KR20020014480A - Fluorescent substance mixed with trace carbon nanotube - Google Patents

Abstract

PURPOSE: A fluorescent substance mixed with a trace of carbon nanotube is provided which improves display luminance by exhibiting higher fluorescent characteristics than an existing fluorescent substance, and easily radiates heat generated from the fluorescent substance since the carbon nanotube has superior thermal conductivity. CONSTITUTION: The fluorescent substance mixed with a trace of carbon nanotube is characterized in that a trace of carbon nanotube is mixed with a fluorescent substance, the carbon nanotube is formed in a three-dimensional network structure inside the fluorescent substance, wherein trace means an amount which does not change a color of the fluorescent substance, the carbon nanotube is mixed with the fluorescent substance using a simple mixing process such as stirring or a mixing process using ultrasonic vibration, and the carbon nanotube is added to the fluorescent substance in an amount of 0.4 wt.% or more.

Description

Fluorescent substance mixed with trace amount of carbon nanotubes {FLUORESCENT SUBSTANCE MIXED WITH TRACE CARBON NANOTUBE}

The present invention relates to a phosphor, and more particularly to a phosphor in which a trace amount of carbon nanotubes is mixed.

In recent years, carbon nanotubes are being actively studied in the world, and they exhibit conductor properties alone, but when stacked in multiple bundles, they exhibit properties of semiconductors. In addition, since the size is very small and the physical properties are varied, it provides infinite applicability that can be used as a memory device, an electronic device and the like.

In addition, since carbon nanotubes have a high aspect ratio of 1000: 1 or more, even when 0.4 wt% carbon nanotubes are added, nanotubes are connected to each other in a matrix to form a three-dimensional network structure.

On the other hand, phosphors emitting red, green, and blue are sequentially applied to the inner wall of the substrate of a display such as a CRT or FED. At this time, the phosphor for CRT is mainly a mixture of zinc sulfide and sulfide containing silver uniformly. It is preferred that the phosphor has high fluorescence properties, which is related to the brightness of the display.

In the conventional phosphor, since the heat generated from the phosphor lowers the brightness of the display, the phosphor did not exhibit high fluorescence. In particular, in the case of an organic phosphor, there is a serious problem when the amount of heat generated by the phosphor is large.

The present invention has been made to solve the above-described problems, an object of the present invention is to provide a phosphor in which a trace amount of carbon nanotubes are mixed. Thus, the phosphor of the present invention exhibits higher fluorescence than conventional phosphors, thereby improving display brightness. In addition, since carbon nanotubes have excellent thermal conductivity, they can easily release heat generated from phosphors.

1 is a block diagram showing a manufacturing process of one embodiment according to the present invention.

2 is a cross-sectional view showing a mesh structure of carbon nanotubes in a phosphor according to the present invention.

3 is a cross-sectional view of a thermal-CVD apparatus.

<Description of main parts of drawing>

1: phosphor 3: carbon nanotube

5: Silicon Wafer with Catalyst Island

7: quartz tube 9, 15: gas valve

11: Heating element (resistance coil) 13: Rotary pump

17: gas supply (hydrogen, acetylene) 19: gas exhaust

The present invention relates to a phosphor mixed with a trace amount of carbon nanotubes, the carbon nanotubes form a three-dimensional network structure in the phosphor. In this case, the trace amount refers to the amount of not changing the color of the phosphor.

The carbon nanotubes are mixed with phosphors using a simple mixing process such as sterling or a mixing process using ultrasonic vibration.

The weight ratio of the carbon nanotubes is preferably added at 0.4% by weight or more.

Carbon nanotubes having a network structure in a phosphor have a characteristic of emitting a large amount of secondary electrons when electrons having high energy collide with each other. Therefore, since the carbon nanotubes emit heat generated from the phosphor to the outside, the heat emission characteristic of the phosphor is greatly improved.

In addition, since the carbon nanotube is added in a very small amount, it does not change color in the red, green, and blue phosphors and is chemically stable, and thus does not react with the phosphors.

On the other hand, in the conventional CRT, that is, cathode ray tube, aluminum is deposited with a thin thickness of several hundred angstroms on the phosphor to reflect the light emitted from the phosphor, thereby improving the luminance of the CRT and preventing local accumulation of charge. However, the present invention can easily dissipate the heat generated in the phosphor as described above by mixing the carbon nanotubes in the phosphor, and can prevent the accumulation of charge locally due to the excellent electron emission characteristics of the carbon nanotubes. .

Example

Preparation of Fluorescent Materials Mixed with Carbon Nanotubes

Referring to Figure 1 in detail the manufacturing steps were synthesized phosphor and carbon nanotubes, respectively. In this case, a phosphor obtained by uniformly mixing zinc sulfide and sulfide containing silver, which is generally used for CRT, was used. In addition, the carbon nanotubes were manufactured using the thermal-CVD (thermal-CVD) apparatus of FIG. In this embodiment, carbon nanotubes having a diameter of 80 to 150 nm and a length of 100 to 150 μm were used.

After adding a predetermined amount of the synthesized carbon nanotubes to the synthesized phosphor and then mixing them using a simple mixing process such as sterling or ultrasonic vibration, the carbon nanotubes 3 in the phosphor 1 are meshed as shown in FIG. 2. A phosphor with a structure was obtained.

In this case, the carbon nanotubes have a mesh structure only by adding 0.4% by weight.

The phosphor of the present invention provides the following effects.

First, the phosphor of the present invention exhibits higher fluorescence than conventional phosphors and as a result enhances the brightness of the display. Secondly, the phosphor of the present invention has an effect of blocking harmful electromagnetic waves emitted from the front of the display because the mesh structure of the carbon nanotubes serves to shield the electromagnetic waves. Third, the phosphor of the present invention facilitates heat release of carbon nanotubes. Fourth, the phosphor of the present invention is enhanced mechanical strength due to the carbon nanotubes inside, and adhesion to the substrate is improved. Fifth, the phosphor of the present invention prevents local charge accumulation.

Claims (2)

A phosphor mixed with a small amount of carbon nanotubes. The phosphor of claim 1, wherein the carbon nanotubes are added in an amount of 0.4 wt% or more.