KR101924070B1 - Highly conductive flexible transparent electrodes based lanthanoid doping and method for manufacturing thereof - Google Patents

Abstract

The present invention relates to a highly conductive transparent electrode based on lanthanide doping and a method of manufacturing the same. More specifically, the present invention relates to a substrate; And an amorphous thin film formed on the substrate and doped with a lanthanide material locally distributed in the nanocrystal dot; And a method for manufacturing the same. BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a lanthanum-based material doping- The present invention can provide a highly conductive, transparent electrode having flexibility and electrical properties applicable to flexible or wearable devices.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a high conductivity conductive transparent electrode based on lanthanide doping and a method of manufacturing the same. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to a highly conductive transparent electrode based on lanthanide doping and a method of manufacturing the same.

Transparent electrodes are being applied as important elements in display devices such as OLEDs, flexible displays and touch panel devices as well as optical devices such as LEDs and solar cells due to inherent characteristics with high conductivity while passing light . An amorphous oxide semiconductor is used for the transparent electrode to be applied to such a photoelectric device, and is typically an indium-tin oxide (ITO) based oxide semiconductor doped with indium oxide and tin oxide.

ITO not only provides high conductivity and high transmittance in the visible light region, but also has good chemical stability and adhesion with the substrate. ITO is grown at a high temperature and heat treated to form a crystalline structure in order to improve optical and electrical properties, and a high degree of charge mobility can be exhibited through the regular arrangement of the crystalline structure. In the transparent electrode made of crystalline ITO, when the transparent electrode is bent or warped by such a crystalline structure, a crack occurs due to stress, so that it is difficult to secure flexibility suitable for a flexible display device. In addition, when crystalline ITO is applied to a flexible substrate, it is difficult to maintain its performance due to low performance or cracks.

A high conductivity, high resolution, and high flexibility amorphous oxide semiconductors are required for transparent or electrode materials in flexible or wearable displays, which are emerging as next generation displays. Amorphous oxide semiconductors with flexibility are being developed, but amorphous structures It is difficult to secure high conductivity and high decomposability corresponding to the crystalline structure due to difficulty in ion substitution due to low crystallinity.

Disclosure of the Invention The present invention has been made to solve the above-mentioned problems and it is an object of the present invention to provide a lanthanide doping-based highly conductive flexible material having high flexibility capable of reducing stress cracking while providing high charge mobility corresponding to a crystalline structure. A transparent electrode can be provided.

The present invention can provide a method for producing a highly conductive transparent transparent electrode based on lanthanide doping according to the present invention.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

According to one aspect of the present invention,

Board; And an amorphous thin film formed on the substrate and doped with a lanthanide material locally distributed in the nanocrystal dot; To a lanthanide doping-based, highly conductive, transparent electrode.

In one embodiment of the present invention, the amorphous lanthanide material and the nanocrystal dot are contained in a weight ratio of 1: 0.0001 to 0.1, and the nanocrystal dot may have a particle diameter of 1 nm to 20 nm.

In one embodiment of the present invention, the substrate is a flexible substrate comprising at least one polymer selected from the group consisting of polyimide, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polycarbonate and polyvinyl alcohol, A substrate, a silicon substrate, and a high heat resistant glass substrate.

As an example of the present invention, the lanthanide-based highly conductive transparent electrode may have a light transmittance of 80% or more and a sheet resistance of 10 ^-4 Ω / sq or less.

According to another aspect of the present invention,

Growing an amorphous thin film doped with a lanthanide material on a substrate using a material target mixed with a lanthanide powder; And annealing the amorphous thin film doped with the lanthanide material to form a locally distributed nanocrystal dot in the amorphous thin film; Wherein the step of forming the nanocrystal dot comprises performing a heat treatment at 200 ° C to 650 ° C for 30 seconds to 5 minutes, and a method of manufacturing a highly conductive transparent electrode based on lanthanide doping.

According to one embodiment of the present invention, the step of growing the thin film may be performed at a temperature of from room temperature to 550 캜.

According to an embodiment of the present invention, the step of forming the nanocrystal dot may be performed in an inert gas atmosphere by heating at a heating rate of 50 ° C to 100 ° C.

The present invention can provide a transparent electrode having excellent electrical characteristics and high decomposability corresponding to a crystalline structure and at the same time having excellent flexibility.

Further, the transparent electrode according to the present invention can maintain optical and electrical characteristics due to bending of the device, stress, or the like, and reliability can be improved.

In addition, the transparent electrode according to the present invention can be applied to a flexible or wearable device since it has excellent flexibility to lower cracks caused by high light transmittance and stress.

FIG. 1 illustrates a flow diagram of a method for manufacturing a highly conductive, transparent electrode based on a lanthanide material of the present invention, according to one embodiment of the present invention.
2 schematically illustrates the structure of an RF magnetron sputtering system used in a method of manufacturing a highly conductive transparent electrode based on lanthanide doping according to an embodiment of the present invention .

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. Also, terminologies used herein are terms used to properly represent preferred embodiments of the present invention, which may vary depending on the user, intent of the operator, or custom in the field to which the present invention belongs. Therefore, the definitions of these terms should be based on the contents throughout this specification. Like reference symbols in the drawings denote like elements.

The present invention relates to a highly conductive transparent electrode based on lanthanide doping, wherein a lanthanide doping-based, highly conductive, transparent electrode, according to an embodiment of the present invention, is doped with a lanthanide material, Structure, and it can exhibit excellent electrical conductivity due to nanocrystal dot formed locally inside and flexibility due to amorphous structure at the same time.

According to an embodiment of the present invention, the transparent electrode includes a substrate; And lanthanide doping based amorphous thin films; . ≪ / RTI >

In one example of the present invention, the substrate may be a flexible substrate applicable to a flexible or wearable device, and may be a flexible substrate such as polyimide, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polycarbonate and polyvinyl A flexible substrate comprising at least one polymer selected from the group consisting of alcohols; And a glass substrate of a sapphire substrate, a silicon substrate, and a high heat-resistant glass substrate; , And the like.

For example, the substrate can be applied considering the heat resistance of the substrate according to the growth temperature and / or the heat treatment temperature. For example, at a temperature of room temperature and 100 ° C or less, a polyethylene terephthalate substrate, A polyimide substrate at a temperature of 300 ° C or higher, a sapphire substrate or a high heat resistant glass substrate or a silicon substrate at a temperature of 600 ° C or higher can be applied.

According to an embodiment of the present invention, the lanthanide-based amorphous thin film may be formed on one or both surfaces of the substrate, and the amorphous thin film may have a thickness of 2 탆 or less; 200 nm to 1 占 퐉; Or 250 nm to 400 nm thick.

In one embodiment of the present invention, the amorphous thin film based on the lanthanide material may have a nanocrystal dot locally distributed in an amorphous lanthanide material. This is because the amorphous thin film doped with the lanthanide material exhibits amorphous characteristics such as high flexibility because the amorphous thin film having amorphous lanthanide material is distributed as a whole, and the amorphous lanthanide material exhibits a band conduction The carrier transport takes place. That is, electrons of the s-orbitals out of the outermost electrons of the metal in the amorphous lanthanide material contribute to charge transport, so that they can exhibit a relatively high charge mobility despite being an amorphous thin film, The presence of local nanocrystal dots formed in the interior contributes to the high charge mobility through the regular arrangement of atoms while maintaining the optical and electrical properties despite bending of the device.

For example, the mixing ratio of the amorphous lanthanide material to the nanocrystal dot is 1: 0.0001 to 0.1; 1: 0.001 to 0.1 weight ratio; Or 1: 0.01 to 0.1; And if it is included in the mixing ratio, it can exhibit excellent electrical and optical characteristics depending on the crystalline structure while having flexibility according to the amorphous structure as a whole.

The amorphous lanthanide material includes at least one selected from the group consisting of La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm and Yb. Metal or oxides thereof. In addition, lanthanide metals or oxides can have the form of powders, nanowires, nanoparticles, nanorods, and the like.

In one embodiment of the present invention, the nanocrystal dot is a crystalline material formed by a heat treatment process of an amorphous thin film doped with a lanthanide material, and is a lanthanide metal or a lanthanide oxide. And may be composed of the same components as the amorphous thin film based on the lanthanide material.

For example, the nanocrystal dot may have a thickness of less than 1 um; 1 nm to 500 nm; 1 nm to 250 nm; 1 nm to 50 nm; Or a particle diameter of 1 nm to 20 nm. When the amorphous thin film is contained within the above-mentioned particle diameter range, cracks due to the stress of the amorphous thin film doped with the lanthanide material, while providing a high charge mobility due to the regular arrangement of the crystalline structure Or the electrical characteristics due to driving can be prevented from being changed.

In one embodiment of the present invention, the highly conductive transparent electrode doped with the lanthanide material may exhibit a high light transmittance and a low sheet resistance, for example, a light transmittance of 80% or more with respect to a visible light region; And an electric resistance of not more than 10 ^-4 ? Cm.

As an example of the present invention, the lanthanide-based highly conductive, transparent transparent electrode as the doping material may be usefully used as a transparent electrode of an electronic device, a touch panel, a display, or the like. For example, a flexible display or a flexible display, a liquid crystal display (LCD), a light emitting display (LED), an organic light emitting diode (OLED) Electronic paper, solar cell, and the like, but is not limited thereto.

The present invention relates to a method for preparing a highly conductive transparent transparent electrode based on a lanthanide doping material according to the present invention. According to an embodiment of the present invention, the amorphous oxide semiconductor is formed by a rapid thermal annealing process to form a local nanocrystal dot inside the amorphous structure, thereby forming a highly conductive and highly efficient lanthanide doping material- Electrode can be provided.

According to one embodiment of the present invention, the method is described with reference to FIG. 1, wherein FIG. 1 is a cross-sectional view of a lanthanide-doped material-based highly conductive transparent electrode according to an embodiment of the present invention. And a flow chart of the manufacturing method. 1, the manufacturing method includes: preparing a substrate (S1); Growing an amorphous thin film based on a Lanthanide doping material (S2); And forming a nanocrystal dot (S3); . ≪ / RTI > The manufacturing method may be a vacuum evaporator, preferably an RF magnetron sputtering system.

According to one embodiment of the present invention, the manufacturing method will be described with reference to Fig. 2, and Fig. 2 exemplarily shows a configuration of an AC voltage-applied vacuum evaporator, according to an embodiment of the present invention. The AC voltage-applied vacuum evaporator shown in FIG. 2 may further include a configuration applied in the technical field of the present invention, provided that it does not deviate from the object of the present invention.

The step of preparing the substrate S1 is a step of selecting a suitable substrate according to the field to which the transparent electrode is applied and placing the substrate in a vacuum evaporator. For example, when the substrate 10 is placed in the chamber 20, And is rotatably disposed on the rotator 21 provided in the rotor. The substrate is the same as that of the lanthanide-based highly conductive transparent electrode.

According to an embodiment of the present invention, the step (S2) of growing an amorphous thin film based on a lanthanide doping material includes growing a lanthanide-based amorphous thin film on a substrate using a powdery lanthanide dopant target on the substrate . Wherein the target comprises a plurality of single or different lanthanide elements or materials; Or a mixture of two or more lanthanide doping elements or materials. For example, a vacuum is generated by the high vacuum pump 22, the low vacuum pump 23 and the vacuum valve 24, and the first sputter gun 26 (FIG. 26) equipped with the first lanthanide target 25 ) And the second sputter gun 28 equipped with the second lanthanide material target 27 were subjected to RF power, the thin film growth temperature was set, and the plasma density was controlled to adjust the entirety of the amorphous thin film based on the lanthanide doping material The thickness and the content of each component can be controlled to grow (deposit) the amorphous thin film based on the Lanthanide doping material.

For example, the step S2 of growing an amorphous thin film based on lanthanide doping may be performed at a temperature of from room temperature to 550 DEG C; Room temperature to 400 ° C; Room temperature to 300 ° C; Room temperature to 200 캜; Room temperature to 150 캜; Room temperature to 100 캜; Or an amorphous thin film based on a lanthanide material can be grown at room temperature for 10 to 20 minutes. When the temperature is within the temperature range of the thin film growth temperature, a flexible lanthanide doping-based amorphous thin film can be formed, and excellent light transmittance and electrical conductivity can be exhibited after formation of the nanocrystal dot.

For example, the lanthanide in the step (S2) for growing the amorphous thin film of a material doped based on a degree of vacuum 2 × 10 ^- maintained below ⁶ Torr, and, while the rotator 21 is rotated at 3 RPM to about 5 RPM working pressure 4 mTorr, and the RF power at the sputter gun 26 may be between 50 W and 100 W.

For example, in the step (S2) of growing a lanthanide doping-based amorphous thin film, the lanthanide-based amorphous thin film has a thickness of 2 탆 or less; 200 nm to 1 占 퐉; Or 250 nm to 400 nm thick.

According to an embodiment of the present invention, the step (S3) of forming the nanocrystal dot may include annealing the amorphous thin film based on lanthanide doping to form a locally distributed nanocrystal dot in the amorphous thin film based on the lanthanide doping . For example, after the step (S2) of growing the amorphous thin film based on the lanthanide doping is completed, the substrate on which the amorphous thin film based on the lanthanide doping is formed is subjected to rapid thermal annealing to form nanocrystals Dots can be formed locally. By this heat treatment, the nanocrystal dot can be formed as a lanthanide oxide. Since the amorphous thin film based on the lanthanide doping after the rapid thermal annealing has an amorphous structure as a whole, the mobility of electrons can be improved due to the localized formation of nanocrystal dot simultaneously with high flexibility.

For example, the step S3 of forming the nanocrystal dot may be performed at a temperature between 200 [deg.] C and 650 [deg.] C; Or from 30 seconds to 5 minutes at a heat treatment temperature of from 300 DEG C to 400 DEG C; 30 seconds to 2 minutes; Or high-speed heat treatment for 1 minute to 2 minutes. When the temperature and the time range are included, it is possible to provide a transparent transparent substrate having excellent electrical conductivity and light transmittance by locally forming nanocrystals in an amorphous oxide. In addition, the step (S3) of forming the nanocrystal dot may be performed in an inert gas atmosphere such as argon, nitrogen, etc. by heating at a temperature raising rate (per minute) of 50 to 100 캜.

It will be understood by those of ordinary skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the following claims And changes may be made without departing from the spirit and scope of the invention.

Example 1

An amorphous lanthanide thin film with a thickness of 250 nm was grown on a polyimide substrate for 15 minutes under the process conditions shown in Table 1, with a powder lanthanum target (Sm or Gd material) mounted in an AC voltage vacuum evaporator. (B) 100 ° C, (c) 200 ° C, and (d) 300 ° C on the basis of the characteristics of (a) room temperature, (b) A sapphire substrate was used at (e) 400 ° C, (f) 500 ° C, (g) 600 ° C and (h) 700 ° C.

 The amorphous structure of the amorphous lanthanide thin films grown at room temperature was measured by XRD pattern measurement.

parameter Lanthanide material Initial vacuum degree
(Base pressure) 2x10 ^{- 6} Torr Working pressure
(Working pressure) 3m Torr Process temperature
(Process temperature) Room temperature Process time
(Deposition time) 15 min RF power 100W
(Lanthanide material) 50W
(Lanthanide material) Gas ratio Ar: 20

The present invention relates to a method for forming a local nanocrystal dot in an amorphous structure through rapid thermal annealing of an amorphous thin film based on a lanthanide material to obtain a lanthanide material capable of exhibiting excellent electrical and optical characteristics depending on the crystal structure and flexibility in an amorphous lanthanide thin film Based highly conductive transparent electrode can be provided.

Claims (5)

Board; And
An amorphous oxide semiconductor thin film formed on the substrate and doped with a lanthanide material locally distributed in a nano crystal dot; / RTI >
Wherein the lanthanide material comprises Sm, Gd or both,
The amorphous lanthanide material and the nanocrystal dot are contained in a weight ratio of 1: 0.0001 to 0.1,
The nanocrystal dot has a particle diameter of 1 nm to 20 nm,
Having a light transmittance of 80% or more and an electrical resistance of 10 ^-4 Ω · cm or less.
delete The method according to claim 1,
The substrate may be a flexible substrate comprising at least one polymer selected from the group consisting of polyimide, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polycarbonate and polyvinyl alcohol, a sapphire substrate, And a heat-resistant glass substrate. 2. The lyso-type material doping-based highly conductive transparent electrode according to claim 1,
delete A method of manufacturing a highly conductive, transparent electrode based on lanthanide doping,
Growing an amorphous thin film doped with a lanthanide material on a substrate using a powdery lanthanide doping material target; And
Annealing the amorphous thin film doped with the lanthanide material to form a locally distributed nanocrystal dot in the amorphous thin film;
Lt; / RTI >
The step of forming the nanocrystal dot may include heat treatment at 200 ° C to 650 ° C for 30 seconds to 5 minutes,
Wherein growing the amorphous thin film doped with the lanthanide material is performed at a temperature of from room temperature to 200 ° C,
The step of forming the nanocrystal dot may be performed by heating at a temperature raising rate of 50 ° C to 100 ° C, performing heat treatment in an inert gas atmosphere,
An amorphous oxide semiconductor thin film formed on the substrate and doped with a lanthanide material locally distributed in a nano crystal dot; / RTI >
Wherein the lanthanide material comprises Sm, Gd or both,
Wherein the transparent electrode comprises amorphous lanthanide material and the nanocrystal dot in a weight ratio of 1: 0.0001 to 0.1, the nanocrystal dot having a particle diameter of 1 nm to 20 nm, a light transmittance of 80% ^And having an electrical resistance of ^-4 · cm m or less.

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