Preparation method of dielectric / metal / dielectric (DMD) multilayer transparent electrode material

Abstract

The invention belongs to the field of optoelectronic materials, and provides a dielectric / metal / dielectric multilayer transparent electrode material which sequentially comprises a substrate, a dielectric layer 2, a metal layer and a dielectric layer 1, the material of the dielectric layer 2 comprises metal oxide doped zinc oxide a; the material of the dielectric layer 1 comprises metal oxide doped zinc oxide b; furthermore, the metal oxide doped zinc oxide a and the metal oxide doped zinc oxide b are respectively and independently selected from one or more of aluminum oxide doped zinc oxide and tin oxide doped zinc oxide. Correspondingly, the invention also provides a preparation method of the dielectric / metal / dielectric multilayer transparent electrode material. Compared with a conventional dielectric / metal / dielectric multilayer transparent electrode material, the dielectric / metal / dielectric multilayer transparent electrode material disclosed by the invention is obviously more stable in photoelectric property, and the sheet resistance stability of the dielectric / metal / dielectric multilayer transparent electrode material is obviously improved especially in a high-temperature and high-humidity environment.

Description

Technical Field

[0001] The present invention belongs to the field of optoelectronic materials, and particularly relates to a method for preparing a dielectric / metal / dielectric (DMD) multilayer transparent electrode material. Background Art

[0002] In recent years, multilayer thin films based on the dielectric / metal / dielectric (DMD) structure have received extensive attention because their sheet resistance is one to two orders of magnitude lower than that of single-layer thin films. These electrodes consist of an ultrathin metal layer sandwiched between two antireflection dielectrics, achieving high transparency and low sheet resistance. For example, the relative transmittance of TiO2 / Ag / ZnO multilayer thin films exceeds 98%, and the sheet resistance is less than 6 Ω / sq. However, the ultrathin metal layer is prone to oxidation in a water vapor environment, significantly affecting the stability and practicality of the DMD structure multilayer thin films.

[0003] To prevent the oxidation of the intermediate metal layer, ZnO is often used as the top and bottom layers in the prior art, or TiO2 is used as the bottom layer. Among them, the application of ZnO as the top layer is more common, especially in flexible substrates. However, the barrier performance of ZnO is poor, resulting in water vapor penetration, which in turn easily oxidizes the intermediate metal layer to form metal oxides, leading to an increase in internal stress and structural relaxation of the thin film, and ultimately affecting the optoelectronic properties of the thin film.

[0004] Currently, transparent conductive oxides (TCOs) such as indium tin oxide (ITO) and aluminum-doped zinc oxide (AZO) have been widely used in optical emission applications such as displays, light-emitting diodes (LEDs), and photovoltaic cells. However, ITO is costly due to the scarcity of indium, limiting its large-scale application. Although AZO has a lower cost and better conductivity, it may not fully meet the optoelectronic performance requirements in some high-performance applications.

[0005] Therefore, the existing dielectric / metal / dielectric (DMD) structure transparent conductive thin films still have the following problems to be solved: poor stability in high-temperature and high-humidity environments, especially the intermediate metal layer is prone to oxidation, resulting in surface damage and microstructural changes of the thin film, thereby leading to a decline in optoelectronic performance. Summary of the Invention

[0006] To solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The present invention provides a dielectric / metal / dielectric multilayer transparent electrode material, including a substrate, a dielectric layer 2, a metal layer, and a dielectric layer 1; the dielectric layer 2 is located on one side of the substrate, the metal layer is located on the layer away from the substrate of the dielectric layer 2, and the dielectric layer 1 is located on the side away from the dielectric layer 2 of the metal layer;

[0008] The material of the dielectric layer 2 includes zinc oxide doped with metal oxide a; the material of the dielectric layer 1 includes zinc oxide doped with metal oxide b.

[0009] Further, the zinc oxide doped with metal oxide a and the zinc oxide doped with metal oxide b are each independently selected from one or more of zinc oxide doped with aluminum oxide and zinc oxide doped with tin oxide.

[0010] Further, in the zinc oxide doped with aluminum oxide, the doping ratio of aluminum oxide is greater than 0 and less than 100%; in the zinc oxide doped with tin oxide, the doping ratio of tin oxide is greater than 0 and less than 100%.

[0011] Further, the thickness of the dielectric layer 2 is 26 nm; the thickness of the metal layer is 6 nm; the thickness of the dielectric layer 1 is 50 nm.

[0012] Further, the material of the metal layer includes silver; the material of the substrate includes one or more of soda-lime glass and flexible material.

[0013] Correspondingly, the present invention also provides a method for preparing the dielectric / metal / dielectric multi-layer transparent electrode material as described above, including sequentially forming the dielectric layer 2, the metal layer, and the dielectric layer 1 on one side of the substrate.

[0014] Further, the method for preparing the dielectric / metal / dielectric multi-layer transparent electrode material includes the following steps:

[0015] S1. Depositing the dielectric layer 2 on the substrate by magnetron sputtering;

[0016] S2. Depositing the metal layer on the dielectric layer 2 by magnetron sputtering;

[0017] S3. Depositing the dielectric layer 1 on the metal layer by magnetron sputtering to obtain the dielectric / metal / dielectric multi-layer thin film structure.

[0018] Further, the conditions of the magnetron sputtering method in step S1 and the conditions of the magnetron sputtering method in step S3 each include: power 50 - 100 W, argon gas flow rate 5 - 20 sccm, working pressure 0.2 - 0.5 Pa, target distance 4 - 7 cm.

[0019] Further, when the material of the metal layer is silver, the conditions of the magnetron sputtering method in step S2 include: power 50 - 80 W, argon gas flow rate 5 - 20 sccm, working pressure 0.2 - 0.5 Pa, target distance 4 - 8 cm.

[0020] Accordingly, the present invention also provides an application of the dielectric / metal / dielectric multilayer transparent electrode material as described above, which is used to improve the photoelectric performance stability of the dielectric / metal / dielectric multilayer transparent electrode material.

[0021] The present invention proposes a stable dielectric / metal / dielectric multilayer transparent electrode material with a DMD structure (the structural schematic diagram is shown in Figure 1 ): The barrier film is used as the bottom layer (i.e., Figure 1 dielectric layer 2), and its thickness is preferably 26 nm; the intermediate metal layer preferably has a thickness of 6 nm; the barrier film is used as the top layer (i.e., Figure 1 dielectric layer 1), and its thickness is preferably 50 nm. The barrier film includes aluminum oxide (Al2O3) doped zinc oxide (ZnO), tin oxide (SnO2) doped zinc oxide (ZnO), etc. The proportion range of aluminum oxide doped zinc oxide can be adjusted; the proportion range of tin oxide doped zinc oxide can be adjusted.

[0022] The present invention uses materials with excellent barrier properties (such as aluminum oxide doped zinc oxide, tin oxide doped zinc oxide) as the top and bottom layers of the DMD structure, which can prevent water vapor penetration and oxidation of the intermediate metal layer, thereby improving the photoelectric performance stability and long-term durability of the dielectric / metal / dielectric multilayer transparent electrode material.

[0023] Compared with the prior art, implementing the present invention has the following beneficial effects:

[0024] 1. In the present invention, the DMD structure uses a barrier film (such as aluminum oxide doped zinc oxide, tin oxide doped zinc oxide) as the top and bottom layer materials, which can effectively prevent water vapor penetration and avoid oxidation of the intermediate metal layer. Therefore, compared with conventional dielectric / metal / dielectric multilayer transparent electrode materials (such as: usually using zinc oxide as the dielectric layer), the dielectric / metal / dielectric multilayer transparent electrode material of the present invention has significantly more stable photoelectric performance, especially when using a flexible substrate, its sheet resistance stability is significantly improved in high-temperature and high-humidity environments.

[0025] 2. By optimizing the multilayer structure and material selection, the dielectric / metal / dielectric multilayer transparent electrode material with a DMD structure in the present invention achieves low sheet resistance, good long-term durability, excellent photoelectric performance while maintaining high transparency, and is applicable to various substrates.

[0026] 3. The dielectric / metal / dielectric multilayer transparent electrode material of the present invention has excellent stability, high transparency and low sheet resistance, with excellent overall performance, and has good application prospects and economic value in the photoelectric field. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the DMD multilayer thin film structure of the dielectric / metal / dielectric multilayer transparent electrode material of the present invention;

[0028] Figure 2 This is a comparison of the high-temperature and high-humidity test results of the dielectric / metal / dielectric multi-layer transparent electrode materials in Example 1 and Comparative Example 1 of the present invention;

[0029] Figure 3 This is a comparison of the high-temperature and high-humidity test results of the dielectric / metal / dielectric multi-layer transparent electrode materials in Example 2 and Comparative Example 1 of the present invention;

[0030] Figure 4 This is a comparison of the high-temperature and high-humidity test results of the dielectric / metal / dielectric multi-layer transparent electrode materials in Example 3 and Comparative Example 2 of the present invention. Detailed implementation manners

[0031] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the specific implementation manners and the accompanying drawings.

[0032] Example 1

[0033] Each layer of film was prepared on a soda-lime glass substrate to obtain a dielectric / metal / dielectric (DMD) multi-layer transparent electrode material. The specific steps are as follows:

[0034] 1) Bottom layer: A dielectric layer was deposited on the substrate by magnetron sputtering as the bottom layer, where the target was 50% aluminum oxide (Al2O3) doped zinc oxide (ZnO), the power was 50 - 100 W, the argon gas flow rate was 5 - 20 sccm, the working pressure was 0.2 - 0.5 Pa, and the target distance was 4 - 7 cm.

[0035] 2) Ag layer: A metal layer was deposited on the bottom layer of step 1 by magnetron sputtering, where the target was Ag, the power was 50 - 80 W, the argon gas flow rate was 5 - 20 sccm, the working pressure was 0.2 - 0.5 Pa, and the target distance was 4 - 8 cm.

[0036] 3) Top layer: A dielectric layer was deposited on the Ag layer of step 2 by magnetron sputtering as the top layer, and finally a dielectric / metal / dielectric multi-layer transparent electrode material with a DMD structure (see the structure schematic diagram in Figure 1 ) was obtained, where the target was 50% aluminum oxide doped zinc oxide, the power was 50 - 100 W, the argon gas flow rate was 5 - 20 sccm, the working pressure was 0.2 - 0.5 Pa, and the target distance was 4 - 7 cm.

[0037] Example 2

[0038] Each layer of film was prepared on a soda-lime glass substrate to obtain a dielectric / metal / dielectric (DMD) multi-layer transparent electrode material. The specific steps are as follows:

[0039] 1) Bottom layer: A dielectric layer is deposited on the substrate by magnetron sputtering as the bottom layer. The target material is 50% tin oxide (SnO2) doped zinc oxide (ZnO), with a power of 50 - 100 W, an argon flow rate of 5 - 20 sccm, a working pressure of 0.2 - 0.5 Pa, and a target distance of 4 - 7 cm.

[0040] 2) Ag layer: A metal layer is deposited on the bottom layer of step 1 by magnetron sputtering. The target material is Ag, with a power of 50 - 80 W, an argon flow rate of 5 - 20 sccm, a working pressure of 0.2 - 0.5 Pa, and a target distance of 4 - 8 cm.

[0041] 3) Top layer: A dielectric layer is deposited on the Ag layer of step 2 by magnetron sputtering as the top layer, and finally a dielectric / metal / dielectric multilayer transparent electrode material with a DMD structure (see the structure schematic diagram in Figure 1 ) is obtained. The target material is 50% tin oxide doped zinc oxide, with a power of 50 - 100 W, an argon flow rate of 5 - 20 sccm, a working pressure of 0.2 - 0.5 Pa, and a target distance of 4 - 7 cm.

[0042] Example 3

[0043] On a flexible substrate, each layer of thin film is prepared to obtain a dielectric / metal / dielectric (DMD) multilayer transparent electrode material. The specific steps are as follows:

[0044] 1) Bottom layer: A dielectric layer is deposited on the substrate by magnetron sputtering as the bottom layer. The target material is 50% tin oxide (SnO2) doped zinc oxide (ZnO), with a power of 50 - 100 W, an argon flow rate of 5 - 20 sccm, a working pressure of 0.2 - 0.5 Pa, and a target distance of 4 - 7 cm.

[0045] 2) Ag layer: A metal layer is deposited on the bottom layer of step 1 by magnetron sputtering. The target material is Ag, with a power of 50 - 80 W, an argon flow rate of 5 - 20 sccm, a working pressure of 0.2 - 0.5 Pa, and a target distance of 4 - 8 cm.

[0046] 3) Top layer: A dielectric layer is deposited on the Ag layer of step 2 by magnetron sputtering as the top layer, and finally a dielectric / metal / dielectric multilayer transparent electrode material with a DMD structure (see the structure schematic diagram in Figure 1 ) is obtained. The target material is 50% tin oxide doped zinc oxide, with a power of 50 - 100 W, an argon flow rate of 5 - 20 sccm, a working pressure of 0.2 - 0.5 Pa, and a target distance of 4 - 7 cm.

[0047] Comparative Example 1

[0048] Layers of thin films are prepared on a soda-lime glass substrate to obtain a dielectric / metal / dielectric (DMD) multi-layer transparent electrode material. The specific steps are as follows:

[0049] 1) Bottom layer: A dielectric layer is deposited on the substrate by magnetron sputtering as the bottom layer. The target material is zinc oxide (ZnO), with a power of 50 - 100 W, an argon gas flow rate of 5 - 20 sccm, a working pressure of 0.2 - 0.5 Pa, and a target distance of 4 - 7 cm.

[0050] 2) Ag layer: A metal layer is deposited on the bottom layer of step 1 by magnetron sputtering. The target material is Ag, with a power of 50 - 80 W, an argon gas flow rate of 5 - 20 sccm, a working pressure of 0.2 - 0.5 Pa, and a target distance of 4 - 8 cm.

[0051] 3) Top layer: A dielectric layer is deposited on the Ag layer of step 2 by magnetron sputtering as the top layer, and finally a dielectric / metal / dielectric multi-layer transparent electrode material with a DMD structure is obtained. The target material is zinc oxide (ZnO), with a power of 50 - 100 W, an argon gas flow rate of 5 - 20 sccm, a working pressure of 0.2 - 0.5 Pa, and a target distance of 4 - 7 cm.

[0052] Comparative Example 2

[0053] Layers of thin films are prepared on a flexible substrate to obtain a dielectric / metal / dielectric (DMD) multi-layer transparent electrode material. The specific steps are as follows:

[0054] 1) Bottom layer: A dielectric layer is deposited on the substrate by magnetron sputtering as the bottom layer. The target material is zinc oxide (ZnO), with a power of 50 - 100 W, an argon gas flow rate of 5 - 20 sccm, a working pressure of 0.2 - 0.5 Pa, and a target distance of 4 - 7 cm.

[0055] 2) Ag layer: A metal layer is deposited on the bottom layer of step 1 by magnetron sputtering. The target material is Ag, with a power of 50 - 80 W, an argon gas flow rate of 5 - 20 sccm, a working pressure of 0.2 - 0.5 Pa, and a target distance of 4 - 8 cm.

[0056] 3) Top layer: A dielectric layer is deposited on the Ag layer of step 2 by magnetron sputtering as the top layer, and finally a dielectric / metal / dielectric multi-layer transparent electrode material with a DMD structure (the structure schematic diagram is shown in Figure 1 ) is obtained. The target material is zinc oxide (ZnO), with a power of 50 - 100 W, an argon gas flow rate of 5 - 20 sccm, a working pressure of 0.2 - 0.5 Pa, and a target distance of 4 - 7 cm.

[0057] Effect Example 1 (soda-lime glass substrate)

[0058] The dielectric / metal / dielectric multi-layer transparent electrode material obtained in Example 1 and the dielectric / metal / dielectric multi-layer transparent electrode material obtained in Comparative Example 1 were heated at 60 °C and a humidity of 90% simultaneously. The experiment lasted for 20 days, and the sheet resistance at the start and end of the experiment was measured. The comparison results of the sheet resistance are shown in Figure 2 . As can be seen from Figure 2 , for the dielectric / metal / dielectric multi-layer transparent electrode material in Example 1 with 50% aluminum oxide-doped zinc oxide as the dielectric layer, its sheet resistance remained basically unchanged after 20 days (staying at 7 Ω / sq), while for the multi-layer transparent electrode material in Comparative Example 1 with ZnO as the dielectric layer, its sheet resistance increased significantly after 20 days (rising from 7 Ω / sq to 11 Ω / sq).

[0059] Effect Example 2 (soda-lime glass substrate)

[0060] The dielectric / metal / dielectric multi-layer transparent electrode material obtained in Example 2 and the dielectric / metal / dielectric multi-layer transparent electrode material obtained in Comparative Example 1 were heated at 60 °C and a humidity of 90% simultaneously. The experiment lasted for 24 days, and the sheet resistance at the start and end of the experiment was measured. The comparison results of the sheet resistance are shown in Figure 3 . As can be seen from Figure 3 , for the dielectric / metal / dielectric multi-layer transparent electrode material in Example 2 with 50% tin oxide-doped zinc oxide as the dielectric layer, its sheet resistance remained basically unchanged after 24 days (staying at 7 Ω / sq), while for the multi-layer transparent electrode material in Comparative Example 1 with ZnO as the dielectric layer, its sheet resistance increased significantly after 24 days (rising from 7 Ω / sq to 12 Ω / sq).

[0061] Effect Example 3 (flexible substrate)

[0062] The dielectric / metal / dielectric multi-layer transparent electrode material obtained in Example 3 and the dielectric / metal / dielectric multi-layer transparent electrode material obtained in Comparative Example 2 were heated at 60 °C and a humidity of 90% simultaneously. The experiment lasted for 6 days, and the sheet resistance at the start and end of the experiment was measured. The comparison results of the sheet resistance are shown in Figure 4 . As can be seen from Figure 4 , for the dielectric / metal / dielectric multi-layer transparent electrode material in Example 3 with 50% tin oxide-doped zinc oxide as the dielectric layer, its sheet resistance remained basically unchanged after 6 days (staying at 7 Ω / sq), while for the multi-layer transparent electrode material in Comparative Example 2 with ZnO as the dielectric layer, its sheet resistance increased significantly after 6 days (rising from 7 Ω / sq to 13 Ω / sq).

[0063] Since the dielectric / metal / dielectric multi-layer transparent electrode materials used in Effect Example 2 all adopted glass substrates, while those in Effect Example 3 all adopted flexible substrates, the intermediate metal layer was more prone to oxidation. Therefore, although the experimental time of Effect Example 3 (6 days) was shorter than that of Effect Example 2 (24 days), for the multi-layer transparent electrode material with a flexible substrate and ZnO as the dielectric layer (Comparative Example 2), the oxidation of the intermediate metal layer was faster and the sheet resistance increased faster compared to the multi-layer transparent electrode material with a glass substrate and ZnO as the dielectric layer (Comparative Example 1).

[0064] In Effect Example 3 with a flexible substrate, when the sheet resistance of Comparative Example 2 increased significantly after the experiment, the sheet resistance of Example 3 showed no obvious change, indicating that even when using a flexible substrate with insufficient barrier performance, the dielectric / metal / dielectric multi-layer transparent electrode material of the present invention can obtain better optoelectronic performance stability and long-term durability.

[0065] From the experimental results and analysis of Effect Examples 1 to 3, it can be seen that after a certain period of high temperature and high humidity, for the dielectric / metal / dielectric multi-layer transparent electrode materials of the embodiments of the present invention using aluminum oxide-doped zinc oxide or tin oxide-doped zinc oxide as the dielectric layer, compared with the comparative examples using zinc oxide as the dielectric layer, the obtained sheet resistance is more stable and durable; further, when using a flexible substrate that is more likely to oxidize the intermediate layer (Effect Example 3), the advantage of sheet resistance stability of the dielectric / metal / dielectric multi-layer transparent electrode material of the present invention is more prominent. It is speculated that this is because the commonly used top and bottom materials (such as ZnO) have poor barrier performance and cannot effectively prevent water vapor penetration; while the present invention uses a barrier film (such as aluminum oxide-doped zinc oxide, tin oxide-doped zinc oxide) as the top or bottom material, which significantly improves the barrier performance and prevents the oxidation of the intermediate metal layer.

[0066] In summary, the dielectric / metal / dielectric multi-layer transparent electrode material of the present invention has significantly enhanced optoelectronic performance stability and long-term durability compared with conventional dielectric / metal / dielectric multi-layer transparent electrode materials (such as those using zinc oxide as the dielectric layer).

[0067] The above-disclosed are only the preferred embodiments of the present invention, and the scope of the rights of the present invention cannot be limited thereby. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. A dielectric / metal / dielectric multilayer transparent electrode material, characterized in that, It includes a substrate, a dielectric layer 2, a metal layer, and a dielectric layer 1; the dielectric layer 2 is located on one side of the substrate, the metal layer is located on the layer of the dielectric layer 2 away from the substrate, and the dielectric layer 1 is located on the side of the metal layer away from the dielectric layer 2; The material of the dielectric layer 2 includes zinc oxide doped with metal oxide a; The material of the dielectric layer 1 includes zinc oxide doped with metal oxide b.

2. The dielectric / metal / dielectric multilayer transparent electrode material according to claim 1, wherein The zinc oxide doped with metal oxide a and the zinc oxide doped with metal oxide b are each independently selected from one or more of zinc oxide doped with aluminum oxide and zinc oxide doped with tin oxide.

3. The dielectric / metal / dielectric multi-layer transparent electrode material according to claim 2, characterized in that, In the zinc oxide doped with aluminum oxide, the doping ratio of aluminum oxide is greater than 0 and less than 100%; in the zinc oxide doped with tin oxide, the doping ratio of tin oxide is greater than 0 and less than 100%.

4. The dielectric / metal / dielectric multi-layer thin film structure according to claim 1, characterized in that, The thickness of the dielectric layer 2 is 26 nm; the thickness of the metal layer is 6 nm; the thickness of the dielectric layer 1 is 50 nm.

5. The dielectric / metal / dielectric multilayer transparent electrode material according to claim 1, wherein The material of the metal layer includes silver; the material of the substrate includes one or more of soda-lime glass and flexible material.

6. A method for preparing a dielectric / metal / dielectric multilayer transparent electrode material as described in claim 1, characterized in that, It includes forming the dielectric layer 2, the metal layer, and the dielectric layer 1 in sequence on one side of the substrate.

7. The preparation method of the dielectric / metal / dielectric multilayer transparent electrode material according to claim 1, characterized in that, It includes the following steps: S1. Deposit the dielectric layer 2 on the substrate by magnetron sputtering; S2. Deposit the metal layer on the dielectric layer 2 by magnetron sputtering; S3. Deposit the dielectric layer 1 on the metal layer by magnetron sputtering to obtain the dielectric / metal / dielectric multi-layer thin film structure.

8. The preparation method of the dielectric / metal / dielectric multilayer transparent electrode material according to claim 1, characterized in that, The conditions of the magnetron sputtering method in step S1 and the conditions of the magnetron sputtering method in step S3 each include: power 50 - 100 W, argon gas flow rate 5 - 20 sccm, working pressure 0.2 - 0.5 Pa, target distance 4 - 7 cm.

9. The preparation method of the dielectric / metal / dielectric multilayer transparent electrode material according to claim 1, wherein, When the material of the metal layer is silver, the conditions of the magnetron sputtering method in step S2 include: power 50 - 80 W, argon gas flow rate 5 - 20 sccm, working pressure 0.2 - 0.5 Pa, target distance 4 - 8 cm.

10. Application of a dielectric / metal / dielectric multilayer transparent electrode material as described in any one of claims 1 to 5, characterized in that, It is used to improve the photoelectric performance stability of the dielectric / metal / dielectric multi-layer transparent electrode material.

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