JP2005046927A - Manufacturing method for zinc sulfide cadmium nanocable and zinc sulfide cadmium nanotube containing cadmium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a zinc sulfide cadmium nanocable and a zinc sulfide cadmium nanotube containing cadmium anticipated to be applied to a solar battery, cathode ray luminescence, a high density photo-recording material, a laser diode, or the like. <P>SOLUTION: The zinc sulfide cadmium nanocable and the zinc sulfide cadmium nanotube containing cadmium are manufactured by heating graphite powder and graphite fiber while leading nitrogen gas containing water vapor, into them, and heating a mixture of zinc sulfide powder and cadmium sulfide powder. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing cadmium-containing zinc cadmium sulfide nanocables and zinc cadmium sulfide nanotubes, which are ternary semiconductor materials. More specifically, the present invention relates to a method for producing zinc cadmium sulfide nanostructures that are widely applied in the fields of solar cells, low-voltage cathodoluminescence, high-density optical recording materials, blue or ultraviolet laser diodes, and the like.
[0002]
[Prior art]
Two-dimensional zinc cadmium sulfide thin films are manufactured by various methods such as CVD, molecular beam epitaxy, sol-gel method, and heat evaporation method (for example, see Non-Patent Documents 1 to 4). Zero-dimensional zinc sulfide nanoparticles are produced by a high temperature reaction, a chemical reduction method, or the like (for example, see Non-Patent Documents 5 and 6).
[0003]
[Non-Patent Document 1]
"AM Salem, Applied Physics A" (Appl. Phys. A), 74, 205, 2002 [Non-patent Document 2]
J. et al. Torres, et al., “Thin Solid Films” 207, 231 1992 [Non-Patent Document 3]
D. S. Boyle, et al., "Journal of Material Chemistry" (J. Mater. Chem.), 10, 2439, 2000 [Non-Patent Document 4]
T.A. Edamura, et al., “Journal of Material Science Letters” (J. Mater. Sci. Lett.), Vol. 14, p. 889, 1995 [Non-patent Document 5]
P. J. et al. Sebastian, et al., “Thin Solid Films” 287, 130, 1996 [Non-Patent Document 6]
W. Wang, et al., “Chemistry of Materials” (Chem. Mater.), 14, 3028, 2002.
[Problems to be solved by the invention]
Since one-dimensional nanostructures are useful for fabricating various nanodevices, their research has become active year by year. However, one-dimensional zinc cadmium sulfide nanostructures are not yet known. An object of the present invention is to provide a method for producing a one-dimensional cadmium-containing zinc cadmium sulfide nanocable and a zinc cadmium sulfide nanotube.
[0005]
[Means for Solving the Problems]
A nitrogen gas stream containing water vapor generated by blowing nitrogen gas into distilled water is heated to 1300 to 1700 ° C. while passing through the graphite powder and graphite fiber, and the mixture of zinc sulfide powder and cadmium sulfide powder is heated to 1000 to 1300 ° C. By heating, the cadmium-containing zinc cadmium sulfide nanocable and the zinc cadmium sulfide nanotube are deposited on the quartz substrate.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
The graphite powder and graphite fiber are heated to 1300-1700 ° C. in a mixed gas stream of nitrogen gas and water vapor generated by blowing nitrogen gas into distilled water. At this time, the flow rate is about 1.5 L / min for nitrogen gas and about 0.3 L / min for water vapor. On the other hand, a mixture of zinc sulfide powder and cadmium sulfide powder is heated to 1000 to 1300 ° C. The heating temperature of the compound is preferably in the range described above. There is no significant improvement in the reaction rate even when the temperature is raised beyond this. In addition, at a temperature below this, the reaction does not proceed sufficiently. The reaction time is preferably 0.5 to 3 hours. No further time is required from the point of reactivity. If it is 30 minutes or less, the reaction is not completed.
[0007]
The weight ratio of the graphite powder and the graphite fiber as the raw material is about 1: 1 to 2: 1, and the weight ratio of the zinc sulfide powder and the cadmium sulfide powder is about 1: 1 to 1: 2. The reason why the weight of cadmium sulfide is the same or larger than that of zinc sulfide is that cadmium sulfide has a higher evaporation rate than zinc sulfide. The above reaction takes place in a high frequency induction furnace, but the product is deposited as a gray powder on the quartz tube wall.
[0008]
【Example】
Next, the present invention will be described in more detail with reference to examples.
Place 1.0 g of graphite powder (purity: 99.99%) manufactured by Wako Pure Chemical Industries, Ltd. and 1.0 g of graphite fiber (purity: 99.99%) manufactured by Wako Pure Chemical Industries, Ltd. into a graphite crucible and attach to a graphite susceptor. And installed in a high-frequency induction heating furnace. On the other hand, a mixture of 0.5 g of zinc sulfide powder (purity 99.9%) manufactured by Sigma Aldrich and 0.5 g of cadmium sulfide (purity 99.9%) manufactured by Sigma Aldrich was put into a graphite crucible, It was placed above the crucible containing graphite powder and graphite fiber. A nitrogen gas stream containing water vapor generated by blowing nitrogen gas into distilled water was passed through graphite powder and graphite fiber at a flow rate of 1.5 L / min. The graphite powder and graphite fiber were heated to 1600 ° C., and the mixture of zinc sulfide powder and cadmium sulfide powder was heated to 1200 ° C. Heating was continued at this temperature for 2 hours and then cooled to room temperature. Gray powder deposited on the quartz tube wall as product.
[0009]
FIG. 1a shows a photograph of one of the products observed using a transmission electron microscope. The resulting nanocable was confirmed to have a length of several micrometers, a diameter of about 100 nanometers, a core diameter of about 90 nanometers, and a sheath thickness of about 8 nanometers.
[0010]
FIG. 1b shows an X-ray energy diffusion spectrum obtained by measuring the radial center portion of the nanocable, and it was found that the chemical composition is composed of cadmium. In this figure, a small amount of zinc and sulfur peaks are observed, which are derived from the peak from the outer sheath. The inset of FIG. 1b shows the X-ray energy diffusion spectrum of the nanocable sheath, which was found to be composed of zinc, cadmium and sulfur.
[0011]
As a result of examining a high-resolution transmission electron microscope image and an electron diffraction pattern of the nanocable, both the cadmium constituting the core and the zinc cadmium sulfide constituting the sheath are single crystals, and the core portion has a lattice constant a = 0.30 nm, c = 0.56 nm. In addition, the lattice constants of the sheath part are a = 0.39 nm and c = 0.64 nm, which is also a hexagonal crystal structure, and the atomic ratio of the chemical composition is confirmed to be composed of Zn0.78Cd0.22S. It was.
[0012]
As a result of examining a transmission electron microscope image of a tube-like product having one end of the product opened, it was found that the diameter was about 80 nanometers and the wall thickness was about 8 nanometers. This nanotube is considered to be formed by evaporating cadmium, which is a constituent component of the core, from the cadmium-containing zinc-sulfide cadmium nanocable. This nanotube was found to be hexagonal Zn0.78Cd0.22S from the electron diffraction pattern.
[0013]
The result of measuring the cathodoluminescence of the cadmium-containing zinc sulfide-cadmium nanocable at 20K is shown in FIG. From this result, it was found that this nanocable has an emission peak at about 490 nm.
[0014]
【The invention's effect】
The present invention makes it possible to produce cadmium-containing zinc cadmium sulfide nanocables and zinc cadmium sulfide nanotubes that are expected to be applied to solar cells, cathodoluminescence, high-density optical recording materials, laser diodes, and the like.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1a is a drawing-substituting photograph of a transmission electron microscope image of a cadmium-containing zinc cadmium sulfide nanocable. FIG. 1 b is a diagram of an X-ray energy diffusion spectrum of cadmium at the core of a cadmium-containing zinc cadmium sulfide nanocable. The inset of FIG. 1b is an X-ray energy diffusion spectrum of zinc cadmium sulfide at the sheath portion of the cadmium-containing zinc cadmium sulfide nanocable.
FIG. 2 is a diagram obtained by measuring cathodoluminescence of a cadmium-containing zinc sulfide cadmium nanocable.

Claims (2)

While passing a nitrogen gas stream containing water vapor generated by blowing nitrogen gas into distilled water, the graphite powder and the graphite fiber are heated to 1300 to 1700 ° C., and the mixture of the zinc sulfide powder and the cadmium sulfide powder is heated to 1000 to 1300 ° C. A method for producing a cadmium-containing zinc sulfide cadmium nanocable and a zinc cadmium sulfide nanotube, characterized in that: 2. The method for producing a cadmium-containing zinc cadmium sulfide nanocable and a zinc cadmium sulfide nanotube according to claim 1, wherein the heating time is 0.5 to 3 hours.

Images