JPS60220507A - Transparent conductive film and method of forming same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a transparent conductive film that can be used primarily in the electronics industry and a method for forming the same.

2. Description of the Related Art Conventional Structures and Problems There has been an increase in demand for transparent conductive films as important constituent materials for various display elements, solar cells, input devices, etc. in recent years.

As the material fl of this material, oxides such as indium and tin-cadmium have been conventionally used and have good electrical conductivity and visible light transmittance.

In particular, an indium oxide thin film doped with tin as an impurity has high electrical conductivity and visible light transmittance, and accounts for the majority of transparent conductive films.
Vacuum deposition method, CVD method.

Spraying methods and coating methods are known, but the coating method is particularly advantageous in terms of mass productivity.

Furthermore, the coating method is expected to enable the formation of patterned marks 111 of a transparent conductive film, and is considered to be a promising formation method in the future.

Conventionally, as a coating solution for forming a transparent electrode film, indium nitrate, tin halide, tin nitrate, etc. were mixed in water, a carbo tank, etc.
Indium naphthenate and tin octylate dissolved in toluene, indium chloride dissolved in alcohol, indium alkoxide and tin alkoxide dissolved in alcohol &? [Indium acetylacetonate dissolved in acetylacetone and acetone, etc.]
Many materials are used, and a transparent conductive film is obtained by applying these materials to a substrate and baking them.

Usually, the cheapest and most commonly used substrate for forming a transparent conductive film is a soda lime glass plate.

This material has a softening point of about 550°C to 700°C, so the firing temperature in the coating method is 660°C.
However, with the above coating liquid, the transparent conductive film obtained by firing in this temperature range has a high specific resistance, a weak film strength, and a large fluctuation in resistance value. There were drawbacks such as difficulty.

Purpose of the Invention The present inventor has discovered that in polycrystalline semiconductors such as indium oxide thin films, the degree of sintering and the density of the material are factors that determine the electrical conductivity and mechanical strength, and that it is usually difficult to sinter. Focusing on the fact that sintering aids are used to sinter polycrystalline ceramics at low temperatures, we developed high conductivity and mechanical properties that cannot be obtained with conventional coating solutions for forming transparent filter membranes. The purpose of the present invention is to provide a transparent conductive film that has high physical strength and small fluctuations in conductivity.

Structure of the Invention To achieve this object, the transparent electrode film of the present invention is produced by dispersing at least one of fine powders of indium oxide and tin oxide in a liquid obtained by dissolving an indium compound and a soot compound in a solvent. The method for forming the coating liquid is to apply the coating liquid to a substrate and then to bake it.

Description of examples The present invention will be explained below with reference to Examples.

(Example 1) To 100 g of a solution mixed with composition A as shown below, o and o19 of indium oxide pulverized to a particle size of 1 pm or less are added and dispersed.

This liquid is applied to a soda lime glass plate using a spin coater. At this time, the coating film had dot-like unevenness, but by holding it in the atmosphere at 500° C. for 60 minutes, a uniform transparent conductive film was formed. The resistivity of this transparent conductive film was 9.5 to 10.5×1o-3Ω.

On the other hand, when we applied a method of rubbing the membrane with a diamond tip under a load of 50 g and evaluating the strength by the number of times the membrane was cut, we found that the strength of the membrane was evaluated by the number of times the membrane was cut.
Amputated.

(Example 2) For 100 g of a solution with the same composition as in Example 1, particle size 1/
Add and disperse 0.019 stannic oxide pulverized to 1 m or less. This is spin-coated (on 11 machines) on a litho-lime glass plate and held in the atmosphere at 500°C for 60 minutes to form a transparent conductive film of r11/cm.The resistivity of this material is 1 to 1. When the strength was evaluated using a 6×10 −2 Ω pan in the same manner as in Example 1, the membrane was broken after 21 to 26 cycles.

(Example 3) For 100g of solution mixed with the following composition, particle size 1/
Add 0.007 g of indium oxide crushed to 1 ML or less and disperse.

This liquid is applied to a soda lime glass plate using a spin coater. This was held at 500°C in the atmosphere for 60 minutes,
A transparent conductive film was obtained. The resistivity of this material is 9 to 10.2
When the film strength was evaluated using the same method as in Example 1, the film was cut after 25 to 32 times.

(Example 4) In solution 1009 with the same composition as in Example 3, a particle size of 171 m was added.
To the following, 0.004 g of pulverized indium oxide and 77 g of the same stannic oxide were added and dispersed. This 'e is applied to Norda 100 group glass using a spin coater. This was held in the atmosphere at 500°C for 60 minutes to obtain a transparent conductive film. The resistivity of this is 9.2~1
0. It was I x 10 Ω. When the same strength evaluation as in Example 1 was carried out, the membrane was cut after 24 to 29 times.

(Comparative Example) Composition A in Examples and liquids having compositions were applied to a soda lime glass plate using a spin coater, and transparent conductive films were obtained in the same manner as in Examples. These resistivities range from 1.7 to 2.6
When the same strength evaluation as in Example 1 was carried out using the X10-2Ω process, the membrane was cut after 10 to 14 cycles.

Effects of the Invention As is clear from the above explanation, the transparent conductive film of the present invention and the method for forming the same can produce a transparent conductive film with higher conductivity and greater strength by containing fine powders of indium oxide and tin oxide. Obtainable.

Claims (2)

[Claims] (1) A transparent conductive material characterized by using a coating liquid in which at least one of fine powders of indium oxide and tin oxide is dispersed in a liquid obtained by dissolving an indium compound and a tin compound in a solvent. film. (2) A coating solution is prepared by dispersing at least one of fine powders of indium oxide and tin oxide in a solution obtained by dissolving an indium compound and a tin compound in a solvent, and this coating solution is applied onto a substrate. A method for forming a transparent conductive film, which comprises applying the film to a transparent conductive film and then firing the film.