JPS61227945A - Electroconductive glass - Google Patents

Abstract

PURPOSE:To improve orientation of <200> crystal face of SnO2 film reducing the resistance of the film and to provide suitable glass for several display electrodes and electrode for solar cell by interposing an undercoating film consisting essentially of ZrO2 between a glass substrate and transparent electroconductive SnO2 film. CONSTITUTION:An electroconductive glass consists by interposing an undercoating film consisting essentially of ZrO2 (contg. >=60mol% ZrO2 and capable of contg. TiO2, CeO2, Al2O3, etc., in not exceeding 40mol% proportion) between a glass substrate (e.g. sodalime.silicate glass) and transparent electroconductive SnO2 film (pref. such SnO2 film contg. 0.3-2wt% F as dopant basing on SnO2). Said undercoating film is easy to cause crystal orientation, and crystallite of SnO2 growing thereon is oriented also depending upon the orientation of the undercoating film, improving the orientation of <200> crystal face and permitting reduction of resistance of the film.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to electrically conductive glass, particularly electrically conductive glass suitable for various display electrodes and solar cell electrodes.

"Prior art" Electrically conductive glass, which has a transparent conductive film formed on the surface of a transparent substrate such as a glass plate, is transparent in the visible light region and has electrical conductivity, and is used in transparent devices such as liquid crystal display elements and electrochromic display elements. Demand has been increasing in recent years as an electrode and also as a transparent electrode for solar cells. The materials for these transparent conductive films are mainly composed of indium oxide and tin oxide, with indium oxide containing Sn and tin oxide containing sb.
, y, etc. are added as impurities to lower the resistance.

"Problems to be Solved by the Invention" When using a transparent conductive film of electrically conductive glass as a transparent electrode for a solar cell, an electrode with as low resistance as possible is required in order to extract the potential difference generated at the pn junction without dropping it. Is required.

As a means of lowering the resistance of a transparent conductive film, there are various methods such as adding appropriate amounts of impurities to increase the carrier concentration, growing larger crystal grains that make up the thin film, reducing grain boundaries, and increasing the mobility of free electrons. Although various methods have been tried, generally speaking, when a thin film is formed on a glass substrate, even if the substrate temperature and film formation rate are controlled, it remains an amorphous film or (100
), (010), (111), etc., and there are limits to controlling the crystal grain size, especially the orientation of high-order plane indices. , lack of change.

``Means for solving the problem'' The inventor has focused on the above points and as a result of research, it has been found that if a thin film material that is easily crystallized even on a glass substrate is used as a base treatment film, growth will occur on it. It was found that tin oxide microcrystals largely depend on the grain size and crystal orientation of the underlying treatment film.

The present invention was invented based on this point, and provides an electrically conductive glass in which a transparent conductive tin oxide film containing tin oxide as a main component is formed on a sea glass substrate. (200) of the tin oxide film with a base treatment film mainly composed of zirconium oxide interposed between the layers.
The present invention provides an electrically conductive glass characterized by enhanced plane crystal orientation.

According to the present invention, it is possible to reduce the resistance by increasing the crystal orientation of the (200) plane of the tin oxide film.

(9) In the case of transparent electrodes for solar cells, selective orientation makes it possible to provide an appropriate uneven structure on the surface of the film, and its light trapping effect improves the power generation efficiency of amorphous silicon solar cells. It is thought that it is possible to measure the improvement of

In addition, as a result of improving the crystallinity, the grain boundary density of the transparent conductive film is reduced, and as a result, scattering of free electrons there is reduced and resistance can be lowered.

The present invention will be explained in more detail below.

FIG. 1 shows a cross-sectional view of the electrically conductive glass according to the present invention, where 1 is soda lime silicate glass;
Aluminosilicate glass Indicates a glass plate made of borosilicate glass, lithium aluminosilicate glass, quartz glass, and other various glasses, 2 is a transparent conductive tin oxide film whose main component is tin oxide, and 3 is a glass plate whose main component is zirconium oxide. The base treatment film as a component is shown.

In the present invention, the tin oxide film contains fluorine as a dopant in an amount of α3 to 3% by weight relative to tin oxide, particularly preferably a tin oxide film containing fluorine as a dopant in an amount of α3 to 2% by weight relative to tin oxide. sno2) film is used, and zirconium oxide (zirconium oxide) is used as the base treatment film.
Zr02)! Those containing S Omol 96 or more are used. In addition, other additive components such as titanium oxide (T102) and cerium oxide (
ceol), aluminum oxide (Auton), etc.
It can be added in an amount not exceeding 0 mol %.

The film thickness of such a base treatment film is such that it functions as a base treatment film for a transparent conductive tin oxide film, for example, as an alkali barrier coat on the surface of a glass plate, and also has the function of controlling the crystal orientation of the conductive tin oxide film. That is, the range of 501 to zooooX is suitable so that the crystal orientation of the (200) plane can be improved. In particular, it is particularly effective to increase the crystal orientation of the (200) plane of the conductive tin oxide film when the film has a thickness of 2OOU to 1aooX. In particular, as a base treatment film, Z
rO2 to 70 mo and TlO2 to 30 mo
A composition having a composition of b% is optimal.

Further, the thickness of the conductive tin oxide film is not particularly defined.

Note that the thicker the film, the lower the resistance according to the relationship R=p-τ (R is the area resistance, P is the specific resistance, and d is the film thickness).

In the electrically conductive glass of the present invention, a silicon oxide (Si02) film or the like may be formed as an alkaline earth metal coating on the glass substrate under the base treatment film, or a silicon oxide (Si02) film or the like may be formed on the upper layer of the conductive tin oxide film. A coating layer or an antireflection layer may also be formed.

In manufacturing the electrically conductive glass of the present invention, a base treatment film mainly composed of zirconium oxide is formed on a glass substrate by a vacuum evaporation method, a sputtering method, an ion blasting method, a CVD method, etc., and then , vacuum evaporation method, sputtering method, ion blating method, OVD method on the base treatment film.
A conductive tin oxide film doped with fluorine is formed using a method.

In particular, in order to form a tin oxide film with a preferable crystal grain size and crystal orientation, a suitable material, 111! The film method, substrate temperature, film forming speed, or oblique evaporation (it may be formed accordingly).

In particular, as a method for forming the base treatment film, the substrate temperature is heated to a certain degree with a sun ray, the content of ZrO2 or other derivatives is limited, and 9mB vacuum evaporation method, or ethoxyzirconium Å, methoxyzirconium Å , CVD using alkoxyzirconium such as floxyzirconium as raw material
law is preferred. In addition, a transparent conductive tin oxide film is subsequently formed on this base treatment film by the CVD method, and due to this base treatment, it has a % (200) ) A highly oriented film is formed.

"Function" Compared to the case where a transparent conductive tin oxide film is directly formed on a glass substrate, the electrically conductive glass of the present invention has the following characteristics: The variety of control of crystal grain size and crystal orientation of transparent conductive tin oxide films is expanding, and thin films with the low resistance and surface topography required as transparent conductive tin oxide films for solar cells are becoming available. Can be manufactured.

"Example" Example 1 79 Force (810*) [(800K) (D Fluka 9 A soda lime silicate glass substrate coated with a barrier coating was thoroughly washed, and an ICB was produced using the zrO! sintered body as a raw material.
By vacuum evaporation method, substrate temperature 350℃, Jll! Zr0 on the above silica film at film speed j, 2X/sec
After forming 4 films at 1500A, the film was heated at 540° C. for 10 minutes and was used as a base treatment film.

Furthermore, a tin oxide film containing 1 weight of fluorine as a dopant was formed on this base treatment film as a transparent conductive film using the CVD method. ! ! It was filmed.

When this sample was compared with a film formed directly on a glass substrate without using a base treatment film by X-ray diffraction, it was found that the tin oxide film formed on the ZrO2 base treatment film had a strong tendency to be oriented in the (200) plane. It was done.

Also, the resistivity is (5~y) x for those without a base treatment film.
The resistance value of Example 10 was as low as 2.5×10 −4 Ω− compared to io−4 Ω−2.

Example 2 A glass substrate coated with an alkali barrier coating (slo, ) film (aooX) was thoroughly washed and treated with 30 mol% Tie.

Using Zr0g sintered body containing as a raw material, by EB vacuum evaporation method, substrate temperature 350°C, film forming rate 1.2X / se
In c, a composite film of ZrO2 and TlO2> was formed on the silica film in a 10ooX film, and then heated at 540°C for 10 minutes, which was used as a base treatment film.

Furthermore, a 2000 μm tin oxide film containing 1 weight of fluorine as a dopant was formed as a transparent conductive film on this base treatment film by CVD method.

Comparing this sample with a film formed directly on a glass substrate without using a base treatment film by X-ray diffraction, it was found that ZrO2 and T
10! It was observed that the tin oxide film #1 formed on the base treatment film consisting of the composite film had a strong tendency to be oriented in the (200) plane.

In addition, the resistivity is 5 to 7X 10- for those without a base treatment film.
40・picture, whereas that of Example 2 is 'LOX1
It showed a low resistance value of 4Ω.

Example 3 A soda lime silicate glass substrate coated with an alkaline barrier coat of silica (810,) film (IIlooA) was thoroughly washed and coated with ZrO containing 30 mo'L% 0e02.
Using the 2 sintered body as a raw material, a 1sooX composite film of ZrO2 and 0e02 was formed on the silica film using the EB vacuum evaporation method at a substrate temperature of 350°C and a film forming rate of 1.2X/sea, and then 54011: The film heated for 10 minutes was used as a base treatment film. Furthermore, a Z o o o X film was formed as a transparent conductive film on this base treatment film by a CtVD method, as a tin oxide film containing 1% by weight of fluorine as a dopant.

Comparing this sample with a film formed directly on a glass substrate without using a base treatment film by X-ray diffraction, it was found that ZrO2 and C
It was observed that the tin oxide film formed on the base treatment film consisting of the OO- composite film had a strong tendency to be oriented in the (200) plane.

In addition, the resistivity is 5 to 7 x 1 for those without a base treatment film.
The country is 0-40, while that of Example B is 2.5.
XI Q-40・9 exhibiting low resistance value.

Example 4 A soda lime silicate glass substrate coated with an alkaline barrier coat of silica (SiOl) film (800X) was thoroughly cleaned and treated with Zr containing 40 mol% of A 1m os.
01 Using the sintered body as a raw material, Zr01 and Al! os composite membrane 100
After forming the 0X film, the film was heated at 540° C. for 10 minutes and was used as a base treatment film. Furthermore, a tin oxide film containing 1% by weight of fluorine as a dopant was formed on this base treatment film as a transparent conductive film using an OVD method to form a 200 ml Al! ! It was filmed.

Comparing this sample with a round film formed directly on a glass substrate without using a base treatment film by X-ray diffraction, it was found that the tin oxide film formed on the base treatment film, which is a composite film of ZrO2 and Mu1-03, was A strong tendency towards (200) plane orientation was observed.

Also, the resistivity is 5 to 7 x 10-4 for those without a base treatment film.
0.Country, whereas the one in Example 4! , aX10
It showed a low resistance value of 4Ω.

Example 5 Soda lime silicate glass coated with an alkaline barrier coat of silica (810,) film (800 μm), the substrate was thoroughly washed, T10 15 mob%, A12011
Using a ZrO2 sintered body containing 5 mol % as a raw material, I
By the CB vacuum evaporation method, the substrate temperature was 350°C and the film forming rate was 1.
ZrO2 and Tie on the silica film at 2 m/sea.
After forming a composite film of 03 and Al at 1500A, 54
The film heated at 0° C. for 10 minutes was used as a base treatment film. Further, on this base treatment film, a tin oxide film containing 1 weight of fluorine as a dopant was formed as a transparent conductive film in a thickness of 2000 μm by the CVN method.

Comparing this sample with a film formed directly on a glass substrate without using a base treatment film by X-ray diffraction, it was found that ZrO2 and T
It was observed that the tin oxide film formed on the base treatment film consisting of a composite film of 1O2 and Al, 03 had a strong tendency to be oriented in the (200) plane.

In addition, the resistivity is 5 to 7X 10- for those without a base treatment film.
40-m, whereas that of Example 5 is 2.4
It showed a low resistance value of 10-4Ω.

Example 6 A soda lime silicate glass substrate coated with an alkali barrier coat of silica (8101)l [(800μ) was thoroughly washed and treated with Ti01 15 mol%, 0@101
15 mobs, zrO including %! Using sintered body as raw material,
'ZrO2 was deposited on the silica film using the ICB vacuum evaporation method at a substrate temperature of 350°C and a film formation rate of 1.2 A/sea.
And T10! A composite film of 0eO1 and 0eO1 was formed at 1300A, and then heated at 540°C for 10 minutes, which was used as a base treatment film. Furthermore, a tin oxide film containing 1% by weight of fluorine as a dopant is deposited on this base treatment film as a transparent conductive film by OVD.
A 2,000-m thick film was formed by the method.

When this sample was compared with a film formed directly on a glass substrate without using a base treatment film by X-ray diffraction, it was found that zrO! and T
10! It was observed that the tin oxide film formed on the base treatment film consisting of a composite film of CeO2 and CeO2 had a strong tendency to be oriented in the (200) plane.

In addition, the resistivity is 5 to 7X 10- for those without a base treatment film.
'Ω・rust, whereas that of Example 6 is 2.3X1
It showed a low resistance value of 0-4Ω.

Example 7 A soda lime silicate glass substrate coated with an alkali/(rear coat) of silica (S10 snow) film (aooR) was thoroughly washed and coated with Co (1215 mol %, A14011).
5 Using a ZrO2 sintered body containing moITo as a raw material, I
By CB vacuum evaporation method, substrate temperature 350°C, film forming speed t
A composite film of ZrO2, CoO2, and M103 was formed at 1500X on the silica film at 2X/sec, and then heated at 540°C for 10 minutes, which was used as a base treatment film. Furthermore, as a transparent conductive film on this base treatment film,
A tin oxide film containing 1% by weight of fluorine as a dopant is
A 2000^ film was formed by the VD method.

Comparing this sample with a film formed directly on a glass substrate without using a base treatment film by X-ray diffraction, it was found that Zr01 and 0
It was observed that the tin oxide film formed on the base treatment film consisting of a composite film of 802 and A 1g 0S had a strong tendency to be oriented in the (200) plane.

Also, the resistivity is Fis ~ 7X 10 without a base treatment film.
""4Ω・i, whereas that of Example 7 is AOX
It showed a low resistance value of lo-4Ω・n.

"Effects of the Invention" The present invention provides that when forming a transparent conductive film mainly composed of tin oxide, the tin oxide film is 20
As seen in the preferential orientation to the 0) plane, the crystal grain size of the tin oxide film, The purpose is to control and diversify the crystal orientation, and in turn, realize a film with low resistance and surface shape required as a transparent conductive film for amorphous silicon solar cells.

[Brief explanation of the drawing]

FIG. 1 shows a cross-sectional view of the electrically conductive glass of the invention.

Claims (1)

[Scope of Claims] (1) In electrically conductive glass in which a transparent conductive tin oxide film containing tin oxide as a main component is formed on a glass substrate, zirconium oxide is added between the glass substrate and the transparent conductive tin oxide film. An electrically conductive glass characterized in that the crystal orientation of the (200) plane of a tin oxide film is enhanced by interposing a base treatment film containing as a main component. (2) 60 mo of zirconium oxide as a base treatment film
The electrically conductive glass according to claim 1, characterized in that a composite film containing 1% or more is used. (3) Additive to zirconium oxide is 40 mol
The electrically conductive glass according to claim 2, wherein titanium oxide, cerium oxide, and aluminum oxide are added alone or in combination in an amount not exceeding %. (4) The electrically conductive glass according to claim 1, wherein the base treatment film has a thickness of 50 Å to 2000 Å, preferably 200 Å to 1000 Å.