METHOD FOR PREPARING METAL FROM METAL PRECURSOR SOLUTION AND THE APPLICATION THEREOF

Abstract

Method for preparing metal from metal precursor solution and the application thereof are provided. The metal precursor solution is treated by atmospheric pressure plasma jet (APPJ) and therefore transform into the metal.

Description

CROSS-REFERENCE TO RELATED APPLICATION AND CLAIM OF PRIORITY

This application claims the benefit of Taiwan Patent Application No. 103116166, filed on May 6, 2014, at the Taiwan Intellectual Property Office, the disclosures of which are incorporated herein in their entirety by reference.

TECHNICAL FIELD

The present disclosure is directed to a method for preparing metal from metal precursor solution and the application thereof, which uses atmospheric pressure plasma jet (APPJ) to convert the metal precursor liquid solution films into solid metal films or particles.

BACKGROUND

A solar cell is a device which is able to directly convert solar power into electrical power. Concept of dye-sensitized solar cells (DSSCs) is firstly disclosed by Tsubomura et al. However, the disclosed DSSC has poor photoelectric conversion efficiency so that it did not attract attention. Until 1991, the research team leading by Professor O'Regan and Professor Grätzel in Swiss Federal Institute of Technology used a porous titanium dioxide film adsorbing pigment molecule of ruthenium complex as a DSSC photoelectrode, where the photoelectric conversion efficiency of the DSSC was raised to 7.1% to 7.9%. According to a recent study, the photoelectric conversion efficiency of DSSC is up to 13.1%. The DSSC has a sandwich-like configuration which is divided into several sections, i.e. transparent conductive electrode, nanoporous titanium dioxide, dye molecule of metal complex, electrolyte and counter electrode. The working principles of DSSCs are directed to redox. Specifically, after the light is absorbed by the dyes, electrons are transited from the ground states to the excited states of the dyes and then are transferred to the titanium dioxide semiconductor. Through the conductive glass, the electrons are guided to an external circuit. Then the electrons flow to the counter electrode to reduce oxidized molecules in electrolyte to complete a complete electron conduction circuit. The counter electrode plays an important role in DSSCs. Generally, a well-functional counter electrode must have high catalytic activity and good electrical conductivity. At present, platinum is the most common material of counter electrode. The common techniques for fabricating the platinum counter electrode are sputtering and liquid spin-coating method. If the platinum counter electrode is fabricated by the liquid spin-coating method, long-time calcination (needing several hours including temperature ramping and cooling durations) is required to remove organic compounds. However, the step of long-time calcination is energy- and time-consuming.

The Taiwan Patent Application No. 097134931, entitled “Method and apparatus for thermally converting metallic precursor layers into semiconductor layers, and also solar module”, discloses a method for thermally converting metallic precursor layers on substrates into semiconducting layers, and an apparatus for carrying out the method and for producing solar modules on substrates. The method and apparatus are achieved through that the substrates having a metallic precursor layer are heated in a furnace, which is segmented into a plurality of temperature regions, at a pressure at approximately atmospheric ambient pressure in a plurality of steps in each case to a predetermined temperature up to the end temperature between a specific range and are converted into semiconducting layers whilst maintaining the end temperature in an atmosphere comprising a mixture of a carrier gas and vaporous chalcogens.

The Taiwan Patent Application No. 099103930, entitled “Process and device for the thermal conversion of metallic precursor layers into semiconducting layers with chalcogen recovery”, discloses a process for the thermal conversion of metallic precursor layers on flat substrates into semiconducting layers with a recovery of chalcogen, as well as a device for carrying out the process. The process and apparatus are achieved by heating substrates in a furnace at approximately atmospheric pressure to a final temperature in the range 400° C. to 600° C. and transforming them into semiconducting layers in an atmosphere formed from a mixture of at least one carrier gas and chalcogen vapor.

The Taiwan Patent Application No. 102114224, entitled “Methods of fabricating dielectric films from metal amidinate precursors”, discloses methods for atomic layer deposition of films comprising mixed metal oxides using metal amidinate precursors. The mixed metal oxide films may comprise a lanthanide and a transition metal such as hafnium, zirconium or titanium.

The U.S. patent application Ser. No. 14/156,712, entitled “Solution processed metal oxide thin film hole transport layers for high performance organic solar cells”, discloses a method for the application of solution processed metal oxide hole transport layers (HTL) in organic photovoltaic devices, where the metal oxide is derived from a metal-organic precursor enabling solution processing of an amorphous, p-type metal oxide, and the HTL layer exposes to oxygen plasma after solution depositing the HTL layer.

Employing experiments and researches full-heartily and persistently, the applicant finally conceived the method for preparing metal from metal precursor solution and the application thereof.

SUMMARY

The present disclosure discloses a method for preparing metal from metal precursor solution and the application thereof. Specifically, the method and application use an atmospheric pressure plasma jet (APPJ) to treat the metal precursor solution to cause it to transform into the metal.

In another aspect, the present disclosure discloses a method for manufacturing an electrode, comprising steps of providing an insulating substrate; providing a metal precursor solution containing a metal precursor dissolved therein; causing the metal precursor solution to distribute on the insulating substrate; and treating the metal precursor solution distributed on the insulating substrate by an atmospheric pressure plasma jet (APPJ) to cause the insulating substrate having thereon the metal precursor solution treated by the APPJ to form the electrode.

In another aspect, the present disclosure discloses a method for manufacturing an electrode, comprising steps of providing a substrate; providing a metal precursor solution containing a metal precursor dissolved therein; causing the metal precursor solution to distribute on the substrate; and treating the metal precursor solution distributed on the substrate by an atmospheric pressure plasma jet (APPJ) to cause the substrate having thereon the metal precursor solution treated by the APPJ to form the electrode.

In another aspect, the present disclosure discloses a method for manufacturing a metal, comprising steps of providing a metal precursor solution containing a metal precursor; and treating the metal precursor solution by an atmospheric pressure plasma jet (APPJ) to cause the metal precursor to transform into the metal.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows voltage-current curves of DSSCs using a furnace-calcined platinum counter electrode and APPJ-treated platinum counter electrodes.

FIGS. 2a, 2b, 2c and 2d show the 5,000× magnified scanning electron micrographs of gold thin films fabricated by the APPJ treatment for 7, 20, 60 seconds and by the furnace calcination for 15 minutes.

FIG. 3 shows the X-ray diffraction patterns of gold thin films fabricated by the APPJ treatment.

DETAILED DESCRIPTION

The present disclosure can be fully understood and accomplished by the skilled person according to the following embodiments. However, the practice of present method is not limited to the following embodiments.

In an embodiment, fluorine-doped tin oxide (FTO) electrically conductive glass is used as a substrate. The substrate is rinsed by acetone for 15 minutes and isopropyl alcohol for 15 minutes. Platinum precursor solution, prepared by 10 mL of isopropyl alcohol containing 20 mg of H₂PtCl₆ being a metal precursor and dissolved therein, is used as material (where the central atom thereof is platinum) and coated on the cleaned substrate by spin coating, where the platinum precursor solution may form a liquid film on the substrate. The platinum precursor solution on the substrate is then treated with the APPJ. From the moment that the substrate temperature reaches 360° C. caused by the jet heating, the platinum precursor solution is further treated with the APPJ for various duration, 20, 40, 60 or 120 seconds, to complete the preparations of platinum electrodes. In this embodiment, the operation parameters of the APPJ are a nitrogen flow rate of 30 slm, operating voltage of 275V and duty cycle of 7/33 microsecond. When the substrate is exposed to the APPJ, the substrate and the APPJ are 2 cm apart, and the opening of the quartz tube has a radius of 1.7 cm. After the APPJ treatment, the dissolved H₂PtCl₆ is transformed into platinum solid particles on the substrate and therefore cause the substrate to have catalytic activity.

A comparative embodiment that the FTO substrate covered thereon the platinum precursor solution is made according to the procedure identical to that of the above-mentioned APPJ-treated embodiment, but it does not undergo the APPJ treatment but rather is calcined by a conventional furnace (400° C., 15 minutes) to form a comparative platinum electrode. A total duration of the conventional furnace calcination process, including heating-up and cooling-down durations, is 3 hours.

Next, each of the comparative platinum electrode and the platinum electrodes treated with various APPJ-treating duration is used to be a counter electrode and assembled with a dye-adsorbed TiO₂ photoanode, having a dense and a porous layers and treated by titanium tetrachloride, to form a DSSC. The photoelectric characteristics, including open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF %) and photoelectric conversion efficiency (η%), of the respective DSSCs are measured and shown in Table 1.

TABLE 1
Platinum counter	Voc	Jsc	FF	η
electrode in DSSC	(V)	(mA/cm2)	(%)	(%)
furnace-calcined for 15 min	0.72	10.70	68.86	5.31
APPJ-treated for 20 sec	0.71	11.26	62.17	4.97
APPJ-treated for 40 sec	0.72	11.94	62.23	5.35
APPJ-treated for 60 sec	0.74	11.69	64.62	5.59
APPJ-treated for 120 sec	0.70	11.93	54.72	4.57

As shown in Table 1, the photoelectric conversion efficiency of the DSSC using the platinum counter electrode treated by the APPJ for 40 seconds or 60 seconds is similar to that of the DSSC using the 15 minute furnace-calcined platinum counter electrode. It can be seen that through the APPJ, an excellent platinum counter electrode can be fabricated in a very short time (no more than 1 minute, and even no more than 40 seconds). In addition, when used in a DSSC, the APPJ-treated platinum counter electrode provides similar photoelectric conversion efficiency to that of the comparative platinum counter electrode.

The voltage-current curves of the DSSCs using the comparative and the APPJ-treated platinum counter electrodes are shown in FIG. 1. Based on FIG. 1, it can be seen that the DSSCs using the comparative and the APPJ-treated electrodes have similar electrical characteristics. However, the required fabrication time of the APPJ-treated electrode is significantly reduced when compared with those of the comparative electrode.

In an embodiment, before the APPJ treatment, the substrate having the spin-coated platinum precursor solution thereon undergoes a short soft bake at 75° C. for 1 min.

In another embodiment, gold precursor solution, prepared by 2 mL of isopropyl alcohol containing 20 mg of HAuCl₄ being a metal precursor and dissolved therein, is used as material (where the central atom thereof is gold) and spin-coated on a clean normal (electrically insulating) glass substrate. From the moment that the substrate temperature reaches 360° C. caused by the jet heating, the gold precursor solution on the substrate is then treated by the APPJ for 7, 20 or 60 seconds. When the gold precursor solution is treated by the APPJ, the highly reactive species (e.g. excited molecules and free radicals) and heat brought by the APPJ will cause the gold precursor solution react so as to cause the metal precursor to transform into solid gold in thin film morphology on the substrate. In this embodiment, the operation parameters of the APPJ are nitrogen flow rate of 30 slm, operating voltage of 275V and duty cycle of 7/33 microseconds.

A comparative embodiment that the glass substrate covered thereon the gold precursor solution is made according to the procedure identical to that of the above-mentioned APPJ-treated embodiment, but it does not undergo the APPJ treatment but rather is calcined by a conventional furnace (400° C., 15 minutes) to form a comparative gold thin film. A total duration of the conventional furnace calcination process, including heating up and cool down time, is 3 hours.

From the aspect of appearance, the APPJ-treated gold thin films are continuous and appear metallic luster, and the comparative thin film is discontinuous and scattered on the substrate.

Please refer to FIGS. 2a, 2b, 2c and 2d which respectively show the images of the gold thin films fabricated by the APPJ treatment for 7 (FIG. 2a), 20 (FIG. 2b) and 60 (FIG. 2c) seconds and the comparative gold thin film (FIG. 2d) observed by the scanning electron microscopy (SEM) with 5,000× magnification. It can be seen that the gold thin films 21, 22 and 23 shown in FIGS. 2a, 2b and 2c are in the continuous morphology, and the gold thin film 24 shown in FIG. 2d is scattered on the substrate and therefore is discontinuous.

Specifically, in the procedure of conventional furnace treatment, because there is sufficient reaction/treatment time, the gold transformed from the precursor solution, influenced by the surface energy at the interface between the transformed gold and the substrate, will form in a way of trying to decrease the interface area to exist in a most stable morphology, e.g. a particle or separated, discontinuous thin films as shown in FIG. 2d. However, regarding the APPJ-treatment embodiments, because the reaction/treatment time is very short, the transformed gold will be in a non-equilibrium/metastable state so that it can exist in a continuous film morphology as shown in FIGS. 2a, 2b and 2c. In addition, the flowing gas during the APPJ treatment may contribute to the formation of the continuous film.

FIG. 3 shows the X-ray diffraction patterns of the gold thin films fabricated by the APPJ treatment for 7, 20 and 60 seconds. Based on FIG. 3, it is known that the composition of the gold thin films fabricated by the APPJ treatment is gold, and, within 60 seconds, the longer the treating duration is, the better the crystallinity is.

In addition, the sheet resistances of the gold thin films fabricated by the APPJ treatment for 7, 20 and 60 seconds are shown in Table 2.

TABLE 2
Gold thin film          Sheet resistance (Ω/□)
APPJ-treated for 7 sec  2.175
APPJ-treated for 20 sec 1.359
APPJ-treated for 60 sec 0.997

Based on Table 2, it can be seen that through the APPJ treatment for 7 seconds, the gold thin film already have low sheet resistance. With the increase of the APPJ-treating duration, the electrical property of the gold thin film is improved so that the sheet resistance of the gold thin film decreases. In addition, as shown in FIG. 2 and Table 2, the continuous gold thin film fabricated through treating the gold precursor solution with APPJ can well cover the glass substrate and make the insulating glass substrate to be a conductive substrate or an electrode. As regards the comparative gold thin film, because its sheet resistance is too high to be measurable by the apparatus so that no sheet resistance value can be obtained.

In an embodiment, before the APPJ treatment, the substrate having the spin-coated gold precursor solution thereon undergoes a short soft bake at 75° C. for 1 min.

The term “continuous” used to define the film in the present disclosure has the same meaning as known in the related fields or, for example, at least means that: the film is a complete one by visual observation or a microscope, the film appears a reticular structure (as shown in FIGS. 2a and 2b, where many pieces of thin film connect to each other) or an integral film without a gap (as shown in FIG. 2c) when observed by the microscope, or the film covers on a substrate and causes an electric current to be electrically conducted on the substrate.

In an embodiment, the working temperature can be set between 250° C. and 750° C.

In an embodiment, HAuCl₄, H₂PtCl₆, PdCl₂, RuCl₃, Pd(C₅H₇O₂)₂, Cu(N₂H₃COO)₂, Pd(C₅H₈O₂)₂, Ru(C₅H₈O₂)₃, Pd(CH₃COO)₂, Cu(CH₃COO)₂, Cu(NO₃)₂, AgNO₃, Ni(NO₃)₂, Co(NO₃)₂ and a combination thereof is used as a metal precursor and dissolved in an appropriate solvent, such as water, chloroform, i-dioxane, toluene, methyl isobutyl ketone, p-xylene, o-xylene, bromobenzene, valeric acid, dimethyl sulfoxide, n-caproic acid or a combination thereof to form a metal precursor solution. The metal precursor solution is then treated with the APPJ, and the central atom, such as Au, Ag, Pt, Pd, Ru, Cu, Ni and Co, corresponding to the metal precursor is therefore transformed into solid metal.

In an embodiment, a metal precursor having a metal central atom is dissolved in a solvent to form a metal precursor solution. Then the metal precursor solution is treated using the APPJ to be transformed into solid metal formed by the metal central atom.

In an embodiment, plasma gas assorting with the APPJ includes but not limited to nitrogen, hydrogen, oxygen, argon, helium and air. In an embodiment, species of power source used to drive the APPJ includes but not limited to DC, AC, pulsed and RF. In an embodiment, species of plasma used to treat the metal precursor solution includes but not limited to plasma jet and dielectric barrier discharge plasma. The metal thin film fabricated through the APPJ treatment as disclosed in the present disclosure at least has one of continuous film morphology and particle morphology.

In an embodiment, a system for fabricating metal from a metal precursor solution is disclosed. The system includes a substrate, the metal precursor solution distributed on the substrate, a supporting device supporting the substrate, and a plasma generator generating APPJ to treat the metal precursor solution to transform the metal precursor solution into the metal. Specifically, when the substrate is a conductive one, the metal at least has one of continuous film morphology and particle morphology, and when the substrate is an insulating substrate, the metal preferably has continuous film morphology.

Embodiments

Embodiment 1 is a method for manufacturing an electrode, comprising steps of providing an insulating substrate; providing a metal precursor solution containing a metal precursor dissolved therein; causing the metal precursor solution to distribute on the insulating substrate; and treating the metal precursor solution distributed on the insulating substrate by an atmospheric pressure plasma jet (APPJ) to cause the insulating substrate having thereon the metal precursor solution treated with the APPJ to form the electrode.

Embodiment 2 is a method as described in Embodiment 1, where the metal precursor solution is treated with the APPJ to cause the metal precursor to transform into a metal disposed on the insulating substrate to cause the insulating substrate to form the electrode.

Embodiment 3 is a method as described in Embodiment 2, where the metal forms a thin film on the insulating substrate to cause the insulating substrate to form the electrode.

Embodiment 4 is a method as described in Embodiment 3, where the thin film is continuous.

Embodiment 5 is a method as described in any of Embodiments 1 to 4, where the metal precursor solution has a solute and a solvent, and the solute is the metal precursor, dissolves in the solvent and is one selected from the group consisting of HAuCl₄, H₂PtCl₆, PdCl₂, RuCl₃, Pd(C₅H₇O₂)₂, Cu(N₂H₃COO)₂, Pd(C₅H₈O₂)₂, Ru(C₅H₈O₂)₃, Pd(CH₃COO)₂, Cu(CH₃COO)₂, Cu(NO₃)₂, AgNO₃, Ni(NO₃)₂, Co(NO₃)₂ and a combination thereof.

Embodiment 6 is a method as described in any of Embodiments 1 to 4, where the metal precursor solution has a solvent selected from the group consisting of water, chloroform, i-dioxane, toluene, methyl isobutyl ketone, p-xylene, o-xylene, bromobenzene, valeric acid, dimethyl sulfoxide, n-caproic acid and a combination thereof, and a solute being the metal precursor and dissolved in the solvent.

Embodiment 7 is a method as described in any of Embodiments 1 to 6, where the APPJ is a nitrogen plasma jet.

Embodiment 8 is a method as described in any of Embodiments 1 to 7, where, from the moment that the insulating substrate temperature reaches a working temperature caused by the APPJ, the metal precursor solution distributed on the insulating substrate is further treated with the APPJ for no more than 2 minutes, preferably for no more than 1 minute, and more preferably for no more than 40 seconds.

Embodiment 9 is a method for manufacturing an electrode, comprising steps of providing a substrate; providing a metal precursor solution containing a metal precursor dissolved therein; causing the metal precursor solution to distribute on the substrate; and treating the metal precursor solution distributed on the substrate with an atmospheric pressure plasma jet (APPJ) to cause the substrate having thereon the metal precursor solution treated by the APPJ to form the electrode.

Embodiment 10 is a method as described in Embodiment 9, where the metal precursor solution is treated with the APPJ to cause the metal precursor to transform into a metal disposed on the substrate to cause the substrate to form the electrode.

Embodiment 11 is a method as described in one of Embodiments 9 and 10, where the substrate is a conductive substrate, and the metal has at least one of a film form and a particle form.

Embodiment 12 is a method as described in one of Embodiments 9 and 10, where the substrate is an insulating substrate, and the metal has a continuous film form.

Embodiment 13 is a method as described in any of Embodiments 9 to 12, where the metal precursor solution has a solute and a solvent, and the solute is the metal precursor, dissolves in the solvent and is one selected from the group consisting of HAuCl₄, H₂PtCl₆, PdCl₂, RuCl₃, Pd(C₅H₂O₂)₂, Cu(N₂H₃COO)₂, Pd(C₅H₈O₂)₂, Ru(C₅H₈O₂)₃, Pd(CH₃COO)₂, Cu(CH₃COO)₂, Cu(NO₃)₂, AgNO₃, Ni(NO₃)₂, Co(NO₃)₂ and a combination thereof.

Embodiment 14 is a method as described in any of Embodiments 9 to 12, where the metal precursor solution has a solvent selected from the group consisting of water, chloroform, i-dioxane, toluene, methyl isobutyl ketone, p-xylene, o-xylene, bromobenzene, valeric acid, dimethyl sulfoxide, n-caproic acid and a combination thereof, and a solute being the metal precursor and dissolved in the solvent.

Embodiment 15 is a method as described in any of Embodiments 9 to 14, where the APPJ is a nitrogen plasma jet.

Embodiment 16 is a method as described in any of Embodiments 9 to 15, where, from the moment that the substrate temperature reaches a working temperature caused with the APPJ, the metal precursor solution distributed on the substrate is further treated with the APPJ for no more than 2 minutes, preferably for no more than 1 minute, and more preferably for no more than 40 seconds.

Embodiment 17 is a method for manufacturing a metal, comprising steps of providing a metal precursor solution containing a metal precursor; and treating the metal precursor solution by an atmospheric pressure plasma jet (APPJ) to cause the metal precursor to transform into the metal.

Embodiment 18 is a method as described in Embodiment 17, where the solution has a solute and a solvent, and the solute is the metal precursor, dissolves in the solvent and is one selected from the group consisting of HAuCl₄, H₂PtCl₆, PdCl₂, RuCl₃, Pd(C₅H₇O₂)₂, Cu(N₂H₃COO)₂, Pd(C₅H₈O₂)₂, Ru(C₅H₈O₂)₃, Pd(CH₃COO)₂, Cu(CH₃COO)₂, Cu(NO₃)₂, AgNO₃, Ni(NO₃)₂, Co(NO₃)₂ and a combination thereof.

Embodiment 19 is a method as described in Embodiment 17, where the solution has a solvent selected from the group consisting of water, chloroform, i-dioxane, toluene, methyl isobutyl ketone, p-xylene, o-xylene, bromobenzene, valeric acid, dimethyl sulfoxide, n-caproic acid and a combination thereof, and a solute being the metal precursor and dissolved in the solvent.

Embodiment 20 is a method as described in any of Embodiments 17 to 19, where the metal has at least one of a film form and a particle form.

Embodiment 21 is a method as described in Embodiment 20, where the film form is a continuous film form.

Embodiment 22 is a method as described in any of Embodiments 17 to 21, where the APPJ is a nitrogen plasma jet.

Embodiment 23 is a method as described in any of Embodiments 17 to 22, where the metal precursor solution is treated with the APPJ for no more than 2 minutes, preferably for no more than 1 minute, and more preferably for no more than 40 seconds.

Based on the above, it can be seen that the present disclosure at least provides methods for fabricating a solid metal film from a simply prepared metal precursor mixture, such as a solution, and the applications thereof. As described in the above-mentioned embodiments, through the APPJ-treatment, the metal precursor solution can rapidly be transformed (reduced) into a continuous metal thin film and/or metal particles at atmospheric environment, which solves problems that low-pressure environment is necessary for plasma treatment, time and power are highly consumed in a furnace heating system, and the procedure to prepare a metal precursor (mixture) is complex of conventional techniques.

While this disclosure is described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the disclosure is not limited to the disclosed embodiments. Therefore, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims, which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.

Claims

1. A method for manufacturing an electrode, comprising steps of:

providing an insulating substrate;

providing a metal precursor solution containing a metal precursor dissolved therein;

causing the metal precursor solution to distribute on the insulating substrate; and

treating the metal precursor solution distributed on the insulating substrate with an atmospheric pressure plasma jet (APPJ) to form the electrode.

2. The method as claimed in claim 1, wherein the metal precursor solution is treated with the APPJ, causing the metal precursor to transform into a metal disposed on the insulating substrate to form the electrode.

3. The method as claimed in claim 2, wherein the metal forms a continuous film on the insulating substrate to form the electrode.

4. The method as claimed in claim 1 further comprising a step of from the moment that the insulating substrate temperature reaches a working temperature caused by the APPJ, the metal precursor solution distributed on the insulating substrate is further treated by the APPJ for no more than 1 minute.

5. The method as claimed in claim 1, wherein the metal precursor solution has a solute and a solvent, and the solute is the metal precursor, dissolves in the solvent and is one selected from the group consisting of HAuCl4, H2PtCl6, PdCl2, RuCl3, Pd(C5H7O2)2, Cu(N2H3COO)2, Pd(C5H8O2)2, Ru(C5H8O2)3, Pd(CH3COO)2, Cu(CH3COO)2, Cu(NO3)2, AgNO3, Ni(NO3)2, Co(NO3)2 and a combination thereof.

6. The method as claimed in claim 1, wherein the metal precursor solution has a solvent selected from the group consisting of water, chloroform, i-dioxane, toluene, methyl isobutyl ketone, p-xylene, o-xylene, bromobenzene, valeric acid, dimethyl sulfoxide, n-caproic acid and a combination thereof, and a solute being the metal precursor and dissolved in the solvent.

7. The method as claimed in claim 1, wherein the APPJ is a nitrogen plasma jet.

8. A method for manufacturing an electrode, comprising steps of:

providing a substrate;

providing a metal precursor solution containing a metal precursor dissolved therein;

causing the metal precursor solution to distribute on the substrate; and

treating the metal precursor solution on the substrate with an atmospheric pressure plasma jet (APPJ) to form the electrode.

9. The method as claimed in claim 8, wherein the metal precursor solution is treated with the APPJ to cause the metal precursor to transform into a metal disposed on the substrate to form the electrode.

10. The method as claimed in claim 9, wherein when the substrate is electrically conductive, the metal has at least one of a film form and a particle form, and when the substrate is electrically insulating, the metal forms a continuous film.

11. The method as claimed in claim 9 further comprising a step of from the moment that the insulating substrate temperature reaches a working temperature caused by the APPJ, the metal precursor solution distributing on the insulating substrate is further treated by the APPJ for no more than 2 minutes.

12. The method as claimed in claim 8, wherein the metal precursor solution has a solute and a solvent, and the solute is the metal precursor, dissolves in the solvent and is one selected from the group consisting of HAuCl4, H2PtCl6, PdCl2, RuCl3, Pd(C5H7O2)2, Cu(N2H3COO)2, Pd(C5H8O2)2, Ru(C5H8O2)3, Pd(CH3COO)2, Cu(CH3COO)2, Cu(NO3)2, AgNO3, Ni(NO3)2, Co(NO3)2 and a combination thereof.

13. The method as claimed in claim 8, wherein the metal precursor solution has a solvent selected from the group consisting of water, chloroform, i-dioxane, toluene, methyl isobutyl ketone, p-xylene, o-xylene, bromobenzene, valeric acid, dimethyl sulfoxide, n-caproic acid and a combination thereof, and a solute being the metal precursor and dissolved in the solvent.

14. The method as claimed in claim 8, wherein the APPJ is a nitrogen plasma jet.

15. A method for manufacturing a metal, comprising steps of:

providing a metal precursor solution containing a metal precursor; and

treating the metal precursor solution with an atmospheric pressure plasma jet (APPJ) to cause the metal precursor to transform into the metal.

16. The method as claimed in claim 15, wherein the solution has a solute and a solvent, and the solute is the metal precursor, dissolves in the solvent and is one selected from the group consisting of HAuCl4, H2PtCl6, PdCl2, RuCl3, Pd(C5H7O2)2, Cu(N2H3COO)2, Pd(C5H8O2)2, Ru(C5H8O2)3, Pd(CH3COO)2, Cu(CH3COO)2, Cu(NO3)2, AgNO3, Ni(NO3)2, Co(NO3)2 and a combination thereof.

17. The method as claimed in claim 15, wherein the solution has a solvent being one selected from the group consisting of water, chloroform, i-dioxane, toluene, methyl isobutyl ketone, p-xylene, o-xylene, bromobenzene, valeric acid, dimethyl sulfoxide, n-caproic acid and a combination thereof, and a solute being the metal precursor and dissolved in the solvent.

18. The method as claimed in claim 15, wherein the metal has at least one of a continuous film form and a particle form.

19. The method as claimed in claim 15, wherein the metal precursor solution is treated by the APPJ for no more than 2 minutes.

20. The method as claimed in claim 15, wherein the APPJ is a nitrogen plasma jet.