JPS6060776A - Manufacture of photovoltaic device - Google Patents

Abstract

PURPOSE:To prevent the formation of a pin hole due to residue by the projection of energy beams by dividing each photoelectric conversion region in an electrode layer by the projection of energy beams after an optical semiconductor layer is laminated. CONSTITUTION:A first electrode layer 11 and an optical semiconductor 12 consisting of an amorphous semiconductor are formed on the surface of an insulating substrate 10 made of glass. The layers 11, 12 are removed through the projection of laser beams, and an adjacent space section 13 is formed. One part of a first electrode layer 11b is removed by a YAG laser. A second electrode layer 14 is shaped. The layer 14 in the space section 13 is removed through the projection of laser beams to form separate second electrode layers 14a, 14b.

Description

[Detailed description of the invention] (a) Industrial application field The present invention converts source energy such as sunlight directly into electrical energy (=
Converting Photovoltaic Device Manufacturing Method I: Relating.

Main) Conventional technology Photovoltaic devices that directly convert light energy into electrical energy, so-called solar cells, use inexhaustible sunlight as their main energy source. There is.

Figure 1 shows such a photovoltaic device, in which (1) is an insulating substrate such as glass or transparent brass, (2a) (21)) (
20) is the -main surface of the insulating substrate (1)! - A plurality of photoelectric conversion regions arranged in parallel, the conversion regions (2a) (21)) (2
0) from the insulating substrate (1) side.
2), Indium tin oxide (In2015-SnO2)
The first electrode of transparent oxide electrode material such as! (5a) (3b) (
gc) and a film-like optical semiconductor 1i1 (4a) (4
1)) (4Q) and the optical semiconductor layer (4IL) (4b) (
4c) of aluminum A7 etc. in ohmic contact with
It has a laminated structure in which electrode layers (5a), (5b), and (5') are sequentially overlapped. Further C:, the above-mentioned parallel photoelectric conversion areas (2a) (2'tl) (2c) are on the right side 1)
Original semiconductor @ (41)) (40) Insulating substrate (1) from the bottom surface
) Exposed parts of the first electrode layer (3b) (5c) (5b') (3c')
a) (41)) The second electrode layer (5a) extending from the top surface
) (5b) extensions (5e:) (51)') are coupled together, thus forming a plurality of photoelectric conversion regions (2a) (211).
(2Q) are electrically connected in series.

In such a device, one factor that affects the light utilization efficiency is the light receiving area (i.e. substrate area) of the entire device.
Photoelectric conversion areas (2a) (2'b) that actually contribute to power generation
(2c) The total area of c7) is the occupied mel ratio. However, the separation regions that inevitably exist at adjacent intervals between the photoelectric conversion regions (21L), (21), and (20) reduce the above-mentioned area ratio.

Therefore, in order to improve the light utilization efficiency, it is necessary to reduce the separation region, which is the interval between adjacent photoelectric conversion regions (2a) (2b) (2a).

Such space reduction is determined by the processing accuracy of each layer, and therefore, photolithography, which has excellent precision processing properties, is promising. In the case of this technique, a step of depositing the first electrode layer on the entire surface of the substrate (1), separation of each individual first electrode layer (!1a) (51)> (30) by photoresist and etching C2, That is, after sequentially repeating the step of removing adjacent spaced portions of each first electrode layer (3a) (5°b)Coo), the same adhesion step and removal step are performed on the optical semiconductor layer (4a)(411)C40. ) and the second electrode &(5a)(51))(5c)in.

However, since the photo-etching technique described above involves a wet process such as washing with water, the photo-semiconductor layer (4a) (4) is formed in a film-like manner.
'b) Pinholes may be formed in (4a), and the second electrode material deposited in the next step passes through the first electrode layer (5a) (3t') (5o) +: As a result, the first electrode layer (5a) (3't+) (5Q
) is electrically connected to the second electrode layer (5IL) (5b) (50) that faces the photoelectric conversion region (21L) (2b) (2o) with the optical semiconductor layer (4a) (4b) (4C) sandwiched therebetween. This caused an accident due to a short circuit. In addition, the second electrode layer (58) (5
b) (5C) or optical semiconductor l5ij (
The contact surfaces of 4a), (41), and (4C) deteriorate the film quality even if no pinholes are formed during the coating and peeling of the photoresist using the above-mentioned photolithography technique and washing with water (:, washing with water C: use). A small amount of the water remaining in the second electrode layer (5a) (5-o) (5-o) will be deposited in the next step.
There is a risk of corroding c) and t).

Japanese Unexamined Patent Publication No. 57-12568 (-The disclosed prior art involves cutting away layers by laser beam irradiation to provide the above-mentioned adjoining spacing, but that technique, which does not use photolithography, does not address the above-mentioned problems. It is extremely effective in solving problems.

When manufacturing a photovoltaic device as shown in FIG. ) (2
It is separated by laser beam irradiation every t') (2'). What must be kept in mind when separating by laser beam irradiation is that the laser beam irradiation 1
:Residues such as molten material of the film (layer) to be removed are in the vicinity of the removed part (=residual adhesion or scattering and forming pinholes in the film (layer) to be applied in the subsequent process) Special I: Optical semiconductor layer (4a) (4b) (4
.

) When a pinhole is formed in the photo-semiconductor layer (4a) (4b) (40), the opposing first electrode & (3a) (5'b) (5c) and the 2 electrodes I
Ei&(5a)(5t))(50) and is thermally short-circuited. Moreover, the film thickness of the optical semiconductor layers (4a), (4b), and (40) is more effective for photoelectric conversion than that of the other electrode layers (3a), (5a), and so on! There are no two effects.

C/→ Purpose of the Invention The present invention has been made in consideration of the above point (1), and it is possible to achieve fine processing without causing pinholes in the optical semiconductor layer (= utilizing a rich energy beam). It is intended to tighten.

2) Structure of the Invention A method for manufacturing a photovoltaic device of the present invention in which a plurality of film-like photoelectric conversion regions are electrically connected in series on an insulating surface of a substrate (1). After superimposing and depositing the first electrode layer and the photosemiconductor layer, the first electrode layer and the photosemiconductor layer are irradiated with an energy beam having an energy higher than the processing threshold energy density of both to separate each of the photoelectric conversion regions (- and (-1) Next, the photosemiconductor layer C2 is irradiated with an energy beam that is equal to or higher than the processing threshold energy density of the photosemiconductor layer and less than that of the first electrode fat, and the part of the first electrode layer that was in the covered state C-1 There are two configurations that selectively expose (two).

Embodiment 1 FIGS. 2 to 7 show the method of the embodiment of the present invention in the order of steps.

In the process shown in Fig. 2, the entire surface area of a transparent glass insulating substrate with a thickness of about 18" and 1500 cm is 500 λ to 4000 cm.
A first electrode layer 0]1 of indium tin oxide of A is deposited by electron beam evaporation.

In the process shown in FIG. 3, the first electrode fat aυ is immediately removed without dividing it (the entire surface of the insulating substrate (I) including the surface of
An optical semiconductor layer az made of an amorphous semiconductor such as amorphous silicon and having a thickness of 5000 to 7000 A is deposited continuously (in double layers). In particular, a P-type amorphous silicon layer is deposited, followed by a sequential deposition of I-type and N-type amorphous silicon layers.
Control of type, that is, control of valence electrons, is easy by appropriately adding diborane (B 2 H6), which contains an impurity that determines the 2P type, and phosphine (PH3), which contains an impurity that determines the N type, in the reaction gas atmosphere!1 I can do what I do.

In the process shown in FIG. 4, the optical semiconductor layer (17
J and the first electrode 1 (1) 1 or in the atmosphere or oxygen gas,
Laser beam irradiation f2 while being sprayed at the same time?
=Removed and individual first electrode layers (11a) (11b)
... and optical semiconductor layers (12a) (12b)... are formed separately.

The appropriate laser to be used is a Na:YAG laser with a wavelength of 106 μm, and the energy density of the irradiated laser beam is such that the processing threshold energy density of the first electrode layer (111 and optical semiconductor layer az) to be removed is 7×107φW, respectively.
/i, 4 x 107 W/cj, 8 x 107 W/a which is higher than the processing threshold energy density of both.
Insulating substrate 00 can be moved with J (XY
The stage is moved C2 at a scanning speed of 5Qm/BeQ (secondary processing is performed.
Electrode layer [111 and optical semiconductor @ arbitrary width (Wl) ~5
0 μm (: set.Individual C: Separately formed first electrodes (11!L) (11'b included and optical semiconductor layer (
An oxide film is formed on the interface of 12m)(t2b)- even though it does not return.

In the process shown in FIG.
. . is the optical semiconductor r= in an inert gas atmosphere 1-
The energy density is equal to or higher than the processing threshold energy density of a'a and lower than that of the first electrode layer ttn, that is, 4×1o'
w/, Ea less than 7x107w/c++ on 7pl: YA
C) A part of the first electrode layer (11'b) which was in the covered state (2) is selectively exposed (2) by being removed by the laser irradiation (C). The laser processing targeted for removal was optical semiconductor @ (1z and 1st
The laser processing C2, which targets the electrode layer J for removal, can be performed continuously by simply controlling the energy density of the laser beam. This laser processing (width (Wl) of the optical semiconductor layer (12b) to be removed from the second
, that is, the width (W) of the exposed portion of the first electrode layer (111)...
l) is set to approximately 150 μm (;

In the process shown in FIG. 6, the second electrode layer 04 is
2a) (12b)- and the first electrode layer (11a) (1
2b) The entire surface C of the insulating substrate (10), including the exposed portions, is coated two times in succession. Such second electrode 5cLS
are Na:Y of the first electrode layer (11a) (11b), .
2X107. which is smaller than the processing threshold energy density for AG laser beam C2. It is composed of a laminate of aluminum with a thickness of about several thousand W/- and a titanium-silver alloy with a thickness of 500 mm.

In the process shown in FIG. 7, the second electrode layer (1) in the adjacent space a3 is removed by laser beam irradiation to form individual second electrode layers (14a), (14b), and so on. That is, as a result of removing a portion of the second electrode layer α4 that covers the exposed portion of the first electrode layer (11′b) and also strays continuously,
The second electrode layer (14a) and the first electrode layer (1rb) of the charge conversion regions (15a) (151)) which are adjacent to each other are electrically connected.

The laser used is Na2YAG laser, and its energy density is 2'X107w/d or more 7x1Q 7W
/d, and the width (W5) of the second electrode layer OJ to be removed is set to about 20 μm (2).

In addition, forming the second electrode layer (141) (for the second time, the original rod conductor layer (12!') (121)) -...Top (: Laser processing (: Adhesion or scattering of residue due to laser processing) is observed. In this case, it is possible to increase the thickness of the second electrode layer (+41).

(F) Effects of the Invention As is clear from the above description, the first electric current mK is individually divided for each photoelectric conversion region by irradiation with a Ni-Lugi beam after laminating the original semiconductor layer. Even if the residue from the energy beam irradiation of the first electrode layer adheres or scatters, the original rod conductor layer has already been formed, and therefore pinholes in the original rod conductor layer caused by the above residues will occur. It is possible to prevent the formation of , and also to reduce the number of laser processes compared to conventional methods, thereby improving workability.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the main part of a typical photovoltaic device, and FIGS. 2 to 7 are enlarged sectional views of the main part showing the process order J= of the manufacturing method of the present invention. Concave...Insulating board, (1,1) (No. 11) (11'b
)...First electrode layer, layer 3 (12a) (12b)
・le semiconductor 1?1, (141 (14a) (141)
) - Second electrode layer. Procedural amendment (voluntary) 1. Display of case 1982 Patent Application No. 169791 2 Name of invention Method for manufacturing a photovoltaic device 6 Name of person making the amendment Relationship to the case Name of patent applicant (188) Sanyo Electric Co., Ltd. 4 Address of agent Moriguchi-type Keihan Hondori 2nd Ryome 18 Contact information: Telephone (Tokyo) 835-1111 Patent Center resident Nakagawa 5, subject of amendment, J! 4 ninini. 6. Insert the entire text below between lines 15 and 16 of page 11 of the detailed statement of amendment. ``On the drawing in Figure 7 above, the same photoelectric conversion area (
15a) (15b) - first electrode layer (Ila) (111
))=− side exposed portion and second electrode layer (14a) (14
b)..., but as mentioned above, when the first electrode layer (11a) (11b)... is irradiated with a laser beam, there is a slight amount of insulation on the exposed side surface (interface). Since the film is formed, electrical contact between the two is prevented. ”

Claims (1)

[Claims] (1) A method for manufacturing a photovoltaic device in which a plurality of film-like photoelectric conversion regions are electrically connected in series on an insulating surface of a substrate (1) a first electrode layer and a photovoltaic device on the insulating surface of the substrate; After superimposing the semiconductor layers, the first electrode layer and the photo-semiconductor layer are irradiated with an energy beam having an energy higher than the processing threshold energy density of both to separate the first electrode layer and the photo-semiconductor layer into a plurality of photoelectric conversion regions (separated into two, and then selectively exposing a portion of the covered first electrode layer by irradiating the photosemiconductor with an energy beam having an energy density equal to or higher than the processing threshold energy density of the optical semiconductor layer and lower than that of the first electrode layer; After that, the second electrode layer that is continuously deposited across the plurality of electrical conversion regions is electrically connected in series with the first electrode layer exposed from the adjacent optical semiconductor layer. manufacturing a photovoltaic device characterized in that a part of the continuous second electrode layer covering the exposed portion of the first electrode layer is removed by irradiation with an energy beam. Method.