CN103359772A - Method for preparing antimony-doped zinc-oxide (ZnO) nanowire - Google Patents

Abstract

The invention provides a method for preparing antimony-doped zinc oxide nanowires, which is characterized in that the method comprises: preparing an antimony-doped solution and a hydrothermal synthesis solution, wherein the antimony-doped solution is antimony acetate, glycolic acid and an aqueous solution of sodium hydroxide, the hydrothermal synthesis solution is an aqueous solution of zinc nitrate hexahydrate, hexamethylene tetraazol and polyethyleneimine; measure the antimony-doped solution and the hydrothermal synthesis solution according to the antimony doping ratio , and ammonia water was added to obtain a mixed solution; finally, the hydrothermal synthesis of antimony-doped ZnO nanowires was carried out in the mixed solution, that is, the substrate prepared with oxidized seed crystals on the surface was placed in the mixed solution for hydrothermal growth and oxidation Zinc nanowires. The method of the invention is used to prepare antimony-doped zinc oxide nanowires in a hydrothermal reaction, the preparation temperature is low, and it can be applied on flexible substrates such as organic matter.

Description

A kind of preparation method of antimony doped zinc oxide nanowire

technical field

The invention relates to the field of nanomaterial preparation, in particular to a method for preparing antimony-doped zinc oxide nanowires.

Background technique

Doped one-dimensional nanomaterials have great significance and broad prospects in the field of nanoelectronics. The combination of n-type and p-type doped materials can make p-n junctions, and p-n junctions have important applications in light-emitting diodes, transistors and photovoltaic devices. Given that ZnO is a material with both semiconductor and piezoelectric effects, and its synthesis method is relatively simple, stable and effective, ZnO has become a mainstay material in nanogenerators and piezoelectric electronics. Zinc oxide that has not been deliberately doped is naturally an n-type semiconductor. In recent years, doping zinc oxide with foreign elements such as nitrogen, phosphorus, and antimony has been extensively studied. The ability to successfully synthesize homogeneous p-n junction ZnO nanowires will enable light-emitting diodes and logic circuits based on single nanowires.

Although the successful p-type doping of ZnO nanowires has been reported previously, the synthesis method used relies on the solid-liquid-gas (VLS) mechanism, which needs to be carried out at extremely high temperatures. This severely limits the types of substrates available for growing ZnO nanowires, and is not suitable for preparing p-type doped ZnO nanowires on flexible substrates such as organic matter.

Contents of the invention

In order to overcome the defect that p-type doping of zinc oxide nanowires needs to be carried out at high temperature, the purpose of the present invention is to provide a method for preparing antimony (Sb) doped zinc oxide nanowires at low temperature.

In order to achieve the above object, the present invention provides a method for preparing antimony-doped zinc oxide nanowires, the method comprising:

Prepare an antimony doping solution and a hydrothermal synthesis solution, wherein the antimony doping solution is an aqueous solution of antimony acetate, glycolic acid and sodium hydroxide, and the hydrothermal synthesis solution is zinc nitrate hexahydrate, hexamethylene tetraazide and poly Aqueous solution of ethyleneimine;

Measure the antimony doped solution according to the antimony doping ratio and mix it with the hydrothermal synthesis solution, and add ammonia water to obtain a mixed solution;

The substrate prepared with zinc oxide seed crystals on the surface is placed in the mixed solution for hydrothermal growth of zinc oxide nanowires.

Preferably, the step of preparing the antimony doping solution comprises:

Dissolving the glycolic acid and sodium hydroxide in deionized water to form an aqueous solution of glycolic acid and sodium hydroxide; slowly adding antimony acetate to form an antimony-doped solution while stirring the aqueous solution of glycolic acid and sodium hydroxide at a constant speed; wherein , the molar ratio of antimony acetate, glycolic acid and sodium hydroxide is 1:12:12.

Preferably, the step of preparing the hydrothermal synthesis solution is to sequentially add zinc nitrate hexahydrate, hexamethylene tetraazol and polyethyleneimine to deionized water, wherein, zinc nitrate hexahydrate, hexamethylene tetraazol and polyethyleneimine The molar ratio is 10:5:2.

Preferably, before the step of placing the substrate prepared with zinc oxide seed crystals on the surface in the mixed solution for hydrothermal growth of zinc oxide nanowires, the step further includes: a step of preheating the mixed solution.

Preferably, the step of preheating the mixed solution is to keep the temperature at 95° C. for 1 hour.

Preferably, the antimony doping ratio is 0%-2%.

Preferably, after the hydrothermal growth of the antimony-doped zinc oxide nanowires, the step of annealing the antimony-doped zinc oxide nanowires is further included.

Compared with the prior art, the vibration detector of the present invention has the following advantages:

The invention provides a method for preparing antimony-doped zinc oxide nanowires. First, an antimony-doped solution and a hydrothermal synthesis solution are prepared, wherein the antimony-doped solution is an aqueous solution of antimony acetate, glycolic acid and sodium hydroxide. The hydrothermal synthesis solution is an aqueous solution of zinc nitrate hexahydrate, hexamethylene tetraazol and polyethyleneimine; then measure the antimony-doped solution and the hydrothermal synthesis solution according to the antimony doping ratio and mix them, and add ammonia water to obtain a mixed solution ; Finally, carry out the hydrothermal synthesis of antimony-doped zinc oxide nanowires in the mixed solution. The method of the invention is used to prepare antimony-doped zinc oxide nanowires in a hydrothermal reaction, the preparation temperature is low, and it can be applied on flexible substrates such as organic matter.

In addition, the method for preparing antimony-doped zinc oxide nanowires of the present invention can prepare ultra-long arrays of antimony-doped zinc oxide nanowires, the length of which can reach 60 microns, which can meet the requirements of preparing light-emitting diodes and LEDs on a single nanowire. requirements for logic circuits, etc.

Description of drawings

The above and other objects, features and advantages of the present invention will be more clearly illustrated by the accompanying drawings. Like reference numerals designate like parts throughout the drawings. The drawings are not intentionally scaled according to the actual size, and the emphasis is on illustrating the gist of the present invention.

Fig. 1 is the flow chart of the preparation method of antimony-doped zinc oxide nanowire of the present invention;

Fig. 2 is the scanning electron microscope image of the antimony-doped zinc oxide nanowire prepared in the embodiment of the present invention;

Fig. 3 is the energy dispersive X-ray spectrogram of the transmission electron microscope of a single 2% antimony-doped zinc oxide nanowire;

Figure 4 is the electrical characterization of 0.2% antimony doped (a) and 2% antimony doped (b) ZnO nanowires by atomic force microscopy;

Fig. 5 is the electrical measurement result of the fixed source-drain bias scanning gate voltage of a field effect transistor prepared by a single 0.2% antimony-doped zinc oxide nanowire.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Apparently, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The existing p-type doping method for zinc oxide nanowires requires the use of a solid-liquid-gas (VLS) mechanism, which needs to be carried out at extremely high temperatures, and is not suitable for preparing p-type doped on flexible substrates such as organic substances. ZnO nanowires, which severely limits the types of substrates available for growing nanowires.

The invention provides a method for preparing antimony-doped zinc oxide nanowires, wherein the method comprises:

Prepare an antimony doping solution and a hydrothermal synthesis solution, wherein the antimony doping solution is an aqueous solution of antimony acetate, glycolic acid and sodium hydroxide, and the hydrothermal synthesis solution is zinc nitrate hexahydrate, hexamethylene tetraazide and poly Aqueous solution of ethyleneimine;

Measure the antimony doped solution according to the antimony doping ratio and mix it with the hydrothermal synthesis solution, and add ammonia water to obtain a mixed solution;

The substrate prepared with zinc oxide seed crystals on the surface is placed in the mixed solution for hydrothermal growth of zinc oxide nanowires.

The preparation method of the antimony-doped zinc oxide nanowire of the present invention is carried out in a hydrothermal reaction, the preparation temperature is low, and it can be applied to flexible substrates such as organic matter. In addition, the method for preparing antimony-doped zinc oxide nanowires of the present invention can prepare ultra-long arrays of antimony-doped zinc oxide nanowires, the length of which can reach 60 microns, which can meet the requirements of preparing light-emitting diodes and LEDs on a single nanowire. requirements for logic circuits, etc.

A specific embodiment of the present invention will be described in detail below in conjunction with the accompanying drawings. The flow chart of the preparation method of the antimony-doped zinc oxide nanowire of the present invention is shown in Fig. 1, including:

Step S1, preparing an antimony-doped solution and a hydrothermal synthesis solution, wherein the antimony-doped solution is an aqueous solution of antimony acetate, glycolic acid and sodium hydroxide, and the hydrothermal synthesis solution is zinc nitrate hexahydrate, hexamethyl tetraazol Aqueous solutions of ketone and polyethyleneimine.

The molar ratio of antimony acetate, glycolic acid and sodium hydroxide in the antimony-doped solution is 1:12:12, and the step of preparing the antimony-doped solution includes: dissolving glycolic acid and sodium hydroxide in deionized water to form glycolic acid and an aqueous solution of sodium hydroxide; the aqueous solution of glycolic acid and sodium hydroxide is placed in a centrifuge tube, and a magnetic rotor is added, and antimony acetate is slowly added under constant stirring to form an antimony-doped solution. Finally, an antimony-doped solution with a volume of 50 mL and a concentration of 0.1 M was obtained, which can be stored stably for a long time at room temperature.

The molar ratio of zinc nitrate hexahydrate, hexamethylene tetraazol and polyethyleneimine in the hydrothermal synthesis solution is 10:5:2, and the step of preparing the hydrothermal synthesis solution is to add zinc nitrate hexahydrate, zinc nitrate hexahydrate, Hexamethylene tetraazol and polyethyleneimine, specifically, in 250ml deionized water, add zinc nitrate hexahydrate (Zn(NO ₃ ) ₂ 6H ₂ O), hexamethylene tetraazol (HMTA) and polyethyleneimine in sequence (PEI), so that the concentration of zinc nitrate hexahydrate (Zn(NO ₃ ) ₂ 6H ₂ O) in the solution is 25mM (mM=1mmol/L, millimole per liter), and the concentration of hexamethylene tetraazol (HMTA) is The concentration of 12.5mM and polyethyleneimine (PEI) is 5mM. After uniform mixing, measure 50mL of the above solution with a graduated cylinder and pour it into the reaction vessel.

Step S2, mix the antimony doped solution with the hydrothermal synthesis solution according to the antimony doping ratio, and add ammonia water to obtain a mixed solution.

According to the antimony doping ratio, add an appropriate amount of antimony doping solution to the hydrothermal synthesis solution prepared in step S1 and mix evenly. The doping ratio can range from 0% to 2% (atomic ratio of antimony and zinc). In this embodiment, 25 μL of antimony-doped solution was added to 50 mL of hydrothermal synthesis solution and mixed evenly, and 2.7 ml of ammonia water with a mass specific gravity of 28% was added and mixed evenly, and the reaction vessel was sealed.

Step S3, placing the substrate prepared with zinc oxide seed crystals on the surface in the mixed solution for hydrothermal growth of zinc oxide nanowires.

Before performing step S3 after the antimony doping solution and the hydrothermal synthesis solution are mixed, a step of preheating the mixed solution may also be included. The specific preheating conditions may be as follows: the sealed reaction vessel in step S2 is placed in a thermostat at 95° C. for 1 hour of heat preservation and preheating. Preheating the mixed solution can make the solution uniformly mixed. After the mixed solution is preheated, in this step, the substrate prepared with zinc oxide seed crystals on the surface is placed in the preheated mixed solution to grow zinc oxide nanowires by hydrothermal method.

Taking the growth of antimony-doped zinc oxide nanowires on a glass substrate as an example, first sputter a zinc oxide seed layer on the glass substrate, put the glass substrate into the reaction vessel in step S2, and after 24 hours After hydrothermal growth, the substrate was removed and rinsed with deionized water. So far, the preparation of antimony-doped zinc oxide nanowires is completed.

In order to remove the organic residues on the prepared antimony-doped zinc oxide nanowires, the method of the present invention may also include the step of annealing the antimony-doped zinc oxide nanowires after step S4, specifically, the prepared antimony-doped zinc oxide nanowires The nanowire substrates were baked at 300 °C for 1 hour to remove organic residues.

The antimony-doped zinc oxide nanowires prepared in this example were characterized, and scanning electron microscopy, transmission electron microscopy, atomic force microscopy (AFM) and field-effect transistor measurements were used to characterize the morphology, chemical composition and electrical properties, etc.

Figure 2 shows a scanning electron microscope image, in which the 0.2% doped nanowires (Figure 2 a and b panels) are about 60 microns in length and 200 nm to 1000 nm in diameter; 2% doped The nanowires (panels c and d in Figure 2) are around 3 microns in length and around 250 nm in diameter.

In the method for preparing antimony-doped zinc oxide nanowires of the present invention, polyethyleneimine (PEI) added to the hydrothermal synthesis solution is used as a shape control agent to obtain nanowires up to 60 microns long, and at the same time, ethanol During the growth process of zinc oxide, antimony ions are incorporated into its crystal lattice. By adopting the method of the invention, ultra-long p-type doped zinc oxide nanowires can be repeatedly and stably prepared.

Figure 3 uses the energy dispersive X-ray spectrometer of the transmission electron microscope to determine the chemical composition of a single nanowire, as shown in Table 1, although 2% antimony is added for doping, due to the material loss during the synthesis process, the actual The doping concentration of the nanowires is 0.55%.

Table 1. Average weight and atomic percentages of different elements in 2% antimony doped nanowires.

elements weight% Atomic % O(K) 16.53 44.82 Zn(K) 81.91 54.61 Sb(L) 1.54 0.55

The piezoelectric output characteristics of the zinc oxide nanowires prepared in this example were measured using an atomic force microscope, as shown in FIG. 4 . After deformation, the output current is negative, indicating that the ZnO nanowires are p-type doped. The reason is that the AFM tip and the zinc oxide nanowire form a Schottky junction, which is unidirectional conduction. After the zinc oxide nanowire is bent by force, the signs of the charges generated on the stretched surface and the compressed surface are opposite, and the unidirectional conductivity of the Schottky junction So that when the tip of the needle touches the two surfaces back and forth, only one of them will output current. For n-type doping, it will be turned on when the needle tip is in contact with the compression surface, corresponding to the positive current in the measurement system; for p-type doping, it will be turned on when the needle tip is in contact with the compression surface, corresponding to the positive current in the measurement system negative current. For ZnO nanowires doped with 0.2% antimony (a in Figure 4) and 2% antimony (b in Figure 4), the maximum output currents are 30 pA and 80 pA, and the maximum output voltages are 7 mV and 15 mV, respectively.

Finally, a field-effect transistor based on a single ZnO nanowire doped with 0.2% antimony was prepared, and the source-drain fixed bias and the electrical measurement of the scanning gate voltage were performed. The relevant measurement results are shown in Figure 5. This result further strictly proves that the synthesized ZnO nanowires are p-type doped.

The above descriptions are only preferred embodiments of the present invention, and do not limit the present invention in any form. Without departing from the scope of the technical solution of the present invention, any person skilled in the art can use the methods and technical content disclosed above to make various possible variations and modifications to the technical solution of the present invention, or modify it into an equivalent implementation of equivalent changes example. Therefore, any simple modifications, equivalent variations and modifications made to the above embodiments according to the technical solution of the present invention, which do not deviate from the technical solution of the present invention, all belong to the scope of protection of the technical solution of the present invention.

Claims (7)

1. A preparation method for antimony-doped zinc oxide nanowires, characterized in that the method comprises: Prepare an antimony doping solution and a hydrothermal synthesis solution, wherein the antimony doping solution is an aqueous solution of antimony acetate, glycolic acid and sodium hydroxide, and the hydrothermal synthesis solution is zinc nitrate hexahydrate, hexamethylene tetraazide and poly Aqueous solution of ethyleneimine; Measure the antimony doped solution according to the antimony doping ratio and mix it with the hydrothermal synthesis solution, and add ammonia water to obtain a mixed solution; The substrate prepared with zinc oxide seed crystals on the surface is placed in the mixed solution for hydrothermal growth of zinc oxide nanowires. 2. preparation method according to claim 1, wherein, the step of preparing antimony doping solution is: Dissolving the glycolic acid and sodium hydroxide in deionized water to form an aqueous solution of glycolic acid and sodium hydroxide; slowly adding antimony acetate to form an antimony-doped solution while stirring the aqueous solution of glycolic acid and sodium hydroxide at a constant speed; The molar ratio of antimony acetate, glycolic acid and sodium hydroxide is 1:12:12. 3. The preparation method according to claim 1, wherein, the step of preparing the hydrothermal synthesis solution is: sequentially adding zinc nitrate hexahydrate, hexamethylene tetraazol and polyethyleneimine in deionized water; zinc nitrate hexahydrate The molar ratio of hexamethylene tetraazol to polyethyleneimine is 10:5:2. 4. The preparation method according to any one of claims 1-3, wherein the method further comprises: placing the substrate prepared with zinc oxide seed crystals on the surface in the mixed solution for hydrothermal growth of zinc oxide Before nanowires: a step of preheating the mixed solution. 5. The preparation method according to claim 4, wherein the step of preheating the mixed solution is to keep the temperature at 95° C. for 1 hour. 6. The preparation method according to claim 1, wherein the antimony doping ratio is 0%-2%. 7. The preparation method according to claim 1, wherein the method further comprises the step of annealing the obtained hydrothermally grown antimony-doped zinc oxide nanowires.

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