JPH1140828A - Method and apparatus for manufacture of photoelectric converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a reflection layer and a transparent resistance layer in a stage such that the conversion efficiency of light into electricity is enhanced by a method wherein, inside a series of vacuum film-formation spaces, the reflection layer is formed on a substrate, the reflection layer is brought into contact with an oxygen ion layer, and the transparent resistance layer is formed on the reflection layer. SOLUTION: A semiconductor layer 104 having a semiconductor junction which is composed of an n-type a-Si layer 105, of an i-type a-Si layer 106 and of a p-type a-Si layer 107 is formed on a transparent resistance layer 103. Then, an antireflection layer 108 which is used also as a transparent electrode is formed on the semiconductor junction. A comb-shaped current collection electrode 109 is formed on it, and a extraction electrode 110 is attached so as to be protected by a protective resin 111, t hereby, obtaining a photoelectric conversion body. In the conversion body, the reflectance of a reflection layer 102 and that of the transparent resistance layer 103 are good, reflected light is absorbed effectively by the semiconductor layer 104, and the photoelectric conversion efficiency of the photoelectric conversion body is enhanced. In addition, the characteristic of the photoelectric conversion body does not change for a long time, and the reliability of the photoelectric conversion body is good as wall.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a photoelectric converter having a reflective layer and a transparent resistance layer, which efficiently utilize incident light to increase the efficiency of converting energy from light to electricity.

[0002]

2. Description of the Related Art A photoelectric conversion element as an independent power source for various electric appliances and a photoelectric conversion element using sunlight as an alternative energy source for system power have already been used, and research and development have been made on these. I have. For example, a crystalline photoelectric converter made of single crystal or polycrystalline silicon having high conversion efficiency, amorphous silicon (hereinafter referred to as a-Si) or CdS.CuI which can be provided at a low price.
A photoelectric conversion unit itself, such as a so-called thin film photoelectric converter using a compound semiconductor such as nSe _{2, has been} actively studied and developed. In addition, technologies other than the photoelectric conversion unit are being actively researched and developed, such as a technology that makes more effective use of the irradiated light, a technology that prevents the diffusion of electrode materials into the photoelectric conversion unit, and a technology that converts the converted electricity. Technologies that efficiently extract energy to the outside are also important technologies. Technologies that make effective use of the irradiated light include a light scattering layer technology that scatters the incident light and lengthens the optical path length in the photoelectric conversion unit, and a light that is not absorbed by the photoelectric conversion unit. There is a technique of a reflection layer for reflecting and reusing the light. As a technique for preventing the diffusion of the electrode material into the photoelectric conversion unit, there is a technique of providing a barrier layer between the reflection layer and the photoelectric conversion unit. Further, as a technique for efficiently extracting the converted electric energy to the outside, there is a technique of providing a resistance layer so that a short circuit occurs due to a defect in the photoelectric converter and the electric energy is not wasted at the defective portion. For example, in U.S. Pat. No. 4,419,533, the surface of a reflective layer on a substrate is made to have an uneven texture structure to scatter light so as to lengthen the optical path length in a photoelectric conversion portion and effectively use incident light. A technique and a technique of providing a barrier layer of zinc oxide or the like so that the reflection layer does not diffuse into the photoelectric conversion unit at the same time are disclosed. It is described that aluminum, gold, silver, copper, or the like can be used as the reflective layer. Also, U.S. Pat.
Japanese Patent No. 32,372 discloses a technique for forming a transparent resistance layer on a reflective layer to prevent a short circuit due to a defect in a semiconductor layer. Further, U.S. Pat. No. 5,500,055 discloses a technique in which a transparent resistive layer serving also as a barrier layer on a reflective layer has an uneven texture structure.

[0003] However, it is not easy to obtain an inexpensive and highly reliable photoelectric converter having a high reflectivity, a sufficient texture structure, and a low cost by using only these conventional techniques. For example, using gold or silver for the reflective layer is expensive, and silver or copper has the problem that it is electrically ionized by the presence of a small amount of moisture and a short circuit may occur through the semiconductor layer. In addition, when aluminum is used, there is a problem that the reflectance may decrease when the transparent resistance layers are laminated.
As a method for forming an aluminum film that can be used as a reflective layer, the following proposals have already been made mainly from the viewpoint of controlling the particle size and increasing reliability. That is, JP-A-62-2
Japanese Patent No. 211377 discloses a method of forming an aluminum film by sputtering while supplying oxygen gas and monitoring the amount by a quadrupole mass spectrometer while controlling the flow rate of oxygen gas. It is described that the particle size can be controlled. JP-A-02-29773
No. 7 discloses a method of sputtering an aluminum film in which an inert gas is kept at a pressure of 10 mTorr or more to prevent corrosion and deformation defects. JP-A-05-1
Japanese Patent Application Laid-Open No. 71434 discloses a method of forming an aluminum film without projections by sputtering an aluminum film while leaving residual air in a vacuum vessel. Japanese Patent Application Laid-Open No. 06-116723 discloses a method of obtaining a smooth aluminum film by repeating a step of forming an aluminum film by sputtering and a step of exposing the aluminum film to a mixed gas of nitrogen and oxygen. Among these methods for forming an aluminum film, there is no disclosure that particularly refers to the light reflectance, and there is no disclosure that mentions the effect of laminating a transparent resistance layer or a semiconductor layer on the aluminum film.

[0004]

SUMMARY OF THE INVENTION A reflection layer, a transparent resistance layer,
The conversion efficiency of the photoelectric converter is expected to be significantly improved by the combination of the photoelectric converters, and the price of the obtained electric energy is expected to decrease. However, according to the findings of the present inventors, the effect is not as expected and the price of the obtained electric energy is not sufficiently low. Further, it is still not enough to obtain high conversion efficiency and long-term reliability for 10 to 20 years. Therefore, the fact is that the photoelectric conversion body has not yet been widely used for system power. In view of the disclosure of the above-mentioned U.S. Patent Specification, the present inventors formed a reflective layer on a substrate for reflecting light not absorbed by the photoelectric conversion unit to the photoelectric conversion unit and reusing the same, The inventor of the present invention has considered the most suitable configuration in which a transparent resistance layer that also serves as a barrier layer for preventing the material of the reflective layer from diffusing into the photoelectric conversion portion and that prevents a short circuit due to a defect in the semiconductor layer is most suitable. As a result, the following problems were found. First, gold and silver used for the reflective layer in the prior art are expensive. Second, when silver or copper is used, there is a problem that a short circuit may occur through the semiconductor layer and power may not be obtained. This problem occurs particularly when moisture is applied and only a part of the photoelectric conversion body is irradiated with light for a long time. The present inventors have studied, when light is irradiated only on a part of the photoelectric conversion body,
A potential of the opposite polarity to the potential generated by normal photoelectric conversion is applied to the portion of the photoelectric converter that is not irradiated with light, and the action of this reverse potential and moisture that cannot be cut off by inexpensive resin protection As a result, it has been found that after long-time use, the metal element of the reflective layer may be ionized and short-circuit the semiconductor layer. It was also found that this problem does not occur with aluminum or gold. We have also found that short-circuiting of the semiconductor layer can be prevented by providing a protective film such as a vitreous material and sufficiently blocking moisture, but it is difficult to produce an inexpensive, lightweight, and flexible photoelectric converter using this method. There was found. The third problem occurs when an aluminum film that does not cause the short-circuit phenomenon of the second problem is used for the reflective layer. This is a problem in that, when an aluminum film as a reflection layer is formed on a substrate, and then a transparent resistance layer for preventing a short circuit between electrodes due to a defect in the semiconductor layer is laminated, the reflectance is reduced. That is, U.S. Pat.
As described in the specification of Japanese Patent Application Laid-Open No. 19,533, an aluminum film serving as a reflection layer is made uneven by increasing its manufacturing temperature or by increasing its thickness so that light is scattered and light is effectively used. If it is set, the reflectance decreases. Increasing the production temperature or increasing the thickness of the aluminum film increases the crystallinity of aluminum and forms irregularities due to crystal grains.However, in this method, the aluminum grain boundaries absorb light and reflectivity decreases. It has been found that the amount of light that can be converted into electricity in the semiconductor layer is reduced. Further, as described in U.S. Pat. No. 5,500,055, when a texture structure is formed with a transparent resistance layer,
As a particularly inexpensive manufacturing method, a roll-to-
Even when a reflective layer and a transparent resistance layer are successively produced by a roll-type apparatus, the reflectance is reduced. This is because the crystallization of the aluminum film proceeds due to the energy when the transparent resistance layer is deposited on the reflective layer, the grain boundaries develop, and the grain boundaries absorb light and reduce the reflectance. It is believed that there is. As described above, it is difficult to obtain an inexpensive and highly reliable reflective layer and transparent resistance layer with a desired texture structure, a high reflectivity, a high reliability, and a low cost using only the conventional technique.

[0005]

Means for Solving the Problems The present invention has been completed as a result of intensive studies to solve the above-mentioned problems in the prior art. The present invention relates to a photoelectric conversion body in which a reflection layer, a transparent resistance layer, and a semiconductor layer are sequentially laminated on a substrate, wherein the reflection layer and the transparent resistance layer are effectively used for incident light to convert light to electricity. It is an object of the present invention to provide a method and an apparatus which can be formed in a state that can improve the conversion efficiency of a device. The method of the present invention is a method of manufacturing a photoelectric converter by sequentially laminating a reflective layer, a transparent resistance layer, and a semiconductor layer on a substrate, wherein the reflective layer comprises aluminum or an aluminum-containing material on the substrate. A step of forming a layer by a sputtering method, a step of contacting the formed layer with oxygen ions, and a step of forming a layer containing zinc oxide as a main component on the layer by a sputtering method as the transparent resistance layer. It is performed continuously in a series of spaces, and the mixing of oxygen gas from the space brought into contact with the oxygen ions into the film formation space of the reflective layer is limited to 10% or less by gas partial pressure. . The apparatus of the present invention is an apparatus for manufacturing a photoelectric converter by sequentially laminating a reflective layer, a transparent resistance layer, and a semiconductor layer on a substrate, wherein a reflective layer made of aluminum or an aluminum-containing substance is formed on the substrate by a sputtering method. Means for forming, a target containing aluminum or an aluminum-containing substance as a main component, and a target containing zinc oxide as a main component, and a means for performing glow discharge in an atmosphere containing oxygen gas using one or both of the targets as a cathode electrode, Means for allowing the formed reflective layer to pass through the glow means, and allowing a substrate to pass between the means for forming the reflective layer and the means for performing the glow discharge, but mixing of oxygen gas into the means for forming the reflective layer And means for forming a transparent resistance layer containing zinc oxide as a main component by a sputtering method.
The photoelectric conversion body having the reflective layer and the transparent resistance layer formed in the present invention can efficiently and effectively utilize incident light even during long-term continuous use, and exhibits a high photoelectric conversion efficiency stably. Then, the photoelectric conversion body can be used for system power. Further, the photoelectric conversion body can be manufactured at low manufacturing cost.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the following embodiments, but the present invention is not limited thereto. FIG.
FIG. 1 is a schematic cross-sectional view schematically showing one example of a photoelectric conversion body in the present invention. In FIG. 1, 101 is a substrate, 102 is a reflective layer, 102 'is a surface region of the reflective layer which has been subjected to oxygen ion treatment, 103 is a transparent resistance layer, and 104 is a semiconductor layer having a semiconductor junction (pin junction) (photoelectric conversion layer). ), 10
5 is an n ^- type amorphous silicon (a-Si) layer, 10
6 is an i ^- type amorphous silicon (a-Si) layer, 10
7 is a p ^- type amorphous silicon (a-Si) or microcrystalline silicon (μc-Si) layer, 108 is an antireflection layer also serving as a transparent electrode, 109 is a current collecting electrode, 110 is an extraction electrode, 111 is a protective resin, It is. FIG. 2 is a schematic diagram showing an example of an apparatus for forming the reflection layer 102 and the transparent resistance layer 103 of the photoelectric conversion body shown in FIG.

[0007] The apparatus shown in FIG.
An example of a method for manufacturing the photoelectric conversion body of the present invention by forming the reflection layer 102 and the transparent resistance layer by a roll-type vacuum film forming apparatus) will be described. A roll 202 of a conductive strip-shaped substrate for the substrate 101 is transferred from the delivery chamber 201 to the take-up chamber 210 and evacuated by a vacuum pump (not shown).
The take-up roll 211 is rotated by a servomotor (not shown) to convey the belt-like substrate 204 at a constant speed. Next, an inert gas such as an argon gas is supplied from the gas supply pipe 230 in the reflective layer forming chamber 205 and sputtered by a DC power supply 219 using a target 214 of aluminum or its contents as a cathode electrode at a predetermined pressure to form the reflective layer 102.
To form Next, the substrate 204 on which the reflective layer 102 has been formed is transported, and a gas containing oxygen gas is supplied from the gas supply pipes 231 and 232 to a predetermined gas pressure.
The surface of the reflective layer is brought into contact with oxygen ions through the oxygen ion generation chambers 206 and 207 which generate glow discharge by applying DC power by 221. A gas gate 226 is provided between the oxygen ion generating chamber and the reflective layer forming chamber 205 to narrow the gap and allow an inert gas such as argon to flow therethrough. Is restricted from being mixed in. The substrate 204 that has been subjected to the oxygen ion contact treatment in the glow discharge space of the oxygen ion generation chambers 206 and 207 as described above is transferred to the transparent resistance layer formation chamber 20.
8,209. Here, gas supply pipes 233, 23
4, an inert gas is supplied into the transparent resistance layer forming chamber to a predetermined gas pressure, and the target 21 mainly containing zinc oxide is formed.
After applying the DC voltage to the DC power supplies 222 and 223 to form the transparent resistance layer 103, the transparent resistance layer 103 is wound on the reel 211 in the winding chamber 210.
By appropriately selecting the film forming temperature and the DC power, unevenness having a size of several hundred nm can be formed on the surface of the transparent resistance layer 103. FIG. 1 schematically shows this unevenness with emphasis. As described above, the reflective layer and the transparent electrode can be continuously formed on the substrate. In the case where the oxygen ion generating chamber and the transparent resistance layer forming chamber are formed of an oxide film, the space between the two chambers does not necessarily need to be separated when the transparent resistance layer is an oxide film. Good.

The transparent resistance layer 10 formed as described above
3, an n-type a-Si layer 105 and an i-type a-Si layer 1 are formed by using another vacuum apparatus (for example, a plasma CVD apparatus).
And a semiconductor layer 104 having a semiconductor junction composed of the p-type a-Si layer 107 is formed. In the case where the semiconductor layer 104 is thin, the entire semiconductor junction often has the same uneven structure as the transparent resistance layer 103 as shown in FIG.
Next, an antireflection layer 108 also serving as a transparent electrode is formed on the semiconductor junction by another vacuum device. A comb-shaped current collecting electrode 109 is provided thereon, a take-out electrode 110 is attached, and protected by a protective resin 111. Thus, the photoelectric converter shown in FIG. 1 is obtained. In the photoelectric conversion body, the reflection layer and the transparent resistance layer formed by the above-described procedure have good reflectance, and the reflected light is effectively absorbed by the semiconductor layer to improve the photoelectric conversion efficiency. In addition, there is no change in characteristics for a long time, and the reliability is good. Here, the case of the roll-to-roll system using a band-shaped substrate has been described, but the present invention is not limited to this system and can be applied to, for example, a single-wafer in-line system as shown in FIG.

Hereinafter, the photoelectric conversion body using the reflection layer and the transparent resistance layer formed according to the present invention will be described in detail.

[0010]

[Substrate] The substrate 101 also functions as one electrode via a semiconductor layer. As the substrate 101, tantalum, molybdenum, tungsten, stainless steel, aluminum, titanium, a carbon sheet, a lead-plated steel sheet, a resin film on which a conductive layer is formed, or the like can be used. Among them, stainless steel plate, zinc steel plate, aluminum plate and the like are suitable for continuous operation because they are relatively inexpensive and can be used in roll form. Depending on the application, a crystal substrate of silicon or the like, a glass or ceramic plate can also be used. The surface of the substrate may be polished, but if the finish is good, for example, a stainless steel plate that has been subjected to a bright anneal treatment, it may be used as it is only by washing with water and blow drying. In addition, a material having irregularities such as dull finish and bowgen finish can be used. In the case of stainless steel plate, SUS
When a ferromagnetic material such as 430 is used, it is possible to convey while controlling the position accurately with a roller having a built-in magnet.

[0011]

[Reflective Layer] Like the substrate 101, the reflective layer 102 may also serve as one electrode via a semiconductor layer. The reflective layer 102 is formed of aluminum or a substance containing aluminum, and can be formed using aluminum or the substance thereof by a sputtering method, a vacuum evaporation method, a chemical vapor deposition method, an ion plating method, an ion beam method, or the like. A DC magnetron sputtering method which is an example of a method for forming the reflective layer 102 using the apparatus shown in FIG. 2 will be described. 20
Reference numeral 5 denotes a reflection layer forming chamber, which can be evacuated by an exhaust pump (not shown). An inert gas such as argon is introduced into the reflective layer forming chamber at a predetermined flow rate using a mass flow controller through a gas inlet pipe 230 connected to a gas cylinder (not shown), the opening of the exhaust valve is adjusted, and the reflective layer forming chamber is formed. The inside of 205 is set to a predetermined gas pressure. Reference numeral 214 denotes a cathode electrode having a target made of aluminum or a substance containing aluminum fixed on the surface thereof and having a magnet (not shown) therein. A DC power supply 219 is connected to the cathode electrode 214, and supplies DC power to perform sputtering of the target.

[Oxygen ion treatment of reflective layer surface] As a method of generating oxygen ions to be brought into contact with the surface of the reflective layer formed as described above, a direct current method using an anode electrode and a cathode electrode, an alternating current method, a high frequency method, and a hollow cathode type And the like, and an ion beam method and a microwave method can be used. About bringing oxygen ions generated into contact with the surface of the reflective layer,
The substrate 204 provided with the reflective layer may be passed through a space in which oxygen gas is supplied to generate oxygen ions by generating a discharge, for example, oxygen ion generation chambers 206 and 207 as shown in FIG. At this time, the oxygen ion generation chambers 206, 20
The mixing of oxygen from 7 into the reflective layer forming chamber 205 is another factor that lowers the reflectance, so it is necessary to limit it to a certain amount or less. As this method, it is effective to use a generally known gate 226 having a narrow and long gap to reduce conductance. Furthermore, this gate 2
It is also possible to increase the separation performance by supplying an inert gas or the like to 26.

[0012]

[Transparent Resistive Layer] The transparent resistive layer 103 can be formed by a sputtering method, a vacuum evaporation method, a chemical vapor deposition method, an ion plating method, an ion beam method, or the like. Transparent resistance layer 1
03 requires transparency in order to transmit light and requires some resistance to suppress current flowing through defects in the semiconductor layer. As a constituent material of the transparent resistance layer 103, zinc oxide, titanium oxide, indium oxide, tin oxide, or a substance containing the same can be used. When an oxide is used as a constituent material of the transparent resistance layer, it can be formed continuously in the same vacuum device as the oxygen ion generation chamber. In addition, several hundred n
Asperities having a size of m can be formed.

[0013]

[Semiconductor Layer] For forming the semiconductor layer 104, a plasma CVD apparatus utilizing high frequency power or microwave power can be used. In this case, the source gas for film formation is S
Discharge power is applied using iH ₄ , SiF ₄ , PH ₃ , H _2, etc., so that the n-type a-Si layer 105 becomes transparent layer 103.
Can be formed on. Further, the i-type a-Si layer 106 can be formed on the n-type a-Si layer 105 by using SiH ₄ , SiF ₄ , H _2, or the like. Then, using SiH ₄ , BF ₃ , H _2, etc., p
The type μc-Si layer 107 can be formed on the i-type a-Si layer 106. Thus, a nip semiconductor junction can be formed. This semiconductor layer is not limited to amorphous or microcrystal, and may have a pin configuration. A plurality of semiconductor junctions may be provided.

[0014]

[Anti-reflection layer] The anti-reflection layer 108 also serves as an electrode on the side opposite to the substrate 101 via the semiconductor layer 104, and preferably has low resistance. The antireflection layer 108 is made of indium oxide, tin oxide, titanium oxide, zinc oxide, or a mixture thereof. The antireflection layer can be formed by a resistance heating or a vacuum evaporation method using an electron beam, a sputtering method, or the like. In order to obtain a good anti-reflection effect, the thickness of the anti-reflection layer is preferably about 1/4 of the refractive index of the film as the anti-reflection layer, compared with the wavelength of light whose reflection is mainly desired to be prevented. .

[0015]

[Current collecting electrode] A grid-like current collecting electrode 109 may be provided on the antireflection layer 108 in order to efficiently collect current. The constituent materials of the collecting electrode include Ti, Cr, Mo,
Examples include metals such as W, Al, Ag, Ni, Cu, and Sn, alloys of these metals, and conductive pastes such as silver paste. As a method of forming the current collecting electrode, sputtering using a mask pattern, resistance heating, CVD method, a method of removing unnecessary portions by etching after depositing a metal film on the entire surface and patterning, a grid electrode directly by optical CVD Examples of the method include a method of forming a pattern, a method of forming a mask having a negative pattern of a grid electrode pattern and then plating, and a method of printing a conductive paste. The conductive paste is usually silver, gold, copper,
A material in which nickel, carbon, or the like is dispersed in a binder resin is used. Examples of the binder resin include resins such as polyester, epoxy, acrylic, alkyd, polyvinyl acetate, rubber, urethane, and phenol. After forming the collecting electrode, the output terminal 110 is attached to the substrate and the collecting electrode in order to extract the electromotive force. Attachment of the output terminal to the substrate can be performed by a method of spot welding or soldering a metal body such as a copper tab. Attachment of the output terminal to the current collecting electrode can be performed by a method of electrically connecting a metal body with a conductive paste or solder.

[0016]

[Protective Resin] As the protective resin 111, various resin films such as polyethylene terephthalate, nylon, polycarbonate, polyethylene, polypropylene, polyvinyl chloride, and acrylic can be used. The resin film is adhered to the photoelectric conversion body with an adhesive resin to form a protective material. Known adhesive resins such as acrylic, polyamide, polychloroprene rubber, butyl rubber, nitrile rubber, phenol, melamine, epoxy, and silicone can be used as appropriate.

[0017]

The present invention will be described in more detail with reference to the following examples. The present invention is not limited by these examples.

[0018]

Example 1 In this example, a photoelectric converter having the structure shown in FIG. 1 was manufactured. 120 m width as the substrate 101
A stainless steel roll 202 of SUS430 having a surface with a thickness of 0.15 mm and a length of 150 m and having a dull finish to leave unevenness is set in the apparatus shown in FIG. 2 and evacuated until the pressure becomes 10 ^-4 Torr or less. did. Thereafter, 30 sccm of argon gas is supplied as an inert gas from the gas supply pipes 230, 233, and 234 to the reflection layer formation chamber 205 and the transparent resistance layer formation chambers 208 and 209, respectively, and oxygen gas is supplied to the oxygen ion generation chambers 206 and 207. Gas supply pipes 231, 2
32 to 10 sccm each. Gas gate 2
Also, 30 sccm of argon gas was supplied to 26. In this state, the opening degree of the exhaust valve (not shown) was adjusted to maintain the pressure in each vacuum chamber at 3 mTorr. The take-up roll 211 is rotated by operating the servo motor,
mm, the transfer of the substrate 204 was started. As the target 214 for forming the reflective layer, aluminum having a size of 25 cm × 25 cm and a purity of 99.99% by weight was used, and a DC power of 400 W was applied. The reflective layer 102 made of an aluminum film having a thickness of about 200 nm was formed in about 90 seconds when the substrate 204 passed over the target 214. DC power of 40 W was applied to the cathode electrodes 215 and 216 of the oxygen ion generation chambers 206 and 207, respectively. The substrate 204 on which the reflective layer was formed was continuously transported and contacted with a plasma containing oxygen gas for about 180 seconds while passing through the oxygen ion generation chamber. The cathode electrode 215 uses an aluminum target having a purity of 99.99% by weight and a size of 25 cm × 25 cm, and the cathode 216 has a purity of 99.99%.
A zinc oxide target with a size of 25 cm × 25 cm in weight% was used. The substrate 204 was continuously transferred to the transparent resistance layer forming chambers 208 and 209. DC power of 800 W was applied using zinc oxide targets 217 and 218 each having a purity of 99.99% by weight and a size of 25 cm × 25 cm. About 1000 nm in about 180 seconds through space
The transparent resistance layer 103 made of a thick zinc oxide film was formed. At this time, the heater unit 2 using an infrared lamp was used.
The substrate temperature is set to 150 ° C. and 250
When the temperature was adjusted to ° C., irregularities having a size of several hundred nm developed on the surface of the transparent resistance layer. Substrate 20 formed up to transparent resistance layer
4 was wound on a reel 211 in a winding chamber 210.
In order to prevent the surface of the transparent resistance layer from being damaged, the interleaving paper 213 made of a polyester film was sandwiched between the substrates when the substrate 204 was wound onto the reel 211. This state was maintained for about 10 hours, and the reflective layer and the transparent resistance layer were formed over a distance of about 100 m at a conveying speed of 170 mm per minute. A part of the substrate on which the reflection layer and the transparent resistance layer were formed was taken out, and the reflectance was measured with a spectrophotometer.
The center value of the vibration due to the interference of m was 66%.

Further, the substrate on which the reflection layer and the transparent resistance layer were formed was cut into a size of 5 cm × 5 cm, and was set in a commercially available capacitively coupled high-frequency CVD apparatus. Rough evacuation and high vacuum evacuation operations were performed by an evacuation pump through the evacuation pipe of the reaction vessel. At this time, the temperature of the substrate was controlled by a temperature control mechanism so as to be 250 ° C. When the sufficiently evacuated is performed, the gas inlet pipe, SiH ₄ 300scc
m, SiF _{4 4} sccm, PH ₃ / H ₂ (1% H ₂ dilution) 5
5 sccm and H ₂ 40 sccm were introduced, the opening of the throttle valve was adjusted, the internal pressure of the reaction vessel was maintained at 1 Torr, and when the pressure was stabilized, 200 W of power was immediately supplied from the high frequency power supply. The plasma was maintained for 5 minutes. Thus, an n-type a-Si layer 105 was formed on the transparent resistance layer 103. After evacuation again, 300 sccm of SiH ₄ , ₄ sccm of SiF ₄ , H
The ₂ 40 sccm was introduced, by adjusting the opening degree of the throttle valve, the internal pressure of the reaction vessel was maintained at 1 Torr, where the pressure is stabilized, immediately put power of 150W from the high frequency power source, plasma was maintained for 40 minutes . Thus, an i-type a-Si layer 106 was formed on the n-type a-Si layer 105. After evacuating again, the SiH
₄ 50 sccm, BF ₃ / H ₂ (1% H ₂ dilution) 50 sccc
m, H ₂ 500 sccm was introduced, the opening degree of the throttle valve was adjusted, the internal pressure of the reaction vessel was maintained at 1 Torr, and when the pressure was stabilized, 3 Hz was immediately supplied from the high frequency power supply.
The power of 00W was turned on. The plasma was maintained for 2 minutes. As a result, the p-type μc-Si layer 107 becomes i-type a-Si
Formed on layer 106. Thereby, the transparent resistance layer 103
The semiconductor layer 104 was formed thereon. The sample on which the semiconductor layer 104 has been formed is taken out of the high-frequency CVD apparatus,
Attached to the surface of the anode of the magnetron sputtering device, the surroundings of the sample were shielded with a stainless steel mask, and a 4.5 cm x 4.5 cm area of the central portion was formed from 10 wt% tin oxide and 90 wt% indium oxide. Sputtering was performed using a target. The deposition conditions were a substrate temperature of 200 ° C. and a flow rate of 50 s of argon as an inert gas.
ccm, oxygen gas 0.5sccm, pressure in the deposition chamber 3m
Torr, input power per unit area of target is 0.2 W / cm ² , thickness is 60 nm in about 100 sec.
The anti-reflection layer 108 is deposited on the semiconductor layer 1 so that
04 on the p-type μc-Si layer 107. The thickness of the film here was set to a predetermined thickness by previously calibrating the relationship with the film formation time under the same conditions and depositing the film. A silver paste is screen-printed on the anti-reflection layer 108 thus formed to form a current collecting electrode 109 in an area corresponding to 2% of the surface area of the anti-reflection layer, and an output terminal 110 is attached.
The protective resin 111 was bonded. Thus, a photoelectric conversion body having the configuration shown in FIG. 1 was obtained. This photoelectric converter is referred to as AM1.5 (1
When the characteristics were evaluated under light irradiation of 00 mW / cm ² ), an excellent photoelectric conversion efficiency of 9.4% was obtained. Further, the sample was subjected to an environmental test for 1000 hours in an environmental test box at a temperature of 85 ° C. and a humidity of 85%. As a result, there was no problem at all, only the photoelectric conversion efficiency was reduced by 0.02%.

[0020]

Embodiment 2 In a state where power is not supplied to one side 207 of the oxygen ion generation chamber and no discharge is generated, only the other side 206 of the oxygen ion generation chamber is used, and DC power is reduced to 40 W using an aluminum target. A photoelectric converter was produced in the same manner as in Example 1 except that the above conditions were satisfied. When the reflectance of the substrate on which the reflection layer and the transparent resistance layer were formed was measured by a spectrophotometer, the reflectance was 65% at the center value of the vibration due to interference at 800 nm. Further, the obtained photoelectric conversion body was identified as AM1.5.
When the characteristics were evaluated under light irradiation of (100 mW / cm ² ), the photoelectric conversion efficiency was 9.4%. Further, the sample was subjected to an environmental test for 1000 hours in an environmental test box at a temperature of 85 ° C. and a humidity of 85%. As a result, there was no problem at all, only the photoelectric conversion efficiency was reduced by 0.03%.

[0021]

Embodiment 3 In a state where no electric power is supplied to one of the oxygen ion generation chambers 206 and no discharge is generated, only another one of the oxygen ion generation chambers 207 is used, and DC power is supplied using a zinc oxide target. A photoelectric converter was produced in the same manner as in Example 1 except that the power was set to 80 W. When the reflectance of the substrate on which the reflection layer and the transparent resistance layer were formed was measured by a spectrophotometer, the reflectance was 64% at the center value of vibration caused by interference at 800 nm. Further, the obtained photoelectric conversion body was designated as AM1.5 (1
When the characteristics were evaluated under light irradiation of 00 mW / cm ² ), the photoelectric conversion efficiency was 9.3%. Further, the sample was placed in an environmental test box at a temperature of 85 ° C. and a humidity of 85%.
An environmental test was performed for 000 hours. As a result, there was no problem at all, only the photoelectric conversion efficiency was reduced by 0.02%.

[0022]

Comparative Example 1 Both oxygen ion generation chambers 206 and 207
The same amount of oxygen gas was supplied, but no DC power was supplied, and a photoelectric converter was produced in the same manner as in Example 1 except that the surface of the reflective layer was not exposed to oxygen ions. When the reflectance of the substrate on which the reflective layer and the transparent resistance layer were formed was measured by a spectrophotometer, the reflectance was 55% at the center value of vibration due to interference at 800 nm. The characteristics of the obtained photoelectric conversion body were evaluated under irradiation with light of AM 1.5 (100 mW / cm ² ). As a result, the photoelectric conversion efficiency was 8.2%. The photoelectric conversion body was found to have lower reflectance and lower photoelectric conversion efficiency than that of Example 1. This is probably because light was absorbed by the crystal grains of the aluminum film.

[0023]

COMPARATIVE EXAMPLE 2 DC power of the oxygen ion generation chamber 206 was reduced to 40
A photoelectric converter was produced in the same manner as in Example 1 except that the power was set to 0 W. When the reflectance of the substrate on which the reflection layer and the transparent resistance layer were formed was measured by a spectrophotometer, the reflectance was 51% at the center value of the vibration due to interference at 800 nm. When the obtained photoelectric conversion body was evaluated for characteristics under light irradiation of AM 1.5 (100 mW / cm ² ), the photoelectric conversion efficiency was 7.2%. The photoelectric conversion body was found to have lower reflectance and lower photoelectric conversion efficiency than that of Example 1. This is presumably because the target aluminum was sputtered and the oxidized aluminum film adhered to the film, which was more effective than the effect of keeping the reflectance of oxygen ions good.

[0024]

Comparative Example 3 A photoelectric converter was manufactured in the same manner as in Example 1 except that the supply of the argon gas to the gas gate 226 was stopped and the supply amount of the argon gas to the reflective layer forming chamber 205 was reduced to 5 sccm. The reflectance of the substrate on which the reflective layer and the transparent resistance layer were formed was measured with a spectrophotometer.
The reflectance was 49% at the center value of the vibration due to the interference of 0 nm. Further, the obtained photoelectric conversion body was AM 1.5 (100 m
W / cm ² ), the characteristics were evaluated under light irradiation.
The photoelectric conversion efficiency was 6.3%. The photoelectric conversion body was found to have lower reflectance and lower photoelectric conversion efficiency than that of Example 1. This is presumably because the aluminum film of the reflective layer was oxidized by the incorporation of oxygen. A gas was supplied to the gas gate to check how much oxygen was mixed, and a mixed gas of oxygen and argon was supplied from the gas supply pipe 230 to fabricate the transparent resistance layer.
ccm and the oxygen gas amount is 2 sccm, 4 sccm, 8
The reflectance at the time of changing to sccm was measured. Each reflectance is 63 at the center value of vibration due to 800 nm interference.
%, 61% and 47%. The reflectivity was remarkably reduced when oxygen was mixed at 4 sccm or more, that is, about 10% or more.

[0025]

Embodiment 4 In this embodiment, a photoelectric conversion element having the structure shown in FIG. 1 was manufactured by using a single-wafer in-line vacuum apparatus shown in FIG. 120 mm × 0.13 mm thick with bright annealed surface as substrate 101
Ten stainless steel substrates of 120 mm size were simultaneously placed in the load chamber 301 of the vacuum apparatus shown in FIG. 3 and evacuated until the pressure became 10 ⁻⁴ Torr or less. Thereafter, 30 sccm of argon gas is supplied as an inert gas from the gas supply pipes 315 and 317 to the reflection layer formation chamber 303 and the transparent resistance layer formation chamber 305, and the opening degree of the exhaust valve is adjusted in this state to adjust the pressure in the vacuum chamber. Was maintained at 3 mTorr. Oxygen gas is supplied to the oxygen ion generation chamber 304 from the gas supply pipe 316 at 10 sccm, and the pressure is set to 0.1 Torr.
Kept. After the gate valve 309 was opened and the substrate 302 was sent to the reflective layer forming chamber 303 and the pressure was stabilized, the following film formation was performed. Aluminum having a purity of 99.99% by weight and a size of 25 cm × 25 cm was used as a target 310 for forming a reflective layer, and a DC power of 400 W was applied for 90 seconds to form an aluminum reflective layer 102 having a thickness of about 200 nm. Substrate 30 on which reflective layer 102 is formed
2 was moved to the oxygen ion generation chamber 304 by opening the gate valve, and at the same time, the next substrate was moved from the load chamber 301 to the reflection layer formation chamber 303. A high frequency power of 13.56 MHz and 40 W was applied to the counter electrode 311 of the oxygen ion generation chamber 304, and the surface of the reflective layer was brought into contact with plasma containing an oxidizing gas for 90 seconds. The gate valve 309 was opened again and the substrate 302 was sent out to the transparent resistance layer forming chamber 305, and at the same time the subsequent substrate was moved. In the transparent resistance layer forming chamber 305, a DC power of 800 W was applied for 90 seconds using a zinc oxide target 308 having a purity of 99.99% by weight and a size of 25 cm × 25 cm. As shown in FIG. 3, three film formation chambers 305 under the same conditions were provided, and processing was performed in these film formation chambers under the above conditions, whereby a transparent resistance layer 103 having a thickness of about 1000 nm could be formed on the reflective layer 102. At this time, the temperature of the substrate was set to 250 ° C. by a heater unit 307 using an infrared lamp.
Was adjusted to Substrate 302 fabricated up to transparent resistance layer 103
Was collected in the unloading chamber 306. By repeating the above operation, a reflection layer and a transparent resistance layer were formed on nine substrates under the same conditions. A part of the substrate on which the reflective layer and the transparent resistance layer were formed was taken out, and the reflectance was measured with a spectrophotometer.
The reflectance was 66% at the center value of the vibration due to the interference of 0 nm. Subsequently, the three substrates on which the reflective layer and the transparent resistance layer were formed were cut into a size of 5 cm × 5 cm, and the semiconductor layer 104, the antireflection layer 108 and the current collecting electrode 109 were formed in the same manner as in Example 1. Then, an output terminal 110 and a protective resin 111 were provided. Thus, three photoelectric converter samples were obtained. The obtained photoelectric conversion body sample was subjected to AM1.5 (1
When the characteristics were evaluated under light irradiation of (00 mW / cm ² ), the photoelectric conversion efficiency was 9.4 ± 1%, which was excellent. Further, the three samples were subjected to an environmental test box of 85 ° C.
A time environmental test was performed. As a result, there was no problem at all, only the photoelectric conversion efficiency decreased by 0.01 to 0.02%.

[0026]

Comparative Example 4 A reflection layer and a transparent resistance layer were formed on one of the substrates set in the load chamber 301 in Example 4 under the same conditions as in Example 4 except that no high-frequency power in the oxygen ion generation chamber 304 was applied. did. That is, oxygen ion contact was not performed. The reflectance of the substrate on which the reflective layer and the transparent resistance layer were formed was measured by a spectrophotometer. The center value of the vibration caused by interference at 800 nm was 57%. Thereafter, the formation of the semiconductor layer and subsequent layers was performed in the same manner as in Example 4 to obtain a photoelectric conversion body. The obtained photoelectric converter was converted to AM1.5 (100
When the characteristics were evaluated under light irradiation of mW / cm ² ), the photoelectric conversion efficiency was 8.4%. It was found that the photoelectric conversion body had lower reflectance and lower photoelectric conversion efficiency than that of Example 4. This is probably because light was absorbed by the crystal grain boundaries of the aluminum film.

[0027]

By forming a reflective layer according to the present invention, the incident light is effectively used, the absorption of light into the semiconductor is increased, a high photoelectric conversion efficiency is exhibited, and there is little deterioration even during long-term continuous use. A photoelectric conversion body can be manufactured efficiently. The photoelectric converter is inexpensive and highly reliable, and can be effectively used for system power.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view schematically illustrating a configuration of an example of a thin-film photoelectric conversion body of the present invention.

FIG. 2 is a schematic view of an example of a vacuum device suitable for forming a reflection layer of the present invention.

FIG. 3 is a schematic view of another example of a vacuum device suitable for forming a reflective layer of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Substrate 102 Reflection layer 102 'Surface region of reflection layer subjected to oxygen ion contact treatment 103 Transparent resistance layer 104 Semiconductor layer having semiconductor junction 105 n-type layer 106 i-type layer 107 p-type layer 108 Anti-reflection layer 109 current collecting electrode 110 output Terminal 111 Protective resin 201 Sending-out chamber 202 Roll-shaped substrate 203 Guide roller 204 Strip-shaped substrate 205 Reflective layer forming chamber 206, 207 Oxygen ion generating chamber 208, 209 Transparent electrode layer forming chamber 210 Winding chamber 211 Winding reel 212 Steering roller 213 Paper roll 214 Reflective layer target 215,216 Glow discharge cathode electrode 217,218 Transparent resistance layer target 219-223 DC power supply 224,225 Substrate heater 226 Gas gate 227,228,229 Threshold plate 30 to 234 Gas introduction pipe 235 Magnet roller 301 Load chamber 302 Substrate 303 Reflection layer formation chamber 304 Oxygen ion generation chamber 305 Transparent electrode layer formation chamber 306 Unload chamber 307 Heater for substrate heating 308 Transparent resistance layer target 309 Gate valve 310 Reflection Layer target 311 Discharge counter electrode 312,314 DC power supply 313 High frequency power supply 315-317 Gas inlet tube

Claims (4)

[Claims] 1. A method for manufacturing a photoelectric conversion body by sequentially laminating a reflection layer, a transparent resistance layer and a semiconductor layer on a substrate,
A step of forming the reflective layer on the substrate, a step of contacting the formed reflective layer with oxygen ions, and a step of forming the transparent resistance layer on the reflective layer. The method for producing the photoelectric conversion body, wherein the method is performed continuously. 2. A method for manufacturing a photoelectric conversion body by sequentially laminating a reflection layer, a transparent resistance layer, and a semiconductor layer on a substrate,
As the reflective layer, a step of forming a layer made of aluminum or an aluminum-containing substance on the substrate by a sputtering method, a step of contacting the formed layer with oxygen ions, and zinc oxide as a main component on the layer. And a step of forming a layer to be formed as the transparent resistance layer by a sputtering method are continuously performed in a series of spaces, and mixing of oxygen gas from a space that is brought into contact with the oxygen ions into a film formation space of the reflective layer is performed. The method for producing the photoelectric conversion body, wherein the partial pressure of the gas is limited to 10% or less. 3. A step of contacting the reflective layer with oxygen ions, wherein one or both of a target mainly composed of aluminum or an aluminum-containing substance and a target mainly composed of zinc oxide are used as a cathode electrode; The method according to claim 2, wherein the method is performed by passing the substrate on which the reflective layer is formed through a space in which glow discharge is generated in an atmosphere containing oxygen gas. 4. An apparatus for manufacturing a photoelectric converter by sequentially laminating a reflective layer, a transparent resistance layer, and a semiconductor layer on a substrate,
Means for forming a reflective layer made of aluminum or an aluminum-containing substance on a substrate by a sputtering method, a target mainly containing aluminum or an aluminum-containing substance, and a target mainly containing zinc oxide, or both of them. Means for performing glow discharge in an atmosphere containing oxygen gas as a cathode electrode; means for passing the formed reflective layer through the glow means; and a substrate between the means for forming the reflective layer and the means for performing the glow discharge. A means for limiting mixing of oxygen gas into the means for forming the reflective layer, and means for forming a transparent resistance layer containing zinc oxide as a main component by a sputtering method. Body manufacturing equipment.