JPH0548633B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a method for manufacturing a tiled photovoltaic device that directly converts light energy such as sunlight into electrical energy.

(b) Prior Art Photovoltaic devices that directly convert light energy into electrical energy, so-called solar cells, use inexhaustible sunlight as their main energy source, so they have been in the spotlight as energy resources become a problem. There is. The sun gives about 1KW/ ^m2 of energy to the earth's surface during clear weather, and if a photovoltaic device that converts this energy into electrical energy is used as a power source at home, it is installed on the roof of the house or on the roof. is common.

Japanese Unexamined Patent Publication No. 1984-68454 or Utility Model Application No. 1983-
A roof tile equipped with a solar cell, ie, a tile-shaped photovoltaic device, disclosed in Japanese Patent No. 11261 is suitable as such a household power source.

(c) Purpose of the Invention The purpose of the present invention is to provide a method for manufacturing a tiled photovoltaic device using a tiled substrate having a curved insulating surface such as a roof tile, which is equipped with a solar cell and is suitable as a household power source. It is about providing.

(d) Structure of the Invention The method for manufacturing a tile-shaped photovoltaic device of the present invention provides a method for manufacturing a tiled photovoltaic device having a curved surface and an insulating surface; A plurality of photoelectric conversion regions are provided on one main surface of the region, in which an electrode film, a semiconductor film, and a transparent conductive film are laminated and arranged at regular intervals, which are directly adhered to each other. A method for manufacturing a tile-shaped photovoltaic device in which the electrode film of one photoelectric conversion region and the transparent conductive film of the other are connected in series by superimposing the electrode film of one photoelectric conversion region and the transparent conductive film of the other photoelectric conversion region in an adjacent interval part of the conversion region, the method comprising: divides the photoelectric conversion region by scanning an energy beam that has passed through an objective lens in parallel with the ridgeline of the curved surface to form the adjacent interval portions, and also divides the adjacent interval portions into adjacent intervals separated by the constant interval. When scanning to the adjacent space, the distance between the surface to be processed in the adjacent space and the objective lens is corrected to a predetermined constant value before scanning to the adjacent space, and then The purpose is to scan.

(e) Example FIGS. 1 and 2 show a tiled photovoltaic device manufactured by the manufacturing method of the present invention, FIG. 1 is a perspective view, and FIG. It is a line cross-sectional view, and 1 is a substrate formed from a translucent and insulating material such as tempered glass or transparent ceramics into a tile shape and provided with a wavy insulating surface; 2, 2, . , a region having substantially uniform thickness between the two principal surfaces, and a plurality of photoelectric conversion regions arranged at regular intervals on the insulating surface of one principal surface of the region. The photoelectric conversion regions 2, 2... are, for example, the substrate 1
From the side, transparent conductive films 3, 3... made of tin oxide, indium tin oxide, etc., and amorphous silicon-based amorphous semiconductor films 4, 4... with semiconductor junctions therein.
and back electrode films 5, 5, etc., made of aluminum or the like, which are in ohmic contact with the semiconductor films 4, 4, etc., are sequentially laminated to have a film shape on the order of microns.

Each amorphous semiconductor film 4, 4... has a P-type layer with a thickness of about 50 to 250 Å from the light-receiving surface side and an I-type (intrinsic) layer with a thickness of about 4000 to 7000 Å in order to form a PIN junction parallel to the film surface. ) layer and an N-type layer of about 300 to 600 Å are sequentially deposited, so that when light is incident through the substrate 1 and the transparent conductive films 3, 3, etc., the I-type layer is mainly in a free state. Electrons and holes are generated, and these electrons and holes are attracted by the PIN junction electric field formed by each of the above layers and are collected by each transparent conductive film 3, 3... and back electrode film 5, 5..., and the adjacent The transparent conductive films 3, 3... of the photoelectric conversion regions 2, 2... and the back electrode film 5,
5... The electrically added power is taken out.

FIGS. 3 to 10 are an enlarged sectional view and a schematic perspective view of essential parts for explaining the manufacturing method of the present invention.

In the process shown in FIG. 3, a film with a thickness of 500 Å to 4000 Å is directly deposited by electron beam evaporation over the entire curved insulating surface including a plurality of photoelectric conversion regions 2, 2, etc. with the peripheral edge of the substrate 1 covered with a mask. A transparent conductive film 3 having a laminated structure of indium tin oxide and tin oxide is divided into photoelectric conversion regions 2, 2, . . . by irradiation with an energy beam such as a laser beam. The laser used is Nd with a wavelength of 1.06μm, an energy density of 7×10 ⁷ W/cm ² , and a pulse frequency of 3KHz:
A YAG laser is suitable, and patterning is performed using an objective lens of f50 mm and a scanning speed of 50 mm/sec. The interval L1 between the transparent conductive films 3 removed by this laser patterning is set to about 50 μm.

What must be kept in mind in such laser patterning is that the distance to the transparent conductive film 3, which is the surface to be processed, must not vary significantly. That is,
The energy density and machining width of the laser beam incident on the objective lens are controlled by the convergence effect of the lens, so if the distance to the workpiece surface changes significantly as described above, the energy density and machining width will also fluctuate. This is because it becomes impossible to perform desired processing.

Therefore, in the present invention, the transparent conductive film 3 directly adhered to the curved insulating surface is attached to each photoelectric conversion region 2,
When dividing the substrate 1 into 2... parts, the XYZ stage 6 on which the substrate 1 is placed and moved in the
The distance between the objective lens 9 and the surface to be processed is kept constant by irradiating the laser beam 8 during the process of moving in the X-axis direction. Next, when the removal of the transparent conductive film 3 located in one adjacent gap is completed by scanning by moving the substrate 1 in the X-axis direction, the XYZ stage 6 moves the transparent conductive film 3 located in the next adjacent gap to be removed. The substrate 1 is moved in the Y-axis direction so that the film 3 and the objective lens 9 face each other. In this state, the distance between the objective lens 9 and the surface to be processed is different from that during the previous laser beam irradiation because the curved insulating surface of the substrate 1 is changing in the Y-axis direction.
The XYZ stage 6 is raised or lowered in the Z-axis direction to once make a correction to a predetermined distance, and after making such correction prior to laser beam irradiation to the transparent conductive film 3 located in the adjacent interval, the XYZ
The stage 6 is moved in the X-axis direction, and the unnecessary transparent conductive film 3 located at the adjacent interval is removed by irradiation with the laser beam 9. Thereafter, such an operation is repeated to pattern the transparent conductive films 3, 3, . . . parallel to the ridge line 7 of the curved surface.

As described above, according to the manufacturing method of the present invention, since the laser beam 8 is irradiated parallel to the ridge line 7,
During laser beam scanning, it is possible to always keep the distance between the objective lens 9 and the surface to be processed constant.

This means that after irradiation with the laser beam 8, when irradiating adjacent spaced parts, the distance between the surface to be processed and the objective lens must be corrected before irradiating the laser beam on that part. If this is done, the above correction during laser beam irradiation can be made unnecessary.

In addition, since such stable correction can be performed, in the tile-shaped photovoltaic device produced by the manufacturing method of the present invention, the characteristics of each photovoltaic conversion region are stabilized, and the characteristics of the photovoltaic device itself are stabilized. You can improve your performance.

After patterning the transparent conductive films 3, 3, . . . , the process moves to the step of depositing the amorphous semiconductor film 2. FIG. 5 shows that glow discharge is excited in an atmosphere of silicon compounds such as monosilane (SiH ₄ ) and disilane (Si ₂ H ₆ ), and amorphous silicon (a
-Si:H), amorphous silicon carbide (a-Si _x
C _ix : H), amorphous silicon tin (a-Si _y Sn _iy :
This schematically shows a step of depositing an amorphous silicon-based amorphous semiconductor film 4 such as H). For example, the fact that a thin film of amorphous silicon can be obtained by glow discharge in a silicon compound atmosphere is reported in
This is already known as disclosed in Publication No. 37718.
That is, in the conventionally known formation of an amorphous semiconductor by glow discharge, a substrate made of glass, stainless steel, etc. to which the semiconductor film is to be deposited is placed between parallel electrodes that face each other and excite glow discharge. In addition, as a result of the substrate being perpendicular to the moving direction of the high-speed charged particles in the plasma, the high-speed charged particles in the plasma collide with the surface of the substrate 1, and the transparent conductive films 3, 3... or are formed. This has the disadvantage that the characteristics of the amorphous semiconductor film 4 are deteriorated. Moreover,
While the surface of the substrate 1 on which the amorphous semiconductor film 4 is deposited has conventionally been flat, the surface of the present invention has a curved surface. When the substrate 1 is arranged, the facing distance between the curved surface and one of the parallel plate electrodes facing the surface becomes uneven, so that the deposited amorphous semiconductor film 4 has to be non-uniform. I don't get it.

Therefore, the substrate 1 with a curved insulating surface used in the present invention is not disposed between corresponding parallel plate electrodes, but is placed outside the parallel plate electrodes and on the opposite surface of the substrate 1. The amorphous semiconductor film 4 is formed by arranging the adhered surface in a substantially vertical direction and moving the substrate 1 in the direction of the curved surface of the surface as shown by the arrow in the figure, that is, in the direction perpendicular to the ridgeline 7. ing. That is, in the embodiment shown in FIG. 5, the parallel plate electrodes are ground electrodes 10, 1.
A multi-electrode structure is constructed in which high-frequency electrodes 0, 10 and high-frequency electrodes 12, 12 connected to a high-frequency power source 11 are made to face each other alternately, and the substrate 1 is moved in the direction in which the electrodes 10, 12, 10... are arranged in parallel. There is.

However, regarding the above multi-electrode structure, basically, a glow discharge is excited between one earth electrode 10 and one high-frequency electrode 12, which face each other, and plasma is generated between both electrodes, which generates a reactive gas. For example, silicon atoms obtained by decomposition adhere to the curved surface of the substrate 1 disposed close to the outside of the two electrodes, so that the amorphous semiconductor film 4 is gradually formed. It is not necessary to adopt an electrode structure.

By arranging the substrate 1 outside the ground electrodes 10, 10, 10 and the high frequency electrodes 12, 12, which face each other in this way, the adhesion surface of the substrate 1 is protected against high-speed charged particles in the plasma. As a result of being removed from the moving region and the collision of such charged particles is significantly reduced, damage to the amorphous semiconductor film 4 is reduced, and the formation (deposition) process of the amorphous semiconductor film 4 is then performed on the substrate. 1 in the process of moving in the curved direction of the surface (the direction in which the electrodes are arranged in parallel), an amorphous semiconductor film 4 with high uniformity can be obtained as shown in FIG.

Moreover, the high frequency output, which has been suppressed to reduce damage caused by high-speed charged particles during the formation of an amorphous semiconductor film, can be increased, and the growth rate of the film can also be increased.

In the embodiment shown in FIG. 5, the substrate 1 has ground electrodes 10, 10,
10 and high frequency electrodes 12, 12, and therefore two substrates 1, 1 are provided at the same time.
On the other hand, formation of the amorphous semiconductor film 4 is performed.
At this time, a heater for heating the substrates 1, 1 is buried and held in a recess in the side wall of the reaction chamber (not shown), and uniformly heats each of the substrates 1, 1 from behind the surface to which it is attached.

FIG. 7 shows another deposition (formation) of the amorphous semiconductor film 4.
The process is schematically shown, and the previous example, that is, the first example, shows the state in which the ground electrodes 10, 10 and the high-frequency electrodes 12, 12 are opposed to the substrate 1, and the gas for discharging the reaction gas. The specific structure of the supply body 13 is different. That is, the opposing surfaces 10a, 12a, . . . of the ground electrodes 10, 10 and high frequency electrodes 12, 12, which face the substrate 1, have curved surfaces having the same shape so as to face parallel to the curved surface of the surface of the substrate 1. Therefore, by applying curved surfaces of the same shape to the opposing surfaces 10a, 12a... of the electrodes 10, 12..., the opposing distances between the opposing surfaces 10a, 12a... and the surface of the substrate 1 become equal, resulting in uniform non-conformity. Although the crystalline semiconductor film 4 can be formed even when the substrate 1 is stopped, in order to obtain a more uniform amorphous semiconductor film 4, it is possible to form the crystalline semiconductor film 4 even when the substrate 1 is stopped. Similarly, the substrate 1 is arranged in the direction in which the ground electrodes 10, 10 and the high frequency electrodes 12, 12 are arranged side by side (in the direction of the ridge line of the substrate 1).
It is preferable to perform this during the process of moving to.

On the other hand, the gas supply body 13 has a large number of discharge ports 14, 1
The gas discharge surface 15 with holes 4... is connected to the ground electrode 1
0, 10 and high-frequency electrodes 12, 12 are placed in between to face the curved surface of the substrate 1, and the gas discharge surface 15 is also arranged to face the curved surface of the substrate 1 in order to equalize the facing distance between the gas discharge surface 15 and the curved surface. It has the same curved shape as the surface. The reactive gas discharged varies depending on the amorphous semiconductor to be formed, but for example, in the case of amorphous silicon, it is based on monosilane (SiH ₄ ) and/or disilane (Si ₂ H ₆ ), and diborane containing P-type impurities. (B ₂ H ₆ ) or phosphine (PH ₃ ) containing an N-type determining impurity is added as appropriate. Incidentally, in place of the gas supply body 13, another substrate 1 may be arranged.

The amorphous semiconductor film 4 can be formed under substantially the same reaction conditions as in the first and second embodiments.

The basic reaction conditions for forming PIN junction type amorphous silicon are described below.

Γ Substrate temperature 250 to 300℃ Γ High frequency power supply 13.56MHz Γ High frequency output 100W Γ Reactive gas (composition ratio) P type layer B ₂ H ₆ /SiH ₄ = 0.1% I type (non-doped) layer SiH ₄ = 100% N type layer PH ₃ /SiH ₄ = 1% Γ gas pressure 0.3 to 1 Torr Γ gas flow rate 10 to 40 c.c./mit Non-crystalline silicon, which is uniformly deposited on the curved surface of the substrate 1, crystalline semiconductor 4
is placed on the XYZ stage 6 as shown in Fig. 4, and in the process shown in Fig. 8, the adjacent spaced portions are removed by irradiation with the laser beam 8 to form separate photoelectric conversion regions 2, 2... At the same time, parts of the transparent conductive films 3, 3, . . ., which were covered with the removed amorphous semiconductor films 4, 4, . The laser used has a wavelength of 1.06 μm and an energy density of 5×10 ⁷ W/cm ² .
It is a Nd:YAG laser with a pulse frequency of 3KHz,
The distance L2 between the removed amorphous semiconductor films 4 is approximately
It is set to 200μm.

The scanning direction of the laser beam 8 is similar to that of the transparent conductive films 3, 3, . . . in order to keep the distance between the objective lens 9 and the surface to be processed constant. The laser beam 8 is scanned in the direction of the ridge line 7 on the surface at a speed of 50 mm/sec by moving the XYZ stage 6 in the X-axis direction. When the scanning of one adjacent space with the laser beam 8 is completed, the XYZ stage 6 is moved in the Y-axis direction so that the amorphous semiconductor film 4 to be removed next faces the objective lens 9, and then It is moved in the Z-axis direction to correct the facing distance between the two to a predetermined constant value. Then, the operation of scanning the laser beam 8 by moving in the X-axis direction is repeated again, and the amorphous semiconductor films 4, 4, . . .
Patterning is performed parallel to the ridge line 7 on the surface.

In the process shown in FIG.
The entire photoelectric conversion area 2, 2 including the surfaces of a, 3a...
It is applied continuously over...

The adjacent interval part of the back electrode film 5 is the following 10th
In the process shown in the figure, the transparent conductive films 3 of the photoelectric conversion regions 2, 2... where the extension parts 5a, 5a... of the back electrode films 5, 5 extending from one photoelectric conversion region 2, 2... are adjacent to each other,
3... is removed by irradiation with a laser beam 8 in order to combine with the exposed parts 3a, 3a..., and the interval L3 is
It is set to 50μm. The laser used is an Nd:YAG laser with a wavelength of 1.06 μm, similar to the transparent conductive films 3, 3..., amorphous semiconductor films 4, 4..., and the speed is 50 mm/sec by moving the XYZ stage 6 in the X-axis direction. is scanned. The operations after scanning in the X-axis direction, ie, correction of the facing distance between the objective lens 9 and the surface to be processed, etc., are the same as in the previous laser patterning (removal) process, and therefore will not be described.

When removing by irradiation with the laser beam 8, care should be taken not to damage other films if they exist below the film to be removed. The processing threshold density of the laser beam 8 for the amorphous silicon-based amorphous semiconductor film 4 is approximately 4×
10 ⁷ W/cm ² is smaller than 7×10 ⁷ W/cm ² of the transparent conductive film 3, so even if the laser beam 8 directly hits the transparent conductive film 3 during the removal process of the amorphous semiconductor film 4, No damage.

However, the material that can form the back electrode film 5, ie, the metal that is in ohmic contact with the amorphous semiconductor film 4, generally has a processing threshold energy density higher than that of the transparent conductive film 3. For example, in the case of aluminum, aluminum has a low laser beam absorption rate and excellent thermal conductivity, so the heat of laser beam irradiation is dissipated, and as a result, at a thickness of about 8 ×10 ⁷ /cm ² , which is a slightly higher value than that of the transparent conductive film 3.

Therefore, in the present invention, the back electrode film 5 is not made of aluminum alone, but the thickness of the aluminum film is approximately several 100 Å in order to reduce the dissipation of irradiated heat.
The processing threshold energy density is reduced to 2×10 ⁷ W/cm ² by making the material thinner and by layering a material with high absorption rate, such as titanium or titanium-silver alloy, with a thickness of about 5000 Å on the surface. There is. Further, the back electrode film 5 may be composed of the above-mentioned titanium or titanium-silver alloy alone.

(F) Effects of the Invention As is clear from the above description, the present invention directly adheres a photoelectric conversion region in the form of a film to the insulating surface of a tiled substrate having a curved surface. It can be used both as a supporting substrate and as a roof tile, eliminating the need for a separate substrate for attaching the photoelectric conversion area, and also eliminating the need for the process of attaching the substrate without the photoelectric conversion area to the tile-shaped substrate. , the configuration and manufacturing process are simplified.

Furthermore, since the energy beam is irradiated parallel to the ridgeline of the curved surface to the film-like photoelectric conversion region that is not directly attached to the tile-like substrate, the photoelectric conversion region can be formed in a state where the distance between adjacent regions is extremely reduced. It can be easily divided into multiple regions along a curved surface, increasing the effective area that contributes to power generation.

Further, according to the present invention, after irradiating the energy beam, when irradiating the adjacent spaced portion, the distance between the objective lens used for irradiating the energy beam at that portion and the surface to be processed is determined in advance. Suitable division can be achieved by once making a correction to a constant value before scanning the energy beam to the adjacent spaced portion.

This means that since the energy beam is irradiated parallel to the above-mentioned ridgeline, the distance correction described above during scanning of the energy beam is not required, and the process is not complicated. Furthermore, such correction makes it possible to stabilize the characteristics of each photoelectric conversion region of the shingled photovoltaic device produced by the manufacturing method of the present invention.

[Brief explanation of the drawing]

The figures show examples of the present invention, and FIG. 1 is a perspective view of a photovoltaic device manufactured by the manufacturing method of the present invention;
Figure 2 is a sectional view taken along line A-A' in Figure 1, and Figure 3
6 and 8 to 10 are enlarged cross-sectional views of main parts for sequentially explaining the manufacturing process, and FIG. 4 is a schematic perspective view of the laser patterning (removal) process.
Figure 5 shows the first step of the amorphous semiconductor deposition (formation) process.
A schematic perspective view showing an embodiment. FIG. 7 is a schematic perspective view showing a second embodiment of an amorphous semiconductor deposition (formation) process. DESCRIPTION OF SYMBOLS 1...Substrate, 2...Photoelectric conversion region, 4...Amorphous semiconductor film, 6...XYZ stage, 8...Laser beam, 10...Ground electrode, 12...High frequency electric field.

Claims (1)

[Claims] 1. A tile-shaped substrate having a curved surface and an insulating surface, the substrate has a region where the thickness is maintained substantially even between the two main surfaces, and one main surface of the region is directly adhered to.
A plurality of photoelectric conversion regions are provided in which an electrode film, a semiconductor film, and a transparent conductive film are laminated and arranged at regular intervals. A method for manufacturing a tile-shaped photovoltaic device formed by superimposing and connecting transparent conductive films in series, wherein the photoelectric conversion region scans an energy beam that has passed through an objective lens in parallel to the ridgeline of the curved surface. By this, the photoelectric conversion region is divided to form the adjacent spaced parts, and when scanning to the adjacent spaced part separated from the adjacent spaced part by the constant distance, the processing surface of the adjacent spaced part and the part to be processed are separated. A method for manufacturing a tile-shaped photovoltaic device, characterized in that the scanning is performed after first correcting the distance from the objective lens to a predetermined constant value prior to scanning to the adjacent spaced portion.