KR20120072237A - Composition of in-ga-si-zn based oxide - Google Patents

Abstract

PURPOSE: An In-Ga-Si-Zn oxide based composition for transparent electrodes is provided to have high permeability and high conductivity by controlling an atomic ratio of In-Ga-Si-Zn within an optimal range. CONSTITUTION: An In-Ga-Si-Zn oxide based composition for transparent electrode comprises indium(In), gallium(Ga), silicon(Si), zinc(Zn), and oxygen(O). An atomic ratio of (In+Ga)/(In+Ga+Si+Zn) is 15at.% or more and 85at.% or less. The indium - gallium - silicon - zinc oxide based composition is used for a transparent conductive film of an electronic device. The electronic device is a display device. A thickness of the transparent conductive film is greater than 0Å and less than 5,000Å.

Description

Indium-gallium-silicon-zinc oxide-based composition for transparent electrodes {Composition of In-Ga-Si-Zn based Oxide}

The present invention relates to a composition for manufacturing a transparent conductive thin film, and more particularly, to a transparent conductive oxide which can be used as a thin film having excellent transparency and conductivity by being coated on a material surface such as glass, ceramic, or plastic.

Transparent conductive thin films are most commonly used in liquid crystal displays (LCDs), plasma displays (PDPs), organic light emitting displays (OLEDs), and touch panels because they have high electrical conductivity and high visible light transmittance. Widely used in battery, antistatic and the like.

In order to prepare a transparent conductive thin film, indium tin oxide (ITO) doped with indium oxide (In ₂ O ₃ ) and tin oxide (SnO ₂ ) 3 to 10 wt% (wt%). There is this. Known methods for producing ITO membranes include spray, vacuum evaporation, sputtering and ion plating, and sputtering methods are most commonly used commercially.

The ITO film prepared by the above methods is not only excellent in transparency and conductivity, but also has excellent etching property and good adhesion to the substrate. However, indium is not only a scarce resource but also harmful to a living body, and may also cause nodule when sputtering an ITO target. Due to such scarcity of resources, human hazards, and nodule generation in sputtering, research on alternative materials that can reduce indium in ITO or replace ITO is needed.

In order to meet these needs, research on new transparent electrode materials has been carried out on tin oxide (FTO, ATO) doped with fluorine or antimony, zinc oxide (AZO, GZO, IZO) doped with aluminum or gallium or indium. It is becoming.

However, these alternative materials also suffer from problems such as high cost, and thus, there is an urgent need for research on a method of stably obtaining a transparent conductive thin film having high transparency and high conductivity in a more economical manner. .

The present invention is to solve the problems of the prior art as described above, more economically high transparency by controlling the atomic ratio of indium, gallium, silicon and zinc in an appropriate range in the oxide containing indium-gallium-silicon-zinc An object of the present invention is to provide an oxide-based composition having degree and high conductivity characteristics.

Indium-gallium-silicon-zinc oxide-based composition according to the present invention comprises indium (In), gallium (Ga), silicon (Si), zinc (Zn) and oxygen (O), and (In + Ga) / An atomic ratio of (In + Ga + Si + Zn) is contained at a ratio of 15 at% or more and 85 at.% Or less.

In addition, the present invention includes indium (In), gallium (Ga), silicon (Si), zinc (Zn), and oxygen (O), and includes (In + Ga) / (In + Ga + Si + Zn). An electronic device including a transparent conductive film formed of an indium-gallium-silicon-zinc oxide-based composition containing an atomic ratio of 15 at% or more and 85 at% or less is provided. Herein, the thickness of the transparent conductive film may be formed to be greater than 0 mm and less than 5,000 mm. The electronic device may be a display device such as a liquid crystal display, a plasma display, an organic light emitting display, a touch panel, or the like.

As described above, the thin film prepared by using the indium-gallium-silicon-zinc oxide-based composition of the present invention has a visible light transmittance of 80% or more, has excellent electrical conductivity, and has good adhesion with a substrate. Not only can be used as an electrode for OLED and touch panel, but also can be used for electromagnetic wave shielding material, heating element, solar cell, etc., so the industrial value is very high.

1 is an image obtained with a scanning electron microscope for a transparent conductive film (Example 2) made of indium-gallium-silicon-zinc oxide according to the present invention.
2 is an image obtained by a scanning electron microscope for a transparent conductive film (Example 7) made of indium-gallium-silicon-zinc oxide according to the present invention.
3 is a scanning electron microscope image of a cross section of a transparent conductive film (Example 2) made of indium-gallium-silicon-zinc oxide according to the present invention.

Indium-gallium-silicon-zinc oxide-based composition according to the present invention comprises indium (In), gallium (Ga), silicon (Si), zinc (Zn) and oxygen (O), and (In + Ga) / An atomic ratio of (In + Ga + Si + Zn) is contained at a ratio of 15 at% or more and 85 at.% Or less.

Such a transparent conductive film can be prepared using the indium-gallium-silicon-zinc oxide-based composition according to the present invention. For example, an oxide composite based on In ₂ O ₃ , Ga ₂ O ₃ , SiO ₂ , and ZnO is manufactured. After that, sputtering may be used to prepare a transparent conductive film. Here, in the oxide composite according to the present invention, for example, (1) In ₂ O ₃ , Ga ₂ O ₃ , SiO ₂ , and an appropriate amount of each of the ZnO oxide powders balance, and then mixed well to form a mixture, (2) The mixture may be prepared by pressing into a mold, forming a mixture, followed by heat treatment and sintering, and (3) sputtering the sintered target to form a film on a substrate. Hereinafter, the embodiment according to the present invention will be described in detail.

< Example > In - Ga - Si - Zn  Preparation of Oxide-Based Compositions and Transparent Conductive Materials

[Powder Mixing Conditions] As raw material powders, indium oxide (In ₂ O ₃ ) powder, gallium oxide (Ga ₂ O ₃ ) powder, silicon oxide (SiO ₂ ), and zinc oxide (ZnO) powder are shown in Table 1 below. Each of the appropriate amounts is added to the composition pot, and the ethanol is sufficiently filled in a pot made of polyethylene. Then, the mixture was mixed by a ball milling method for 24 hours using a zirconia (ZrO ₂ ) ball, and then the mixture was dried with sufficient stirring on a plate at a temperature of 120 ° C.

[Molding and Sintering Conditions] The dried powder powder thus dried was put into a mold, press-molded at a pressure of 300 Kg / cm 2, and sintered in air. The rate of temperature increase for sintering was 5 ° C./min and sintering was carried out at 1400 ° C. for 6 hours. Composition analysis of the molded body was carried out using an EPMA (electron probe microanalyzer) (see Table 1 for the element composition ratio of each component).

[Vacuum Deposition Conditions] Next, the above sintered body was deposited on a substrate by a vacuum deposition method. Here, a glass substrate was used as the substrate, and was performed at a gas pressure of 3 × 10 ⁻³ Torr with an RF power of 50 W, wherein a gas flow rate of arcon (Ar) was 40 sccm. The temperature of the substrate was performed at room temperature, and the film thickness was formed to be 2,000 kPa to 5,000 kPa.

[Evaluation Conditions] The composition of the transparent conductive film thus formed was measured using EPMA, and the results are shown in Table 3. The electrical conductivity of the transparent conductive film was measured using a four-point probe surface resistance meter on a film having a thickness of 3,000 kPa. In addition, the transparency measurement measured the transmittance | permeability at 550 nm with respect to the film of 3000 micrometers thickness. Physical properties of the transparent conductive film are shown in Table 4 below.

[Composition Analysis Results of Sintered Body ( atomic  %)]
division Elemental composition ratio (atomic%) In Ga Zn Si O (In + Ga) /
(In + Ga + Si + Zn) Example 1 13.58 17.94 15.42 0.00 53.06 67.02 Example 2 14.02 4.03 24.36 3.00 54.59 39.74 Example 3 8.61 8.12 16.60 4.00 62.67 44.81 Example 4 11.33 12.41 11.72 5.00 59.54 77.93 Remarks 5 9.10 9.00 27.25 0.00 54.65 39.91 Example 6 7.10 7.00 27.25 4.00 54.65 31.09 Example 7 2.05 12.03 27.37 3.00 55.54 30.98

Of target  Shrinkage (%): ( Sintered Volume - Sintered volume ) / Sintered Volume * 100 division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Shrinkage 42.75 20.49 28.79 27.25 19.43 34.85 36.99

Composition analysis result of thin film atomic  %)
division Elemental composition ratio (atomic%) In Ga Zn Si O (In + Ga) /
(In + Ga + Si + Zn) Example 1 13.38 14.40 13.92 0.00 58.30 66.62 Example 2 12.36 3.98 24.25 2.97 55.44 37.51 Example 3 8.54 7.82 16.54 3.95 63.15 44.39 Example 4 11.29 12.32 11.65 4.76 59.98 58.99 Remarks 5 9.09 8.87 27.02 0.00 55.02 39.92 Example 6 7.08 6.96 27.21 3.98 54.77 31.04 Example 7 2.01 11.86 26.86 2.98 56.29 31.73

Evaluation result of thin film division Transmittance (%)
(550 nm) resistance
(Ohm / □) XRD features Remarks Example 1 92 101 Amorphous Good adhesion Example 2 80 96 Amorphous Good adhesion Example 3 83 106 Amorphous Good adhesion Example 4 82 102 Amorphous Good adhesion Remarks 5 91 122 Crystalline Good adhesion Example 6 85 113 Crystalline Good adhesion Example 7 83 112 Crystalline Good adhesion

The dielectric glass prepared according to the present invention was analyzed using an X-ray diffraction analyzer and an electron microscope. As a result, Examples 1 to 4 were amorphous and Examples 5 to 7 were crystalline. As shown in Table 4, the transparent conductive thin film prepared by using the indium-gallium-silicon-zinc oxide-based composition belonging to the scope of the present invention exhibited an average visible light transmittance of 80% or more and an excellent electrical conductivity. Moreover, the adhesiveness with the board | substrate also showed favorable. For example, scanning electron microscope images of Examples 2 and 7 are shown in FIGS. 1 and 2, respectively, and in Example 2, the cross-sectional structure of the scanning electron microscope was confirmed by the scanning electron microscope. Could see.

As described above, the transparent conductive film formed of the indium-gallium-silicon-zinc oxide-based composition according to the present invention was found to have excellent transparency, conductivity, and adhesion to the substrate. A transparent conductive film having high transparency and high conductivity characteristics can be formed. The composition according to the present invention can be used as a transparent conductive film in display devices such as electronic devices, for example, liquid crystal displays, plasma displays, organic light emitting displays, touch panels, and the like, in addition to electromagnetic wave shielding materials, heating elements, solar cells, and antistatic devices. It can be used advantageously.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. Therefore, the embodiments of the present invention described herein are to be considered in descriptive sense only and not for purposes of limitation, and the scope of the present invention is shown in the appended claims rather than the foregoing description, and all differences within the equivalent scope of the present invention Should be interpreted as being included in.

Claims (4)

It contains indium (In), gallium (Ga), silicon (Si), zinc (Zn) and oxygen (O), and the atomic ratio of (In + Ga) / (In + Ga + Si + Zn) is 15 at% or more. And an indium-gallium-silicon-zinc oxide-based composition, which is contained at a ratio of 85 at% or less.
It contains indium (In), gallium (Ga), silicon (Si), zinc (Zn) and oxygen (O), and the atomic ratio of (In + Ga) / (In + Ga + Si + Zn) is 15 at% or more. And a transparent conductive film formed of an indium-gallium-silicon-zinc oxide-based composition, which is contained at a rate of 85 at% or less.
The method of claim 2,
The electronic device includes a transparent conductive film formed of an indium-gallium-silicon-zinc oxide-based composition, characterized in that the display device.
The method of claim 2,
And the thickness of the transparent conductive film is greater than 0 mm and less than 5,000 mm.

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