JPS5996779A - Photoelectric conversion device - Google Patents

Abstract

PURPOSE:To contrive that a leakage current does not generate from the second electrode of the second element to that of the first element by providing an open groove which performs the isolation of the second electrodes of the first and second elements by cutting and isolating also a semiconductor layer under this electrode. CONSTITUTION:A plurality of photoelectric conversion elements having the first electrode 2 of a photo transmitting conductive film, a non single crystal semiconductor 3 having a P-N or a P-I-N junction on this electrode 2, and the second electrode 4 on this semiconductor 3 are arranged on an insulation substrate 1 in mutually electrically series connection. In such a photoelectric conversion device, the first electrode 2 of the first photoelectric conversion element 31 is electrically joined to the second electrode 4 of the second element 11, the open groove 20 between the second electrodes 4 of the first and second elements is provided by isolating also an N or a P type semiconductor layer 44 in close contact with the second electrode 4 under this open groove 20.

Description

Detailed Description of the Invention The present invention provides a photoelectric conversion element (also simply referred to as an element) in which a non-single crystal semiconductor including an amorphous semiconductor having at least one P-N or PN junction is provided on a light-transmitting insulating substrate. The present invention relates to a photoelectric conversion device that can generate high voltage by electrically connecting a plurality of photoelectric conversion devices 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 scribing method.

In the present invention, an opening groove for separating the second electrodes of the first and second elements is formed by separating and cutting a P- or N-type semiconductor layer of a semiconductor having a PN or P-to-N junction under the electrode. The purpose of this provision is to prevent leakage current from occurring from the second electrode of the second element to the second electrode of the first element.

Therefore, by providing the groove that separates the second electrodes of the first and second elements over the semiconductor of the first element, it is possible to provide redundancy to improve manufacturing yield. It is a feature.

In this invention, the electrical connection at the connecting portion is
By extending the second electrode of the second element to the surface or side surface of the transparent conductive film (OTF) constituting the electrode and bringing it into close contact, the area required for the connection part can be reduced. It is characterized by a decrease in

For this reason, the groove separating the semiconductors of the first and second elements is provided over the first electrode position of the first element to provide manufacturing redundancy.

Conventionally, in the mask matching method, the connecting part is 5 to 1 m long.
I needed a width of 1/10 to 1/1/2 m.
100 μm to 350 μm to 30 μm, preferably 2oo μm to 50 μm. In a hybrid system that requires 10 to 50 stages of these connecting parts, the area for photovoltaic power generation of all panels used as photoelectric conversion devices (effective (referred to as area or effective area) is 97-90 compared to the conventional 75-50.
%K, thereby substantially improving the effective conversion efficiency by 10 to 20%.

In this invention, by using a laser beam scribing method, the address to be scribed is determined in advance by a computer (microcomputer) using the alignment mark as a reference.
By storing the data in the memory of the computer, it is possible to avoid all manufacturing problems such as mask misalignment required in the conventional mask matching method, 9. It is characterized by eliminating the causes of price increases and yield decreases at once.

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

For example, JP-A-55-4994, JP-A-55-1242
'74 Furthermore, the patent application for the invention water was filed in 1983-900.
97/90098/90099 (Showa 54.7.16
application) is known. For example, in the patent application for the present invention, the semiconductor is a heterojunction of S i x O, . It is characterized in that it is an integrated or hybridized non-single crystal semiconductor having at least one PN-& or P-N junction to which hydrogen or a norogen element containing a microcrystalline structure is added in addition to an amorphous structure.

However, in these conventional inventions, as shown in FIG. 1, which is a vertical cross-sectional view, all of them are based on the mask alignment method, and the alignment accuracy is insufficient and a large area is required for the connecting portion.For example, a metal mask is used. In such a case, in a method of directly selectively manufacturing a conductive layer or a semiconductor layer, the mask that provides this selectivity may shift by 5 to 3 mm during film formation. Furthermore, since a film component is formed on this mask, the mask becomes contaminated, the peripheral edge of the film formed by the mask is not clear, and crosstalk (lead current) between adjacent electrodes occurs. It has many drawbacks, such as being a contributing factor to the outbreak.

Furthermore, in conventionally known screen printing methods, conductors or semiconductors formed entirely on a substrate are independently and selectively etched away using a mask. However, in this method, the process of aligning the screen printing mask, coating the resist, baking and solidifying it, etching the conductor or semiconductor, and removing the resist takes a lot of time, which increases the manufacturing cost. I couldn't escape it.

However, in the KW film type C photoelectric conversion device of the present invention, the conductive layer for the electrode, which is each thin film layer,
It was also found that the semiconductor layers had a thickness of 5oo'p and ~1μ, respectively, and that by using the laser scribing method, it was possible to fabricate them without requiring any mask alignment. In place of 8, in the present invention, no mask is used at all, so it is called a nucleation process, and this scribing process is extremely simple and highly accurate due to the combined use of a microcomputer, resulting in a reduction in the manufacturing cost of the device. Therefore, the object of the present invention is to provide an extremely innovative photoelectric conversion device that can be manufactured at a cost of 500 yen/W.

Furthermore, in addition to using this laser scribing process, the present invention has a redundancy (margin) in the alignment accuracy of the scribe line.
It is important to have a degree of precision.

Therefore, the first electrode (lower side) between adjacent elements and the second electrode (lower side electrode) of another element may extend beyond the second electrode. By electrically connecting the electrode to its side surface or surface, redundancy could be provided 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 vertical sectional view of a conventionally known photoelectric conversion device using a mask alignment method.

In the drawings, a transparent conductive film (abbreviated as C!TF) constituting the first electrode is selectively formed on a transparent substrate (for example, a glass plate) (1) in a mask alignment step 81. 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 are two connecting parts α between the elements (11) and (31), and in the connecting part, CTF /7: One side surface (10 is covered by the semiconductor layer (3), and the other surface is 0CTF). In order to prevent the semiconductor layer (3) from covering the
0→0720 requires a gap of 1 to 5 mm, for example 3 mm.

Furthermore, the first electrode (37) and the second L:r, electrode (38)
is electrically connected on the surface of 0yu, but this part is (39
A gap (6) of 1 to 5 mm, for example 3 mm, is required to prevent the second electrode 9 from short-circuiting, including spreading caused by blurring of the mask. Since these three masks do not have any cell alignment properties, the connecting portion α requires 1 to 8 mm, typically 4 mm. Furthermore, if it is less than K], the mask alignment accuracy will be extremely strict, and the yield will be extremely reduced. If the gap between the connecting parts is 5 mm or more, for example, 20 cm x 60 cm and a width of 15 mm (20 cm x 1
5mm) and an end portion of 5mm, 20
Only direct connections between stages are possible. Also, even if the gap at this connecting part is 3 mm, there will be 33 stages, and there will be a total loss of loam (area of 200 cmL) at the connecting part, and as a result, the effective area will only be 75% if the peripheral area is taken into account. I was thinking.

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

The details of the embodiment are shown below according to the drawings.

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

0 In the drawings, the transparent substrate (1) is, for example, a glass plate (for example, 1.2 mm thick, 960 am long in the horizontal direction in the drawings,
A width of 20 cm) was used. Furthermore, a light-transmitting conductive film such as TO (approximately 1500)+S n is applied to the entire upper surface.
0L (200-400λ) or...A transparent conductive film (150
0 to 2000X) was formed by a vacuum evaporation method, an LPCVD method, a plasma CVD method, or a spray method.

After that, an output of 5 to 8 W is applied from a YAG laser processing machine (manufactured by Nippon Laser) K to the lower side or lower side of this substrate.
A spot diameter of 30 to 70 pf (typically 50 μm) was irradiated under the control of a microcomputer, and an open groove 01 for a syscall line was formed by scanning, and a first electrode (2) was created between each element. .

Open grooves formed by scribing (13 is approximately 5 mm wide)
Each of the 1c 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 part of the substrate (1) was sometimes gouged out (a recess was formed).Thus, the first element (31) and the second element (1)
) was set to have a width of 0 to 20 mm.

Using the above laser scribing method, cTF(2) constituting the first electrode was cut and separated to form open grooves. After this, plasma CVD or LPCVD is applied to this upper surface.
The non-single crystal semiconductor layer (3) having a PN or P-N junction is formed by a method with a thickness of 0.2 to 0.7μ, typically 0.4 to 0.5μ.
It was formed to a thickness of μ. A typical example is a P-type semiconductor (Si
XO+-x
A non-single crystal semiconductor with one PIN junction, or a P-type semiconductor (S i X (!+-
,! ) - N type, P type Si semiconductor - ■ type 5iXGe + -
A-semiconductor - Tandem-type P-NP-N having two P-N junctions and one (7) PN junction made of N-type Si semiconductor.
...P-N 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), a second open groove (18) was formed on the left side of the first open groove 03 by a second laser scribing process.

It may be carried out either from below the Cono V-Savarus (1) or from above this substrate.

Thus, the second open groove 08) extends along the side surface of the first electrode (8).
(9) was exposed. The side surface (9) of this second groove may be provided on the left side of the first electrode (3) side surface aQ, that is, provided over the 117th electrode position of the first element.

It is characterized by the fact that As an extreme example of this, as shown in FIG. 2(B), the first electrode (31)
You may even get inside the . Furthermore, as shown in the conventional example, the present invention does not necessarily require exposing the surface o4 of the first electrode (see Fig. 1), and the CTF (3'7) was removed in the depth direction, and as a result, the side surface (8
)K There is no practical problem even if the second electrode (38) is placed in close contact with each other 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, a second electrode (4) on the back side is further formed on this soil surface as shown in FIG. ) was established.

Silver was formed on the upper surface to a thickness of 300 to 500 mm, and then aluminum or a two-layer film of aluminum and nickel was formed on the upper surface. For example, IT, O is 1
050': A1 silver was made into a two-layered structure of :hooo mold and UQA. This T○ and silver promote reflection of the incident light (10) on the back surface side and effectively photoelectrically convert long wavelength light of 600 to 800 nm. Furthermore, nickel is used to improve adhesion with the external lead electrode (c). These degrade the semiconductor layer using electron beam evaporation or plasma CVD.
It was formed at a temperature below 00°C.

This process also helps 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 like this is irradiated with laser light from above and the second
This shows the case where the electrode is cut and separated to form an open groove (20). This laser light is applied to the N
Or, cut out a little of the P-type semiconductor layer. This prevents the occurrence of leakage current.

In particular, this semiconductor (3) includes a P-type semiconductor layer (42), an N-type semiconductor layer (43), an N-type semiconductor layer (4 and, for example, one P-type semiconductor layer).
This N-type semiconductor layer has a microcrystalline or polycrystalline structure. Its electrical conductivity is 1~zoo (acm
), it is extremely important to hollow out the N-type semiconductor layer of the present invention and provide a semiconductor in the recessed portion to prevent leakage current generation. Does this extraction go beyond the molded semiconductor layer? It is preferable that the temperature does not reach 0CTF K for the first electrode. The present invention removes not only the second electrode but also the CP or N-type semiconductor layer below the second electrode by forming an open groove using a laser beam, and furthermore, the groove is formed below the second electrode by 0.2μ or more.
Since it can be stopped in the middle of the mold semiconductor layer, it is important in industry to be able to provide an allowance for the thickness of the mold semiconductor layer in the opening groove part during the single-layer process.

Thus, as shown in FIG. 2(0), a plurality of elements (
31) (We were able to create a photoelectric conversion device that connects 1υ in series at the connecting part.

Figure 2 (D) shows the attempt to further complete the present invention as a light amount conversion device, in which a silicon nitride film Q]) of 500~
It was formed to a thickness of 2,000 mm to prevent leakage current between each element. Furthermore, connect the external lead terminal (c) to the peripheral part (
5) Provided with K. These were filled with an organic resin (c) such as polyimide polyamide, Kapton or epoxy.

Thus, for the irradiation light 00)K, the substrate (6
0cm x 20cm), each element has a width of 14°35m.
Width of m connection part 150μ, width of external extraction electrode part 10mm
Peripheral area 4mm K, actual K 580mm x 1! ;
It has 40 stages within 12mm, and the effective area (19zmm x 1
It was possible to obtain 4.35 mm x 40 stages of 1102 cm2, or 91°8%. As a result, segment t is 1
If the conversion efficiency is 0.6, the panel will have a conversion efficiency of 9.7%.
(It was possible to have an output power of 11.6 W at AMI (1 oomw/cJ).

This is 55% (
This is a very significant effect compared to the case of 40 stages). Furthermore, since no metal mask is used, 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 embodiments, when the present invention is used to cut and separate the second electrode using the laser scribing method, the N- or P-type semiconductor layer under the second electrode is also removed at the same time. Therefore, the leakage current between these two electrodes could be reduced from 10 mA/cm to 10-A/cmK. For this reason, for general consumer use, Fig. 2 (D)
It has also become possible to omit the silicon nitride film coating Cυ.

Furthermore, since the electrical connection between the first electrode and the second electrode can be made on the side of the first electrode, the area required for this contact portion can be reduced to 1/10 or less compared to the conventional method. Figure 3 shows the positional relationship of the most typical grooves created in three laser scribing processes. FIG. 2 is a cross-sectional view and a plan view (end portion).

Numbers etc. are the same as in FIG. 2.

FIG. 3(A) C: First open groove o, first (7) element (31
), a second element 0]), and a connecting portion 0.

As is clear from the drawing, the first groove o3 slightly hollows out the substrate (1). Further, a second open groove (le) is provided across the semiconductor (3) that constitutes the first element and the first electrode (2), and both of these are removed. ) of the first electrode (2) and the second electrode (2) of
The narrow surface (
8), and the two elements are connected in series.

Further in the drawing, a semiconductor (3) with at least one PN or P-N junction is shown, here one S I
0r-q (0<X<1) P type (42)-I type 5
A semiconductor having one P-N junction such as i(43)-microcrystallized iJ type 5i(44) is provided.

The third opening groove (4) shown in the knife-shaped semiconductor (43) through this semiconductor, especially the N-type semiconductor (44), has the depth of the groove. Thus the pile 1 and the second element (31) α
The second electrodes (4) of each of the
It was possible to reduce the size to less than 10A per cm width.

In order to improve long-term reliability, a coating film of silicon nitride film may be formed on the upper surface by plasma CVD, as shown in FIG. 2(B)K. Furthermore, this third open groove is
The Yth element ≠ the neck is provided, and by applying the laser scribe 44G 14t in that direction, the scribing spot has a width of 105μ, for example, 75μ + (75μ in the left direction in y and 30μ in the direction). Considering that the scribing accuracy is generally ±15 μ, it can be seen that this is sufficient for mass production.

FIG. 3(B) shows a plan view, and the first, second and third open grooves α3. (], 8)
, a fence is provided. In order to further reduce leakage in this direction, the structure is such that the semiconductor (3) covers the first electrode (2), thereby reducing short circuits between the first and second electrodes.

In this drawing, the 11th 2nd C opening groove width is 50 to 30μ,
The width of the third open groove was 75 to 50 μm (metal is slightly wider because the laser beam conducts in the lateral direction a little better), and the width of the connecting portion was 150 to 100 μm.

FIG. 4(A) shows a case where the second laser scribing step is performed from above the substrate at the connecting portion α, and a part of the CTF of the first electrode remains in the open groove αfG.

Fig. 4(B) shows the first open groove part 03 and the second open groove part 08)
This is the case in which the side surface 0O of the first electrode and the side surface (9) of the second electrode are insulated by the semiconductor (3), and the third open groove part 0O is insulated from the side surface (9) of the second electrode. The width provided over the first element side on the right side is reduced to minimize the loss area required for the connection part, and lOOμ ~ 6
It was possible to have a connecting portion with a width of 0μ.

The above YAG laser spot layer has an output of 3 to 5 W (
30μ) 5 to 8W (50μ) is used, but by further reducing the spot diameter based on the technical concept, it is possible to further reduce the size of this connection portion and further improve the effective area as a photoelectric conversion device. It has an inventive step in that it can be done.

FIG. 5 is an enlarged view of the externally drawn electrode portion when the photoelectric conversion device Y, which is smaller than a large panel for a calculator or the like, is to be manufactured in large quantities at the same time.

FIG. 5(A) corresponds to FIG. 2, but the external extraction electrode part (5) has a pad (49) that contacts the conductive rubber electrode (47), and this pad (49) It is connected to the second electrode (upper electrode) (4). At this time, the pressure on the electrode (47) is so strong that the pad (49) is pressed against the first electrode (
2) and the semiconductor (3), an open groove 0 island is provided so as not to cause a short circuit even if the semiconductor (3) is passed through. Moreover, the outer part is cut and separated by an open groove 0-. Furthermore, Fig. 5 (B) shows the lower first
Another pad (48) connected to the electrode (2) is provided with a second electrode material.

In addition, the pad (4 pads) has the characteristic that it can contact the conductive rubber electrode (46) and make several photoelectric conversion devices. For example, in a 20 cm x 60 cm panel, a 6 cm x 1
．． If you try to make a 5cm photoelectric conversion device (for a calculator),
It turns out that 130 solar cells for calculators can be made at one time. In other words, the photoelectric conversion device is an organic resin mold (
In step (a), the electrode parts (5) and (45) are covered, and then cut with a glass cutter if a small power solar cell is to be made. Furthermore, this panel, for example, 40cm
It is possible to provide panels for NEDO standard dog power of 20cm or 60cmXX40cm.

In addition, the NEDO standard panel is made of Seaflex, and the reflective surface side (upper side in the drawing) of the photoelectric conversion device of the present invention is laminated with another glass plate, and the photoelectric conversion device is placed between them. It is also effective to increase mechanical strength against wind pressure, rain, etc.

In FIGS. 2 to 5, light was incident from the lower glass plate. However, the present invention does not limit the light incident side to the lower side.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a conventional photoelectric conversion device. FIG. 2 is a vertical cross-sectional view showing the manufacturing process of the photoelectric conversion device of the present invention. FIG. 3 is an enlarged view of a vertical sectional view and a plan view of the photoelectric conversion device of the present invention. 4 and 5 are partially enlarged longitudinal sectional views of another photoelectric conversion device of the present invention. IJI+ 1'l ・ 1 ・ 3112 I+ House 11 Diagram C0) 31 12 I+ 1□ μ (17 4t's 2nd 2o 4r CD) J5['s

Claims (1)

[Claims] 1. A non-single crystal semiconductor having a first electrode of a transparent conductive film on an insulating substrate and at least one PN junction or P-N junction of the electrode, and A plurality of photoelectric conversion elements having a second electrode are electrically connected to each other in series, and an N- or P-type semiconductor layer in close contact with the second electrode under the insulating base groove is also provided separately. A photoelectric conversion device characterized by: 2. The photoelectric conversion device according to claim 1, wherein the groove separating the second electrodes of the first and second elements is provided over the semiconductor of the first element.