WO2013155924A1

WO2013155924A1 - Nano-generator and manufacturing method thereof

Info

Publication number: WO2013155924A1
Application number: PCT/CN2013/073258
Authority: WO
Inventors: 朱光; 王中林; 王琪
Original assignee: 纳米新能源（唐山）有限责任公司
Priority date: 2012-04-19
Filing date: 2013-03-27
Publication date: 2013-10-24
Also published as: CN102646788B; CN102646788A

Abstract

A nano-generator and manufacturing method thereof, the nano-generator comprising a base (5), a first electrode (4), a zinc oxide nano-wire array (3), a polymer insulation layer (2), and a second electrode (1); the first electrode (4) is disposed on the base (5); the zinc oxide nano-wire array (3) vertically grows on a first electrode (4) layer; a zinc oxide nano-wire array (3) layer is coated with the polymer insulation layer (2) thereon; the polymer insulation layer (2) covers the zinc oxide nano-wire array (3); the second electrode (1) is disposed on the polymer insulation layer (2); the first electrode (4) and the second electrode (1) are the voltage and current output electrodes of the nano-generator. The nano-generator adopts a unique structure, thus effectively improving the electrical performance output and stability.

Description

Nano generator and manufacturing method thereof

Technical field

The present invention relates to a nanogenerator and a method of fabricating the same, and more particularly to a power generating device made of a nanocompressive material. Background technique

Energy harvesting and conversion devices built with nanotechnology are likely to play a key role in the manufacture and driving of self-powered nanodevices and nanosystem devices. Due to their unique self-generating and self-driven properties, they have recently received research from various countries. More and more attention. In 2006, Professor Wang Zhonglin from the Georgia Institute of Technology in the United States successfully realized the first piezoelectric nanogenerator that converts mechanical energy into electrical energy using oxidized nanowires. Subsequently, based on the piezoelectric effect, various nano-generators based on different materials and structures were successively developed. Currently, nanogenerators are capable of driving commercial light-emitting diodes (LEDs), small liquid crystal displays, and even self-powered wireless data transmission equipment. However, the output power of nanogenerators is still a key factor constraining its development.

Chinese patent application CN200710097875.8 discloses an alternating current nano-generator. The invention discloses combining the oxidized nanorod array with the micro-motor structure, and utilizing the piezoelectric effect generated by the bending deformation of the oxidized nanorods, The mechanical vibration energy on the structure of the micro-motor is converted into electrical energy to form an AC nanogenerator. A plurality of such generators or diode-capacitor boosting devices are connected in series to raise the minute voltage to a certain voltage. This patent application attempts to boost the electricity generated by the nano-generator by means of a diode-capacitor, etc., however, it only increases the voltage during voltage transmission and does not increase the power generation capability of the generator itself.

Chinese patent application CN201110253998.2 discloses a heterojunction piezoelectric nano-generator comprising a semiconductor nanorod array, a semiconductor nano-slot array, a conductive substrate, and a package method, and a method for fabricating the same a layer and a lead, the semiconductor nanorod array is vertically disposed on a conductive substrate as a lower electrode of the generator, the semiconductor nanogroove array and the semiconductor nanorod array form a nested structure, and the semiconductor nanogroove array is an upper electrode of the generator, generating electricity Upper and lower electrodes They are not connected by different leads; the semiconductor nano-slot array and the semiconductor nano-rod array are provided with an encapsulation layer on the outer periphery. This patent application replaces the Schottky junction in a piezoelectric nanogenerator with a pn heterojunction to achieve a one-way conduction of the circuit, which is a change in the characteristics of the semiconductor. The nanogenerator structure is also disclosed in U.S. Patent No. 8,003,982. The solution disclosed in this patent application has problems such as low power generation output, low stability of the generator, and difficulty in manufacturing. Summary of the invention

The present invention provides a nano-generator with higher output efficiency and more stable performance and a method of manufacturing the same in order to solve the problems in the prior art.

The present invention provides a nano-generator comprising a substrate, a first electrode, an oxidized nanowire array, a polymer insulating layer and a second electrode, wherein the first electrode is disposed on a substrate, and the oxidized nanometer The line array is vertically grown on the first electrode layer, and the oxidized nanowire array layer is coated with the polymer insulating layer, and the polymer insulating layer coats the oxidized nanowire array, and the second electrode The first electrode and the second electrode are voltage and current output electrodes of the nano generator.

Further preferably, the oxidized nanowire array is grown in a plurality of regions divided by the surface of the first electrode, and a gap exists between the region and the region, and the polymer insulating layer is coated on the oxidized nanowire array and filled into In the interstitial space, a gap filling portion is formed, and the oxidized nanowire array is divided and coated.

The substrate is selected from the group consisting of a silicon substrate, a gallium nitride substrate, a conductive metal plate substrate, a conductive ceramic substrate, or a substrate of a polymer material plated with a metal electrode. The polymer insulating layer is one selected from the group consisting of phthalic acid acrylate (PMMA), polydithiosiloxane (PDMS) or p-type polymer material. The first electrode is selected from one of indium tin metal oxide (ITO), graphene or silver nanowire film coating, or is selected from the group consisting of gold, silver, platinum, aluminum, nickel, copper, titanium, One of chromium, tin or an alloy thereof. The material of the second electrode is selected from one of gold, silver, platinum, aluminum, nickel, copper, titanium, chromium, tin or alloy thereof, and is set to be high by coating, vacuum sputtering or evaporation. On the molecular insulation layer.

The nanogenerator further includes a package outer casing, and the outer casing is made of a polymer insulation material. The nano-generator provided by the invention can be composed of the single nano-generators in parallel or in series to form a generator set, thereby increasing the output voltage or current of the generator.

The invention also provides a nano-generator manufacturing method, comprising:

a. The first electrode layer and the oxidized seed layer are sequentially disposed on the substrate by radio frequency sputtering; b. the oxidized nanowire array is grown by wet chemical method, and the oxidized nanowires are vertically grown on the surface of the oxidized word;

c coating the polymer insulating layer on the oxidized nanowire array layer by spin coating;

d. Apply a second electrode to the polymer insulation layer.

The step b preferably further comprises:

e. providing a photoresist layer on the oxidized seed layer and forming an oxidized nanowire growth region by a microfabrication lithography method;

f. in a plurality of growth regions formed by the photoresist material, the oxidation chemical nanowire array is grown by wet chemical method, so that the oxidized nanowires are only grown on the exposed seed surface;

g. Peel off all remaining photoresist material.

Steps e, f, g consist in a method of preferably forming an array of vertically grown oxidized words comprising a plurality of regions.

The nano-generator manufacturing method, wherein the step g further comprises annealing the oxidized nanowires, and the heat treatment by the heat annealing can reduce the density of the oxidized nanowires themselves with free charges.

The substrate in the step a is selected from one of a silicon substrate, a gallium nitride substrate, a conductive metal plate, a conductive ceramic or a polymer material coated with a metal electrode. The material of the first electrode in the step a is selected from one of indium tin metal oxide (ITO), graphene or silver nanowire film coating. The material of the polymer insulating layer in the step e is selected from one of polydecyl methacrylate (PMMA) or polydisiloxane (PDMS). In the step f†, the material of the second electrode is selected from one of gold, silver, platinum, aluminum, nickel, copper, titanium, chromium, tin or an alloy thereof.

The nanogenerator provided by the invention has the advantage that the presence of the insulating layer provides an infinitely high barrier due to the use of a polymer insulating layer on the oxidized nanowire array layer, preventing oxidation of the nanometer. The piezoelectric electrons on the line are derived from the inside of the oxidized/metal contact surface to form a piezoelectric electric field; the piezoelectric electric field further forms an induced charge between the first electrode and the second electrode, and the induced charge is formed when the external circuit is turned on. Current loop. In addition, the polymer insulating layer is dispersedly filled in the gap between the nanowires and forms a covering layer on the topmost layer. When an external force is applied in the vertical direction, the stress can be transmitted to the nanowires under all the force applying regions through the covering layer, which greatly improves the height. The efficiency of the nano-generator; at the same time, the cover layer is also coated on the top and the periphery of the nanowire array, which plays a certain degree of buffering effect when the nanowire is subjected to an external force, and strengthens the contact between the nanowire array and the first electrode, thereby improving The stability of the nanogenerator.

In addition, the oxidized nanowires are semiconductors and have a certain degree of conductivity. When the oxidized nanowires are in contact with each other, the charges carried by the oxidized nanowires will interact with each other during the deformation power generation process, thereby canceling part of the piezoelectric charge, resulting in The output power of the power generation is reduced, which reduces the power generation performance of the nano-generator. In the present invention, however, the oxidized nanowire array grows only in a designated region or a regular region, and has little influence on each other. Due to the method of sub-regional growth of the oxidized nanowire array, and by using a polymer insulating layer to divide and coat it, when subjected to an external force, the piezoelectric charge-generating nanowire is not directly pressed without generating a piezoelectric charge. A shield division is formed between the nanowires, thereby preventing a decrease in the piezoelectric potential, thereby increasing the amount of power generation. DRAWINGS

1 is a schematic structural view of a nano-generator embodiment of the present invention.

2 is a schematic structural view of another nano-generator embodiment of the present invention.

3 is a schematic view showing the growth of the oxidized nanowires in the present invention.

4 is a perspective view of a nanogenerator according to the present invention. Figure 6 is a graph showing electrical performance of a specific embodiment of a nanogenerator according to the present invention. In the figure: 1, the second electrode, 2, the polymer insulation layer, 3, the oxidation of the nanowire array, 4, the first electrode, 5, the substrate, 6, the gap filling part of the polymer insulation layer, 7, the oxidation of the nanowire zone division. detailed description Hereinafter, specific embodiments of the present invention will be further described with reference to the accompanying drawings.

Figure 1 of the specification provides a specific embodiment of the nanogenerator of the present invention. As shown in Fig. 1, the first electrode 4 is coated with an indium tin oxide (ITO) layer and an oxidized seed layer (not shown). The ITO coating is applied not only as a conductive electrode but also to adhesion between the oxidized seed and the silicon substrate by RF sputtering on the pre-cleaned silicon substrate 5. On the oxidized seed layer, the oxidized nanowire array 3 is grown by wet chemical method. The wet chemical growth oxidized nanowire array can be realized by a known technique, and a method of hydrothermal synthesis of an oxidized nanorod array can be employed in the patent application 201110253998.2. After the oxidation of the nanowire array is completed, it is subjected to heat annealing. Then, the oxidized nanowire array 3 was covered with a polymer insulating layer 2 poly(mercapto acrylate) layer by spin coating, and then aluminum metal was applied as a second electrode 1 on the top layer. Finally, the outer casing is encapsulated with another poly(mercapto acrylate) coating. The first electrode 4 and the second electrode 1 serve as voltage and electrode output electrodes of the nanogenerator.

Figure 2 provides another embodiment of the nanogenerator of the present invention, in which a first electrode 4 indium tin oxide (ITO) coating and an oxidized seed layer (not shown) are sequentially sputtered by radio frequency. A pre-cleaned silicon substrate 5 is used. Then, the photoresist layer is covered on the oxidized seed layer, and a plurality of regular square window arrays are formed on the photoresist material by micro-machining lithography, as shown in FIG. 3 of the specification, the area inside the square window is oxidized. The seed, as the region 7 of the oxidized nanowire array growth (see Fig. 3), has a photoresist material in the square window gap to prevent the oxidized nanowire from growing. The photoresist material is equivalent to a zoned mold during the subsequent growth of the oxidized nanowires, so that the oxidized nanowires are only grown on the exposed regions of the oxidized words, thereby realizing the growth of the regions of the oxidized nanowire array. Next, all remaining photoresist material is peeled off and the nanowire array is thermally annealed. Then, a polydecyl acrylate acrylate layer as the polymer insulating layer 2 is coated on the oxidized nanowire array by spin coating, and an oxidized nanowire region filling portion 6 is formed, which divides the oxidized nanowire into predetermined amounts. Area. Finally, another polyacrylonitrile acrylate coating is used for the outer casing encapsulation. The first electrode 4 and the second electrode 1 serve as voltage and current output electrodes of the nanogenerator. The nanogenerator of this embodiment can be seen in Figure 4 of the specification, and the scanning electron micrograph of the local high magnification is shown in Figure 5 of the specification.

The process flow for manufacturing a nano-generator according to the present invention is consistent with a batch production process, allowing a plurality of silicon The substrates are processed in parallel and then cut into cubes to form a single generator. Therefore, it is superior in terms of expanding production scale and reducing costs.

In a second embodiment, the oxidized nanowires can only be grown in a controlled region, and the regular controllable regions can be fabricated by microfabrication lithography. This design allows each unit to work independently, not only to enhance the energy gain of the nanowires, but also to improve the stability of the tolerance to defects. High magnification scanning electron micrographs show that the resulting nanowire arrays are vertically aligned. As shown in Figure 5 of the specification, the nanowires are densely grown, with most of the nanowires in a single region interconnected or even mixed. Figure 5 further shows that the decyl methacrylate is tightly packed in the gaps where the nanowires and nanowire arrays are directly partitioned from one another.

The nanogenerators produced by this method undergo mechanical compression or bending deformation in dynamic shocks of linear motors that are controlled by pressure, speed and frequency. Connecting a commercial bridge rectifier to the nanomotor output electrode converts the AC output to a DC output. Test a nanometer generator of effective size lcm 1 cm x 10 μηι occupied by oxidized nanowires. The open circuit voltage (Voc) and short circuit current (Isc) are as high as 37V (Fig. 6a) and 12μΑ at IMPa pressure, respectively. 6b).

According to the theoretical calculation of the piezoelectric potential, the calculated potential difference between the two electrodes under the applied stress of IMPa should be 45V. The reason why the experimental results are smaller than the analog values is probably due to the mutual shielding effect of the free charges in the nanowires.

The superior performance and stability of the nanogenerator in this embodiment is attributed to the polymer insulating layer polydecyl acrylate layer between the nanowire array and the metal electrode. This thin layer of insulating layer has many advantages. First, it is an insulating layer that provides an infinite height barrier that prevents the inductive electrons in the electrode from "leaking" through the oxidized/metal contact surface. It replaces Schottky contacts and P/N junction contacts in the prior art. Further, decyl methacrylate is dispersedly filled in the spaces between the nanowires, and a cover layer is formed on the topmost layer. Therefore, when a force is applied in the vertical direction, stress can be transmitted to the nanowires under all the force-applying regions through the cover layer, greatly enhancing the efficiency of the nano-generator. This can also effectively improve the case where only a part of the nanowires of suitable length are deformed by contact, and it acts as a buffer layer to protect the nanowires from intimate interaction with the electrodes, thereby improving the stability of the nanogenerator.

It is also worth noting that the nanowires are selectively grown in areas designated by photolithography. This sub-regional design is designed to optimize the output of the nanogenerator. Heat treatment will decrease during manufacturing Due to the concentration of the charged body, there is still limited conductivity in the oxidized nanowires. Therefore, the freely charged body in the nanowire will partially shield the piezoelectric potential, resulting in a reduction in the power level of the power generation, thereby reducing the performance of the nanogenerator. Figure 2 is a cross-sectional view of the device with the nanowires densely packed and aligned parallel to each other. If an external force is applied in a region smaller than the device size or the applied external force distribution is not uniform, the nanowires directly under the force-receiving region generate a piezoelectric potential, and thus they are called active nanowires. Due to the existence of sub-regions, the original free electrified bodies in the nanowires (called inactive nanowires) that are not directly compacted under the stressed region are separated from the active nanowires, so they do not affect each other and prevent The piezoelectric potential is further reduced. However, if there are no sub-regions in the nanowire, the free charge in the inactive nanowire tends to migrate toward the high voltage potential side of the active nanowire, which will lower the local piezoelectric potential and reduce the output.

The electrical performance output can be effectively scaled up by linear superposition. Nine single-cell nano-generators were fabricated in parallel to form a nano-generator set. The operator slammed with the palm of his hand, and the peak values of open circuit voltage (Voc) and closed circuit current (Isc) exceeded 58V and 134μ, respectively. With this nanogenerator, no more than 20 strokes can be used to charge a 2 F capacitor to more than 3V.

In summary, the nanogenerator provided by the present invention, or the nanogenerator set provided by the invention can achieve a high record of electrical performance output of 58 V and 134 μΑ, and the maximum power density is 0.78 W/cm ³ , which is in the prior art. The highest output power never reached by nanogenerators.

The present invention is not limited to the above-described embodiments, and any variations, modifications, and alterations that can be conceived by those skilled in the art are included in the scope of the present invention without departing from the spirit of the invention.

Claims

Claim

A nano-generator comprising a substrate, a first electrode, an oxidized nanowire array, a polymer insulating layer and a second electrode, wherein

The first electrode is disposed on the substrate, the oxidized nanowire array is vertically grown on the first electrode layer, and the oxidized nanowire array layer is coated with the polymer insulating layer, the polymer insulation The layer encapsulates the oxidized nanowire array, and the second electrode is disposed on the polymer insulating layer; the first electrode and the second electrode are voltage and current output electrodes of the nanogenerator.

2. The nanogenerator according to claim 1, wherein the oxidized nanowire array is grown in a plurality of regions divided by a surface of the first electrode, and a gap exists between the region and the region, and the polymer insulating layer is coated. The oxidized nanowire array is overlaid and filled in the gap of the region to form a gap filling portion, and the oxidized nanowire array is divided and coated.

The nanogenerator according to claim 1 or 2, wherein the substrate is selected from a silicon substrate, a gallium nitride substrate, a conductive metal plate substrate, a conductive ceramic substrate or a polymer substrate material coated with a metal electrode. One of them.

The nanogenerator according to claim 1 or 2, wherein the polymer insulating layer is one selected from the group consisting of polydecylmercaptoacrylate, polydidecylsiloxane or p-type polymer material.

The nanogenerator according to claim 1 or 2, wherein the material of the first electrode is selected from one of indium tin metal oxide, graphene or silver nanowire film coating, or is selected from gold. One of silver, platinum, aluminum, nickel, copper, titanium, chromium, tin or alloys thereof.

The nanogenerator according to claim 1 or 2, wherein the material of the second electrode is selected from the group consisting of gold, silver, platinum, aluminum, nickel, copper, titanium, chromium, tin or an alloy thereof. .

The nanogenerator according to claim 1 or 2, wherein the nanogenerator further comprises a package outer casing, and the outer casing is made of a polymer insulation material.

A nanogenerator set characterized by comprising the unitary nano-motors of claims 1-7 in parallel or in series.

9. A method of manufacturing a nanogenerator, comprising the steps of:

a. The first electrode layer and the oxidized word layer are sequentially disposed on the substrate by radio frequency sputtering; b. using a wet chemical method to grow an oxidized nanowire array, so that the oxidized nanowires are vertically grown on the surface of the oxidized seed;

C. coating the polymer insulating layer on the oxidized nanowire array layer by spin coating;

d. A second electrode is disposed on the polymer insulating layer.

10. The method of manufacturing a nanogenerator according to claim 9, wherein the step b comprises:

e. providing a photoresist layer on the oxidized seed layer, and forming a plurality of growth regions of the oxidized nanowire by microfabrication lithography;

f. in a plurality of growth regions formed by the photoresist material, vertically growing the oxidized nanowire array by wet chemical method, so that the oxidized nanowires are only grown on the exposed seed surface;

g. Peel off all remaining photoresist material.

11. The nanogenerator manufacturing method according to claim 10, wherein the step g further comprises heating annealing the oxidized nanowires.

The method of manufacturing a nano-generator according to claim 9 or 10, wherein the substrate in the step a is selected from the group consisting of a silicon substrate, a gallium nitride substrate, a conductive metal plate, a conductive ceramic or a polymer coated with a metal electrode. One of the polymeric materials.

The method of manufacturing a nano-generator according to claim 9 or 10, wherein the first electrode in the step a is selected from one of indium tin metal oxide, graphene, silver nanowire film or metal coating Kind.

The method of manufacturing a nano-generator according to claim 9 or 10, wherein the material of the polymer insulating layer in the step e is selected from the group consisting of polydecyl acrylate or polydithiosiloxane. Kind.

The nano-generator manufacturing method according to claim 9 or 10, wherein the second electrode of the step f is made of gold, silver, platinum, aluminum, nickel, copper, titanium, chromium, tin. Or one of its alloys.

The nanogenerator manufacturing method according to claim 9 or 10, wherein the nanogenerator further comprises a package outer casing, and the outer casing is made of a polymer insulation material.