Metal net transparent conductive film with electric heating and electromagnetic shielding performances

Abstract

The invention belongs to the technical field of functional thin film materials, and particularly provides a metal net transparent conductive thin film with electric heating and electromagnetic shielding properties, which has excellent conductivity, electric heating property and electromagnetic shielding property and good mechanical flexibility while keeping higher visible light transmittance. Therefore, the application requirements in the fields of flexible electronic devices, transparent heaters, electromagnetic shielding devices and the like are met. The metal net transparent conductive film comprises a transparent flexible substrate, a transition layer and a metal net conductive layer, the transition layer and the metal net conductive layer are sequentially deposited on the transparent flexible substrate, the transition layer adopts Cr or Ti, and the metal net conductive layer has a random grid structure to form a continuous conductive path. In conclusion, the metal net transparent conductive film provided by the invention has multiple functions of transparent conduction, electric heating, electromagnetic shielding, high flexibility and the like, and can be applied to the fields of flexible electronic devices, transparent heaters, transparent electromagnetic shielding devices and the like.

Description

Technical Field

[0001] This invention belongs to the field of functional thin film materials technology, and relates to transparent conductive films. Specifically, it provides a metal mesh transparent conductive film that combines electroheating and electromagnetic shielding properties, while also possessing transparent conductivity, electroheating, electromagnetic shielding properties, and high flexibility and bending stability. Background Technology

[0002] Transparent conductive films (TCFs) are a class of functional thin-film materials that possess high transmittance in the visible light band while also exhibiting good conductivity. They have wide applications in touch display devices, flexible electronic devices, solar cells, transparent heaters, and electromagnetic shielding windows. With the rapid development of flexible electronics and smart display technologies, higher demands are being placed on transparent conductive films. These films not only require low sheet resistance and high optical transmittance, but also excellent mechanical flexibility and multifunctional application characteristics.

[0003] Currently, the most widely used transparent conductive material is Indium Tin Oxide (ITO). While this material exhibits good photoelectric properties, it is inherently a brittle ceramic material, prone to cracking under mechanical deformation conditions such as bending or stretching. This leads to a significant increase in resistance or even conductivity failure, thus limiting its application in flexible electronic devices. In recent years, researchers have proposed various novel transparent conductive material systems, such as transparent conductive films based on metal nanostructures, including metal nanowire networks, ultrathin metal films, and metal mesh films. Among these, metal mesh structures, with their continuous metal conductive paths, low resistance, and good mechanical flexibility, are considered a promising new type of transparent conductive structure.

[0004] However, current research on transparent conductive films with metal mesh largely focuses on optimizing the balance between optical transmittance and sheet resistance, while research on their multifunctional properties remains relatively limited. In many practical applications, such as transparent defogging glass, transparent heaters, and electromagnetic shielding windows, materials are required not only to possess excellent transparent conductivity but also to simultaneously provide electrothermal functionality, electromagnetic shielding capabilities, and stable conductivity under long-term bending conditions. Therefore, developing a multifunctional transparent conductive film that maintains high transmittance and low sheet resistance while also possessing electrothermal properties, electromagnetic shielding, and excellent flexibility and stability is of great significance for expanding the application of transparent conductive films in flexible electronic devices and multifunctional transparent devices. Summary of the Invention

[0005] The purpose of this invention is to provide a transparent conductive film with metal mesh that combines electroheating and electromagnetic shielding properties. While maintaining high visible light transmittance, it has excellent conductivity, electroheating performance, electromagnetic shielding performance, and good mechanical flexibility, thereby meeting the application needs of flexible electronic devices, transparent heaters, and electromagnetic shielding devices.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A transparent conductive film with both electrothermal and electromagnetic shielding properties is characterized by comprising: a transparent flexible substrate, a transition layer, and a metal mesh conductive layer, wherein the transition layer and the metal mesh conductive layer are sequentially deposited on the transparent flexible substrate; the transition layer is made of Cr or Ti and has a thickness of 1 nm to 5 nm; the metal mesh conductive layer has a random grid structure to form a continuous conductive path and has a thickness of 20 nm to 200 nm.

[0008] Furthermore, the conductive layer of the metal mesh is made of gold, silver, or copper.

[0009] Furthermore, the transparent flexible substrate is polyethylene terephthalate (PET), polyimide (PI), or polycarbonate (PC).

[0010] Furthermore, the sheet resistance of the transparent conductive metal mesh film is 1 Ω / sq ~ 25 Ω / sq.

[0011] Furthermore, the transparent conductive film of the metal mesh has a transmittance of 65% to 85% at a wavelength of 550 nm.

[0012] Furthermore, the transparent conductive film of the metal mesh heats up to 40℃~100℃ within 100 seconds under a voltage of 3V.

[0013] Furthermore, the electromagnetic shielding effectiveness of the metal mesh transparent conductive film is 20 dB to 40 dB in the frequency band of 8.2 GHz to 12.4 GHz.

[0014] Furthermore, the transparent conductive film of the metal mesh remains conductive after being cyclically bent 10,000 times at a bending radius of 2.5 mm and a bending speed of 40 ° / s.

[0015] Based on the above technical solution, the beneficial effect of the present invention is that it provides a transparent conductive film with metal mesh that combines electroheating and electromagnetic shielding properties, and simultaneously possesses electroheating performance, electromagnetic shielding performance, and excellent flexibility and stability. Specific advantages are as follows:

[0016] 1) This invention constructs a conductive metal mesh structure, enabling the thin film to maintain high light transmittance while having low sheet resistance;

[0017] 2) The conductive metal mesh of the present invention can generate a Joule heating effect under energized conditions, thereby realizing the transparent electric heating function;

[0018] 3) The conductive metal mesh structure of the present invention can reflect and absorb electromagnetic waves, thus having good electromagnetic shielding performance;

[0019] 4) The random metal mesh structure of the present invention can effectively alleviate bending stress and maintain stable conductivity under multiple bending conditions, exhibiting excellent flexibility and stability.

[0020] 5) This invention improves the adhesion between the metal conductive layer and the substrate by introducing a metal transition layer, so that the film can maintain stable conductivity under multiple bending conditions and has excellent flexibility and stability.

[0021] 6) The transparent conductive film of the present invention has multiple functions such as transparent conductivity, electric heating, electromagnetic shielding and high flexibility, and can be applied to fields such as flexible electronic devices, transparent heaters and transparent electromagnetic shielding devices. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the transparent conductive film with metal mesh that combines electric heating and electromagnetic shielding properties in this invention.

[0023] Figure 2 This is a transmittance curve of a transparent conductive metal mesh film that combines electric heating and electromagnetic shielding properties in an embodiment of the present invention.

[0024] Figure 3 This is a test curve of the electroheating performance of the transparent conductive metal mesh film that combines electroheating and electromagnetic shielding properties in an embodiment of the present invention.

[0025] Figure 4 This is a graph showing the electromagnetic shielding performance test of a transparent conductive metal mesh film that combines electric heating and electromagnetic shielding properties in an embodiment of the present invention.

[0026] Figure 5 This is a graph showing the bending cycle stability test results of a transparent conductive metal mesh film that combines electric heating and electromagnetic shielding properties in an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0028] Example 1

[0029] This embodiment provides a transparent conductive metal mesh film that combines electric heating and electromagnetic shielding properties. A flexible PET substrate is used as the substrate. First, a Cr transition layer with a thickness of about 2 nm is deposited on its surface to improve the adhesion between the metal layer and the substrate. Then, an Au metal mesh conductive structure with a thickness of 20 nm is deposited on its surface.

[0030] The obtained transparent conductive film has a transmittance of approximately 80% at a wavelength of 550 nm and a sheet resistance of approximately 22 Ω / sq. Its transmittance test results are as follows: Figure 2 As shown.

[0031] In the electric heating test, under a voltage of 3 V, the temperature of the thin film rose to approximately 42 °C within 100 seconds. The electric heating test results are as follows: Figure 3 As shown.

[0032] In electromagnetic shielding tests, within the 8.2 GHz–12.4 GHz frequency band, the electromagnetic shielding effectiveness of the film was approximately 21 dB. The electromagnetic shielding test results are as follows: Figure 4 As shown.

[0033] In the flexible bending test, a cyclic bending experiment was conducted with a bending radius of 2.5 mm and a bending speed of 40° / s. After 10,000 bending cycles, the film resistance became 1.67 times the initial value, while maintaining continuous conductivity. The test results of the sheet resistance changing with the number of bending cycles are as follows: Figure 5 As shown.

[0034] Example 2

[0035] This embodiment provides a transparent conductive film with both electric heating and electromagnetic shielding properties. The difference between this embodiment and Embodiment 1 is that the Au layer thickness is 50 nm.

[0036] The obtained transparent conductive film has a transmittance of approximately 65% ​​at a wavelength of 550 nm and a sheet resistance of approximately 6.3 Ω / sq. Its transmittance test results are as follows: Figure 2 As shown.

[0037] In the electric heating test, under a voltage of 3 V, the film temperature rose to approximately 64 °C within 100 seconds. The electric heating test results are as follows: Figure 3 As shown.

[0038] In electromagnetic shielding tests, within the 8.2 GHz–12.4 GHz frequency band, the electromagnetic shielding effectiveness of the film was approximately 28.5 dB. The electromagnetic shielding test results are as follows: Figure 4 As shown.

[0039] In the flexible bending test, a cyclic bending experiment was conducted with a bending radius of 2.5 mm and a bending speed of 40° / s. After 10,000 bending cycles, the film resistance became 2.1 times the initial value, while maintaining continuous conductivity. The test results of the sheet resistance changing with the number of bending cycles are as follows: Figure 5 As shown.

[0040] The above description is merely a specific embodiment of the present invention. Any feature disclosed in this specification may be replaced by other equivalent or similar features unless otherwise specified. All disclosed features, or steps in all methods or processes, may be combined in any way except for mutually exclusive features and / or steps.

Claims

1. A transparent conductive film with both electric heating and electromagnetic shielding properties, characterized in that, include: A transparent flexible substrate, a transition layer, and a conductive metal mesh layer, wherein: The transition layer and the conductive metal mesh layer are sequentially deposited on a transparent flexible substrate; The transition layer is made of Cr or Ti and has a thickness of 1 nm to 5 nm. The conductive metal mesh layer has a random grid structure to form a continuous conductive path, and has a thickness of 20 nm to 200 nm.

2. The transparent conductive film with both electric heating and electromagnetic shielding properties according to claim 1, characterized in that, The conductive layer of the metal mesh is made of gold, silver, or copper.

3. The transparent conductive metal mesh film with both electric heating and electromagnetic shielding properties according to claim 1, characterized in that, The transparent flexible substrate is polyethylene terephthalate (PET), polyimide (PI), or polycarbonate (PC).

4. The transparent conductive film with both electric heating and electromagnetic shielding properties according to claim 1, characterized in that, The sheet resistance of the transparent conductive metal mesh film is 1 Ω / sq ~ 25 Ω / sq.

5. The transparent conductive film with both electric heating and electromagnetic shielding properties according to claim 1, characterized in that, The transparent conductive film of the metal mesh has a transmittance of 65% to 85% at a wavelength of 550 nm.

6. The transparent conductive film with both electric heating and electromagnetic shielding properties according to claim 1, characterized in that, The transparent conductive film of the metal mesh heats up to 40℃~100℃ within 100 seconds under a voltage of 3V.

7. The transparent conductive film with both electric heating and electromagnetic shielding properties according to claim 1, characterized in that, The transparent conductive metal mesh film has an electromagnetic shielding effectiveness of 20 dB to 40 dB in the frequency band of 8.2 GHz to 12.4 GHz.

8. The transparent conductive film with both electric heating and electromagnetic shielding properties according to claim 1, characterized in that, The transparent conductive metal mesh film remains conductive after being cyclically bent 10,000 times at a bending radius of 2.5 mm and a bending speed of 40 ° / s.

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