A transparent conductive heating material and a method of making the same

Abstract

The application discloses a kind of transparent conductive heating material and preparation method thereof, belong to conductive heating material technical field, can solve the problems of high surface resistance, low light transmittance, poor temperature uniformity and short service life of existing conductive heating material.The preparation method comprises the following steps: S1, pretreatment is carried out to the substrate to obtain the treated substrate;S2, depositing buffer target material on the treated substrate to form a stress buffer layer;S3, depositing conductive heating target material on the stress buffer layer to form a conductive heating layer; the conductive heating target material is zirconium-doped indium oxide;S4, preparing an electrode layer on the conductive heating layer.The application is used for the preparation of transparent semiconductor heating material.

Description

A transparent conductive heating material and its preparation method Technical Field

[0001] This invention relates to a transparent conductive heating material and its preparation method, belonging to the technical field of conductive heating materials. Background Technology

[0002] Currently, the main heating materials on the market include flexible heating films and rigid heating glass. Flexible heating films are mostly prepared using coating or screen printing processes, resulting in film thicknesses typically in the micrometer range. Uniformity is difficult to control, and the production process easily generates pollutants, which is environmentally unfriendly. Furthermore, heating materials produced in this way usually have low light transmittance; while heating materials with high transparency often lack flexibility, thus limiting their application scenarios.

[0003] Heating glass on rigid substrates is typically fabricated using two methods: one involves embedding a mesh of metal heating wires at the center of the glass, which heats up when electricity is applied, thus heating the glass. This method suffers from poor stability; under voltage fluctuations, the thin-diameter metal wires can only carry a small current, making them prone to overload damage. Furthermore, the heat from the heated wires must be conducted through the glass, which is slow, resulting in low overall heating efficiency. The other method involves coating the glass with a conductive paste, but the resulting film thickness remains above the micrometer level, leading to low light transmittance. Additionally, coating or screen printing processes can cause uneven film distribution, affecting the uniformity of the heating temperature.

[0004] In general, existing flexible transparent heating materials often face the problem of high surface resistivity, while materials with lower surface resistivity often have light transmittance of less than 80%. Heating glass prepared by coating slurry generally suffers from poor temperature uniformity and thick film layers that affect light transmission; while heating glass with embedded metal wires has higher light transmittance, it is limited by the thin diameter of the metal wires, weak current carrying capacity, insufficient stability and short service life. Summary of the Invention

[0005] This invention provides a transparent conductive heating material and its preparation method, which can solve the problems of high surface resistance, low light transmittance, poor temperature uniformity and short service life of existing conductive heating materials.

[0006] On one hand, the present invention provides a method for preparing a transparent conductive heating material, the method comprising:

[0007] S1. Pre-treat the substrate to obtain the treated substrate;

[0008] S2. Deposit a buffer target on the treated substrate to form a stress buffer layer;

[0009] S3. Deposit a conductive heating target on the stress buffer layer to form a conductive heating layer; the conductive heating target is zirconium-doped indium oxide.

[0010] S4. An electrode layer is prepared on the conductive heating layer.

[0011] Optionally, the buffer target is gallium-doped zinc oxide or aluminum-doped zinc oxide.

[0012] Optionally, after S1, the method further includes:

[0013] An adhesion target is deposited on the treated substrate to form an adhesion layer; the adhesion target comprises silicon.

[0014] Accordingly, S2 specifically involves depositing a buffer target on the adhesion layer to form a stress buffer layer.

[0015] Optionally, after S4, the method further includes:

[0016] A protective target is deposited on the electrode layer to form an antioxidant protective layer.

[0017] Optionally, S1 specifically includes:

[0018] The substrate was immersed in ethanol for ultrasonic cleaning.

[0019] The substrate was rinsed with ultrapure water after ultrasonic cleaning.

[0020] The rinsed substrate is dried to obtain the treated substrate.

[0021] Optionally, after rinsing the substrate with ultrapure water following ultrasonic cleaning, the method further includes:

[0022] Immerse the rinsed substrate in ethanol;

[0023] Accordingly, the rinsed substrate is dried to obtain the treated substrate, specifically: the soaked substrate is dried to obtain the treated substrate.

[0024] Optionally, after S3, the method further includes:

[0025] The conductive heating layer is annealed in situ in an annealing environment for 20 to 40 minutes.

[0026] The annealing environment is an ambient temperature of 80℃~150℃ and an oxygen partial pressure of 80ppm~120ppm.

[0027] Optionally, the gallium or aluminum doping amount in the buffer target is 0.1% to 1%.

[0028] Optionally, the zirconium doping amount in the conductive heating target is 2% to 10%.

[0029] On the other hand, the present invention provides a transparent conductive heating material prepared by any of the above-described methods, wherein the transparent conductive heating material comprises:

[0030] Base;

[0031] A stress buffer layer is disposed on the substrate;

[0032] A conductive heating layer is disposed on the stress buffer layer; wherein the conductive heating layer is made of zirconium-doped indium oxide.

[0033] An electrode layer is disposed on the conductive heating layer.

[0034] The beneficial effects that this invention can produce include:

[0035] The transparent conductive heating material and its preparation method provided by this invention, through Doping To fabricate a conductive heating layer, the carrier concentration and carrier mobility of the conductive heating layer are significantly increased, resulting in a substantial reduction in film thickness and a significant increase in light transmittance; simultaneously, a stress buffer layer is used to match... The crystal lattice releases stress, thereby significantly improving the overall structural flexibility (100,000 bends). This invention prepares a transparent conductive heating material through physical deposition, which has the properties of low sheet resistance, high light transmittance, good film uniformity, uniform heating, and good flexibility on a flexible substrate. Attached Figure Description

[0036] Figure 1 is a flowchart of the preparation method of the transparent conductive heating material provided in the embodiment of the present invention;

[0037] Figure 2 is a schematic diagram of the transparent conductive heating material structure provided in an embodiment of the present invention.

[0038] Figure label:

[0039] 11. Substrate; 12. Adhesion layer; 13. Stress buffer layer; 14. Conductive heating layer; 15. Electrode layer; 16. Antioxidant protective layer. Detailed Implementation

[0040] The present invention will now be described in detail with reference to the embodiments, but the present invention is not limited to these embodiments.

[0041] This invention provides a method for preparing a transparent conductive heating material, as shown in Figures 1 and 2. The preparation method includes:

[0042] S1. Pre-process the substrate 11 to obtain the processed substrate.

[0043] Specifically, the process includes: first, immersing the substrate 11 in ethanol for ultrasonic cleaning; then rinsing the ultrasonically cleaned substrate 11 with ultrapure water; and finally drying the rinsed substrate 11 to obtain the treated substrate.

[0044] Furthermore, after rinsing the ultrasonically cleaned substrate 11 with ultrapure water, the method further includes: immersing the rinsed substrate 11 in ethanol.

[0045] Accordingly, the rinsed substrate 11 is dried to obtain the treated substrate, specifically: the soaked substrate 11 is dried to obtain the treated substrate.

[0046] In the actual processing, the substrate 11 can be first placed in ethanol and sonicated, then rinsed with a large amount of ultrapure water, then soaked in ethanol, and finally taken out and dried.

[0047] In this invention, the material of the substrate 11 can be any one of PET, PI, polytetrafluoroethylene PTFE, glass, and ceramic.

[0048] S2. Deposit a buffer target on the treated substrate 11 to form a stress buffer layer 13.

[0049] The buffer target is gallium-doped zinc oxide or aluminum-doped zinc oxide; furthermore, the doping amount of gallium or aluminum in the buffer target is 0.1% to 1%.

[0050] Following S1, the method further includes:

[0051] An attachment target is deposited on the processed substrate 11 to form an attachment layer 12; wherein the attachment target contains silicon.

[0052] Accordingly, S2 specifically involves depositing a buffer target on the adhesion layer 12 to form a stress buffer layer 13.

[0053] The present invention uses physical vapor deposition methods (such as roll-to-roll magnetron sputtering, radio frequency magnetron sputtering, pulsed laser deposition, vacuum evaporation and molecular beam epitaxy) to prepare the adhesion layer 12.

[0054] In preparing the adhesion layer 12, the adhesion target material used contains silicon. During the sputtering process, oxygen and nitrogen are introduced as reaction gases in a pure argon environment, and the adhesion layer 12 is formed by sputtering at room temperature.

[0055] In practical applications, the material of the adhesion layer 12 can be... The adhesion layer 12 can increase the surface energy of the PET substrate 11 by >60mN / m. The adhesion layer 12 can also increase the adhesion, mainly by increasing the pull-out force of the subsequently deposited layer, so that the pull-out force is >8B.

[0056] During sputtering of the deposited layer 12, argon and nitrogen are introduced, with nitrogen as the reactant gas. The mass ratio of these gases can be 15:1 to 20:1. The sputtering pressure is 0.3 Pa to 0.5 Pa. The substrate 11 is at room temperature, and the sputtering power density is 2 W / cm². 2 ~5W / cm 2 The gas flow rate is 100 ml / min to 500 ml / min, and the preparation thickness can be 5 nm to 15 nm.

[0057] After the adhesion layer 12 is prepared, a stress buffer layer 13 is prepared on the adhesion layer 12 by magnetron sputtering.

[0058] In practical applications, gallium-doped zinc oxide or aluminum-doped zinc oxide can be prepared by magnetron sputtering to form a stress buffer layer 13, with the doping amount preferably being 0.1% to 1%. The stress buffer layer 13 can release bending stress and match the crystal lattice.

[0059] Specifically, gallium-doped zinc oxide : lattice constant ,and Conductive heating layer Mismatch ≤0.15%, 100,000 cycles .

[0060] Aluminum-doped zinc oxide : lattice constant ,and Conductive heating layer 14 mismatch ≤0.25%, 100,000 cycles .

[0061] When sputtering the stress buffer layer 13, argon and oxygen are introduced, with oxygen as the reactant gas. The gas mass ratio is 20:1 to 30:1, the sputtering pressure is 0.4 Pa to 0.6 Pa, the substrate temperature 11 is between room temperature and 100°C, and the sputtering power density is 3 W / cm³. 2 ~8W / cm 2 The gas flow rate is 120 ml / min to 500 ml / min, and the thickness is 10 nm to 30 nm.

[0062] S3. A conductive heating target is deposited on the stress buffer layer 13 to form a conductive heating layer 14; the conductive heating target is zirconium-doped indium oxide. The zirconium doping content in the conductive heating target is 2%~10%.

[0063] When preparing the conductive heating layer 14, the sputtering target is a ceramic target with a zirconium oxide content of 2% to 10%.

[0064] In practical applications, The content of zirconium oxide is generally selected from 3wt% to 5wt%. Zirconia can improve carrier density and mobility, and reduce resistance; the sheet resistance of the conductive heating layer 14 prepared by the above method is within the range of... Among them, higher than A high resistance value limits its application range; for example, at low voltages, the power density per unit voltage decreases, and the heating temperature cannot reach high temperatures; while below... When the deposition thickness increases, the light transmittance decreases; therefore, the sheet resistance of the conductive heating layer 14 prepared by this method is in the range of It can meet both the heating temperature and light transmittance requirements.

[0065] In this invention, during the sputtering preparation of the conductive heating layer 14, argon and oxygen are introduced, with oxygen as the reactant gas. The gas mass ratio is 20:1 to 50:1, the sputtering pressure is 0.4 Pa to 0.7 Pa, the substrate temperature is between room temperature and 150°C, and the sputtering power density is 4 W / cm². 2 ~9W / cm 2 The gas flow rate is 150 ml / min to 500 ml / min, and the thickness is 120 nm to 180 nm.

[0066] Furthermore, after S3, the method further includes:

[0067] The conductive heating layer 14 is annealed in situ for 20 to 40 minutes in an annealing environment with an ambient temperature of 80 to 150 degrees Celsius and an oxygen partial pressure of 80 to 120 ppm.

[0068] After preparing the conductive heating layer 14, the conductive heating layer 14 is annealed in situ at a temperature of 80℃~150℃ and an oxygen partial pressure of 80ppm~120ppm for 20min~40min to activate it. Doping reduces oxygen vacancies and increases mobility to .

[0069] S4. An electrode layer 15 is prepared on the conductive heating layer 14.

[0070] In practical applications, electrode layer 15 can be prepared by combining one or more of the following methods: mask sputtering, photolithography etching, and screen printing; the material of electrode layer 15 can be... , , , Any of the following. Sheet resistance of electrode layer 15 It can play a role in establishing and controlling the electric field.

[0071] For example, the electrode layer 15 can be prepared by screen printing silver paste and fixing copper strips on it to reduce contact resistance.

[0072] Furthermore, after S4, the method further includes:

[0073] A protective target material is deposited on the electrode layer 15 to form an antioxidant protective layer 16.

[0074] The protective target for sputtering can be alumina, zirconium oxide, or aluminum-doped zinc oxide, etc. When the protective target is aluminum-doped zinc oxide, the amount of aluminum doping in the protective target is 0.1% to 0.5%.

[0075] When the protective target is alumina, the thickness of the antioxidant protective layer 16 is 5nm~15nm; when the protective target is zirconium oxide, the thickness of the antioxidant protective layer 16 is 5nm~10nm.

[0076] Antioxidant protective layer 16 of alumina, zirconium oxide or aluminum-doped zinc oxide material, and The conductive heating layer has a lattice mismatch of less than 0.5%, which can significantly reduce thermal cycling stress; at the same time, the high dielectric constant shields against external ion contamination.

[0077] During the sputtering of the antioxidant protective layer 16, argon and oxygen were introduced, with oxygen as the reactant gas. The mass ratio of the gases was 30:1 to 40:1. The sputtering pressure was 0.3 Pa to 0.6 Pa. The temperature of the substrate 11 was between room temperature and 100°C, and the sputtering power density was 2 W / cm³. 2 ~5W / cm 2 The gas flow rate is 120 ml / min to 500 ml / min, and the thickness is 5 nm to 10 nm.

[0078] The antioxidant protective layer 16 can play a role in anti-oxidation, reducing reflection and maintaining transmittance.

[0079] Another embodiment of the present invention provides a transparent conductive heating material prepared by any of the above-described methods, wherein the transparent conductive heating material comprises:

[0080] Base 11;

[0081] Stress buffer layer 13 is disposed on substrate 11;

[0082] A conductive heating layer 14 is disposed on the stress buffer layer 13; wherein, the conductive heating layer 14 is made of zirconium-doped indium oxide;

[0083] Electrode layer 15 is disposed on conductive heating layer 14.

[0084] Another embodiment of the present invention provides a specific transparent conductive heating material, wherein the substrate 11 is selected as PET with a thickness of 125um, and is prepared by cleaning and drying according to the parameters in Table 1.

[0085] Table 1. Preparation parameters of each film layer

[0086]

[0087] After preparing the transparent conductive heating material, this invention compared it with existing transparent conductive heating materials with similar surface resistance. The tests revealed that the transparent conductive heating material prepared according to the steps of this invention has the characteristics of low resistance, high light transmittance, and good flexibility. Specific comparison conclusions are shown in Table 2.

[0088] Table 2 Comparison Results of Various Transparent Conductive Heating Materials

[0089]

[0090] In Comparative Example 1, for Type semiconductor ( medium doping ), lattice with Primarily octahedral, High bond energy and good order result in fewer slip systems and difficulty in activating dislocations, which manifests as low toughness, with cracks appearing when the bending radius is less than 5 mm.

[0091] In Comparative Example 2, In order to improve conductivity, it is necessary to increase the amount of [unspecified substance] during membrane preparation. Doping level, but Ionic radius ( (less than) ( ), each time a This will generate an extra electron, and the carrier concentration and mobility will not cause lattice distortion. However, a high carrier concentration will induce carrier absorption (near-IR free electron absorption) and band gap contraction, which will reduce the transmittance in the visible light region.

[0092] In this invention, migrate radius and Similar, high solid solubility, and 4d energy level and The 5s conduction band resonance does not introduce additional band tail states; the ionized impurity scattering cross section is small, and the mobility can reach [missing information]. Compared to traditional More than 50% higher. When the resistance is the same, Below, due to carrier mobility High, carrier concentration With material thickness Both can be reduced, so the film thickness can be significantly reduced and the light transmittance can be significantly increased; specifically, the film thickness can be directly reduced by 20nm~30nm.

[0093] Magnetron sputtering is a commonly used physical deposition method, but the surface energy of flexible substrates (PET, CPI) is low, and the film-substrate bonding strength is <5B (cross-cut), which leads to peeling after 100 bends.

[0094] The present invention provides a stress buffer layer 13 to enable... The conductive heating layer 14 is more mechanically compatible with the flexible substrate 11, increasing the flexibility of the transparent conductive heating material. Stress buffer layer. As a substrate, it reduces dislocation density. Furthermore, the stress buffer layer 13 is compared to... The conductive heating layer 14 has a low modulus, which reduces the internal stress generated.

[0095] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0096] (1) The present invention is achieved through Doping To prepare the conductive heating layer 14, the carrier concentration of the conductive heating layer 14 is increased to [value missing]. Mobility remains The above achieves Low resistance.

[0097] (2) This invention reduces the critical radius of bending crack to 3mm through a multi-layer stress buffer + protective layer design, and can withstand 100,000 cycles. .

[0098] (3) The transparent conductive heating material prepared by the present invention has a total thickness of <220nm and an average visible light reflectance of <10%, achieving a high light transmittance of over 85%.

[0099] (4) In the preparation of transparent conductive heating materials, the present invention has no indium enrichment in all target materials, the raw material cost is reduced by ≥30% compared with ITO, the roll-to-roll process is compatible, and it is suitable for large-area preparation.

[0100] (5) The transparent conductive heating material prepared by the present invention is suitable for high-end scenarios such as flexible wearable heating film, foldable screen defogging film, and vehicle smart window.

[0101] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing a transparent conductive heating material, characterized in that, The preparation method includes: S1, pretreating the substrate to obtain a pretreated substrate; depositing an attachment target on the pretreated substrate to form an attachment layer; in preparing the attachment layer, the attachment target material includes silicon, and during sputtering, oxygen and nitrogen are introduced as reaction gases in a pure argon environment, and the attachment layer is formed by sputtering at room temperature; S2, depositing a buffer target on the attachment layer to form a stress buffer layer; the buffer target is gallium-doped zinc oxide or aluminum-doped zinc oxide; S3, depositing a conductive heating target on the stress buffer layer to form a conductive heating layer; the conductive heating target is zirconium-doped indium oxide; annealing the conductive heating layer in situ for 20 min to 40 min in an annealing environment; the annealing environment is an ambient temperature of 80℃ to 150℃ and an oxygen partial pressure of 80 ppm to 120 ppm; S4, preparing an electrode layer on the conductive heating layer; depositing a protective target on the electrode layer to form an antioxidant protective layer.

2. The preparation method according to claim 1, characterized in that, S1 specifically includes: immersing the substrate in ethanol for ultrasonic cleaning; rinsing the ultrasonically cleaned substrate with ultrapure water; and drying the rinsed substrate to obtain the treated substrate.

3. The preparation method according to claim 2, characterized in that, After rinsing the ultrasonically cleaned substrate with ultrapure water, the method further includes: immersing the rinsed substrate in ethanol; and drying the immersed substrate to obtain the treated substrate.

4. The preparation method according to claim 1, characterized in that, The gallium or aluminum doping content in the buffer target is 0.1% to 1%.

5. The preparation method according to claim 1, characterized in that, The zirconium doping content in the conductive heating target is 2% to 10%.

6. A transparent conductive heating material prepared by the method for preparing a transparent conductive heating material according to any one of claims 1 to 5, characterized in that, The transparent conductive heating material includes: a substrate; an adhesion layer disposed on the substrate; a stress buffer layer disposed on the adhesion layer; a conductive heating layer disposed on the stress buffer layer; wherein the conductive heating layer is made of zirconium-doped indium oxide; an electrode layer disposed on the conductive heating layer; and an anti-oxidation protective layer disposed on the electrode layer.

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