JPS62295467A - Photoelectric convertor - Google Patents

Abstract

PURPOSE:To prevent a leakage current between two electrodes from flowing by simultaneously removing an N-type or P-type semiconductor layer under the second electrode by cutting and separating by a laser scribing method to form the second electrode. CONSTITUTION:A second groove 18 for electrically connecting first and second elements 31, 11 is formed by removing a nonsingle crystal semiconductor 3 having a P-N or PIN junction and a first electrode 2 disposed thereunder and connecting a second electrode 4 of a second element 11 with the side of the first electrode 2 of a first element 31. In this case, the groove 18 is formed over the interior of the electrode 4 of the element 31. Thus, the elements 31, 11 can be electrically separated between the first electrodes completely.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention The present invention provides a photoelectric conversion element ( The present invention relates to a photoelectric conversion device that is capable of generating high voltage and has a plurality of electrically connected elements (also simply referred to as elements) in series.

This invention reduces the area required for connecting multiple elements to 1/10 to 1/100 of the conventional mask alignment method.
It is characterized by the use of a laser scribe method.

In the present invention, the second groove for electrically connecting the first and second elements is removed by removing a single crystal semiconductor having a PN or PIN junction and the first electrode thereunder, A second electrode of a second element is connected to a side surface of a first electrode of the first element, and the second groove extends inside the second electrode of the first element. By providing
The purpose of this is to achieve more complete electrical isolation between the first electrodes of the first element and the second element.

For this reason, the groove separating the second electrodes of the first and second elements is provided over the semiconductor of the first element, thereby providing redundancy for improving manufacturing yield.

In this invention, the electrical connection at the connecting portion is
By extending the second electrode of the second element to the side surface of the transparent conductive film (referred to as CTP) constituting the electrode of the device, and using the second electrode in close contact with the side surface, the area required at the connecting portion is reduced. It is characterized by

For this reason, an opening groove separating the semiconductors of the first and second elements is provided over the first electrode position of the first element, and L
It is characterized by providing manufacturing redundancy (margin) due to fluctuations in the scanning of S.

Conventionally, in the mask matching method, the connecting part is 5 to 1
I needed a width of ll1l11, but this is 1/1
10 to 1/100 of 350 to 30μ, preferably 200 to 30μ
By setting the diameter to 50μ, in a hybrid system that requires 10 to 50 stages of connecting parts, the area for generating photovoltaic power (referred to as effective area or effective area) of all panels used as photoelectric conversion devices is smaller than the conventional 75μ. It can be increased from ~50% to 97~90%, increasing the effective conversion efficiency by 10~2
It is characterized by a substantial improvement of 0%.

In this invention, by using a laser beam scribing method, the address to be scribed using the alignment mark as a reference is stored in advance in the memory of a computer (microcomputer), which is not necessary in the conventional mask alignment method. Mask misalignment, warping,
The feature is that all causes of price increases and yield decreases in manufacturing, such as decreases in manufacturing yields due to alignment accuracy, are eliminated at once.

Conventionally, many examples of photoelectric conversion devices (hereinafter simply referred to as devices), that is, devices in which a plurality of elements are arranged on the same substrate and are integrated or hybridized, are known.

For example, JP-A-55-4994, JP-A-55-12427
4 Furthermore, a patent application filed in 1972--9009 was filed as an unsuccessful application.
7 /9009B/90099 (Showa 54.7.1
6) is known.

For example, the patent side that ends up with an unsuccessful application is the semiconductor 5ix
C,, -3t heterojunction, which is different from the case of simply using other amorphous silicon semiconductors, and furthermore, this semiconductor is a PN to which hydrogen or halogen elements are added that contain a microcrystalline structure in addition to the amorphous structure. Alternatively, it is characterized in that it is an integrated or hybridized non-single crystal semiconductor having at least one PIN junction.

However, in these conventional inventions, a vertical cross-sectional view of which is shown in FIG. 1, all of them employ a mask alignment method, which results in insufficient alignment accuracy and requires a large area for the connecting portion.

For example, when a metal mask is used, in a method of directly and selectively producing a conductive layer or a semiconductor layer, the mask that provides this selectivity may shift by 0.5 to 3II1 m during film formation. Furthermore, since a film component is formed on this mask, the mask is contaminated, and the peripheral edge of the film formed by the mask is not clear, causing crosstalk (leakage current) between adjacent electrodes. It had many drawbacks, such as being a factor in

Furthermore, conventionally known screen printing methods and the like are methods in which conductors or semiconductors formed entirely on a substrate are independently and selectively etched away using a mask. However, in this method, the process is extremely time-consuming, such as the process of aligning the mask for screen printing, the process of coating the resist, the process of beta solidification, the process of etching the conductor or semiconductor, and the process of removing the resist, which increases the manufacturing cost. could not be avoided.

However, in the photoelectric conversion device of the present invention, particularly the thin film type photoelectric conversion device, each of the thin film layers, the conductive layer for electrodes and the semiconductor layer, each has a thickness of 500 to 1 μm, and by using a laser scribing method, (It is now possible to produce without the need for mask alignment.)

As a result, in place of the conventional mask alignment process, in the present invention, no mask is used at all, so it is called a scribing process, but this scribing process is extremely simple and highly accurate due to the combined use of a microcomputer. brought about a reduction in costs. Therefore 5
By providing an extremely innovative photoelectric conversion device that can be manufactured at a price of 100 to 200 yen/W by expanding the manufacturing scale.

Furthermore, in the present invention, in addition to using this laser scribing process, it is important to have a degree of redundancy (margin) in the alignment accuracy of the scribe lines. Therefore, the first electrode (lower side) between adjacent elements and the second electrode (upper electrode) of another element are electrically connected to the first electrode and its side surface by a lead extending from the second electrode. By connecting it to the scribe line, it was possible to provide redundancy in the position of the open groove of the scribe line.

A conventional example and the structure of the present invention will be described below according to the drawings.

FIG. 1 is a longitudinal sectional view of a conventionally known photoelectric conversion device using a mask alignment method.

In the drawings, a transparent conductive film (abbreviated as CTF) constituting a first electrode is selectively formed on a transparent substrate (for example, a glass plate) (1) by a first mask alignment step. Further, a semiconductor layer (3) is similarly selectively formed by a second mask alignment step. Further, a second electrode (4) is provided by a third mask alignment step.

In Fig. 1, there is a connecting part (12) between the elements (11) and (31), and in the connecting part, one side surface (16) of the CTF is covered with a semiconductor layer (3), and the surface of the other CTF is covered with a semiconductor layer (3). In order to prevent the semiconductor layer (3) from covering (14),
Between CTF (13) is 1~5m111 e.g. 3III1
1 gap is required. Furthermore, since the first electrode (37) and the second electrode (38) must not be short-circuited, including the spread caused by mask blur, 1
~5s11, for example, requires a gap (6) of 311Ill. These three masks do not have any self-alignment properties, so in the connection part (12), 1 to 8III11
Typically, 4+UI is required. Furthermore, if this is set to 1 mm or less, the mask alignment accuracy will be extremely strict, and the yield will be extremely reduced. If the gap of this connecting part (12) is 511Ill or more, for example, 2
0cm x 60c++ to 11115m+11(20c
If an element with a size of 15 mm (s x 15 mm) and an end portion 5IIIl are fabricated, only 20 stages can be directly connected. Furthermore, even if the gap at this joint is 3ml11, there are 33 stages, resulting in a total loss of 10cm (area of 200cA) at the joint, and as a result, the effective area remains at 75% when the peripheral area is taken into account. .

The present invention eliminates such process complexity and reduces the effective area to 86.
The object of the present invention is to provide an extremely innovative photoelectric conversion device that can increase the photoelectric conversion efficiency by 97%, for example, 92%.

The details of the embodiment will be shown below according to the drawings.

FIG. 2 is a longitudinal sectional view showing the manufacturing process of the present invention.

In the drawings, a substrate with an insulating surface, such as a transparent substrate (
1) That is, a glass plate (for example, thickness 1.2 + n + n, length 60 cm in the horizontal direction in the drawing, width 20 cm) was used. Furthermore, a light-transmitting conductive film such as ITO (approx. 1500) + SnO (200 to 400
A light-transmitting conductive film (1,500 to 2,000 layers) containing tin oxide as a main component or tin oxide doped with a halogen element was formed by vacuum evaporation, LP CVD, plasma CVD, or spraying. After that, a YAG laser processing machine (manufactured by Nippon Laser) applies an output of 5 to 8 W from the bottom or top of this substrate, and the spot diameter is 30 to 70μφ.
Typically, 50 μΦ is irradiated under the control of a microcomputer, and by scanning it, an open groove for a scribe line (1
3) was formed, and a first electrode (2) was produced between each element.

The open groove (13) formed by scribing has a width of approximately 5
Each of the first electrodes was completely cut and separated at a length of 0μ and a depth of 20cm. For this reason, as is clear from the drawings, a portion of the substrate (1) may be pinched (a recessed portion may be formed). Thus, the first element (31) and the second element (11
) was set to a width of 10 to 2011I11.

Using the above laser scribing method, the CTF (2) constituting the first electrode was cut and separated to form an open port.

After this, plasma CVD method or LP CVD method is applied to this upper surface.
The thickness of the non-single crystal semiconductor layer (3) having a PN or PIN junction is 0.2 to 1.0 μm, typically 0.4 to 0.5 μm.
It was formed to a thickness of μ. A typical example is a P-type semiconductor (Si
xC1-, x = 0.850 ~ lSQ person)-1 type amorphous or semi-amorphous silicon semiconductor (0,
4-0.5μ) - non-single crystal semiconductor with one PIN junction consisting of a semiconductor with N-type microcrystals (100-200), or P-type semiconductor (SixC+-X) - I type, N type, Tandem type PINFIN having two PI'N junctions and one PN junction made of P-type St semiconductor - I-type 5ixGe+-* semiconductor - N-type SL semiconductor...
This is a PIN junction semiconductor (3).

Such a non-single crystal semiconductor (3) was formed to have a uniform thickness over the entire surface. Furthermore, as shown in FIG. 2(B), there is a second open groove (18) on the left side of the first open groove (13).
was formed by a second laser scribing step over a distance of 100 to 500 μ over a width of 50 μ. The laser may be applied either from below the glass (1) or from above the substrate.

The second open groove (18) thus forms a side surface (8) of the first electrode.
(9) was exposed. The presence of the right side surface (9) of the first electrode formed by this second groove causes the first electrode (3
7) is characterized in that it is provided over the first electrode position of the first element on the left side of the side surface (16). Then, as shown in FIG. 2(B), the first electrode (31
), the side surfaces of the first electrode are exposed as (8) and (9). As a result, a portion of the first electrode (37) of the first element remains on the right side of the second groove. If there is no such residual area, the high heat (~2000℃) of the laser beam will cause CTF (2)
The first open groove (13
) is blown away.

Therefore, isolation between the first electrodes of the first and second elements becomes impossible. From this, the 29th (B
), it is very important that the second groove is provided inside the first electrode. This (9
) The CTF remaining in the portion had a width of 50 to 500μ.

Furthermore, the present invention does not expose the surface (14) of the first electrode (see Figure 1) as shown in the conventional example, but the laser beam is too strong at 5 to IOW and the CTF
(37) in the depth direction, and as a result, there is no practical problem even if the second electrode (38) is brought into close contact with the side surface (8) as shown in FIG. 2(C). That is, it is extremely important for the industrial application of the present invention to be able to provide a margin for the intensity of the output pulse of the laser beam.

In FIG. 2, as shown in FIG. 2(C), a second electrode (4) on the back surface is further formed on this top surface, and a third groove for cutting and separation in the third laser scribing method is formed. (
20) was established.

This second electrode (4) has a transparent conductive film of 700 to 140
It is made of ITO (indium tin oxide) to a thickness of 0.000 mm, and a reflective metal of silver is coated on the top surface with a thickness of 300 to 300 mm.
It was formed to a thickness of 0.00 people. Furthermore, a two-layer film of aluminum or aluminum and nickel was formed on the upper surface. For example, 1050 people hold ITO, 1000 people hold silver,
Furthermore, a three-layer structure with 1,500 nickel members was used. This I
TO and silver promote reflection of incident light (10) on the back side, and 6
This is for effectively photoelectrically converting long wavelength light of 00 to 800 nm. Furthermore, nickel is used for external extraction electrodes (2
This is to improve the adhesion with 3). These were formed using an electron beam evaporation method or a plasma CVD method at a temperature of 300° C. or lower, which does not cause deterioration of the semiconductor layer.

This ITO also serves to prevent a decrease in reliability due to a chemical reaction between the semiconductor (3) and the back electrode (4), that is, to improve reliability.

The back electrode is irradiated with a laser beam from above to cut and separate the second electrode, forming a third groove (20) (width 50 μm).
) is formed. This laser beam slightly gouges out the semiconductor, especially the N or P type semiconductor layer that is in close contact with the top surface. Alternatively, the occurrence of crosstalk (leakage current) due to conductive semiconductors was prevented.

In particular, this semiconductor (3) is a P-type semiconductor layer (42), I
For example, one PIN junction is formed with the N-type semiconductor layer (43) and the N-type conductor layer (44), and this N-type semiconductor layer has a microcrystalline or polycrystalline structure. Its electrical conductivity is 1-20
When the conductivity is as high as 0 (0 cm)-', the N of the present invention
It was extremely important to hollow out and remove the mold semiconductor layer and provide semiconductor in the recessed portions to prevent leakage current generation. It is preferable that this gouging does not go beyond the I-type semiconductor layer and do not reach the CTF for the first electrode. The present invention uses laser light to form grooves not only on the second electrode, but also in the process of forming the groove portion (20) with a margin equal to the thickness of the I-type semiconductor layer that is 0.2μ or more below the second electrode. It is industrially important to make it durable.

Thus, as shown in FIG. 2(C), a plurality of elements (
31) and (11) were connected in series at the connecting part to create a photoelectric conversion device.

FIG. 2(D) shows the attempt to further complete the present invention as a photoelectric conversion device, that is, a silicon nitride film (21) with a thickness of 500 to
It was formed to a thickness of 2,000 mm to prevent leakage current between each element. Furthermore, an external lead-out terminal (23) was provided at the peripheral portion (5). These were filled with an organic resin (22) such as polyimide, polyamide, Kapton or epoxy.

Thus, for the irradiation light (10), each element is
4.35mm, the width of the connecting part 150μ, the width of the external extraction electrode part 10man, and the peripheral part 411I11, the effective area (192IIIn+ x 14.35■ x 40 stages 11
02- that is, 91.8%). As a result, if the segment has a conversion efficiency of 10.6%, the panel has a conversion efficiency of 9.7% (AMI (100mW/cd)
), it was possible to have an output power of 11.6H.

This is 55% (
This is a very significant effect compared to the case of 40 stages). Furthermore, since no metal mask is used at all, there is no industrial problem in the manufacturing process of large-area panels, making it extremely suitable for large-area, low-cost mass production for generating large amounts of power.

As is clear from the above examples, the N or P type semiconductor layer under the second electrode was also removed at the same time by cutting and separating using the laser scribing method to form the second electrode according to the present invention. We were able to reduce the leakage current between the two electrodes from 10-'mA/cm to 10-''A/cm.For this reason, for general consumer use, the second
It has also become possible to omit the silicon nitride film coating (21) in Figure (D).

Furthermore, regarding the connection part, since the first electrode is connected to the second electrode of the adjacent element on the side surface, the area required for this connection part (contact part) is reduced to 1/10 or less compared to the conventional method. As a result, the effective area of the panel can be improved.

WAG laser spot layer with output power of 3~5W
(30μ) and 5 to 8W (50μ), but by further reducing the spot diameter based on the technical concept, this connection part can be made smaller and the effective area as a photoelectric conversion device can be further improved. It has an inventive step in that it can be done.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a conventional photoelectric conversion device. FIG. 2 is a longitudinal sectional view showing the manufacturing process of the photoelectric conversion device of the present invention.

Claims (1)

[Claims] 1. A first electrode on a substrate having an insulating surface, a non-single crystal semiconductor having at least one PN or PIN junction on the electrode; A plurality of photoelectric conversion elements each having a second electrode made of a transparent conductive film of ITO (indium tin oxide), a layer of silver in contact with the ITO, and a layer of nickel or aluminum in contact with the silver. In the photoelectric conversion device disposed on the insulating substrate and electrically connected to each other in series, the first and second
An opening groove separating the semiconductor of the element and the first electrode thereunder is provided over the first electrode position of the first element, and extends from the second electrode of the second element. A photoelectric conversion device characterized in that the connecting portion is provided in close contact with a side surface of the first electrode of the first element. 2. In claim 1, an opening groove separating the semiconductors of the first and second elements, which is provided over the first electrode position of the first element, is located inside the first electrode. A photoelectric conversion device characterized in that it is installed inside.