A method for preparing a single silver nanowire device

Abstract

The present invention relates to the technical field of single silver nanowire production, and in particular to a method for preparing a single silver nanowire device, comprising the following preparation steps: selecting a quartz glass sheet, marking a cross-finger electrode pattern after cleaning with an organic solvent; etching the marked pattern; cleaning; plating two layers of metal according to the etched mark; rinsing and drying; preparing a silver nanowire dispersion, dripping it on the quartz glass sheet, and obtaining an electrode overlapped by a single silver nanowire; the concentration of the silver nanowire dispersion is 1.8-2.2 mg / L. The method for preparing a single silver nanowire device of the present invention can efficiently and economically realize the overlap of a single silver nanowire by limiting the electrode spacing, the length of the silver nanowire and the concentration of the dispersion, has universality, and the prepared single silver nanowire is more widely used in the market.

Description

Technical Field

[0001] The invention relates to the technical field of single silver nanowires, and in particular to a method for preparing a single silver nanowire device. Background Art

[0002] Nanowires are a type of nanometer-scale (1 nanometer = 10^-9 meters) wire. Depending on the material they are made of, nanowires can be divided into different types, including metal nanowires (such as Ni, Pt, Ag, etc.), semiconductor nanowires (such as InP, Si, GaN, etc.) and insulator nanowires (such as SiO2, TiO2, etc.). Molecular nanowires are composed of repeating molecular elements and can be organic (such as DNA) or inorganic (such as Mo6S9-xIx). As an important component of nanotechnology, nanowires can be used to make ultra-small circuits. Among them, silver nanowires not only have the excellent conductivity of silver, but also have excellent light transmittance and flex resistance due to the size effect at the nanoscale, which makes it possible to realize flexible, bendable LED displays, touch screens, etc. In addition, due to the large aspect ratio effect of silver nanowires, they also have outstanding advantages in the application of conductive adhesives, thermal conductive adhesives, etc. For example, optical applications: solar energy (crystalline silicon, thin sheets on PET or glass), optical limiters, medical imaging, surface enhanced spectroscopy, surface plasmonic devices; conductive applications: high-brightness LEDs, conductive adhesives, touch screens, computer boards, LCDs, sensors; antimicrobial applications: air and water purification, sterile equipment, bandages, food preservation; chemical and thermodynamic applications, catalysts, sensors, chemical vapor sensors, conductive adhesives, pastes, polymers, in addition, there are relatively mature applications - transparent nano silver wire films. Its related materials are also widely used in many fields such as energy, catalysis, biology, and electronics. Based on the above applications, studies have shown that the characteristics of a single silver nanowire and its response under external conditions (light, electricity, and heat) are important factors affecting functional applications. In this case, studying the characteristics of a single silver nanowire and its response under external conditions (light, electricity, and heat) can help further explore the characteristics of a single silver nanowire, which has great practical significance. There is a patent report (CN202110174657.X) that successfully prepared a single silver nanowire device by introducing a seed crystal at the tip of a capillary tube, but this method obviously has high requirements for chemical synthesis process control and cannot achieve the transfer and characterization of a single silver nanowire. In addition, there are literature reports that the dispersion of a single silver nanowire was achieved through the microfluidic chip method, but the actual device is a plurality of silver nanowires, and it is impossible to study a single silver nanowire under different external conditions, making it difficult to prepare a single silver nanowire device that can be used for optical, electrical, thermal and other performance studies. Summary of the invention

[0003] In order to solve the above problems, based on the existing preparation of a single metal nanowire, the present invention provides a method for preparing a single silver nanowire device.

[0004] The present invention adopts the following technical solutions:

[0005] A method for preparing a single silver nanowire device comprises the following steps:

[0006] (1) Select a quartz glass sheet, clean it with an organic solvent, and mark the interdigital electrode pattern;

[0007] (2) etching a marked interdigital electrode pattern on a quartz glass sheet using an electron beam lithography machine;

[0008] (3) Place in a plasma cleaning machine and clean with oxygen or nitrogen plasma;

[0009] (4) Place the magnetron sputtering machine and plate two layers of metal according to the etched marks;

[0010] (5) After rinsing with an organic solvent, blow drying with oxygen or nitrogen plasma;

[0011] (6) Prepare a silver nanowire dispersion and drop it onto a quartz glass sheet to obtain an electrode with a single silver nanowire connected.

[0012] The concentration of the silver nanowire dispersion prepared in step (6) is 1.8-2.2 mg / L.

[0013] Furthermore, the two layers of metal plated in step (4) include a thin layer covering the quartz glass sheet and a thick layer covering the thin layer; the metal of the thin layer is nickel or chromium, and its thickness is 15-25nm; the metal of the thick layer is gold, and its thickness is 90-110nm.

[0014] More preferably, the metal thickness of the thin layer in step (4) is 20 nm, and the metal thickness of the thick layer is 100 nm.

[0015] Furthermore, the electrode spacing of the interdigitated electrode pattern in step (1) is 1 / 2-2 / 3 of the length of the silver nanowires in the silver nanowire dispersion in step (6).

[0016] More preferably, the electrode spacing of the interdigitated electrode pattern in step (1) is 1 / 2-7 / 12 of the length of the silver nanowire in step (6).

[0017] Furthermore, the concentration of the silver nanowire dispersion prepared in step (6) is 1.9-2.1 mg / L.

[0018] More preferably, the concentration of the silver nanowire dispersion prepared in step (6) is 2 mg / L.

[0019] Furthermore, the silver nanowires in the silver nanowire dispersion prepared in step (6) have a length of 10-100 μm and a diameter of 10-100 nm.

[0020] Furthermore, the organic solvent in step (1) is 85%-95% acetone, or 90%-95% ethanol.

[0021] More preferably, the organic solvent in step (1) is 95% acetone and 95% ethanol.

[0022] Furthermore, the electron beam exposure dose in step (2) is 250-350 μC / cm 2 , the electron beam acceleration voltage is 15-25kV, and the electron beam current is 250-350pA.

[0023] More preferably, the electron beam exposure dose in step (2) is 300 μC / cm 2 , the electron beam acceleration voltage is 20 kV, and the electron beam current is 300 pA.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. In the preparation method of a single silver nanowire device provided by the present invention, the designed nanowire concentration can avoid the silver nanowire agglomeration or excessive dispersion caused by too high or too low silver nanowire concentration to the maximum extent, and can efficiently and economically realize the overlap of single silver nanowires. The overlapped silver nanowire device can well carry out the transfer and related characterization tests of single silver nanowires, which is convenient for the subsequent research on the optical, electrical, thermal and other properties of single silver nanowires. The operation is simple and has universal applicability.

[0026] 2. In the preparation method of a single silver nanowire device provided by the present invention, acetone and ethanol organic solvents are selected as polar cleaning solvents to better absorb dust on the substrate and play a better cleaning role; the preparation method of a single silver nanowire device provided by the present invention can form a hydrophilic interface through oxygen and nitrogen plasma to better achieve the cleaning effect; the preparation method of a single silver nanowire device provided by the present invention has a thin layer of metal plated on the surface of quartz glass, and nickel and chromium have strong adhesion; the thick layer of metal gold has strong conductivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1This is a scanning electron microscope image of a single silver nanowire overlapped in Example 1 of the present invention;

[0029] Figure 2 This is a laser confocal microscope image of a single silver nanowire overlapped in Example 1 of the present invention;

[0030] Figure 3 This is a laser confocal microscope image of a single silver nanowire overlapped in Example 2 of the present invention;

[0031] Figure 4 This is a laser confocal microscope image of a single silver nanowire overlapped in Example 3 of the present invention;

[0032] Figure 5 This is a laser confocal microscope image of a single silver nanowire overlapped in Example 4 of the present invention;

[0033] Figure 6 This is a laser confocal microscope image of Comparative Example 1 of the present invention;

[0034] Figure 7 This is a laser confocal microscope image of Comparative Example 2 of the present invention; DETAILED DESCRIPTION

[0035] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0036] Example 1

[0037] A single silver nanowire device, the preparation steps are as follows:

[0038] (1) Select a quartz glass sheet, clean it with 95% acetone, and mark a forked electrode pattern. The line width and electrode spacing of the forked electrode pattern are both 10 μm, the finger length is 1.2 mm, and there are 20 pairs of 40 fingers;

[0039] (2) The electron beam exposure dose is 300 μC / cm 2 , an electron beam exposure machine with an electron beam acceleration voltage of 20 kV and an electron beam current of 300 pA etches a marked interdigital electrode pattern on a quartz glass sheet;

[0040] (3) Place the quartz glass sheet with the etched interdigital electrode pattern into a plasma cleaning machine and clean it with oxygen plasma for 10 minutes;

[0041] (4) The cleaned quartz glass sheet is placed in a magnetron sputtering machine, and a thin layer of metal chromium with a thickness of 20 nm is first plated on the surface according to the etched mark, and then a thick layer of metal gold with a thickness of 100 nm is plated on the surface of the thin layer of metal chromium.

[0042] (5) After the magnetron gold-plated quartz glass sheet is cleaned with 95% acetone, it is passed through oxygen plasma for 10 minutes and blown dry;

[0043] (6) Prepare a silver nanowire dispersion with a concentration of 2 mg / L, a length of 15 μm, and a diameter of 20 nm, drop it onto a quartz glass sheet, and search for electrodes connected by a single silver nanowire under a laser confocal microscope.

[0044] Figure 1 This is a scanning electron microscope image of a single silver nanowire bonded to this embodiment. Figure 2 This is a laser confocal microscope image of the overlap of a single silver nanowire in this embodiment. It can be seen from the image that the overlap of the single silver nanowire is clearly visible.

[0045] Example 2

[0046] A single silver nanowire device, the preparation steps of which are as follows:

[0047] (1) Select a quartz glass sheet, clean it with 95% acetone, and mark a forked electrode pattern. The line width and electrode spacing of the forked electrode pattern are both 10 μm, the finger length is 1.2 mm, and there are 20 pairs of 40 fingers;

[0048] (2) The electron beam exposure dose is 300 μC / cm 2 , an electron beam exposure machine with an electron beam acceleration voltage of 20 kV and an electron beam current of 300 pA etches a marked interdigital electrode pattern on a quartz glass sheet;

[0049] (3) Place the quartz glass sheet with the etched interdigital electrode pattern into a plasma cleaning machine and clean it with oxygen plasma for 10 minutes;

[0050] (4) The cleaned quartz glass sheet is placed in a magnetron sputtering machine, and a thin layer of metal chromium with a thickness of 20 nm is first plated on the surface according to the etched mark, and then a thick layer of metal gold with a thickness of 100 nm is plated on the surface of the thin layer of metal chromium.

[0051] (5) After the magnetron gold-plated quartz glass sheet is cleaned with 95% acetone, it is passed through oxygen plasma for 10 minutes and blown dry;

[0052] (6) A silver nanowire dispersion with a concentration of 1.8 mg / L, a length of 20 μm, and a diameter of 20 nm was prepared and dropped onto a quartz glass sheet. The electrodes connected by a single silver nanowire were searched under a laser confocal microscope.

[0053] Figure 3 This is a laser confocal microscope image of the overlap of a single silver nanowire in this embodiment. It can be seen from the image that the overlap of the single silver nanowire is clearly visible.

[0054] Example 3

[0055] A single silver nanowire device, the preparation steps of which are as follows:

[0056] (1) Select a quartz glass sheet, clean it with 95% acetone, and mark a forked electrode pattern. The line width and electrode spacing of the forked electrode pattern are both 10 μm, the finger length is 1.2 mm, and there are 20 pairs of 40 fingers;

[0057] (2) The electron beam exposure dose is 300 μC / cm 2 , an electron beam exposure machine with an electron beam acceleration voltage of 20 kV and an electron beam current of 300 pA etches a marked interdigital electrode pattern on a quartz glass sheet;

[0058] (3) Place the quartz glass sheet with the etched interdigital electrode pattern into a plasma cleaning machine and clean it with oxygen plasma for 10 minutes;

[0059] (4) The cleaned quartz glass sheet is placed in a magnetron sputtering machine, and a thin layer of metal chromium with a thickness of 20 nm is first plated on the surface according to the etched mark, and then a thick layer of metal gold with a thickness of 100 nm is plated on the surface of the thin layer of metal chromium.

[0060] (5) After the magnetron gold-plated quartz glass sheet is cleaned with 95% acetone, it is passed through oxygen plasma for 10 minutes and blown dry;

[0061] (6) Prepare a silver nanowire dispersion with a concentration of 2.2 mg / L, a length of 16 μm, and a diameter of 20 nm, drop it onto a quartz glass sheet, and search for electrodes connected by a single silver nanowire under a laser confocal microscope.

[0062] Figure 4 This is a laser confocal microscope image of the overlap of a single silver nanowire in this embodiment. It can be seen from the image that the overlap of the single silver nanowire is clearly visible.

[0063] Example 4

[0064] A single silver nanowire device, the preparation steps of which are as follows:

[0065] (1) Select a quartz glass sheet, clean it with 95% acetone, and mark a forked electrode pattern. The line width and electrode spacing of the forked electrode pattern are both 10 μm, the finger length is 1.2 mm, and there are 20 pairs of 40 fingers;

[0066] (2) The electron beam exposure dose is 300 μC / cm 2, an electron beam exposure machine with an electron beam acceleration voltage of 20 kV and an electron beam current of 300 pA etches a marked interdigital electrode pattern on a quartz glass sheet;

[0067] (3) Place the quartz glass sheet with the etched interdigital electrode pattern into a plasma cleaning machine and clean it with oxygen plasma for 10 minutes;

[0068] (4) The cleaned quartz glass sheet is placed in a magnetron sputtering machine, and a thin layer of metal chromium with a thickness of 20 nm is first plated on the surface according to the etched mark, and then a thick layer of metal gold with a thickness of 100 nm is plated on the surface of the thin layer of metal chromium.

[0069] (5) After the magnetron gold-plated quartz glass sheet is cleaned with 95% acetone, it is passed through oxygen plasma for 10 minutes and blown dry;

[0070] (6) Prepare a silver nanowire dispersion with a concentration of 1.8 mg / L, a length of 17 μm, and a diameter of 20 nm, drop it onto a quartz glass sheet, and search for electrodes connected by a single silver nanowire under a laser confocal microscope.

[0071] Figure 5 This is a laser confocal microscope image of the overlap of a single silver nanowire in this embodiment. It can be seen from the image that the overlap of the single silver nanowire is clearly visible.

[0072] Comparative Example 1

[0073] A single silver nanowire device, which differs from Example 1 only in the concentration of the silver nanowire dispersion, is prepared as follows:

[0074] (1) Select a quartz glass sheet, clean it with 95% acetone, and mark a forked electrode pattern. The line width and electrode spacing of the forked electrode pattern are both 10 μm, the finger length is 1.2 mm, and there are 20 pairs of 40 fingers;

[0075] (2) The electron beam exposure dose is 300 μC / cm 2 , an electron beam exposure machine with an electron beam acceleration voltage of 20 kV and an electron beam current of 300 pA etches a marked interdigital electrode pattern on a quartz glass sheet;

[0076] (3) Place the quartz glass sheet with the etched interdigital electrode pattern into a plasma cleaning machine and clean it with oxygen plasma for 10 minutes;

[0077] (4) The cleaned quartz glass sheet is placed in a magnetron sputtering machine, and a thin layer of metal chromium with a thickness of 20 nm is first plated on the surface according to the etched mark, and then a thick layer of metal gold with a thickness of 100 nm is plated on the surface of the thin layer of metal chromium.

[0078] (5) After the magnetron gold-plated quartz glass sheet is cleaned with 95% acetone, it is passed through oxygen plasma for 10 minutes and blown dry;

[0079] (6) Prepare a silver nanowire dispersion with a concentration of 2.4 mg / L, a length of 15 μm, and a diameter of 20 nm, drop it onto a quartz glass sheet, and search for electrodes connected by a single silver nanowire under a laser confocal microscope.

[0080] The experimental results are shown in Figure 6 , which is a laser confocal microscope effect diagram of this embodiment. It can be seen from the figure that due to the high concentration of silver nanowires, the silver nanowires are agglomerated between the electrodes and the overlapping of single silver nanowires is not achieved.

[0081] Comparative Example 2

[0082] A single silver nanowire device, which differs from Example 1 only in the concentration of the silver nanowire dispersion, is prepared as follows:

[0083] (1) Select a quartz glass sheet, clean it with 95% acetone, and mark a forked electrode pattern. The line width and electrode spacing of the forked electrode pattern are both 10 μm, the finger length is 1.2 mm, and there are 20 pairs of 40 fingers;

[0084] (2) The electron beam exposure dose is 300 μC / cm 2 , an electron beam exposure machine with an electron beam acceleration voltage of 20 kV and an electron beam current of 300 pA etches a marked interdigital electrode pattern on a quartz glass sheet;

[0085] (3) Place the quartz glass sheet with the etched interdigital electrode pattern into a plasma cleaning machine and clean it with oxygen plasma for 10 minutes;

[0086] (4) The cleaned quartz glass sheet is placed in a magnetron sputtering machine, and a thin layer of metal chromium with a thickness of 20 nm is first plated on the surface according to the etched mark, and then a thick layer of metal gold with a thickness of 100 nm is plated on the surface of the thin layer of metal chromium.

[0087] (5) After the magnetron gold-plated quartz glass sheet is cleaned with 95% acetone, it is passed through oxygen plasma for 10 minutes and blown dry;

[0088] (6) Prepare a silver nanowire dispersion with a concentration of 1.5 mg / L, a length of 15 μm, and a diameter of 20 nm, drop it onto a quartz glass sheet, and search for electrodes connected by a single silver nanowire under a laser confocal microscope.

[0089] The experimental results are shown in Figure 7, which is a laser confocal microscope effect diagram of this embodiment. It can be seen from the figure that due to the low concentration of silver nanowires, the silver nanowires are too dispersed between the electrodes and the overlap of single silver nanowires is not achieved.

[0090] The present invention provides a method for preparing a single silver nanowire device. By limiting the concentration of the silver nanowire dispersion liquid, the single silver nanowire can be overlapped efficiently and economically. The overlapped silver nanowire device can well transfer the single silver nanowire and carry out related characterization tests, which is convenient for subsequent research on the optical, electrical, thermal and other properties of the single silver nanowire. The operation is simple and has universal applicability. In the method for preparing a single silver nanowire device provided by the present invention, the use of acetone and ethanol organic solvents can have a better cleaning effect, and a better cleaning effect can be achieved by oxygen and nitrogen plasma. The thin layer of metal nickel and chromium plated on the surface of the quartz glass has strong adhesion; the thick layer of metal gold has strong conductivity.

[0091] The present invention is further described above with the aid of specific embodiments. However, it should be understood that the specific description here should not be construed as limiting the essence and scope of the present invention. Various modifications made to the above embodiments by ordinary technicians in the field after reading this specification are all within the scope of protection of the present invention.

Claims

1. A method for preparing a single silver nanowire device, characterized in that: The method comprises the following preparation steps: (1) Select a quartz glass sheet, clean it with an organic solvent, and mark the interdigital electrode pattern; (2) using an electron beam lithography machine to etch a marked interdigital electrode pattern on a quartz glass sheet; (3) Place in a plasma cleaning machine and clean with oxygen or nitrogen plasma; (4) Place the substrate in a magnetron sputtering machine and plate two layers of metal according to the etched marks; (5) After rinsing with an organic solvent, blow drying with oxygen or nitrogen plasma; (6) preparing a silver nanowire dispersion and dropping it onto a quartz glass sheet to obtain an electrode with a single silver nanowire connected; The concentration of the silver nanowire dispersion prepared in step (6) is 1.8-2.2 mg / L.

2. The method for preparing a single silver nanowire device according to claim 1, characterized in that: The two layers of metal plated in step (4) include a thin layer covering the quartz glass sheet and a thick layer covering the thin layer; the metal of the thin layer is nickel or chromium, and its thickness is 15-25nm; the metal of the thick layer is gold, and its thickness is 90-110nm.

3. The method for preparing a single silver nanowire device according to claim 1, characterized in that: The electrode spacing of the interdigitated electrode pattern in step (1) is 1 / 2-2 / 3 of the length of the silver nanowires in the silver nanowire dispersion in step (6).

4. The method for preparing a single silver nanowire device according to claim 3, characterized in that: The electrode spacing of the interdigitated electrode pattern in step (1) is 1 / 2-7 / 12 of the length of the silver nanowires in the silver nanowire dispersion in step (6).

5. The method for preparing a single silver nanowire device according to claim 1, characterized in that: The concentration of the silver nanowire dispersion prepared in step (6) is 1.9-2.1 mg / L.

6. The method for preparing a single silver nanowire device according to claim 1, characterized in that: The silver nanowires in the silver nanowire dispersion prepared in step (6) have a length of 10-100 μm and a diameter of 10-100 nm.

7. The method for preparing a single silver nanowire device according to claim 1, characterized in that: The organic solvent in step (1) is 85-95% acetone or 90-95% ethanol.

8. The method for preparing a single silver nanowire device according to claim 1, characterized in that: Step (2) The electron beam exposure dose is 250-350 μC / cm 2 , the electron beam acceleration voltage is 15-25kV, and the electron beam current is 250-350pA.

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