Thin film, method for manufacturing the same, and display device

Abstract

A thin film for a display device and a method for preparing the same, as well as the display device, are disclosed. The thin film includes a main film layer comprising a metal oxide and a second metal. The metal oxide contains a first metal, and both the first metal and the second metal are transition elements. The content of the first metal in the thin film is greater than the content of the second metal. The first metal and the second metal have different atomic numbers, and the metal oxide is in a crystalline state.

Description

Technical Field

[0001] This disclosure relates to the field of thin film technology, specifically to a thin film for a display device, a method for preparing the same, and the display device. Background Technology

[0002] With the development of display and lighting technologies, people are spending increasingly more time in front of artificial light sources such as electronic screens. Most white light lighting used in the industry employs blue light chips in conjunction with yellow phosphors to produce white light, and blue light (wavelength range of 400-500nm), as one of the three primary colors, is indispensable in full-color displays and in regulating human biological rhythms.

[0003] However, blue light has many harmful effects. It can cause photoaging and hyperpigmentation of the skin, damage the retina and other eye structures, leading to a series of diseases such as refractive errors and macular degeneration, and disrupt the body's circadian rhythm. Summary of the Invention

[0004] This disclosure provides a thin film for a display device, a method for preparing the same, and the display device.

[0005] This disclosure provides a thin film for a display device, comprising a main film layer, the main film layer comprising: a metal oxide and a second metal, wherein the metal oxide contains a first metal, both the first metal and the second metal are transition elements, the content of the first metal in the thin film is greater than the content of the second metal in the thin film, the first metal and the second metal have different atomic numbers, and the metal oxide is in a crystalline state.

[0006] In some embodiments, the metal oxide is mixed with the second metal, and the molar ratio of the second metal to the first metal is between 1:0.05 and 1:0.8.

[0007] The atomic number of the first metal is greater than the atomic number of the second metal.

[0008] In some embodiments, the average surface roughness of the thin film under a scanning electron microscope is between 0.01 and 0.04 μm, and the thickness of the main film layer is between 50 and 1000 μm.

[0009] In some embodiments, the main film layer has the highest absorption rate for blue light in the wavelength range of 415–455 nm, with an average cutoff rate of 56.2%; the main film layer has an average transmittance of 94.0% for light in the wavelength range of 500–800 nm.

[0010] In some embodiments, the first metal includes at least one of zinc, titanium, and copper, and the second metal includes at least one of silver, gold, and platinum group metals.

[0011] In some embodiments, the film further includes an antireflective film stacked with the main film layer.

[0012] In some embodiments, the antireflective film is made of silicon oxide.

[0013] In some embodiments, the thickness of the antireflective film is between 50 and 1000 nm.

[0014] This disclosure also provides a method for preparing the above-mentioned thin film, wherein the thin film includes a main film layer, and the preparation steps of the main film layer include:

[0015] A precursor solution for preparing the metal oxide, wherein the precursor solution is doped with the second metal;

[0016] The precursor fluid is coated onto the substrate;

[0017] The mixed solution on the substrate is dried and annealed.

[0018] In some embodiments, in the precursor fluid of the metal oxide, the molar ratio of the second metal to the first metal is between 1:0.05 and 1:0.8.

[0019] In some embodiments, when annealing the mixed solution on the substrate, the annealing temperature is between 300°C and 800°C.

[0020] In some embodiments, the precursor fluid is coated onto the substrate using a spin-coating process.

[0021] In some embodiments, the spin coating speed in the spin coating process is between 500 and 3000 r / min.

[0022] In some embodiments, the method further includes:

[0023] An antireflective membrane is formed on the substrate, which is superimposed on the main membrane layer.

[0024] In some embodiments, the antireflective film is formed by magnetron sputtering.

[0025] This disclosure also provides a display device, including a display panel and the aforementioned thin film, the thin film being located on the light-emitting side of the display panel. Attached Figure Description

[0026] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0027] Figure 1This is a schematic diagram of a thin film provided as an example of this disclosure.

[0028] Figure 2 The ultraviolet-visible transmission spectra of the main film layers in Examples 1 to 4 are shown.

[0029] Figure 3 The XRD patterns (X-ray diffraction analysis patterns) of the main film layers in Examples 1 to 4 are shown.

[0030] Figure 4A The images show the microstructure of ATO1 to ATO4 using SEM.

[0031] Figure 4B The graph shows the relationship between the surface roughness of the main film layer and the annealing temperature.

[0032] Figure 5 The ultraviolet-visible light transmission spectra of the main film layers formed in Examples 3, 5 to 7 are shown.

[0033] Figure 6 The XRD patterns of the main films formed in Examples 3, 5 to 7 are shown.

[0034] Figure 7 The images are scanning electron microscope (SEM) images of the master films formed in Examples 8 and 6.

[0035] Figure 8 The UV-Vis transmission spectra of the master films formed in Examples 8 and 6 are shown.

[0036] Figure 9 This is a schematic diagram of the thin film provided in some other embodiments of this disclosure.

[0037] Figure 10 The ultraviolet-visible light transmission / absorption spectra are those of a thin film with and without an antireflection coating.

[0038] Figure 11 CIE 1931 chromaticity diagrams of the display panel before and after the film is applied.

[0039] Figure 12 Images show the live / dead cell staining experiments of ARPE-19 cells on substrates covered with and uncovered with blue light after a period of time.

[0040] Figure 13 This is a flowchart illustrating a method for preparing a thin film provided in some embodiments of this disclosure. Detailed Implementation

[0041] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0042] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0043] Unless otherwise defined, the technical or scientific terms used in the embodiments of this disclosure should have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0044] It should be understood that when a layer or element is referred to as being on another layer or substrate, it can mean that the layer or element is directly on the other layer or substrate, or that there is an intermediate layer between the layer or element and the other layer or substrate.

[0045] This document describes exemplary embodiments with reference to cross-sectional views and / or plan views, which are idealized exemplary drawings. In the drawings, the thickness of layers and regions is enlarged for clarity. Therefore, variations in shape relative to the drawings are contemplated due to, for example, manufacturing techniques and / or tolerances. Thus, exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing processes. For example, etched regions shown as rectangular would typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of the regions of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0046] To address the problem of eye damage caused by high-energy blue light, this disclosure provides a thin film for use in display devices. Figure 1 A schematic diagram of a thin film provided in one example of this disclosure, such as... Figure 1 As shown, for example, the thin film 2 can be disposed on the substrate 1 and can be disposed on the light-emitting side of the display panel to absorb at least a portion of the blue light emitted by the display panel.

[0047] In this embodiment, the thin film 2 includes a main film layer 21, which comprises a metal oxide and a second metal. The metal oxide contains a first metal, and both the first and second metals are transition elements with different atomic numbers. The content of the first metal in the thin film is greater than the content of the second metal. The metal oxide is in a crystalline state.

[0048] The content of the first metal and the content of the second metal in the thin film can refer to mass fraction, atomic percentage, or molar ratio. Transition elements are chemical elements from Group IIIB to Group VIII of the periodic table. The aforementioned "atomic number" refers to the element's position in the periodic table, numerically equal to the nuclear charge (i.e., the number of protons) of the atomic nucleus or the number of electrons outside the nucleus of a neutral atom. The phrase "metal oxide in a crystalline state" in this disclosure can mean that the metal oxide is in a microcrystalline state, a partially crystalline state, a fully crystalline state, or a combination of various different crystalline states.

[0049] In this embodiment of the disclosure, by doping the crystalline metal oxide corresponding to the first metal with a second metal (both the first and second metals are transition elements), the band gap of the metal oxide can be reduced, and the spectral response range can be broadened. When the second metal is doped, the appearance of the intermediate energy level is equivalent to providing a springboard for photoelectrons to transition, allowing lower-energy photons to excite electrons and generate energy transfer. In the spectrum, this is manifested as a redshift of the light cutoff wavelength, thereby ensuring the absorption rate of blue light in a specific wavelength range (e.g., 415–455 nm), achieving a blue light protection effect.

[0050] In some embodiments, the metal oxide and the second metal are mixed together, and the molar ratio of the second metal to the first metal is between 1:0.05 and 1:0.8; the atomic number of the first metal is greater than that of the second metal. By setting the molar ratio of the second metal to the first metal between 1:0.05 and 1:0.8, the flatness of the thin film and the absorption rate of blue light in a specific wavelength range can be guaranteed.

[0051] In some preferred embodiments, the molar ratio of the second metal to the first metal is between 1:0.05 and 1:0.4, which facilitates the preparation of the main film layer 21 by the sol-gel method, thereby simplifying the preparation process and reducing production costs.

[0052] In some embodiments, the average surface roughness of the thin film under a scanning electron microscope is between 0.01 and 0.04 μm, and the thickness of the main film layer 21 is between 50 and 1000 μm. For example, the average surface roughness of the main film layer 21 under a scanning electron microscope is 0.03 μm, and the thickness of the main film layer 21 is between 200 and 500 nm, for example, 247 nm, 300 nm, 400 nm, 427 nm, or 500 nm.

[0053] The average surface roughness refers to the absolute value of the height difference between the highest and lowest points of a thin film observed at a microscopic scale using equipment such as scanning electron microscope (SEM), transmission electron microscope (TEM), atomic force microscope (AFM), and white light interferometer.

[0054] In this embodiment of the disclosure, by controlling the average surface roughness of the scanning electron microscope to be between 0.01 and 0.04, the smoothness of the subsequent film preparation can be guaranteed without affecting the display effect of the display device.

[0055] In some embodiments, the main film layer 21 comprises multiple sub-film layers stacked sequentially, and at least one sub-film layer is made of the aforementioned metal oxide and the aforementioned second metal. Each sub-film layer can be formed by spin coating and annealing processes, thereby allowing for better control over the thickness and thickness uniformity of the main film layer.

[0056] In some embodiments, the main film layer 21 has the highest absorption rate for blue light in the wavelength range of 415–455 nm, with an average cutoff rate of 56.2%; the main film layer 21 has an average transmittance of 94.0% for light in the wavelength range of 500–800 nm.

[0057] In some embodiments, the first metal includes at least one of zinc, titanium, and copper, and the second metal includes at least one of silver (Ag), gold (Au), and platinum group metals.

[0058] In one example, the first metal is titanium (Ti), and the second metal is silver (Ag). The main film layer 21 is a titanium dioxide (TiO2) film layer containing silver nanoparticles. When titanium dioxide crystallizes in the anatase phase, it can block ultraviolet light. After introducing silver nanoparticles, there are freely moving electrons around the nano-metal particles. Under normal conditions, these electrons are in a state of random motion. When light enters the main film layer 21, these electrons will be deflected by the electric field, and the electrons themselves are also subject to the Coulomb force. These two opposing forces together cause the electrons to reciprocate. Resonance occurs when the frequencies of light and electrons are equal, at which point the particles absorb the incident light and generate energy transfer. This light absorption method is selective; if the frequencies of the two are not equal, resonance absorption will not occur. Studies have shown that silver nanoparticles have strong absorption in the blue light band. In this disclosure, setting the molar ratio of the second metal to the first metal between 1:0.05 and 1:0.8 can enhance the blue light blocking effect of the main film layer 21 and improve the transmittance of the film in bands other than blue light.

[0059] Figure 2 The ultraviolet-visible transmission spectra of the main film layers in Examples 1-4 are shown. Figure 3 The images show the XRD patterns (X-ray diffraction analysis patterns) of the main films in Examples 1-4. Each main film in Examples 1-4 is designated ATO1-ATO4. The preparation process for each main film includes: preparing a silver-doped titanium dioxide precursor solution, coating the silver-doped titanium dioxide precursor solution onto the substrate surface, and then drying and annealing to form the corresponding main film. In ATO1-ATO4, the molar ratio of Ti to Ag is 1:0.2, and the annealing temperatures for ATO1-ATO4 are 300℃-600℃, respectively. Figure 2 It can be seen that when the molar ratio of Ti to Ag is controlled at about 1:0.2 and the annealing temperature is controlled between 500℃ and 600℃, the prepared film can play a good role in preventing blue light.

[0060] The phase and crystal structure of the main film were characterized to obtain the corresponding XRD patterns, such as... Figure 3 As shown. For the main films ATO1, ATO2, and ATO3, the film structure is mainly composed of TiO2 with anatase tetragonal crystal structure as the dominant phase and Ag with face-centered cubic structure as the secondary phase; for the main film ATO4, the film structure is mainly composed of TiO2 with rutile tetragonal crystal structure as the dominant phase and Ag with face-centered cubic structure as the secondary phase. From Figure 3As can be seen, the main phase in the ATO4 main film layer annealed at 600℃ is TiO2 with a rutile tetragonal crystal structure. The diffraction peak of Ag is not obvious, possibly because TiO2 is too crystallizable at high temperature, which weakens the diffraction peak of Ag. The main diffraction peak of ATO3 obtained by annealing at 500℃ is Ag, and the diffraction peak of TiO2 is weaker than that of Ag. The main film layer prepared in the embodiments of this disclosure has a film layer structure mainly in a crystalline state, wherein the crystalline state can be a microcrystalline state, a partially crystalline state, a fully crystalline state of metal oxide, or a combination of multiple different crystalline states.

[0061] Figure 4A These are SEM images of the microstructure of ATO1 to ATO4. SEM images are surface and cross-sectional images of thin films observed using equipment such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), and white light interferometer. Figure 4A It can be seen that no obvious TiO2 crystalline structure was observed in the main film layer ATO1 obtained at annealing temperature of 300℃. The film surface was flat with only slight cracks, which is speculated to be due to the incomplete decomposition of organic components in the film, resulting in an overall amorphous structure. The slight cracking on the film surface may be because at high temperatures, atoms gain some energy, but their migration ability is insufficient, and the internal stress of the atoms cannot be released in the form of kinetic energy, but can only release energy through macroscopic cracking. In the main film layer ATO2 obtained at annealing temperature of 400℃, a large number of uniformly distributed spherical particles with an average particle size of about 50nm can be observed; in the main film layer ATO3 obtained at annealing temperature of 500℃, the spherical particles are more densely packed, and the original circular pores are almost filled; in the main film layer ATO4 obtained at annealing temperature of 600℃, the particle size of the spherical particles increases to about 80nm. The reason why the film did not crack at high temperatures of 400-600℃ is that when the annealing temperature continues to rise, the migration ability of atoms increases, and the internal stress can be released through diffusion, thereby avoiding film cracking.

[0062] Figure 4B The graph shows the relationship between the surface roughness of the main film layer and the annealing temperature. Figure 4B The curves were measured using an example where the molar ratio of titanium to silver in the main film was 1:0.2. Figure 4B It can be seen that when the annealing temperature is between 300℃ and 500℃, the surface roughness of the main film layer is low, between 0.01 and 0.03 μm. Therefore, in the preferred embodiment, an annealing temperature of 500℃ can be used.

[0063] Figure 5 The images show the UV-Vis transmission spectra of the main films formed in Examples 3 and 5-7. Figure 6The images show the XRD patterns of the main films formed in Examples 3 and 5-7. In Example 3, the ATO3 formed is the same as described above. The main films in Examples 5-7 are designated ATO5, ATO6, and ATO7, respectively. The preparation process of each main film includes: preparing a silver-doped titanium dioxide precursor solution, coating the silver-doped titanium dioxide precursor solution onto the substrate surface, and then drying and annealing to form the main film. The annealing temperature in each example is 500℃. In the main films ATO5, ATO6, and ATO7, the molar ratios of Ti and Ag are 1:0.5, 1:0.1, and 1:0.4, respectively.

[0064] from Figure 5 It can be seen that ATO3 and ATO5-ATO7 all have a certain degree of blue light protection. In some examples, ATO6 can be used as the main film layer, thereby reducing the impact on the color of the display screen while still providing blue light protection. From Figure 6 It can be seen that all the spectral lines have diffraction peaks of TiO2 at 25.308° and 48.406°, and Ag at 38.116°, 44.277°, 64.426° and 77.472°. By comparing the PDF cards 71-1166 and 04-0783, the diffraction peaks of (101) and (200) of anatase TiO2 (Anatase) and the diffraction peaks of (111), (200), (220) and (311) of elemental Ag, respectively. Apart from these, there are no other impurity peaks, which proves that TiO2 has good crystallinity at an annealing temperature of 500℃ and Ag exists in elemental form. Furthermore, as the Ag doping concentration increases, the (101) and (200) diffraction peaks of TiO2 remain almost unchanged, while the (111), (200), (220), and (311) diffraction peaks of Ag gradually increase, mainly growing towards the (111) direction.

[0065] Figure 7 SEM images of the cross-sections of the main films formed in Examples 8 and 6 are shown. The main film in Example 8 is denoted as ATO6', which differs from ATO6 in Example 3 in its thickness; ATO6 has a thickness of 247 nm, while ATO6' has a thickness of 427 nm. Figure 7 As can be seen, the surface of the thin film is relatively flat under a scanning electron microscope.

[0066] Figure 8 The images show the UV-Vis transmission spectra of the main films formed in Examples 8 and 6. It can be seen that the ATO6' with a thickness of 427 nm has a higher blue light protection effect compared to the ATO6 with a thickness of 247 nm. Therefore, in a preferred example of this disclosure, the main film can be set to ATO6', i.e., the molar ratio of titanium to silver is 1:0.1, the annealing temperature is 500 °C, and the thickness of the main film is 427 nm.

[0067] Figure 9 This is a schematic diagram of the thin film provided in some other embodiments of this disclosure, such as... Figure 9 As shown, in addition to the main film layer described above, the thin film may also include an antireflection film stacked on top of the main film layer. By providing the antireflection film, the transmittance of the thin film in other visible light regions can be improved.

[0068] In some embodiments, the antireflective film material includes silicon oxide (SiOx), such as silicon dioxide (SiO2). Silica films have advantages such as strong film adhesion, high hardness, high light transmittance, and strong corrosion resistance. Using silica as the material for an antireflective film can give the film overall higher transmittance and improve its service life.

[0069] The thickness of the antireflective coating is between 50 and 1000 nm, thus ensuring the antireflective effect while maintaining a relatively small overall film thickness. In one example, the antireflective coating may be 50 nm, 100 nm, 200 nm, 400 nm, 500 nm, 700 nm, or 1000 nm.

[0070] Figure 10 The ultraviolet-visible light transmission / absorption spectra are shown for films with and without an antireflection coating. The antireflection coating material includes SiO2. From... Figure 10 It can be seen that when an antireflective film is set in the film and stacked with the main film layer, the transmittance of the film to other visible light above 500nm is not less than 90%.

[0071] Figure 11 Table 1 shows the CIE 1931 chromaticity diagrams before and after the film was applied to the display panel, and also presents the changes in screen parameters before and after the film was applied. Figure 11 The data in Table 1 were measured when the thin film simultaneously included the aforementioned main film layer and antireflection film. Among them, L... B Ra indicates blue light damage, Ra represents the color rendering index, and CCT represents the correlated color temperature. From Figure 11 As can be seen from Table 1, applying the thin film disclosed herein to the display panel can reduce high-energy blue light.

[0072] Table 1

[0073] <![CDATA[L B (Wm-2sr-1nm-1)]]> Ra CCT(K) CIE chromaticity coordinates (x, y) Before covering with film 0.373 79.3 6446 (0.3136,0.3280) After covering with film 0.245 76.3 6223 (0.3166,0.3429)

[0074] Figure 12 Images show live / dead cell staining of ARPE-19 cells on substrates covered with and uncovered with blue light after a period of irradiation. The blue light wavelengths ranged from 415 to 455 nm, with the specific wavelength used in the experiment being 435 nm. ARPE-19 cells are human retinal epithelial cells. Figure 12 The gray spots in the image represent cells. The membrane used in the experiment includes both the main membrane layer and the anti-reflection membrane described above. Figure 12 It can be seen that after covering with the film, the number of dead cells generated after 12 hours and 24 hours of blue light irradiation was lower when the film was covered than when the film was not covered. This indicates that the film in this embodiment can reduce the transmittance of short-wave high-energy blue light in the spectrum and reduce damage to the human eye.

[0075] This disclosure also provides a method for preparing the above-mentioned thin film. Figure 13 This is a flowchart illustrating a method for preparing a thin film provided in some embodiments of this disclosure, wherein, as... Figure 13 As shown, the method for preparing the thin film includes forming the aforementioned thin film on a substrate. The thin film includes a main film layer, and the steps for preparing the main film layer include:

[0076] S1. Prepare a precursor solution for the metal oxide, wherein the precursor solution is doped with the second metal.

[0077] S2. The precursor fluid is coated onto the substrate.

[0078] S3. The mixed solution on the substrate is dried and annealed to form the main film layer of the thin film.

[0079] The method for preparing the thin film of this disclosure will be described below with reference to specific examples. In some embodiments, the method for preparing the thin film includes the following steps S01 to S3.

[0080] S01. Clean the substrate. The substrate can be ultra-clear glass, i.e., ultra-transparent low-iron glass.

[0081] Cleaning the substrate can improve the uniformity of the distribution of the subsequently formed film and enhance the adhesion of the film.

[0082] In some embodiments, step S01 may include S01a to S01c:

[0083] S01a. Immerse the substrate in deionized water containing a cleaning agent and perform continuous ultrasonic cleaning. For example, the cleaning time is 20 minutes, and the cleaning agent is a glass cleaner.

[0084] S01b. The substrate, after being cleaned with the cleaning agent, is placed in an acetone solution and subjected to continuous ultrasonic cleaning to remove the organic solvent from the substrate. For example, the acetone solution has a mass fraction of 99.9%, and the ultrasonic cleaning time is 15 minutes.

[0085] S01c. Place the acetone-cleaned substrate into anhydrous ethanol and perform continuous ultrasonic cleaning to remove residual acetone solution from the substrate. For example, the ultrasonic cleaning time is 20 minutes.

[0086] In some embodiments, step S01 is followed by step S02, which involves pre-processing the substrate.

[0087] In some embodiments, step S02 includes: purging the substrate with helium gas, and then placing the substrate in an ozone environment for about 10 minutes to disinfect bacteria on the substrate.

[0088] After step S02, step S1 is performed: a precursor liquid for preparing the metal oxide is prepared, wherein the precursor liquid is doped with the second metal.

[0089] In the precursor fluid prepared in step S1, the molar ratio of the second metal to the first metal is between 1:0.05 and 1:0.8.

[0090] In some embodiments, the second metal is silver and the first metal is titanium. Step S1 specifically includes:

[0091] S11. Mix tetrabutyl titanate, anhydrous ethanol, and glacial acetic acid, then add concentrated nitric acid to obtain a titanium dioxide precursor solution with a pH value between 2 and 6, and let it stand for a period of time, for example, 24 hours.

[0092] The volume ratio of tetrabutyl titanate, anhydrous ethanol, and glacial acetic acid ranges from 4:(10 to 50):(0.5 to 2). For example, the volume ratio of tetrabutyl titanate, anhydrous ethanol, and glacial acetic acid is 4:20:1.

[0093] S12. Add silver nitrate solution to the titanium dioxide precursor solution obtained in S11, ensuring the molar ratio of titanium to silver in the precursor solution is between 1:0.05 and 1:0.8. Then add polyethylene glycol (PEG400) to prevent hydrolysis. Afterward, allow to stand for 24 hours. In one example, the concentration of silver nitrate solution is 1.5 mol / L, and the volume ratio of polyethylene glycol to tetrabutyl titanate added in step S11 can be 1:3.

[0094] After step S1, step S2 is performed: the precursor fluid is coated onto the substrate.

[0095] In some embodiments, the precursor liquid is coated onto the substrate using a spin coating process. In some embodiments, the spin coating speed is between 500 and 3000 r / min. By employing high-speed spin coating, the uniformity of the coating can be ensured.

[0096] In some embodiments, the spin coating time can be between 30 seconds and 2 minutes.

[0097] In a specific example, step S2 may include: fixing the substrate on a spin coater, adding 200 μL of silver-doped titanium dioxide precursor liquid, accelerating it to 500 r / min at 100 r / s and holding it for 5 s, and then accelerating it to 2000 r / min at 100 r / s and holding it for 60 s.

[0098] After step S2, step S3 is performed: the mixed solution on the substrate is dried and annealed to form the main film layer of the thin film.

[0099] In some embodiments, step S3 specifically includes:

[0100] S31. Dry the substrate at 100°C for 5-10 minutes.

[0101] S32. Anneal the dried substrate.

[0102] In some embodiments, the annealing temperature in step S3 is between 300°C and 800°C. Preferably, the annealing temperature is between 500°C and 600°C, which helps to improve the blue light protection effect of the main film layer and reduce the roughness of the main film layer. In some embodiments, the annealing time is between 1.5 and 2 hours.

[0103] It should be noted that, in this embodiment, the number of times steps S2 and S3 are performed is not limited. For example, steps S2 and S3 can each be performed once. Alternatively, steps S2 and S3 can each be performed N times, where N is an integer greater than 1. In this case, each time steps S2 and S3 are performed, a sub-film layer is formed, thus forming a main film layer with a relatively large and uniform thickness. In one example, the main film layer includes three stacked sub-film layers.

[0104] In some embodiments, the preparation method further includes: S4, forming an antireflection membrane superimposed on the main membrane layer on a substrate.

[0105] In some embodiments, the antireflective film is formed by magnetron sputtering. The specific working principle of magnetron sputtering involves introducing gaseous raw materials such as NH4 and N2 into a heated reaction chamber, where the gases react chemically to form a new material, which is then deposited onto the substrate. The film thickness is controlled by adjusting the gas flow rate and time; higher chamber temperatures result in better film density.

[0106] For example, the antireflective coating is made of silicon dioxide and has a thickness of 200 nm.

[0107] This disclosure also provides a display device, including the aforementioned thin film and display panel, wherein the thin film is disposed on the light-emitting surface of the display panel.

[0108] By employing the thin film in any of the above embodiments, the harmful blue light in the display panel with a wavelength range of 415nm to 455nm is reduced or avoided from damaging the human eye. At the same time, it can ensure the high transmittance requirements of other visible light residual bands and maintain the color balance of the transmitted light of the eye protection device, thereby ensuring the eye protection performance and normal light emission effect of the eye protection device.

[0109] The eye protection device can be: LCD panel, OLED panel, MLED panel, QD-OLED panel and QLED panel, as well as any product or component with display function such as TV, mobile phone, tablet, laptop, monitor, digital photo frame, navigator and so on corresponding to each type of panel; the eye protection device can also be: any lighting device such as a lamp.

[0110] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. A thin film for a display device, characterized in that, The film includes a main film layer, which comprises a metal oxide and a second metal. The metal oxide contains a first metal, and both the first metal and the second metal are transition elements. The content of the first metal in the film is greater than the content of the second metal in the film. The first metal and the second metal have different atomic numbers, and the metal oxide is in a crystalline state. The first metal includes titanium, and the second metal includes silver; The metal oxide is mixed with the second metal, and the molar ratio of the second metal to the first metal is between 1:0.05 and 1:0.

8.

2. The thin film according to claim 1, characterized in that, The average surface roughness of the film under a scanning electron microscope is between 0.01 and 0.04 μm, and the thickness of the main film layer is between 50 and 1000 μm.

3. The film according to any one of claims 1 to 2, characterized in that, The main film layer has the highest absorption rate for blue light in the wavelength range of 415–455 nm, with an average cutoff rate of 56.2%; the main film layer has an average transmittance of 94.0% for light in the wavelength range of 500–800 nm.

4. The film according to any one of claims 1 to 2, characterized in that, The film also includes an antireflective film stacked on top of the main film layer.

5. The thin film according to claim 4, characterized in that, The antireflective film is made of silicon oxide.

6. The thin film according to claim 4, characterized in that, The thickness of the antireflective coating is between 50 and 1000 nm.

7. A method for preparing a thin film as described in any one of claims 1 to 6, characterized in that, The thin film includes a main film layer, and the preparation steps of the main film layer include: A precursor solution for preparing the metal oxide, wherein the precursor solution is doped with the second metal; The precursor fluid is coated onto the substrate; The mixed solution on the substrate is dried and annealed; In the precursor fluid of the metal oxide, the molar ratio of the second metal to the first metal is between 1:0.05 and 1:0.8; the first metal in the metal oxide includes titanium, and the second metal includes silver.

8. The preparation method according to claim 7, characterized in that, When annealing the mixed solution on the substrate, the annealing temperature is between 300°C and 800°C.

9. The preparation method according to claim 7, characterized in that, The precursor liquid is coated onto the substrate using a spin coating process.

10. The preparation method according to claim 9, characterized in that, The spin coating speed in the spin coating process is between 500 and 3000 r / min.

11. The preparation method according to any one of claims 7 to 10, characterized in that, The method further includes: An antireflective membrane is formed on the substrate, which is superimposed on the main membrane layer.

12. The preparation method according to claim 11, characterized in that, The antireflective film is formed by magnetron sputtering.

13. A display device comprising a display panel, characterized in that, It also includes the thin film according to any one of claims 1 to 6, the thin film being located on the light-emitting side of the display panel.

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