irradiating a laser beam through a straightening plate and dividing the laser beam. 2. A series connection of unit cells each having an amorphous semiconductor layer between first and second electrode layers formed by dividing a thin film formed on a light-transmitting flexible insulating substrate. In the method for manufacturing a thin-film solar cell, at least one surface is a smooth surface after the thin film is formed, and at least one is fixed with a flexible insulating substrate sandwiched between the smooth surfaces of two straightening plates having translucency. And irradiating the laser beam through a translucent correction plate and a translucent flexible insulating substrate,
A method for manufacturing a thin-film solar cell device, which comprises dividing. 3. The thin film according to claim 1, wherein the wavelength of the laser beam projected for processing the amorphous semiconductor layer and the second electrode layer is shorter than the wavelength of the laser beam projected for processing the first electrode layer. A method for manufacturing a solar cell device. 4. The thin-film solar cell according to claim 1, wherein the flexible substrate and the correction plate are mounted on an XY stage which can be moved in a plane perpendicular to the laser light projection direction by computer control during processing by laser light projection. A method for manufacturing a battery device.