JPH01119073A - Manufacture of flexible photoelectric conversion element - Google Patents

Abstract

PURPOSE:To enable use of SnO2 to be realized and facilitate texturing which is efficient for increasing light path length within a semiconductor layer to be easily achieved by using a support consisting of a metal foil or a metal thin plate on a macromolecular film substrate and by forming a transparent electrode layer on a metal support. CONSTITUTION:A transparent electrode film consisting of a Sb2O3-SnO2 film is formed by a strip of aluminum foil as the first support. Then, a polyimide precursor solution is applied to the side surface of this transparent electrode layer by the casting method, the side of polyimide film substrate corresponding to it is overlapped, and heat and pressure are applied under the following conditions by a heating press for laminating it. Then, etching is performed and a transparent electrode layer of a specified pattern is exposed. Furthermore, a specified transparent electrode pattern layer is formed on a single surface and a transparent polyimide film substrate with the second support (stainless steel plate) is formed on the other surface. A photoelectric semiconductor layer consisting of a p-type-i-type-n-type amorphous silicon thin film is formed on a transparent polyimide film substrate through a transparent electrode pattern layer. A flexible photoelectric conversion element consisting of a substrate, a transparent electrode layer, a semiconductor layer, a rear face electrode layer, and an electrical insulation layer is peeled off the second supporting plate.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Industrial Application Field The present invention relates to a method for manufacturing a flexible photoelectric conversion element, and in particular to a flexible photoelectric conversion element using a transparent polymer film as a substrate and having improved charge conversion efficiency. The present invention relates to a method for manufacturing a photoelectric conversion element.

(b) Prior Art Photoconductive elements, photodiodes, solar cells, phototransistors, photothyristors, and the like are known as photoelectric conversion elements that input light and output electricity.

Semiconductors having photovoltaic properties are used in these photoelectric conversion elements, and among them, those using amorphous silicon are inexpensive and widely used as solar cells or optical sensors.

For example, in a solar cell, n-type crystalline silicon, 1-type amorphous silicon, and p-type amorphous silicon are sequentially deposited in thin films on a substrate made of a metal plate that also serves as an electrode.
Furthermore, a transparent electrode layer is laminated thereon, or a transparent electrode layer, p-type crystalline silicon, i-type crystalline silicon, and n-type crystalline silicon are sequentially deposited on a substrate made of a glass plate. , and on which a metal electrode layer made of aluminum or the like is further laminated has been put into practical use.

The substrate, which also serves as a metal electrode layer, is made of, for example, a foil or thin plate of stainless steel, aluminum, or copper, and the transparent electrode layer is made of, for example, tin oxide, oxidized infrastructure, ITO, or the like.

In the former case, which uses a metal substrate, the electric resistance of the substrate is sufficiently low, so a large output can be obtained from a substrate of a fixed area.

In the latter case, in which a glass plate is used as a substrate, since the substrate has insulating properties, a plurality of semiconductors are placed adjacent to each other, and these are connected in series with a conductor.
It is extremely easy to obtain more than double the voltage.

By the way, solar cells using such amorphous silicon (referred to as amorphous silicon solar cells) are currently undergoing efforts to reduce material costs, be lighter, thinner, etc., and to improve the production process. Alternatively, it has been proposed to use a flexible substrate in order to facilitate handling during transportation and reduce production costs, transportation costs, and the like.

For example, a proposal has been proposed in which a heat-resistant glassy film such as a polyimide film is used as a substrate, and a metal electrode layer such as a stainless steel foil or thin plate, an amorphous silicon layer, and a transparent electrode layer are laminated on this substrate. (For example, JP-A-54-149489, JP-A-55-4994)
No. 1, JP-A-55-29154, JP-A-57-
103839).

This type of amorphous silicon solar cell is lightweight, thin, and has low material cost, and is highly flexible, so it can be rolled into a roll and processed continuously, reducing production costs and transportation. This is very advantageous in reducing costs.

Furthermore, since it can be formed into any shape, it is expected to have a wide range of applications and uses.

(e) Problems to be Solved by the Invention However, flexible photoelectric conversion elements that use a polymer film as a substrate have many features compared to thin photoelectric conversion elements that use a glass plate or the like as a substrate. However, there are many restrictions on the manufacturing method, and there are some aspects in which the characteristics are inferior.

In particular, there is the problem of curling of product devices due to the difference in thermal expansion coefficients between the substrate film and the amorphous silicon layer, and the applicant has developed a method for manufacturing flexible photoelectric conversion devices that prevents curling of the laminated structure. (Patent application 1986-38)
805 Specification).

In this manufacturing method, a transparent glass substrate and a laminate, that is, a semiconductor layer, are formed on a support such as a glass plate, a back electrode layer is laminated thereon, and then the above-mentioned transparent A flexible photoelectric conversion element is created by forming a photoelectric conversion element by providing a flexible electrical insulating layer with a coefficient of thermal expansion approximately equal to that of the glass substrate, and then finally peeling off the support. It is.

This method of manufacturing a flexible photoelectric conversion element has a significant effect in preventing curling, but it is difficult to create a transparent glass substrate on a support (glass plate, etc.) using a spin cord, etc. It was necessary to adopt a method that was not very advantageous in terms of production efficiency.

Furthermore, to form a transparent electrode layer on a glass substrate, tin oxide (hereinafter referred to as S n O2), which is desirable for the characteristics of photoelectric conversion elements, cannot be used due to the heat resistance of the substrate, and a lower temperature sputtering method, etc. is required. There is no choice but to use indium oxide and tin oxide (hereinafter referred to as ITO), which can be deposited using

ITO films have a good balance between sheet resistance and transparency, but during use, atomic indium in ITO diffuses into the amorphous silicon layer, reducing light transmittance. During the deposition of high-quality silicon, ITO is reduced in a hydrogen plasma atmosphere, and as a result, the generated atomic indium diffuses into the amorphous silicon layer, reducing photoelectric conversion efficiency. An ITO film is often used with a SnO2 layer interposed between it and a silicon layer.

Although this is also a problem due to the heat resistance limitations of the substrate, unevenness is formed on the surface due to the growth of crystal grains due to high-temperature deposition of 5N02 or TO and high-temperature annealing, which can be performed on a glass substrate. Surface roughening (texturing)
Although the photoelectric conversion efficiency can be improved by this method, this surface roughening (texturing) cannot be performed on a film substrate.

Furthermore, this problem is not limited to rigid film substrates with supports; the same applies to glass substrates, but since the above transparent electrode layer is manufactured using a single plate, it is not necessary to continuously process it in roll form. There is a problem with production efficiency compared to production.

Furthermore, this also applies to glass substrates, but in order to chemically remove the 5th and 102nd surfaces, it is necessary to coat the surface with zinc powder and then etch it with hydrochloric acid, etc. 50-28919), this zinc coating film is not stable, so it is necessary to repeat the coating several times to complete the etching.
There are problems such as being very complicated and economically disadvantageous.

(d) Means for Solving the Problems The present inventors have found that the above-mentioned problems can be solved (as a result of extensive studies), ① a transparent electrode layer of 5n02, ITO, etc. is formed on one side of the first support by CVD. When forming the first support using a metal method, spray method, sputtering method, vapor deposition method, etc., Sn
It is easy to grow crystal grain agglomerates such as O2 and form a transparent electrode layer with unevenness, and furthermore, when an electrolytic copper foil or the like with unevenness on one side is used as the first support,
It is very convenient for unevenness. (1) A transparent polymer film substrate is formed on the transparent electrode layer, and a metal foil or a metal foil is formed on the polymer film substrate directly or through an adhesive layer. A second support made of a metal plate or sheet glass is laminated, and then part or all of the first support is removed to expose a transparent electrode layer, and a semiconductor layer and a back surface are formed on the transparent electrode layer. The present invention was completed based on the knowledge that a charge conversion element with excellent photoelectric conversion efficiency can be obtained by sequentially forming an electrode layer and an electrical insulating layer.

That is, the method for manufacturing a flexible photoelectric conversion element of the present invention includes a step (A) of forming a transparent electrode layer on one side of a first support made of metal foil or a thin metal plate, and a transparent electrode layer formed in the above step (A). Step (B) of forming a transparent polymer film substrate on the transparent electrode layer formed in the above step (B), directly or through an adhesive layer, metal foil or A step (C) of laminating a second support made of a metal plate or sheet glass, removing part or all of the first support from the laminate formed in the above step (C) to form a transparent electrode layer. (D), forming a semiconductor layer on the transparent electrode layer exposed in the above step (D), forming a back electrode layer on the semiconductor layer formed in the above step (E). Step (F) of forming an electrically insulating layer having heat shrinkability equivalent to that of the polymer film substrate and flexibility on the back electrode layer side formed in step (F). G), Peeling the flexible photoelectric conversion element consisting of the substrate, transparent electrode layer, semiconductor layer, back electrode layer, and electrical insulating layer obtained through the above steps (A) to (G) from the second support. The process of doing (H
).

By the way, the present invention relates to a method for manufacturing a flexible photoelectric conversion element, and in the present invention, a flexible photoelectric conversion element is an element that inputs light and outputs electricity, and has flexibility. It includes everything that has a photoconductive element, a photodiode, a solar cell, a phototransistor, a photocylisk, etc. Furthermore, the light referred to here includes not only visible light but also infrared and ultraviolet rays.

The present invention will be explained in detail below.

In the present invention, first, the step (A) of forming a transparent electrode layer on one side of a first support made of gold MM or a thin metal plate
Implement.

As the first support used in this step (A), a foil or thin plate made of metals such as zinc, tin, copper, aluminum, or alloys containing these as main components is used.

If the thickness of this support is too thick, it will be difficult to process each step continuously or to etch the support in the final step.

On the other hand, if it is too thin, it will lack the rigidity as a support.
Curling occurs after forming the substrate and during forming the semiconductor layer.

However, even if the substrate curls inward at room temperature, the substrate layer will thermally expand and curl at the semiconductor layer formation temperature (for example, around 250°C, which is convenient for glow discharge method and amorphous silicon deposition). It is desirable to adjust so that it is corrected,
The temperature for forming the substrate using the resin solution (for example, polyimide precursor) for forming the polymer film substrate formed on the transparent electrode layer in the post-process (B), and the semiconductor layer deposition (formation) temperature It is very advantageous to keep them close together.

By the way, when the substrate curls inward at room temperature, curling can be forcibly prevented by winding it into a roll.

Under the above circumstances, it is convenient that the thickness of the support is 5 to 500 μm, preferably 10 to 300 μm.

Among these, aluminum or copper metal foil is most suitable for carrying out each process continuously.

In this case, the thickness of the aluminum foil is 10 to 300 mm.
The thickness of the copper foil is preferably in the range of 10 to 300 μI.

A transparent electrode layer made of a known material, such as Snot, In203, or a solid solution thereof, ITO, is formed on one side of the first support by a CVD method, a spray method, a sputtering method, a vapor deposition method, or the like. In this case, since the first support is made of metal, crystal grains such as SnO2 are grown by high-temperature reaction or high-temperature annealing to form an uneven transparent electrode layer. In this case, if an electrolytic @whistle or the like with unevenness on one side is used as the first support, 1. It is very convenient for unevenness, and in particular, electro-deposited copper foil has a rough texture due to its manufacturing conditions.
It is possible to vary the shape of the surface unevenness over a wide range, which is convenient for optimizing the texture structure.

These selections are advantageous in forming a textured structure that is important for photoelectric conversion efficiency.

In this step (A), a transparent electrode layer is formed on one side of the supporting band by a method such as sputtering, vapor deposition, or printing.

The thickness of the transparent electrode layer is not particularly limited, but
For example, if there are 500 to 5,000 people, there will be a lot of heat.

If the thickness of the transparent electrode layer becomes too thin, the desired conductivity (surface resistance of 1000 Ω/mouth or less) cannot be obtained, which is undesirable.On the other hand, if it becomes too thick, the transparency of the transparent electrode layer may decrease. So I don't like it.

Note that when a plurality of cells are formed on one substrate, unnecessary portions of the transparent electrode layer are removed by, for example, a technique such as 7-etching.

Further, on one side of the first support, a transparent electrode layer composited with SnO2 may be formed on the 171st layer, and ITO or the like may be formed on the second layer.

Forming these transparent electrode layers in a continuous manner in roll form is more advantageous in terms of production efficiency.

In the present invention, next, a step (B) of forming a transparent polymer film substrate on the transparent electrode layer formed in the above step (A) is carried out.

The transparent polymer film constituting the substrate is not particularly limited as long as it has heat resistance, flexibility, and electrical insulation properties, and typical examples include polyimide,
Films such as polyether sulfone, polysulfone, polyetherimide, and 4-methylpentene terephthalate may be mentioned.

Among these, in particular, the following general formula (1) or (It),
Alternatively, a polyimide transparent polymer film mainly composed of polyimide having repeating units represented by (1) and (II) is particularly recommended since it has good heat resistance and light transmittance.

That is, this polyimide film has visible light (500 na+) for a polyimide film with a film thickness of 50±5 μ-.
The transmittance is 70% or more and the yellow index is 40 or less.

It should be noted that the term "main component" as used herein means that the entire component corresponds to the above general formula (1
) and/or (II) only.

And/or such a substrate made of a transparent polyimide film can be produced by, for example, forming a colorless transparent polyimide film having excellent heat resistance, flexibility, and electrical insulation properties on the surface of the support by the following process. Formed as a substrate.

That is, such a polyimide film substrate is produced by the reaction between phenyltetracarboxylic dianhydride represented by the general formula (I[[) and aromatic diamino compounds represented by the general formulas (IV) and (V). obtained by. .

In the polyimir r obtained in this way, the higher the content of the polyimide represented by the repeating unit represented by the above general formula (1) and/or the repeating unit represented by the above general formula (n), the better the polyimide. The colorless transparency of the polyimide produced is increased.

In the present invention, in order to transmit light from the transparent polymer film substrate side, the substrate is required to have a certain level of transparency, and this required transparency is based on the above general formula (I). It can be obtained if the polyimide represented by the repeating unit represented by V/ or the repeating unit represented by the above general formula (II) is contained in an amount of 70 mol % or more.

That is, the polyimide represented by the repeating unit represented by the above general formula (1) and/or the repeating unit represented by the above general formula (n) is preferably contained in an amount of 70 mol% or more, most preferably It is desirable that the content is 95 mol% or more.

In this step (B), to form the colorless and transparent polyimide film substrate on the transparent electrode layer, the aromatic tetracarboxylic dianhydride and the aromatic noamino compound are placed in an organic polar solvent at a temperature of 80°C. A polyimide precursor solution is prepared by polymerization below, and this polyimide precursor solution is used to form a shaped body of a desired shape on the surface of the transparent electrode layer by a method such as casting or roll coating. The polyimide precursor is dehydrated and ring-closed while the organic polar solvent is removed by evaporation at a temperature of 50 to 350° C. under normal pressure or reduced pressure in air or in an inert medium.

Further, instead of the above method, the polyimide precursor can be obtained by a method such as using a benzene solution of pyridine and acetic anhydride, and removing the solvent and imidizing the polyimide precursor to form a polyimide.

The above organic polar solvents include dimethylformamide,
Preferred are trimethylacetamide, diglyme, Risol, halogenated phenol, etc. (a') Particularly preferred is trimethylacetamide because it is a good solvent and has an extremely low boiling point. These organic polar solvents may be used alone, or two or more of them may be used in combination without any problem. This has great advantages in terms of production efficiency.

In the present invention, next, a second support made of metal foil, metal plate, or sheet glass is placed on the polymer film substrate formed in the above step (B) directly or via an adhesive layer. A step (C) of pasting together is carried out.

In this step (C), the metal foil or metal plate includes, in addition to the above metals, foils and plates made of metals such as iron, nickel, chromium, stainless steel, and aluminum. It is preferable to use chemically stable stainless steel that does not corrode during the etching of the support, and the plate glass is not particularly limited as long as it is used in the field concerned.

Further, examples of the adhesive layer used in this step (C) include a layer formed of an adhesive such as a polyether sal 7-one adhesive or a polyether ether ketone adhesive.

Then, in this step (C), the second support is laminated onto the polymer film substrate directly or via an adhesive layer, and this lamination is performed by hot pressing.

Specifically, for example, after coating the resin liquid for the polymer film substrate described above, it is brought into a B-stage state, and the second support is directly laminated thereon and heated and pressurized with a hot press, or Alternatively, with or without interposing the adhesive layer between the polymer film substrate and the second support,
These are approximately 10℃ higher than the formation temperature of the polymer film substrate.
This is done by heating and pressurizing at a high temperature and a pressure of about 500 kg/am2.

This step (C) may be carried out continuously, but the laminated film with the first support is cut according to the dimensions of the second support, and the laminated film with the first support is cut into a single plate by a multistage press. It is also possible to process a large number of sheets.

In this way, a laminate is obtained in which a transparent electrode layer and a polymer film layer are formed between the first support and the Pt52 support.

In the present invention, next, a step (D) is performed in which part or all of the first support is removed from the laminate formed in the step (C) to expose the transparent electrode layer.

In this step (D), part or all of the first support is removed, and the most preferable method for this removal is etching. A transparent electrode layer is exposed on the film substrate.

When selecting this etching solution, the following points should be noted:
When a foil or plate of aluminum and zinc or an alloy thereof is used as a support, the first support can be selectively etched away by using an alkaline etching solution such as an ammonium salt or an ammonia complex. If an acidic etching solution is used, the underlying transparent electrode layer as well as the first support are removed at the same time.

For example, when manufacturing products such as solar cells, usually
- A process is performed in which a large number of cells are formed on a substrate, these cells are connected in series, and the voltage is increased. For this purpose, it is necessary to properly slam the transparent electrode layer. An etching resist (by the printing method or the 7-oto method) is applied on the first support in accordance with the shape of the transparent electrode layer to be left in a slam-like manner on the transparent polymer film substrate, and then acidic When etching is performed with an etching solution, the exposed portion of the first support and the transparent electrode layer thereunder are simultaneously removed.

Next, the etching lens on the first support is peeled off,
i When the removed first support is removed with an alkaline etching solution, a slam-like transparent electrode layer appears from below.

If this transparent electrode layer is made of SnO2, it is chemically very stable.
The nO2 film needs to be etched while being coated with zinc powder, but in the manufacturing method of the present invention, the fjSl support on the SnO2 film functions in the same way as the zinc powder coated film in this case. , reduction of tin oxide progresses due to release of hydrogen gas, etc., and zinc powder coating is not necessary.

Furthermore, if there is a possibility that the second support may be dissolved or removed during this etching, it is necessary to perform etching after masking the surface of the second support.

In the present invention, next, a step (E) of forming a semiconductor layer on the transparent electrode layer exposed in the above step (D) is performed.

The semiconductor constituting the semiconductor layer is not particularly limited as long as it has photovoltaic properties, and examples include infrared dermanium (G e), selenium (S e), indium antimony (INSb), X-ray 1st. Cadmium sulfide (CdS) for gamma rays and visible light, cadmium selenide (Cds e), silicon (Si) for visible light.
Examples include:

Furthermore, cadmium chloride (CdCL), ti4 chloride (CuCj!2), and silver salts may be freely used as active impurities in these semiconductors.

For example, it is advantageous to deposit p-type valvate silicon, i-type valvate silicon, and n-type valvate silicon in sequence in order to reduce the thickness of the semiconductor layer.

In addition, p-type valvous crystalline silicon, i-type valvous crystalline silicon and n
As a method for sequentially depositing crystalline silicon, various methods such as a glow discharge method and a photo-CVD method can be employed.

For example, if we take the case of adopting the glow discharge method as an example and explain it specifically, the temperature will be around 250℃ (200~350℃).
) The substrate with the transparent electrode layer obtained in step (D) exposed is held in a holder heated to
．． At about 2 Torr, a mixture of silane diluted with hydrogen to about 10 mol % and noborane diluted with hydrogen to about 5 wOOOOppm [B108/ (S iH4+ B
2Ha) = 0, 1 to 0.6 mol%, preferably 0
．． 3 mol %] was injected at a full flow rate of 1008 CC, and in that atmosphere, the holder was used as one electrode, and a high frequency power of about 10 W at 13.56 MHz was applied between the holder and the opposite electrode to form the transparent electrode. A layer of p-type crystalline silicon doped with boron is deposited over the layer to a thickness of 200 nm.

Subsequently, only the hydrogen-diluted silane was added to the 100th SC.
In the atmosphere introduced by CM, a non-doped i-type crystalline silicon layer was deposited to a thickness of 4,500 yen in the same manner as above, and further treated with hydrogen diluted silane and hydrogen. OO
A mixture of 7 osphin (PH, ) diluted to Oppm [
P H3/ (S i H-+ P H3) = 0
.

1 to 0.6 mol %, preferably 0.3 mol %] is introduced with a total flow rate of 1008 CC, a layer of n-type crystalline silicon doped with phosphorus is similarly deposited to a thickness of 500 nm .

By the way, for convenience, p is used as a photovoltaic semiconductor layer.
-1-Although the explanation has been given using the example of n-type amorphous silicon, p
In addition to amorphous silicon, the layer contains p-type amorphous silicon carbide (the film composition is expressed as SixC+-, X=0.6-0.9).
5. A film doped with diborane BzHs or the like, preferably with x=0.8, can also be used.

In this case, the carbon source used is a saturated hydrocarbon such as methane or ethane, or an unsaturated hydrocarbon such as ethylene or propylene.

The molar ratio of silane (SiH4) or nosilane (S1286) used as the raw material gas and the above-mentioned hydrocarbons is determined as follows.

That is, for example, to produce a film with a film composition of S io, ac O,2, the molar ratio of S i H4 and CH, 0.8 to 0.2.
(Also, 0.4 vs. 0.2 for 5i2Ha and CH4), 5
0.8 vs. 0.1.5izHs and C for iH- and C2H*
In 2H, the molar ratio is determined from the number of Si atoms and the number of C atoms in the source gas, such as 0.4:0.1.

In the present invention, a step (F) of forming a back electrode layer on the semiconductor layer thus obtained is performed.

The back electrode layer is made of metal such as aluminum, nickel, titanium, lithium, iron, stainless steel, nickel-chromium, or the like.

The back electrode layer is formed by a printing method, a sputtering method, a vapor deposition method, or the like. For example, in the vapor deposition method, 10-4 to ITo
The evaporation is carried out in a vacuum of rr, with the temperature of the ffi source being close to the melting point of the materials used.

The thickness of the back electrode layer is not particularly limited, but it must be thick enough to have the required conductivity without significantly reducing the flexibility of the entire flexible photoelectric conversion element, for example. , 0.1 μ- in case of aluminum electrode
The degree is appropriate.

In this way, a photoelectric conversion element is produced in which a transparent electrode layer, a semiconductor layer, and a back electrode layer are laminated on a heat-resistant, flexible, and electrically insulating transparent polymer film substrate with a second support. (a solar cell in the above example) is formed.

In this case, if the second support is made of a glass plate, it is possible to evaluate the characteristics of the photoelectric conversion element by inputting light from the support plate side at this stage.

In the present invention, a step (G
).

That is, on the back electrode layer thus laminated, an electrical insulating layer is further laminated except for a part of the back electrode layer (the part where the electrode terminals are attached).

This electrically insulating layer must have electrically insulating properties, heat resistance, and flexibility, and must also have heat shrinkability equivalent to that of the transparent polymer film substrate.

As will be described later, this electrical insulating layer generates stress that acts in the direction of canceling the curl caused by the difference in heat shrinkage between the polymer film substrate and the semiconductor layer due to the difference in heat shrinkage between it and the semiconductor layer. It is for the purpose of

That is, for example, in the case where the semiconductor layer is composed of a p-type-1-n-type crystalline silicon layer, curling of the flexible photoelectric conversion element or the semiconductor layer due to the difference in thermal shrinkage rate may occur. If the radius of curvature of becomes smaller than 401, cracks will occur in the semiconductor layer, so the thermal expansion coefficient of the substrate is α1, the thermal expansion coefficient of the electrically insulating layer is α2, and the sum of the thickness of the substrate and the thickness of the electrically insulating layer. Assuming that h(■) is the temperature difference between the amorphous silicon deposition temperature and the room temperature, ΔT3 is the temperature difference between the electrical insulating layer formation temperature and the room temperature, and ΔT2 is the temperature difference between the electrical insulating layer formation temperature and the room temperature, it is necessary to satisfy the following. Most preferably, the polymer film substrate and the electrical insulating layer are made of exactly the same material and have the same shape and dimensions (same thickness). For example, a resin solution similar to that used when forming a polymer film substrate is cast onto the back electrode layer to a similar thickness to form a film, and then dried with hot air to provide electrical insulation, heat resistance, and flexibility. It is possible to form an electrically insulating layer having heat shrinkability equivalent to that of a polymer film substrate.

In the present invention, finally, the above steps (A) to (G)
A step (H) of peeling off the flexible photoelectric conversion element consisting of the substrate, transparent electrode layer, semiconductor layer, back electrode layer, and electrical insulating layer obtained through the above steps from the second support is performed.

As a method for this peeling, when the laminate obtained in the above step (G) is immersed in water, water penetrates between the flexible photoelectric conversion element and the second support, and the second support Examples include a method in which the second support is easily peeled off, and a method in which the second support is removed by etching.

In this case, since the photoelectric conversion element is protected by being sandwiched between the polymer film substrate and the electrical insulating layer, the photoelectric conversion element is not damaged during this peeling.

In this way, the polymer film substrate, the transparent electrode layer,
A flexible photoelectric conversion element consisting of a semiconductor layer, a back electrode layer and an electrically insulating layer is obtained.

The thus obtained flexible photoelectric conversion element is prevented from curling by the electrically insulating layer.

(e) Function As described above, according to the present invention, the first support made of metal foil or thin metal plate is used, and the transparent electrode layer is formed on the metal support. This allows the use of SnO2, which requires deposition at high temperatures of 500°C or higher. Furthermore, when ITO is used, it also has the effect of making it possible to create irregularities due to the growth of crystal grain agglomerates due to high-temperature annealing.

Furthermore, since a roll-shaped support can be used as the first support, the formation of the transparent electrode layer and the formation of the transparent polymer film substrate can be performed continuously.

Furthermore, since the surface of the transparent electrode layer has a replica image relationship with the surface of the PlfJl support, by appropriately changing the surface shape of the first support, reflection of incident light can be reduced, Texturing, which is effective for increasing the optical path length in the semiconductor layer, is easily performed. In this case, especially electrolytic g+! When foil is used as the first support, unevenness can be easily achieved.

Furthermore, when laminating the second support onto the first support-attached polymer film substrate, the first support improves the rigidity of the polymer film substrate, making it easy to handle. This not only improves operability but also prevents damage to the transparent electrode layer and the adhesion of dust.

After laminating the tjS2 supports in this manner, when part or all of the first support is removed by etching, the transparent electrode layer is exposed.

In this case, the aluminum foil or the like forming the first support acts as a reducing agent for the SnO□ film, making it unnecessary to apply zinc powder, which is a conventional method during etching.

That is, by using an acidic (hydrochloric acid, phosphoric acid, etc.) etching solution, the Snoz layer is etched away along with the aluminum foil layer.

Also, when an alkaline (ammonia-based) etchant is used, only aluminum foil and copper foil are dissolved and removed when selected.

When the semiconductor layer is formed on the transparent electrode layer, since the second support provides reinforcement, the laminate does not curl during and after the deposition, even when the temperature is returned to room temperature.

Further, a back electrode layer is formed on the semiconductor layer, and a flexible, electrically insulating polymeric material is coated on the back electrode layer side, leaving an electrode terminal portion, and is dried and cured by heating. As this polymer material, one is selected and used that has the same heat shrinkability as the transparent polymer film serving as the substrate.

Next, when the above-mentioned laminate is immersed in water, for example, water penetrates between the second support and the transparent polymer film substrate, creating a curl-free textured structure on the transparent electrode layer and the substrate. As a result, a flexible photoelectric conversion element with improved photoelectric conversion efficiency can be efficiently formed.

(f) Examples Hereinafter, the present invention will be explained in detail based on Examples, but the present invention is not limited thereto.

Example 1 Nitrogen was introduced and bubbled into a 30% by weight aqueous solution of stannic chloride (SnCL) and a 9% by weight aqueous solution of antimony trichloride (SbCl).

On the other hand, as the first support, the thickness is 50 μm and the width is 300 mm.
Using a strip of aluminum foil, this was maintained at a temperature of 500°C in a Pelger-type quartz reaction vessel, and then
The above solution and water vapor are supplied to one side of the S b
A transparent electrode layer made of zo 3 S no 21K was formed, and this was further subjected to a 7-year treatment at a temperature of 420° C. for 180 minutes [Step (A)].

In the reaction vessel, the roll-shaped first support (aluminum M) was continuously fed out and deposited. in this case,
The deposition time was 15 seconds, and the obtained 5bzo3Sn
o The film thickness of the 2 film is 0.65μ15 average crystal grain size (irregularities on the transparent electrode layer surface) 0.4μ theory, Sb/Sn ratio 1.1aL
om%.

Next, on this transparent electrode layer side, a separately prepared polyimide precursor solution shown below was coated by a casting method, and heated at 300°C for 1 hour to form a transparent layer with a thickness of 50 μm.
A polyimide film substrate was formed [Step (B)]
].

Polyimide precursor solution: using N,N-dimethylacetamide as a solvent, 3.
3.3' for 3'-diaminodiphenylsulfone
4. 4'-Biphenyltetracarboxylic dianhydride was reacted once to obtain a solution of a polyimide precursor.

Next, as a second support, the thickness is 1. Using a stainless steel plate (dimensions: 300 x 300 ms2), the substrate side of the polyimide film substrate with the above-mentioned first support (aluminum?i!f) was placed on top of it, and heated under the following conditions. [Step (C)] The sheets were laminated together by heating and pressurizing.

Hot press conditions: Temperature: 330°C Pressure: 500 kg/Cs2 Time: 10 seconds Furthermore, the first support (
7 Otrenost was coated on the aluminum M) side, exposed and developed by a conventional method, and an etching solution Ill was formed in an appropriate stamp shape to partially mask it. This Rennost shape is made to correspond to the required transparent electrode button.

Next, this laminate is immersed in the following etching solution for 5 minutes to perform etching.

Etch solution: Composition Hydrochloric acid 50% by weight Nitric pH 5% Water 4 5% by weight Temperature 40°C Thus, the unmasked portion of the first support and the S b. o, -S no
The two transparent electrode layers are etched away at the same time.

Furthermore, after peeling and removing the remaining etch resist film by a conventional method, this is immersed in the following alkaline etch solution to dissolve and remove the exposed first support, exposing the transparent electrode layer of the desired pattern. [Step (D)].

Etching liquid: Product name: Process A (Meltex Co., Ltd.), that is, made of a transparent polyimide film with the required transparent electrode batten layer formed on one side and a second support (stainless steel plate) on the other side. A substrate is formed.

The thus obtained laminate was subjected to internal 'I4-pole type 0 high frequency (
13.56MHz) It was kept in a holder with a heater in a glow discharge device, and after keeping the temperature around 250℃, it was heated with silane diluted to 10 mol% with hydrogen and 5,000p with hydrogen.
Diporan diluted to pm was mixed [B2H 6/ (S
iH A + B 2H a) = 0, 3 mol%,
This was introduced into a glow discharge device at a total flow rate of 200 SCCM, and a high frequency power of 30 W was applied in an atmosphere with a degree of vacuum of 0.2 Torr to dope boron on the substrate.
A p-type crystalline silicon layer of 0.000 nm was provided.

Subsequently, only the above hydrogen-diluted silane was introduced, and a similar reaction was carried out to deposit a non-doped I-type valvous silicon thin film with a thickness of 4500 nm on the p-type valvate silicon layer.
Further, hydrogen-diluted silane and 7-osphine (P H , ) diluted with hydrogen to 5,000 ppm were mixed [P H3/
(S iH4 + PH3) = 0, 5 mol %] and injected into a glow discharge device with full wave -fi 200scCM.
500 N-type crystalline silicon ms were formed by doping phosphorus into an i-type crystalline silicon thin film.

That is, a photovoltaic semiconductor layer consisting of a p-type, i-type, and n-type amorphous silicon thin film was formed on a transparent polyimide film substrate through a transparent electrode layer [step (E)]. )].

Next, this was held in a vacuum evaporation apparatus, and an aluminum back electrode layer having a thickness of 0.1 μm was laminated on the n-type crystalline silicon thin film by a normal evaporation method [Step (F)].

Next, with the second support attached, leaving a space for terminal attachment on the back electrode layer, the same polyimide precursor solution as above was cast to the same thickness as the above substrate, and hot air was applied. An electrical insulating layer was formed by drying and further heating at a temperature of 200° C. for 5 hours to completely imidize [Step (G)].

When the laminate obtained through the above steps (A) to (G) is immersed in water at room temperature for about 1 hour, the substrate, transparent electrode layer, semiconductor layer, back electrode layer and electrical insulating layer are separated from the second support plate. The flexible photoelectric conversion element consisting of layers has peeled off [Step (H)
].

The photoelectric conversion efficiency of the thus obtained flexible photoelectric conversion element product was measured using an AM-1, 100 mW/cm2 solar simulator and was found to be 5.2%.

The flexible photoelectric conversion element thus obtained had a completely flat appearance and no curling occurred.

Comparative Example 1 The substrate was a conventional commercially available polyimide film (manufactured by DuPont, trade name: Kapton H) with a thickness of 50 μm.
) was dried at a temperature of 10° C. for 30 minutes and then kept in a sputtering device to form a stainless steel back electrode layer with a thickness of 1000 mm on one side.

Next, this was held in the same glow discharge device used in Example 1 and heated to a temperature of 250°C. Since curling occurred, the film was held under tension and the phosphorus-doped thickness was heated to 250°C. A 500-layer n-type valkyrystallic silicon layer and a 200-layer p-type amorphous silicon layer doped with boron were formed in the same order as in Example 1. .

However, when the film in which the back electrode layer and the semiconductor layer were combined in this manner was taken out at room temperature, severe curling occurred with the polyimide film inside.

Next, the film was kept under tension in the same sputtering apparatus used in Example 1, and a transparent electrode layer of 600 nm thick ITO was formed on the p-type crystalline silicon layer.

The thus obtained photoelectric conversion element was tightly curled with the substrate inside. When the photoelectric conversion element was forcibly expanded and the photoelectric conversion efficiency was measured, cracks were found in the amorphous silicon layer. The photovoltaic ability of most of the cells could not be confirmed due to the internal disconnection.

Comparative Example 2 A cathode consisting of 80% by weight of indium oxide (Ink, 1% by weight) and 20% by weight of tin oxide (Snow) was used on one side of an aluminum foil (support) similar to that used in Example 1, and a pressure of 1× was applied. 10-→~1.5X10-'T.

Sputtering was performed for 20 minutes at an aluminum foil temperature of 150°C under RR, with a film thickness of 6,000 mm and an average crystal grain size of 0.
An ITO film of 1 μm was obtained.

Next, a polyimide precursor solution was applied onto this ITOIIiX by a casting method in the same manner as in Example 1, and heated to form a polyimide substrate having a thickness of 50 μm.

Next, without attaching the second support, 7-etch resist was applied to the aluminum foil side, and after forming an etch resist in the form of a bang, with an HCl-HNO3 based etchant,
The exposed aluminum foil and the underlying ITO film were removed by etching.

Furthermore, after peeling off the etch resist, etch the exposed aluminum flakes and IT'Oy! J was exposed.

Next, a semiconductor layer was formed in the same manner as in Example 1.

When the sample (semi-finished product) was taken out of the glow discharge device, it curled completely with the polyimide substrate inside.

This is forcibly taut and kept flat with the vacuum attached directly to it.
A 0.1 μm aluminum back electrode layer was laminated on the crystalline silicon film.

The obtained sample was tightly curled and no photovoltaic properties could be confirmed due to the disconnection.

Table 1 The unevenness of the ITO film surface on the substrate was measured using a transmission electron microscope.

Example 2 A 37 μI electrolytically untreated copper foil having a plated surface with unevenness of 2 to 5 μI was used as the first support, and a transparent electrode was formed on the plated surface under the same conditions as described in Example 1. The layer was deposited for 7 seconds, with a thickness of 0.3μ on its surface, an average grain size of 0.15μ, and an Sb/Sn ratio of 1,1 atom.
A transparent electrode layer consisting of % S bzo , -S nO□m was obtained.

Next, sputtering was performed on this transparent electrode layer for 10 minutes in the same manner as in Comparative Example 1 to form a composite transparent electrode layer with a total thickness of 0°6μ and an average crystal grain size (irregularities on the surface of the transparent electrode layer) of 0°25μ. I got it.

Thereafter, in the same manner as in Example 9, a transparent polyimide film substrate was formed and further thermocompression bonded to a glass plate having a thickness of 4 a+m to obtain a laminate.

Furthermore, in the same manner as in Example 1, unnecessary portions of the first support (copper foil) and the transparent electrode layer were etched seven times to form a transparent electrode layer.

However, when etching the copper foil, ferric chloride (FeC1z
The test was carried out using an etcher spraying an aqueous solution of 380 g/l) at 40°C.

Thereafter, a flexible photoelectric conversion element was obtained through the same steps as in Example 1.

This is converted into a tool large mini-lator (AM= 1.100mW
/c Ugly 2) When the photoelectric conversion efficiency was measured, it was 5.3.
%Met.

(g) Effects of the Invention According to the method of the present invention, an S n Oz film that must be deposited at high temperatures (400°C or higher) can be used as a transparent electrode layer even though it is a photoelectric conversion element using a polymer film substrate. We have it.

In addition, since the transparent electrode layer can be annealed when deposited at high temperatures (400°C or higher), the transparent electrode layer such as Sn02M1 or ITO film can be textured, and the irregularities on the incident light side of the flexible photoelectric conversion element can be textured. This has the effect of significantly improving the photoelectric conversion efficiency.

Furthermore, according to the method of the present invention, when etching the transparent electrode layer,! The support of No. 51 acts in the same way as a conventional zinc powder coating, and as a result, it has the effect of eliminating the need for a zinc powder coating.

In particular, the present invention provides a flexible photoelectric conversion device having a laminated structure in which a transparent electrode layer, a semiconductor layer, and a back electrode layer are sandwiched between a transparent glass substrate on the transparent electrode layer side and an electrical insulating layer on the back electrode layer side. This is a device manufacturing method in which a flexible photoelectric conversion device is formed at a high temperature and then cooled to room temperature. The electric insulating layer, which has a thermal expansion coefficient almost equal to that of the substrate, acts in a direction to cancel out the thermal contraction force, and as a result, the appearance of curling the flexible optical Nf: converting element is The above thermal shrinkage force is reduced or eliminated, and curling of the flexible photoelectric conversion element is prevented. Therefore, the flexible photoelectric conversion element has excellent photoelectric conversion efficiency and reliability. This has the effect that the element can obtain.

Furthermore, according to the flexible photoelectric conversion element and manufacturing method of the present invention,
The support is wound into a roll and is continuously rolled out to create a flexible photoelectric conversion element! ! l! Moreover, the flexible photoelectric conversion element is prevented from curling during this manufacturing process, and has the effect of significantly improving productivity.

In addition, in the manufacturing process of the present invention, the first support is not mechanically and forcibly peeled off or removed, but the support is chemically removed. There is no distortion in the charge conversion element body, and there is no damage to the photoelectric conversion element body due to mechanical stress, and from this point of view as well, a highly reliable flexible photoelectric conversion element can be obtained.

Claims (7)

[Claims] (1) Step (A) of forming a transparent electrode layer on one side of a first support made of metal foil or thin metal plate; a transparent polymer film substrate on the transparent electrode layer formed in step (A) above; Step (B) of forming a second support made of metal foil, metal plate, or sheet glass on the polymer film substrate formed in step (B), directly or through an adhesive layer. (C), a step (D) of removing part or all of the first support from the laminate formed in the above step (C) to expose the transparent electrode layer, and the above step (D). A step (E) of forming a semiconductor layer on the transparent electrode layer exposed in step (E), a step (F) of forming a back electrode layer on the semiconductor layer formed in step (E) above, formed in step (F) above. Step (G) of forming an electrical insulating layer having heat shrinkability and flexibility equivalent to that of the polymer film substrate on the back electrode layer side that has been formed; Steps (A) to (G) above; A step (H
), a method for manufacturing a flexible photoelectric conversion element. (2) The method for manufacturing a flexible photoelectric conversion element according to claim 1, wherein the first support is an aluminum foil. (3) The method for manufacturing a flexible photoelectric conversion element according to claim 1, wherein the first support is a copper foil. (4) The semiconductor layer is a p-i-n type amorphous silicon layer or
Claim 1, which is an i-p type amorphous silicon layer.
3. A method for manufacturing a flexible photoelectric conversion element according to any one of items 1 to 3. (5) The method for manufacturing a flexible photoelectric conversion element according to any one of claims 1 to 4, wherein the polymer film substrate is a transparent polyimide substrate. (6) The method for manufacturing a flexible photoelectric conversion element according to any one of claims 1 to 5, wherein the second support is a stainless steel foil or thin plate. (7) The method for manufacturing a flexible photoelectric conversion element according to any one of claims 1 to 5, wherein the second support is a glass plate.