JP5962663B2 - Glass plate with transparent conductive film - Google Patents

Description

The present invention relates to a transparent conductive film-attached glass plate to form a transparent conductive film on the surface.

  The glass plate with a transparent conductive film is used as a glass substrate for a thin film solar cell, a low radiation glass plate (Low-E glass plate) and the like. Such a glass plate with a transparent conductive film usually requires high light transmittance.

  For example, a glass substrate for a thin film solar cell is required to have a sufficiently high visible light transmittance (hereinafter referred to as Tv) and solar radiation transmittance (hereinafter referred to as Te). For this reason, the glass plate serving as the base of the glass substrate for a thin-film solar cell has a highly transmissive glass plate (so-called white plate) made of soda-lime silica glass in which the content of coloring components (particularly iron) is extremely reduced and Tv and Te are increased. Glass) is used (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2007-1112710

By the way, in the glass plate with a transparent conductive film, Na ⁺ eluted over time on the surface of the glass plate causes thermal diffusion of Na ⁺ when producing the thin film solar cell element, thereby generating power from the thin film solar cell element. The properties of the layer are degraded. Therefore, an alkali barrier film containing SiO ₂ as a main component is provided between the glass plate and the transparent conductive film.

However, even if an alkali barrier film is provided, when a current flows through the transparent conductive film of the glass substrate for a thin-film solar cell for a long time, Na ⁺ contained in the glass plate is electrically attracted to the transparent conductive film, and Na ⁺ It was found that the phenomenon of diffusion to the surface of the alkali barrier film and peeling of the transparent conductive film occurred.

  The present invention provides a glass plate with a transparent conductive film and a glass plate for forming a transparent conductive film in which peeling of the transparent conductive film is suppressed.

The glass plate with a transparent conductive film of the present invention is a glass plate with a transparent conductive film having a glass plate and a transparent conductive film,
The glass plate is an oxide-based mass percentage display,
SiO _2: 68~75%,
Al ₂ O _3: 0~2.5%,
CaO: 0 to 15%,
MgO: 0 to 12%,
Na ₂ O: 5~20%,
K ₂ O: 0.8~5%,
SrO: 0 to 1%,
BaO: 0 to 1%,
_{K 2 O + SrO + BaO:} 1.1~7%,
Total iron in terms of Fe ₂ O _3: 0~0.06%,
Only including,
The glass plate has a volume resistivity (log (ρ [Ω · cm])) at 150 ° C. of 8.8 to 12.0 .
The glass plate with a transparent conductive film of the present invention is a glass plate with a transparent conductive film having a glass plate and a transparent conductive film,
The glass plate is an oxide-based mass percentage display,
SiO _2: 69~74%,
Al ₂ O ₃ : 0.3 to 2.3%,
CaO: 3 to 12%,
MgO: 1 to 10%,
Na ₂ O: 7~17%,
K ₂ O: 1.0~4.5%,
SrO: 0.1-0.8%
BaO: 0.1 to 0.8%,
_{K 2 O + SrO + BaO:} 1.5~6%,
Total iron in terms of Fe ₂ O ₃ : 0 to 0.05%,
It is characterized by including.

The volume resistivity (log (ρ [Ω · cm])) at 150 ° C. of the glass plate is preferably 8.8 to 12.0.
The maximum temperature (T _max ) at which film peeling does not occur in the DHB test described later is preferably 150 ° C. or higher.
The glass plate with a transparent conductive film of the present invention preferably has an alkali barrier film provided between the glass plate and the transparent conductive film .
The term “to” indicating the numerical range described above is used to mean that the numerical values described before and after it are used as the lower limit value and the upper limit value, and unless otherwise specified, “to” is the same in the following specification. Used with meaning.

  In the glass plate with a transparent conductive film of the present invention, peeling of the transparent conductive film is suppressed.

It is sectional drawing which shows an example of the glass plate with a transparent conductive film of this invention. It is sectional drawing which shows an example of a thin film solar cell. It is sectional drawing which shows an example of a multilayer glass.

<Glass plate with transparent conductive film>
The glass plate with a transparent conductive film of the present invention has a glass plate and a transparent conductive film, and preferably has an alkali barrier film provided between the glass plate and the transparent conductive film. Another film may be provided between the glass plate and the alkali barrier film, between the alkali barrier film and the transparent conductive film, and / or on the surface of the glass plate opposite to the transparent conductive film side.

  FIG. 1 is a cross-sectional view showing an example of a glass plate with a transparent conductive film of the present invention. The glass plate 10 with a transparent conductive film includes a glass plate 12, an alkali barrier film 14 formed on one surface of the glass plate 12, and a transparent conductive film 16 formed on the surface of the alkali barrier film 14.

(Glass plate for forming transparent conductive film)
The glass plate used as the base of a glass plate with a transparent conductive film has the following composition (I). The glass plate preferably has the following composition (II), more preferably has the following composition (III), and particularly preferably has the following composition (IV).
Hereinafter, in the present specification, the “glass plate for forming a transparent conductive film” is also simply referred to as “glass plate”. The glass plate with a transparent conductive film is referred to as a glass plate with a transparent conductive film.

(I) In mass percentage display based on the following oxides:
SiO _2: 60~75%,
Al ₂ O _3: 0~3%,
CaO: 0 to 15%,
MgO: 0 to 12%
Na ₂ O: 5~20%,
_{K 2 O + SrO + BaO:} 1.1~15%,
Total iron in terms of Fe ₂ O _3: 0~0.06%,
including.
(II) In mass percentage display based on the following oxides:
SiO _2: 68~75%,
Al ₂ O _3: 0~2.5%,
CaO: 0 to 15%,
MgO: 0 to 12%,
Na ₂ O: 5~20%,
K ₂ O: 0.8~5%,
SrO: 0 to 1%,
BaO: 0 to 1%,
_{K 2 O + SrO + BaO:} 1.1~7%,
Total iron in terms of Fe ₂ O _3: 0~0.06%,
including.

(III) In mass percentage display based on the following oxides:
SiO _2: 69~74%,
Al ₂ O ₃ : 0.3 to 2.3%,
CaO: 3 to 12%,
MgO: 1 to 10%,
Na ₂ O: 7~17%,
K ₂ O: 1.0~4.5%,
SrO: 0.1-0.8%
BaO: 0.1 to 0.8%,
_{K 2 O + SrO + BaO:} 1.5~6%,
Total iron in terms of Fe ₂ O ₃ : 0 to 0.05%,
including.

(IV) In mass percentage display based on the following oxides:
SiO _2: 69.3~73%,
Al ₂ O ₃ : 0.5 to 2.1%,
CaO: 5 to 10%,
MgO: 3-8%
Na ₂ O: 9~15%,
K ₂ O: 1.3~4.0%,
SrO: 0.2-0.7%
BaO: 0.2-0.7%,
_{K 2 O + SrO + BaO:} 2~5%,
Total iron converted to Fe ₂ O ₃ : 0 to 0.03%,
including.

The glass plate in the present invention is expressed in mass percentage on the basis of oxide, and the total content of K ₂ O, SrO and BaO is contained in ordinary soda lime silica glass (including ordinary high transmission glass plate). The total content is higher than the total content (for example, 0.4% or less in the case of a highly transmissive glass plate).

When the K / Na ratio increases, the volume resistivity of the glass plate increases due to the mixed alkali effect (that is, the electrical conductivity decreases). Also, the alkaline earth metal / Na ratio shows the same tendency as K / Na, and this tendency is particularly remarkable in the case of Sr and Ba having a large atomic radius. Thus, the content of K 2 _O (or K _{2 O,} the total content of SrO and BaO) is, the larger than normal soda-lime-silica glass (including normal high transmittance glass sheet.), A glass plate Since the volume resistivity is high (that is, the electric conductivity is low), even if a current flows through the transparent conductive film of the glass plate with a transparent conductive film for a long time, Na ⁺ contained in the glass plate is electrically transparent. It becomes difficult for the film to be attracted to the film, and it becomes difficult for Na ⁺ to diffuse to the surface of the alkali barrier film. Therefore, peeling of the transparent conductive film from the alkali barrier film can be suppressed.

The content of K ₂ O is 0 to 5% in terms of an oxide-based mass percentage. When the content of K ₂ O exceeds 5%, the raw material cost is remarkably increased, or the viscosity at high temperature is increased and the solubility is deteriorated. The content of K ₂ O is expressed in terms of mass percentage based on oxide, and is preferably 1.1 to 4.5%, more preferably 1.3 to 4.0%.

  The content of SrO is 0 to 5% in terms of oxide based mass percentage. When the content of SrO exceeds 5%, the devitrification characteristics (that is, the characteristics that devitrification hardly occurs at the time of forming the glass plate) are deteriorated. The SrO content is expressed in terms of mass percentage based on oxide, and is preferably 0 to 4%, more preferably 0 to 2%.

  The content of BaO is 0 to 5% in terms of mass percentage based on oxide. When the content of BaO exceeds 5%, the devitrification characteristics deteriorate. The content of BaO is an oxide-based mass percentage display, preferably 0 to 4.5%, more preferably 0 to 4%.

The total content of K ₂ O, SrO and BaO (hereinafter, this total amount is also referred to as “K ₂ O + SrO + BaO” in this specification) is 1.1 to 15% in terms of oxide based mass percentage. It is. When K ₂ O + SrO + BaO is less than 1.1%, peeling of the transparent conductive film from the alkali barrier film cannot be sufficiently suppressed. If K ₂ O + SrO + BaO exceeds 15%, the liquidus temperature rises and the possibility that the devitrification characteristics deteriorate is increased. K ₂ O + SrO + BaO is an oxide-based mass percentage display, preferably 1.4 to 13%, more preferably 1.4 to 12%.

Fe ₂ O ₃ is a coloring component inevitably mixed in production.
The total iron content converted to Fe ₂ O ₃ is 0% to 0.06% in terms of oxide based mass percentage. If the total iron content converted to Fe ₂ O ₃ is 0.06% or less, a decrease in Tv can be suppressed. The total iron content converted to Fe ₂ O ₃ is expressed in terms of mass percentage based on oxides, and is preferably 0 to 0.05%, more preferably 0 to 0.03%. In particular, by making the total iron content 0.01% or less, it becomes easy to make the Te (plate thickness 4 mm equivalent) of the glass plate 90% or more, and the Tv (plate thickness) of the glass plate. 4 mm thickness conversion) is preferably 90% or more, which is preferable.

In the present specification, the total iron content is expressed as the amount of Fe ₂ O ₃ according to the standard analysis method, but not all iron present in the glass is present as trivalent iron. Usually, divalent iron is present in the glass. Divalent iron has an absorption peak mainly in the vicinity of a wavelength of 1000 to 1100 nm, absorption also at a wavelength shorter than a wavelength of 800 nm, and trivalent iron has an absorption peak mainly in the vicinity of a wavelength of 400 nm. An increase in divalent iron results in an increase in absorption in the near-infrared region of around 1000 nm, and when this is expressed in Te, it means that Te decreases. Therefore, when paying attention to Tv and Te, by suppressing the content of total iron converted to Fe ₂ O ₃ , the decrease in Tv can be suppressed, and trivalent iron can be increased more than divalent iron. Suppresses the decline. Therefore, Tv, in terms of suppressing the decrease of Te, reduce Zentetsuryou, mass percentage of divalent iron in terms of _Fe 2 _{O 3} in the total iron in terms of _Fe 2 _{O 3} (hereinafter referred to as Redox. ) Is preferably kept low.

  The Redox in the glass plate is preferably 35% or less. If Redox is 35% or less, a decrease in Te can be suppressed. The Redox is more preferably 30% or less.

SiO ₂ is a main component of glass.
The content of SiO ₂ is 60 to 75% in terms of mass percentage based on oxide. When the content of SiO ₂ is less than 60%, the stability of the glass is lowered. If the content of SiO ₂ exceeds 75%, the melting temperature of the glass rises and there is a possibility that it cannot be melted. The content of SiO ₂ is preferably 62 to 73% and more preferably 62 to 72% in terms of mass percentage based on oxide. Further, the content of SiO ₂ may be 68 to 75%, preferably 69 to 75%, and more preferably 69.3 to 73%.

Al ₂ O ₃ is a component that improves weather resistance.
The content of Al ₂ O ₃ is 0 to 3% in terms of mass percentage based on oxide. When the content of Al ₂ O ₃ exceeds 3%, the solubility is remarkably deteriorated or the volume resistance is too low. The content of Al ₂ O ₃ is an oxide-based mass percentage display, preferably 0 to 2.8%, more preferably 0 to 2.5%. Further, the content of Al ₂ O ₃ may be 0.3 to 2.3%, preferably 0.5 to 2.1%.

CaO is a component that promotes melting of the glass raw material and adjusts viscosity, thermal expansion coefficient, and the like.
The content of CaO is 0 to 15% in terms of oxide based mass percentage. When the content of CaO exceeds 15%, the devitrification temperature increases. The content of CaO is an oxide-based mass percentage display, preferably 3 to 12%, more preferably 3 to 11%. Further, the content of CaO may be 5 to 10%.

MgO is a component that promotes melting of the glass raw material and adjusts viscosity, thermal expansion coefficient, and the like.
The content of MgO is 0 to 12% in terms of mass percentage based on oxide. When the content of MgO exceeds 12%, the devitrification temperature increases. The content of MgO is preferably 2 to 12% and more preferably 2 to 6% in terms of mass percentage based on oxide. Further, the content of MgO may be 1 to 10%, preferably 3 to 8%.

Na ₂ O is an essential component that promotes melting of the glass raw material.
The content of Na ₂ O is 5 to 20% in terms of mass percentage based on oxide. When the content of Na ₂ O is less than 5%, it becomes difficult to dissolve the glass raw material. When the content of Na 2 _O exceeds 20%, weather resistance and stability of the glass plate may be deteriorated. The content of Na ₂ O is 7% to 19% and more preferably 9% to 17% in terms of mass percentage based on oxide. Further, the content of Na ₂ O may be 9 to 15%.

The glass plate of the present invention is not essential, but may further contain TiO ₂ , ZrO ₂ , Li ₂ O, and B ₂ O ₃ .
When TiO ₂ is contained, the content of TiO ₂ is preferably expressed as a percentage by mass on the oxide basis and is preferably 0 to 2%. When the content of TiO ₂ exceeds 2%, the glass plate is colored, Tv and Te decreases.

ZrO ₂ is a component that improves the chemical durability of glass and improves physical strength such as elastic modulus and hardness.
When ZrO ₂ is contained, the content of ZrO ₂ is preferably 0 to 3% in terms of oxide-based mass percentage. When the content of ZrO ₂ exceeds 3%, the melting characteristics deteriorate, and the devitrification temperature increases.

Li ₂ O is a component that promotes melting of the glass raw material and lowers the melting temperature.
If Li ₂ O is contained, the content of Li ₂ O, by mass percentage based on oxides, 0 to 3%. When the content of Li ₂ O exceeds 3%, the stability of the glass deteriorates. Moreover, raw material cost will rise remarkably.

B ₂ O ₃ is a component that promotes melting of the glass raw material, but when added to soda lime silica glass, there are many disadvantages such as generation of striae due to volatilization and furnace wall erosion, which is not suitable for production. .
When B ₂ O ₃ is contained, the content of B ₂ O ₃ is preferably 1% or less, more preferably substantially not contained, in terms of a mass percentage based on the oxide. Here, “substantially not contained” means that an amount of impurities may be mixed.

The glass plate preferably contains SO ₃ used as a fining agent. The total sulfur content converted to SO ₃ is expressed in terms of mass percentage based on oxide, and is preferably 0.01 to 0.5%. If the total sulfur content converted to SO ₃ exceeds 0.5%, reboyl is generated in the process of cooling the molten glass, and the foam quality may be deteriorated. If the total sulfur content converted to SO ₃ is less than 0.01%, a sufficient clarification effect cannot be obtained. The total sulfur content in terms of SO ₃ is expressed in terms of mass percentage on an oxide basis, more preferably 0.05 to 0.5%, and still more preferably 0.2 to 0.4%.

The glass plate may contain SnO ₂ used as a fining agent. The content of total tin converted to SnO ₂ is expressed in terms of mass percentage based on oxide, and is preferably 0 to 1%. Further, the surface layer of the glass substrate cullet with a transparent conductive film glass SnO ₂ film is laminated may be used as the glass raw material of SnO ₂ component as a transparent electrode material.

The glass plate may contain Sb ₂ O ₃ used as a fining agent. The content of all antimony converted to Sb ₂ O ₃ is preferably 0 to 0.5%. If the content of all antimony converted to Sb ₂ O ₃ exceeds 0.5%, the glass plate after forming becomes cloudy in the float method. The content of all antimony converted to Sb ₂ O ₃ is expressed by mass percentage based on oxide, and is preferably 0 to 0.1%.

Glass plate is colored _components, S, NiO, MoO _{3, CoO,} preferably contains no _{Cr 2 O 3, V 2 O} 5, or MnO substantially. Substantially free of S, NiO, MoO ₃ , CoO, Cr ₂ O ₃ , V ₂ O ₅ , or MnO means that S, NiO, MoO ₃ , CoO, Cr ₂ O ₃ , V ₂ O ₅ , or It means that MnO is not contained at all or S, NiO, MoO ₃ , CoO, Cr ₂ O ₃ , V ₂ O ₅ , and MnO may be included as impurities inevitably mixed in production. If S, NiO, MoO ₃ , CoO, Cr ₂ O ₃ , V ₂ O ₅ , or MnO is not substantially contained, a decrease in Tv and Te can be suppressed.

Te of the glass plate (4 mm thickness conversion, that is, the glass plate thickness is converted to 4 mm) is preferably 80% or more, and more preferably 82.7% or more. Te is the solar radiation transmittance calculated by measuring the transmittance with a spectrophotometer according to JIS R 3106 (1998) (hereinafter simply referred to as JIS R 3106).
Further, when the content of Fe ₂ O ₃ which is a coloring component in the composition is 0.01% or less, Te (4 mm thickness conversion) is preferably 90% or more, 91% or more, more preferably 91.5%. The above is more preferable.

Tv (4 mm thickness conversion) of the glass plate is preferably 80% or more, and more preferably 82% or more. Tv is the visible light transmittance calculated by measuring the transmittance with a spectrophotometer in accordance with JIS R 3106. As the coefficient, the standard light A and the value of the 2-degree visual field are used.
Further, when the content of Fe ₂ O ₃ which is a coloring component in the composition is 0.01% or less, Tv (4 mm thickness conversion) is preferably 90% or more, and more preferably 91% or more.

The volume resistivity (log (ρ [Ω · cm])) at 150 ° C. of the glass plate is preferably 9.0 to 12, and more preferably 9.1 to 12. If the volume resistivity at 150 ° C. of the glass plate is 9.0 or more, peeling of the transparent conductive film from the alkali barrier film can be more reliably suppressed. Similarly, the volume resistivity (log (ρ [Ω · cm])) at 200 ° C. of the glass plate is preferably 7.8 to 12, and more preferably 7.9 to 11. If the volume resistivity at 200 ° C. of the glass plate is 7.8 or more, peeling of the transparent conductive film from the alkali barrier film can be more reliably suppressed.
Here, the volume resistivity of the glass plate is measured by a method based on ASTM C657-78.

A glass plate is manufactured through the following process (i)-(V) in order, for example.
(I) Various glass matrix composition raw materials, cullet, fining agent, etc. are mixed so as to obtain a target composition to prepare glass raw materials.
(Ii) A glass raw material is melted to obtain molten glass.
(Iii) After the molten glass is clarified, it is formed into a glass plate having a predetermined thickness by a float method or a downdraw method (fusion method).
(Iv) Cool the glass plate.
(V) A glass plate is cut into a predetermined size.
In addition, after the said process (iii), the process (iii-1) of forming an alkali barrier film on the glass plate surface is added, and the process of forming a transparent conductive film on the alkali barrier film surface of this glass plate (iii- 2) may be added. By adding these steps (iii-1) and (iii-2), a glass plate with a transparent conductive film can be produced online using a glass plate production process.

Examples of the glass matrix composition raw material include those used as raw materials for ordinary soda lime silica glass, such as silica sand, dolomite, and soda ash.
Examples of the clarifying agent include SO ₃ , SnO ₂ , and Sb ₂ O ₃ .

  The glass raw material is melted, for example, by continuously supplying the glass raw material to a glass melting furnace (melting kiln) and heating to about 1300 to 1600 ° C. with heavy oil, gas, electricity, or the like.

The glass plate with a transparent conductive film is formed by forming a transparent conductive film on the surface of the glass plate manufactured as described above, or by forming an alkali barrier film on the surface of the glass plate manufactured as described above. It is manufactured by forming a transparent conductive film on the surface. Moreover, in the manufacturing process (i)-(V) of an above described glass plate, the above-mentioned alkali barrier film formation process (iii-1) was added, and the alkali barrier film surface of the manufactured glass plate surface with an alkali barrier film was manufactured. A transparent conductive film may be formed on the substrate. Moreover, the glass plate with a transparent conductive film is manufactured by adding the process (iii-2) of forming a transparent conductive film on the alkali barrier film surface after the alkali barrier film forming process (iii-1). Also good.
(Transparent conductive film)
Examples of the transparent conductive film include a film mainly composed of SnO ₂ , a film mainly composed of ZnO, and a film mainly composed of tin-doped indium oxide (ITO). A film containing SnO ₂ as a main component is preferable from the viewpoint of a material having little influence on the power generation layer when components are mixed into the power generation layer. Here, the “main component” means that the component is contained in 90% or more in terms of oxide based mass percentage.

Examples of the film containing SnO ₂ as a main component include a film made of SnO ₂ , a film made of fluorine-doped tin oxide (FTO), and a film made of antimony-doped tin oxide.
Examples of the method for forming the transparent conductive film include a thermal decomposition method, a CVD method, a sputtering method, a vapor deposition method, an ion plating method, and a spray method.
The thickness of the transparent conductive film is preferably 200 to 1200 nm.

(Alkali barrier film)
As the alkali barrier film, a film containing SiO ₂ as a main component, a film containing a mixed oxide of SiO ₂ and SnO ₂ as a main component, a multilayer film of SiO ₂ and SnO ₂ , Al ₂ O ₃ , ZrO ₂ , or SiOC And the like. Here, the “main component” means that the component is contained in 90% or more in terms of oxide based mass percentage.

Examples of the method for forming the alkali barrier film include a thermal decomposition method, a CVD method, a sputtering method, a vapor deposition method, an ion plating method, and a spray method.
The thickness of the alkali barrier film is preferably 10 nm or more from the viewpoint of alkali barrier performance, and is preferably 500 nm or less from the viewpoint of cost.

(Other membranes)
Examples of other films that may be provided between the glass plate and the alkali barrier film include a TiO ₂ film and a SnO ₂ film.
Examples of other films that may be provided between the alkali barrier film and the transparent conductive film include mixed oxides of SiO ₂ and SnO ₂ and multilayer films.
Examples of other films that may be provided on the surface of the glass plate opposite to the transparent conductive film include an antireflection film.
Other films themselves may have alkali barrier performance.

In the glass plate with a transparent conductive film of the present invention described above, the content of K ₂ O is 0.8% or more in terms of oxide based mass percentage, and K ₂ O, SrO and BaO. Since the total content of is 1.1% or more in terms of mass percentage based on oxide, the volume resistivity of the glass plate is increased (that is, the electrical conductivity is decreased). As a result, even if a current flows through the transparent conductive film of the glass plate with the transparent conductive film for a long time, Na ⁺ contained in the glass plate is not easily attracted to the transparent conductive film, and Na ⁺ is the surface of the alkali barrier film. Difficult to diffuse. Therefore, peeling of the transparent conductive film can be suppressed.
The content of total iron in terms of _Fe 2 _{O 3} is, as represented by mass percentage based on oxides, since a 0-0.06%, Tv becomes sufficiently high.

<Thin film solar cell>
The glass plate with a transparent conductive film of the present invention is suitable as a glass substrate for a thin film solar cell.
FIG. 2 is a cross-sectional view showing an example of a thin film solar cell. In the thin film solar cell 20, a thin film solar cell element 22 is formed on one surface of a glass plate 12 via an alkali barrier film 14. An antireflection film (not shown) or the like may be provided on the other surface of the glass plate 12 (that is, the surface opposite to the surface on which the thin film solar cell element 22 is formed).
The glass plate with a transparent conductive film of the present invention can be suitably used for all thin film solar cells in which a transparent conductive film is provided on a glass plate such as a thin film silicon solar cell and a CdTe thin film solar cell.

The thin film solar cell element 22 includes a transparent electrode layer 24, a photoelectric conversion layer 26 (that is, a power generation layer), and a back electrode layer 28 in order from the glass plate 12 side.
The transparent electrode layer 24 is a layer made of the transparent conductive film 16 described above.
The photoelectric conversion layer 26 is a layer made of a thin film semiconductor. Examples of the thin film semiconductor include an amorphous silicon semiconductor, a microcrystalline silicon semiconductor, a compound semiconductor (for example, chalcopyrite semiconductor, CdTe semiconductor, etc.), an organic semiconductor, and the like.
Examples of the material for the back electrode layer 28 include materials that do not transmit light (for example, silver and aluminum) and materials that transmit light (for example, ITO, SnO ₂ , and ZnO).

<Multilayer glass>
Since the glass plate with a transparent conductive film of the present invention has Low-E (Low Emissivity, low radiation) performance, it can also be used as a Low-E glass plate.
FIG. 3 is a cross-sectional view showing an example of a multi-layer glass using a Low-E glass plate. The multilayer glass 30 includes two glass plates 12, a frame-like spacer 34 that is disposed at the periphery of the glass plate 12 so that a gap 32 is formed between the glass plates 12, the spacer 34, and the glass plate 12 and a sealing material (not shown) provided between the glass plate 12 and the glass plate 12 on the gap 32 side of the multilayer glass in order from the glass plate 12 side. A glass plate with a transparent conductive film provided with a film 16 is used. A low reflection film (not shown) or the like may be provided on the surface of the glass plate 12 on the side opposite to the gap 32 side.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to these examples.
[Examples 1-31]
Examples 2-31 are examples and Example 1 is a comparative example.
Each performance of the glass plate for transparent conductive film formation and the glass plate with a transparent conductive film was measured and determined as follows.

(Redox)
The amount of Fe ₂ O ₃ in the obtained glass plate is the total iron content (% = mass percentage) calculated by fluorescent X-ray measurement and converted to Fe ₂ O ₃ .
The amount of divalent iron in the glass plate required for the calculation of Redox was obtained by converting from the transmittance at a wavelength of 1000 nm obtained by transmittance measurement. Here, after subtracting the influence of reflection at a wavelength of 1000 nm as 8%, it was converted into an absorption coefficient, and the amount of divalent iron was quantified based on a calibration curve prepared in advance by a wet analysis method.

(Tv)
The obtained glass plate was polished to a thickness of 4 mm, and the visible light transmittance (Tv) defined by JIS R 3106 (by the A light source) was measured.

(Te)
The obtained glass plate was polished to a thickness of 4 mm, and the solar transmittance (Te) defined by JIS R 3106 was measured.

(Volume resistivity)
The volume resistivity of the glass plate was measured by a method based on ASTM C657-78. As the glass plate, a glass plate having a size of about 50 mm × 50 mm and optically polished on both sides to a thickness of about 4 mm was used. A metal Al film was formed on both surfaces of the glass plate by vapor deposition to form electrodes, and volume resistivity at 100 ° C., 150 ° C., and 200 ° C. was measured. Further, the volume resistance value at an arbitrary point is obtained by using the slope A and the intercept B obtained from the relationship between the volume resistivity (log (ρ [Ω · cm])) at each temperature and the reciprocal of absolute temperature (1 / T). It was calculated from the following prediction formula.
log (ρ [Ω · cm]) = A / T + B

(DHB test)
The ease of peeling of the transparent conductive film can be estimated by a Dump Heat Bias (DHB) type durability test (hereinafter referred to as a DHB test).
The DHB test is a test for simultaneously evaluating electrical and thermal attack on a test piece coated with a thin film. As shown in the following (1) to (4), a glass plate with a transparent conductive film (sample) is heated for a sufficient time until it is stabilized at a set temperature, and an electric field is simultaneously applied to the glass plate with a transparent conductive film. Is called.

(1) The sample was placed between two electrodes. The side where the transparent conductive film was not formed was brought into contact with the graphite electrode (anode), and the transparent conductive film side was brought into contact with the copper electrode (cathode) covered with aluminum. After heating to the set temperature, the voltage was maintained at 500 V and the voltage application time was maintained for 15 minutes.
(2) After cooling to room temperature, the transparent conductive film side of the sample was exposed to an atmosphere having a relative humidity of 100% for 1 hour to cause aggregation on the transparent conductive film side. The aggregation humidity and water temperature were 55 ° C., and the vaporization temperature was 50 ° C. ± 2 ° C.
(3) It was confirmed whether or not peeling of the transparent conductive film occurred on the surface of the sample on the transparent conductive film side. In addition, the presence or absence of peeling was defined as having occurred even if there was only one peeling portion that could be visually confirmed in the sample.
(4) A plurality of other samples prepared under the same conditions were prepared, and the test was performed three times for each set temperature. The temperature at which the sample transparent conductive film was peeled off was defined as T _max (° C.). It was judged that the higher the _Tmax , the more difficult the transparent conductive film was peeled for a long period of time (that is, the higher the durability).

The peeling mechanism at the interface between the alkali barrier film (SiO ₂ ) and the transparent conductive film (SnO ₂ ) is that Na ⁺ contained in the glass plate is applied with the glass plate side as the positive electrode and the transparent conductive film side as the negative electrode. It moves to the interface by the applied voltage, and the following reaction takes place at the interface, so that peeling occurs at the interface that is in close contact by Sn—O bonds.
1. Na ⁺ + e ⁻ → Na
2. H ₂ O + Na → NaOH + 1 / 2H ₂
3. 2H ₂ + SnO ₂ → Sn + 2H ₂ O

Production of the glass plates of Examples 1 to 31 was performed as follows.
Silica sand, other various glass matrix composition raw materials, and a clarifying agent (SO ₃ ) were mixed to prepare glass raw materials so as to have the compositions shown in Tables 1-1 to 1-5. The glass raw material was put in a crucible and heated in an electric furnace at 1500 ° C. for 3 hours to obtain molten glass. Molten glass was poured onto a carbon plate and cooled. Both surfaces were polished to obtain a glass plate having a thickness of 4 mm. About the glass plate, the transmittance | permeability was measured for every 1 nm using the spectrophotometer (the Hitachi, Ltd. make, U-4100), and Tv, Te, and the volume resistivity were calculated | required. The results are shown in Tables 1-1 to 1-5.

On the surface of the glass plate heated to 580 ° C., a TiO ₂ film having a thickness of 8 nm, an alkali barrier film made of SiO _{2 having} a thickness of 25 nm, and a transparent conductive film made of SnO _{2 having a} thickness of 550 nm were formed. A DHB test was conducted on the glass plate with a transparent conductive film. T _max is shown in Table 1. Here, the temperature at which the volume resistivity (log (ρ [Ω · cm])) at 150 ° C. is 8.8 is defined as the predicted T _max when the glass thickness is 4 mm, and is estimated using the above prediction formula. Indicates temperature.
In Tables 1-1 to 1-5, A [K] and B indicate an inclination A and an intercept B (non-dimensional) in obtaining the volume resistance value.

In Example 1 (corresponding to Example 5 of Patent Document 1) where the total content of K ₂ O + SrO + BaO is small, the temperature T _{max at} which peeling of the transparent conductive film occurs in the DHB test was low. On the other hand, in Examples 2-31, in which the total content of K ₂ O, SrO, and BaO is 1.1% or more in terms of oxide-based mass percentage, the temperature T at which peeling of the transparent conductive film occurs by the DHB test It was found that _max was increased to 160 ° C. or higher, and peeling of the transparent conductive film from the alkali barrier film was suppressed over a long period of time.

The glass plate with a transparent conductive film of the present invention is useful as a glass substrate for a thin film solar cell, a low emission glass plate (Low-E glass plate) and the like.
It should be noted that the entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2011-212265 filed on September 28, 2011 are incorporated herein as the disclosure of the present invention. .

10 Glass plate with transparent conductive film 12 Glass plate (Glass plate for forming transparent conductive film)
DESCRIPTION OF SYMBOLS 14 Alkali barrier film 16 Transparent electrically conductive film 20 Thin film solar cell 22 Thin film solar cell element 24 Transparent electrode layer 26 Photoelectric conversion layer 28 Back surface electrode layer 30 Multi-layer glass 32 Space | gap 34 Spacer

Claims (5)

A glass plate with a transparent conductive film having a glass plate and a transparent conductive film,
The glass plate is a mass percentage display based on the following oxide,
SiO _2: 68~75%
Al ₂ O _3: 0~2.5%
CaO: 0 to 15%
MgO: 0 to 12%
Na ₂ O: 5~20%
K ₂ O: 0.8 to 5%
SrO: 0 to 1%
BaO: 0 to 1%
_{K 2 O + SrO + BaO:} 1.1~7%
Total iron in terms of Fe ₂ O _3: 0~0.06%,
Only including,
The glass plate with a transparent conductive film, wherein the glass plate has a volume resistivity (log (ρ [Ω · cm])) at 150 ° C. of 8.8 to 12.0 . A glass plate with a transparent conductive film having a glass plate and a transparent conductive film,
The glass plate is a mass percentage display based on the following oxides,
SiO _2: 69~74%,
Al ₂ O ₃ : 0.3 to 2.3%,
CaO: 3 to 12%,
MgO: 1 to 10%,
Na ₂ O: 7~17%,
K ₂ O: 1.0~4.5%,
SrO: 0.1-0.8%
BaO: 0.1 to 0.8%,
_{K 2 O + SrO + BaO:} 1.5~6%,
Total iron in terms of Fe ₂ O ₃ : 0 to 0.05%,
Including, permeable transparent conductive film-attached glass plate. The glass plate with a transparent conductive film according to claim 2 , wherein a volume resistivity (log (ρ [Ω · cm])) at 150 ° C. of the glass plate is 8.8 to 12.0. The glass plate with a transparent conductive film according to any one of claims 1 to 3, wherein a maximum temperature (T _max ) at which film peeling does not occur in a DHB test is 150 ° C or higher.   The glass plate with a transparent conductive film as described in any one of Claims 1-4 which has an alkali barrier film provided between the said glass plate and the said transparent conductive film.

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