KR101401924B1 - Nanowire/quantum dot heterostructures and method of manufacturing the same - Google Patents

Abstract

The present invention relates to a CdTe nanowire grown on a solid substrate by liquid-liquid-solid (SLS) growth, a CdTe / ZnSe nanowire in the form of a core / shell and a method for producing the same, wherein the CdTe nanowire according to the present invention has a uniform diameter And is a high-density nanowire of high crystallinity. The CdTe nanowire according to the present invention was coated with ZnSe nanocrystals to fabricate a CdTe / ZnSe nanowire having a core / shell structure. Thus, the type I energy band structure and the quantum well structure were investigated. Lt; / RTI > emission (PL) emission compared to the < RTI ID = 0.0 > Therefore, the CdTe / ZnSe nanowire in the form of a core / shell coated with CdTe nanowires and ZnSe nanocrystals according to the present invention can be applied to the growth of semiconductor systems and developed as various low-cost high-performance nano devices such as sensors and solar cells .

Description

[0001] The present invention relates to a nanowire / quantum dot heterostructure and a method of manufacturing the same,

The present invention relates to a nanowire / quantum dot heterostructure and a method of manufacturing the same, and more particularly, to a cadmium telluride (CdTe) nanowire / zinc selenide (ZnSe) quantum dot heterostructure of a core- will be.

Semiconductor nanowires have attracted attention as one of the most promising nanostructures with potential for use in various applications including information technology, biological technology, environment / energy technology, and the like. There have been two distinct ways to grow semiconductor nanowires, one of which is a vapor growth method, such as a gas-liquid-solid (VLS) growth mechanism and a gas-solid (VS) growth mechanism, - Solid phase (SLS) Growth mechanism, hydrothermal method, Oriented Attachment, template method and so on. Compared with the vapor growth method, the solution growth method is a very effective and inexpensive method which shows a wide range of applications as a low temperature synthesis method. A glass substrate or a polymer film can be used as a substrate for growing nanowires by a low-temperature process. A template-assisted growth method using anodized aluminum (AAO) or polymeric molds has been introduced to grow high density linear nanowire arrays through solution phase growth methods. However, despite the ease of this process, after removing the template, most of the nanowires collapse and aggregate to form a bundle shape, which results in the loss of the desired nanostructure. On the other hand, the SLS growth method, in which a liquid precursor solution is impregnated into a liquid catalyst to grow into solid nanowires, is a suitable method for the purpose of this study. However, to date, there have been only a very limited number of examples of successful growth of SLSs with high quality of semiconductor nanowires on any type of solid substrate. We have successfully grown CdS nanowires on fluorine-doped tin oxide (FTO) -coated soda lime glass substrates and have demonstrated the potential for use in solar cell applications.

CdTe is a II-VI compound semiconductor whose direct energy bandgap is narrowed to 1.44 eV. CdTe has been used as a light absorbing layer in a high efficiency CdS / CdTe thin film solar cell because it absorbs light in the entire visible region. CdTe has also been used as a fluorescent dye for red light or green light. SLS growth of colloidal CdTe nanowires randomly dispersed in solution was reported by two researchers. One synthesized high quality colloidal CdTe nanowires in straight and branched form through SLS growth method. Another is the synthesis of colloidal CdTe nanowires using SLS and precisely controlling the energy band gap of the CdTe nanowires by precise diameter control.

However, SLS growth of high-density CdTe nanowires on a solid substrate has not been reported so far, and nanowire structures of core / shell heterostructure in which another semiconductor material is bonded to the CdTe nanowire surface grown on the substrate by SLS have been reported There is no need for research on this.

The present invention provides a CdTe / ZnSe heterostructure of a core-shell structure coated with solution-liquid-solid (SLS) CdTe nanowires and a ZnSe quantum dot on a solid substrate, and a method of manufacturing the same.

However, the technical problem to be solved by the present invention is 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.

The present invention provides solution-liquid-solid (SLS) grown CdTe nanowires and a CdTe / ZnSe heterostructure of a core-shell structure on a solid substrate.

In one embodiment of the present invention, there is provided a method of preparing a solution comprising: a) preparing a solution containing a) a Cd precursor; B) continuously depositing a CdTe seed layer and a Bi catalyst layer on a solid substrate; C) The solid substrate deposited in the step b) is immersed in a polyvinyl alcohol (PVC) solution, and the Bi catalyst layer is heat-treated to be decomposed into Bi catalyst nanoparticles to form a Bi catalyst, and then charged into the solution prepared in a) step; And d) growing a CdTe nanowire by an SLS mechanism by injecting a solution containing a Te precursor into a solution in which the solid substrate is loaded in the step c); E) coating ZnSe quantum dots on the surface of the CdTe nanowires grown in step d) to provide a core-shell heterostructure of CdTe / ZnSe.

The present invention relates to a CdTe / ZnSe heterostructure of a CdTe nanowire and a core-shell structure grown by a solution-liquid-solid (SLS) mechanism on a solid substrate and a method of manufacturing the same, wherein the CdTe nanowire according to the present invention has uniform High-density nanowire of straight-line, high-crystallinity one-diameter. In the present invention, the surface of the CdTe nanowire is coated with ZnSe nanocrystals to form a core-shell structure of CdTe / ZnSe heterostructure. Thus, a type-I type energy band structure and thus a quantum well structure are realized. Lt; / RTI > (PL) intensity relative to the < RTI ID = 0.0 > Accordingly, the CdTe / ZnSe heterostructure of the core-shell structure coated with CdTe nanowires and ZnSe nanocrystals according to the present invention can be applied to the growth of semiconductor systems and is applicable to various low-cost high-performance nano devices such as sensors and solar cells .

FIG. 1 shows an X-ray diffraction (XRD) pattern of a CdTe / ZnSe nanowire in the form of a core / shell coated with CdTe nanowires and ZnSe nanocrystals.
FIGS. 2 (a) and 2 (b) show scanning electron microscope (FESEM) photographs of CdTe nanowires, and FIGS. 2 (c) and 2 (d) show ZnSe nanocrystal coated core / (FESEM) photograph of the CdTe / ZnSe nanowire.
3 (a) and 3 (b) show a transmission electron microscope (TEM) and a high resolution transmission electron microscope (HRTEM) photograph of CdTe nanowires, (TEM) and high resolution transmission electron microscope (HRTEM) photographs of the coated core / shell type CdTe / ZnSe nanowires.
FIG. 4 shows UV-visible absorption and photoluminescence (PL: excitation at 690 nm) spectrum of CdTe / ZnSe nanowires coated with CdTe nanowires and ZnSe nanocrystals coated core / shell type.

Thus, the present inventors prepared solution-liquid-solid (SLS) grown CdTe nanowires on a solid substrate. Furthermore, CdTe nanowires were coated with ZnSe nanocrystals to fabricate CdTe / ZnSe nanowires in the form of core / shell, and type I band structures and quantum well structures were realized. In addition, the present invention has been completed by examining and comparing the light absorption and luminescence characteristics of CdTe nanowires and ZnSe nanocrystals coated CdTe / ZnSe nanowires in the form of a core / shell.

Hereinafter, the present invention will be described in more detail.

The present invention provides solution-liquid-solid (SLS) grown CdTe nanowires on a solid substrate, and in particular the CdTe nanowires can be CdTe / ZnSe nanowires in the form of a core / shell coated with ZnSe nanocrystals. At this time, the thickness of the ZnSe nanocrystals is preferably 5-7 nm.

The CdTe nanowire is linear with a uniform diameter, and the diameter of the CdTe nanowire is preferably 10-15 nm. When the CdTe nanowire has a small diameter of 10-15 nm, it is possible to maximize the surface-to-volume ratio, which is a very important factor in constructing a high-performance nano device such as a sensor and a solar cell.

The kind of the solid substrate is not limited, but is preferably soda lime glass.

The present invention also relates to a method of producing CdTe nanowires comprising the steps of: a) preparing a solution containing a) a Cd precursor; B) continuously depositing a CdTe seed layer and a Bi catalyst layer on a solid substrate; C) immersing the solid substrate deposited in step b) in a polyvinyl alcohol (PVC) solution, heat-treating the Bi catalyst layer to decompose the Bi catalyst nanoparticles into Bi catalyst nanoparticles, and charging the solution into the solution prepared in step a); And (d) injecting a solution containing a Te precursor into a solution in which the solid substrate is loaded in (c) above, to provide solution-liquid-solid (SLS) grown CdTe nanowires on a solid substrate do.

The present invention also relates to a method for producing a core / shell type CdTe / ZnSe nanowire coated with ZnSe nanocrystals, comprising the steps of: a) preparing a solution containing a Cd precursor; B) continuously depositing a CdTe seed layer and a Bi catalyst layer on a solid substrate; C) immersing the solid substrate deposited in step b) in a polyvinyl alcohol (PVC) solution, heat treating the Bi catalyst layer to obtain Bi catalyst nanoparticles, and charging the Bi catalyst nanoparticles into the solution prepared in step a); D) injecting a solution containing a Te precursor into the solution charged with the solid substrate in the step c); (E) dripping a solution containing ZnSe nanocrystals onto a solid substrate on which CdTe nanowires have been grown, and drying the solution to coat CdTe nanowires with ZnSe nanocrystals; And c) thermally treating the CdTe nanowire coated in step e). The present invention also provides a method of manufacturing a core / shell type CdTe / ZnSe nanowire.

The step a) is a step of preparing a solution containing a Cd precursor and dissolving cadmium oxide in a mixture of oleic acid, hexadecylamine (HDA), trioctylphosphine oxide (TOPO) and 1-octadecene , And the solution is heated with magnetic stirring to prepare a solution containing the Cd precursor.

At this time, the Cd precursor is preferably cadmium oxide, but is not limited thereto. The Cd precursor is effective to prevent the CdTe nanowire from growing in the lateral direction by maintaining a low concentration. In addition, the hexadecylamine (HDA), trioctylphosphine oxide (TOPO) and 1-octadecene (ODE) functions as a surfactant, thereby preventing lateral growth of CdTe nanowires.

The step b) is a step of continuously depositing a CdTe buffer layer and a Bi catalyst layer on a solid substrate. In the present invention, the deposition is performed by DC sputtering, but any method known in the art can be used.

At this time, the CdTe seed layer is very effective for growing highly crystalline high-density CdTe nanowires. Glass substrates without a CdTe seed layer exhibit low-crystallinity, low-density CdTe nanowire growth. In the present invention, a CdTe seed layer was used for the homoepitaxy growth of CdTe nanowires, but the CdTe nanowires did not grow in the vertical direction because of the low crystalline and / or disordered crystal orientation of the preformed CdTe seed layer. Because of this problem, CdTe nanowires have grown obliquely instead of vertical growth. Therefore, an increase in the crystallinity of the CdTe seed layer may further increase the vertical growth of the CdTe nanowire.

In the step c), the solid substrate deposited in step b) is immersed in a polyvinyl alcohol (PVC) solution, the Bi catalyst layer is heat-treated and pulverized into Bi catalyst nanoparticles, and then charged into the solution prepared in the step a) .

At this time, the polyvinyl alcohol (PVC) solution plays an important role in fixing the liquid Bi catalyst layer on the surface of the glass substrate during CdTe nanowire growth. The coating of polyvinyl alcohol (PVC) solution plays a major role in the growth of CdTe nanowires by holding the Bi catalyst layer on a glass substrate in solution-liquid-solid (SLS) growth of CdTe nanowires. In the absence of a polyvinyl alcohol (PVC) coating, most of the Bi catalyst nanoparticles are lost, making it impossible to grow CdTe nanowires on a glass substrate.

In addition, the Bi catalyst nanoparticles were spherical and easily observed at the ends of most CdTe nanowires, suggesting that a solution-liquid-solid (SLS) mechanism is a mechanism for growing CdTe nanowires on a glass substrate . The CdTe nanowires were about 30% smaller in diameter than the average diameter of the Bi catalyst nanoparticles because of the low concentration of Cd and Te atoms supersaturated in the liquid Bi alloy. At low temperatures, the solute particles may be supersaturated at low concentrations in the liquid alloy. Due to the low concentration of Cd and Te in the liquid Bi alloy, small nuclei may be formed and the diameter of the CdTe nanowires may be smaller than the diameter of the Bi catalyst nanoparticles.

The step d) is a step of injecting a solution containing the Te precursor into the solution charged with the solid substrate in the step c).

At this time, the Te precursor is preferably Te-tributylphosphine (TBP). In addition, the Te precursor is effective in preventing the CdTe nanowire from growing in the lateral direction by maintaining a low concentration.

The steps d) and d) are steps for manufacturing a core / shell type CdTe / ZnSe nanowire coated with ZnSe nanocrystals, wherein a solution containing ZnSe nanocrystals is dripped onto a solid substrate on which CdTe nanowires are grown And then the surface of the CdTe nanowire is coated with ZnSe nanocrystals and then heat-treated.

At this time, the synthesis of ZnSe nanocrystals can be performed by modifying the conventional TOP / TOPO method.

The present invention also provides a nanodevice comprising a CdTe nanowire and a core / shell type CdTe / ZnSe nanowire according to the present invention. The nano device may be a sensor, a solar cell, a transistor, a light emitting element, a light receiving element, a photodetector, a light emitting diode, a PL (photoluminescence) element, a laser diode, an electroluminescence And a CL (Cathodeluminescence) element.

Hereinafter, preferred embodiments of the present invention will be described in order to facilitate understanding of the present invention. However, the following examples are provided only for the purpose of easier understanding of the present invention, and the present invention is not limited by the following examples.

Example 1. Preparation of CdTe nanowire [CdTe NW]

Solution-liquid-solid (SLS) growth of CdTe nanowires was performed in a similar manner to solution-liquid-solid (SLS) growth of conventional CdS nanowires. At this time, all of the chemicals used were obtained from Aldrich Chemical Co. (Milwaukee, Wis.).

First, 0.05 mmol of cadmium oxide (99.99%) was dissolved in 0.5 mL of oleic acid, 20 mg of hexadecylamine (HDA) (98%) and 150 mg of trioctylphosphine oxide (TOPO) in a 100 mL three- 99%) and 8 mL of 1-octadecene (ODE). The solution was heated to 220 DEG C under argon flow with magnetic stirring to prepare a solution containing the Cd precursor. A CdTe seed layer (~ 40 nm thick) and a Bi catalyst layer (~ 5 nm thick) were continuously deposited on the soda lime glass substrate by DC sputtering. The soda lime glass substrate on which the Bi catalyst layer was deposited was immersed in a polyvinyl alcohol (PVC) solution. The Bi catalyst layer was heat-treated in a tubular furnace at 220 캜 under a stream of argon gas to be pulverized into Bi nanoparticles. Solution. Then, a solution-liquid-solid (SLS) growth reaction was carried out while 0.5 mL of a 5 wt% Te-tertiary butylphosphine (TBP) solution was injected into the solution charged with the soda lime glass substrate and stirred for 4 hours with slight stirring.

Example 2. Preparation of CdTe / ZnSe nanowire [CdTe / ZnSe NW] in the form of core / shell coated with ZnSe nanocrystals

Synthesis of ZnSe nanocrystals was performed by modifying the conventional TOP / TOPO method by Chen et al. In a three-necked flask, 2 mM of ZnO powder was dissolved in 20 mM of stearic acid, and 1.9 mM of trioctylphosphine oxide (TOPO) was added to the solution. N ₂ And mixed in a glove box filled with gas. The mixed solution was heated to 300 DEG C in the mantle. 2 mM of Se powder was dissolved in 4.5 mM trioctylphosphine (TOP) using ultrasonic waves, and this solution was rapidly injected into a Zn-containing solution in a three-necked flask. By injecting the solution at room temperature, the temperature of the mixed solution dropped to 270 ° C and ZnSe nanocrystals precipitated. As ZnSe nanocrystals were synthesized, they were washed several times with chloroform / hexane and dispersed in chloroform.

Then, the ZnSe nanocrystal-containing solution was added dropwise to the soda lime glass substrate on which the CdTe nanowires grown in Example 1 had been grown, until the soda lime glass substrate was completely wetted. Then, the solution containing the ZnSe nanocrystals was dropped again and dried, and the above steps were repeated five times. Finally, CdTe nanowires coated with ZnSe nanocrystals were annealed at 500 ℃ for 30 minutes under argon atmosphere to form a strong interfacial bond between ZnSe nanocrystals and CdTe nanowires.

Experimental example. Characteristics of CdTe / ZnSe nanowire [CdTe / ZnSe NW] in the form of core / shell type coated with CdTe nanowire [CdTe NW] and ZnSe nanocrystals

(1) X-ray diffraction (XRD) pattern

X-ray diffraction analysis (XRD) was used to investigate the crystal structure of the CdTe nanowire prepared in Example 1 and the CdTe / ZnSe nanowire prepared in Example 2.

Figure 1 shows an X-ray diffraction (XRD) pattern of CdTe nanowires and CdTe / ZnSe nanowires.

As shown in Fig. 1, the CdTe nanowire has a diffraction pattern corresponding to the zinc zinc structure (JCPDS # 15-0770). The relative diffraction peak intensities of CdTe nanowires were different from the JCPDS data for standard CdTe powders. The relative (111) diffraction peak intensity of CdTe nanowires was much higher than that of standard CdTe powders, indicating that CdTe nanowires could preferentially grow in the [111] orientation. However, the intensity of other diffraction peaks, such as (220) and (311), which means that the CdTe nanowire could not grow vertically from the glass substrate, is still substantially high.

Further, as shown in FIG. 1, the ZnSe nanocrystal-coated core / shell type CdTe / ZnSe nanowire ZnSe nanocrystals diffract with the CdTe nanowire, meaning that it is thick enough to exhibit X-ray diffraction Diffraction of zinc oxide ZnSe nanocrystals (JCPDS # 37-6413) was confirmed. The Scherrer equation based on the half width of (111), (220) and (311) diffraction peaks was used and the average particle size of ZnSe nanocrystals was measured to be 4.1 nm. Diffraction peaks due to the newly formed secondary phase or diffraction peaks due to mutual diffusion were not detected at all in the X-ray diffraction pattern. Therefore, CdTe and ZnSe did not react with each other during the heat treatment of CdTe nanowires coated with ZnSe nanocrystals at 500 ° C. for 30 minutes, indicating that they did not form any new phase. It also shows that there is no interdiffusion between CdTe and ZnSe, which can shift the diffraction peak position (Two-theta) by lattice constant change.

(2) Scanning electron microscope (FESEM) photograph

A scanning electron microscope (FESEM) was used to examine the morphological characteristics of the CdTe nanowire prepared in Example 1 and the ZnSe nanocrystal-coated core / shell type CdTe / ZnSe nanowire prepared in Example 2 .

FIGS. 2 (a) and 2 (b) show scanning electron microscope (FESEM) photographs of CdTe nanowires, and FIGS. 2 (c) and 2 (d) show ZnSe nanocrystal coated core / (FESEM) photograph of the CdTe / ZnSe nanowire.

As shown in Fig. 2 (a), the average diameter of CdTe nanowires was 10-15 nm and the length was 2-3 m. Also, FIG. 2 (b) shows the growth of CdTe nanowires on a soda lime glass substrate on which a CdTe seed layer is deposited. At this time, strong interfacial bonding was confirmed in CdTe nanowire, CdTe seed layer and soda lime glass substrate.

Further, as shown in Fig. 2 (c), the CdTe nanowire was almost completely coated with ZnSe nanocrystals. In FIG. 2 (d), the surface is roughened due to the coating of ZnSe nanocrystals, but the linearity of the CdTe nanowire is still maintained.

(3) Transmission electron microscopy (TEM) and high resolution transmission electron microscope (HRTEM) photographs

To examine the detailed microstructure and crystal structure of the CdTe nanowire prepared in Example 1 and the ZnSe nanocrystalline coated core / shell type CdTe / ZnSe nanowire prepared in Example 2, a transmission electron microscope (TEM) And high resolution transmission electron microscopy (HRTEM).

3 (a) and 3 (b) show a transmission electron microscope (TEM) and a high resolution transmission electron microscope (HRTEM) photograph of CdTe nanowires, (TEM) and high resolution transmission electron microscope (HRTEM) photographs of the coated core / shell type CdTe / ZnSe nanowires.

Fig. 3 (a) shows the formation of linear CdTe nanowires of uniform diameter. In FIG. 3 (b), the lattice pattern of the CdTe nanowire is clearly observed, and the d - spacing of 0.372 nm corresponding to the CdTe (111) atomic plane means that the nanowire grows preferentially in the [111] direction , CdTe nanowires were fabricated by a low temperature liquid phase process, but high crystallinity was confirmed.

In FIG. 3 (c), a 5 to 7 nm thick ZnSe layer corresponding to the size of one or two ZnSe nanocrystals is formed on the CdTe surface. In FIG. 3 (d), ZnSe nanocrystals having an average size of 4 nm or less are formed on the surface of CdTe, and an interplanar d- spacing of 0.324 nm corresponding to a ZnSe (111) atomic surface having an island zinc structure is shown.

(4) UV-visible absorption and PL spectra

In order to compare the absorption and luminescence characteristics of the CdTe nanowire prepared in Example 1 and the ZnSe nanocrystal-coated core / shell type CdTe / ZnSe nanowire prepared in Example 2, UV-visible absorption And a photoluminescence (PL: excitation at 690 nm) spectrum were used.

FIG. 4 shows UV-visible absorption and photoluminescence (PL: excitation at 690 nm) spectrum of CdTe / ZnSe nanowires coated with CdTe nanowires and ZnSe nanocrystals coated core / shell.

Figure 4 shows that the UV-visible absorption of CdTe nanowires is initiated near 788 nm, corresponding to 1.57 eV. Considering the bulk energy band gap of 1.44 eV for CdTe corresponding to 861 nm, the CdTe nanowire exhibits a blue-shift in the UV-visible absorption start wavelength. The migration to such a short wavelength is due to the quantum confinement since the bore radius of CdTe having a large volume is 7.3 nm and the average diameter of the CdTe nanowire is 10-15 nm. Thus, exciton quantum confinement could occur through the lateral direction of the CdTe nanowire.

Additional UV-visible absorption of the core / shell type CdTe / ZnSe nanowires coated with ZnSe nanocrystals was observed near 416 nm, corresponding to 2.98 eV. This additional UV-visible absorption is due to UV-visible absorption by ZnSe nanocrystals coated on the surface of CdTe nanowires. The bulk energy bandgap of ZnSe is 2.70 eV and ZnSe nanocrystals also exhibit quantum confinement. The bore radius of the large volume ZnSe was 3.8 ㎚ and the average size of the ZnSe nanocrystals was about 4 ㎚.

Further, as shown in FIG. 4, the strong light emission intensity of the CdTe nanowire and the core / shell type CdTe / ZnSe nanowire coated with ZnSe nanocrystals may be derived from the high crystallinity and high density of the CdTe nanowire, Due to the crystallinity, the light emission is incompatible with other liquid-phase synthesized nanowires. ZnSe nanocrystal coated core / shell CdTe / ZnSe nanowires increased the photoluminescence intensity by 36.5%. The main reason for this was the immobilization of broken dangling bonds on the surface of CdTe nanowires . Surface broken atomic bonds acting as active trap sites for excitons in CdTe nanowires can be overcome by coating ZnSe nanocrystals. ZnSe nanocrystal coated CdTe / ZnSe nanowires in the form of core / shell form the I - type energy band structure by the larger energy band gap (2.70 eV) of ZnSe, and thus the quantum well structure can be constituted. Excitons generated in CdTe by external light stimuli can be confined within this CdTe well. In addition, extra electrons excited from ZnSe can be injected into the CdTe quantum well and CdTe can have more excitons. Thus contributing to increased PL emission in ZnSe nanocrystalline CdTe nanowires. In addition, the CdTe / ZnSe nanowires coated with ZnSe nanocrystals coated with a core / shell of CdTe / ZnSe nanowires have a slightly shorter peak wavelength than the CdTe nanowires, resulting from compressive deformation caused by ZnSe nanocrystals. The lattice parameters of CdTe and ZnSe are 6.48 Å and 5.67 Å, respectively, so that CdTe can be compressively deformed. In general, migration from a semiconductor core / shell form to a longer wavelength typically occurs because the electron wave function in the core extends to the shell. However, if the shell is sufficiently thick, the compressive strain effect on the core is dominant over the elongation effect of the electron wave function, and the energy band gap of the core is also increased. Thus, the increase in PL emission in FIG. 4 means that the compressive strain did not cause crystal defects such as stacking faults that might act as active trap sites for the excitons.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

Claims (9)

Cadmium telluride (CdTe) nanowires grown on a solid substrate as solution-liquid-solid (SLS); And
A cadmium telluride / zinc selenide nanowire in the form of a core / shell comprising zinc selenide (ZnSe) nanocrystals coated on the cadmium telluride nanowire. The method according to claim 1,
A cadmium telluride / zinc selenide nanowire in the form of a core / shell, wherein the thickness of the zinc selenide (ZnSe) nanocrystals is 5-10 nm. The method according to claim 1,
A cadmium telluride / zinc selenide nanowire in the form of a core / shell in which the diameter of the cadmium telluride (CdTe) nanowire is 5-100 nm. The method according to claim 1,
A cadmium telluride / zinc selenide nanowire in the form of a core / shell in which the solid substrate is soda lime glass. A) preparing a solution containing a Cd precursor;
B) continuously depositing a CdTe seed layer and a Bi catalyst layer on a solid substrate;
C) immersing the solid substrate deposited in step b) in a polyvinyl alcohol (PVC) solution, heat treating the Bi catalyst layer to obtain Bi catalyst nanoparticles, and charging the Bi catalyst nanoparticles into the solution prepared in step a);
D) injecting a solution containing a Te precursor into the solution charged with the solid substrate in the step c) to prepare solution-liquid-solid (SLS) grown CdTe nanowires on the solid substrate;
(E) dripping a solution containing ZnSe nanocrystals onto a solid substrate on which the CdTe nanowires have been grown, and drying the solution to coat CdTe nanowires with ZnSe nanocrystals; And
A method of manufacturing a core / shell type cadmium telluride / zinc selenide nanowire comprising: c) thermally treating a CdTe nanowire coated in step c) to obtain a CdTe / ZnSe core shell structure. 6. The method of claim 5,
Wherein the Cd precursor is a cadmium telluride / zinc selenide nanowire in the form of a core / shell. 6. The method of claim 5,
Wherein the Te precursor is Te-tributylphosphine (TBP). ≪ RTI ID = 0.0 > 11. < / RTI > A nanodevice comprising a core / shell type cadmium telluride / zinc selenide nanowire according to claim 1. 9. The method of claim 8,
The nano device may be a sensor, a solar cell, a transistor, a light emitting device, a photodetector, a light emitting diode, a laser diode, an EL (electroluminescence) device, a PL And CL (Cathodeluminescence) devices.

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