Thin film, method of making the same, and eyewear

Abstract

The application provides a film, a preparation method thereof and an eye protection device. The film comprises a metal oxide and a second metal, the content of the metal oxide in the film is greater than the content of the second metal in the film, the metal oxide contains a first metal, the first metal and the second metal are both transition elements, and the atomic numbers of the first metal and the second metal are different. The film comprising the metal oxide and the second metal is non-toxic and has good chemical stability, so the stability of the film is strong, and the film can meet the requirements of long service life and multi-environment application of a display product using the film. On the other hand, the film can effectively absorb most of harmful blue light with a wavelength range of 415nm-455nm, while retaining most of beneficial blue light of other wave bands, ensuring high transmittance requirements of other visible light remaining wave bands, maintaining color balance of transmitted light, and avoiding secondary damage of reflected blue light.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of blue light prevention, and particularly relates to a film, a preparation method thereof and an eye protection device. BACKGROUND

[0002] With the development of display and lighting technology, people spend more and more time in front of electronic screens and other artificial light sources. The white light illumination used in the industry mostly uses a blue light chip combined with yellow fluorescent powder to generate white light, and blue light (wavelength range of 400-500 nm) is indispensable in full-color display and adjustment of human biological rhythm.

[0003] However, long-term exposure to high-energy blue light can cause visual fatigue, affect the secretion of melatonin and thus affect the sleep quality of people, and may also induce the occurrence of diseases such as cataract, retinopathy and age-related macular degeneration. Therefore, in today's information age, it is imperative to prevent harmful blue light from entering the human eye in excess and to protect the eyes. SUMMARY

[0004] The present application provides a film, a preparation method thereof and an eye protection device to solve the problem of high-energy blue light damaging the human eye. The film has strong stability, can meet the requirements of long service life and multi-environment application of display products using the film, and on the other hand, can effectively absorb most of the harmful blue light with a wavelength range of 415-455 nm, while retaining most of the beneficial blue light in other wavebands and ensuring high transmittance requirements of other visible light in the remaining waveband, maintaining the color balance of transmitted light, and avoiding secondary damage from reflected blue light.

[0005] The present application provides a film for a display device, the film comprising a metal oxide and a second metal, a content of the metal oxide in the film being greater than a content of the second metal in the film, wherein the metal oxide contains a first metal, the first metal and the second metal are both transition elements, and atomic numbers of the first metal and the second metal are different.

[0006] Optionally, the metal oxide and the second metal are mixed with each other, a molar ratio of the second metal to the metal oxide ranges between 3% and 6%, and the atomic number of the first metal is less than the atomic number of the second metal.

[0007] Optionally, a surface average roughness of the film under a scanning electron microscope ranges between 150 nm and 250 nm, and a thickness of the film ranges between 100 nm and 2 microns.

[0008] Optionally, the film comprises a plurality of sub-film layers stacked in sequence, and a material of at least one of the sub-film layers comprises the metal oxide and the second metal.

[0009] Optionally, the film has the highest absorption rate for blue light with a wavelength range of 415-455 nm, and an average cutoff rate of 57.1%; the film has an average transmittance of 87.2% for light with a wavelength range of 500-800 nm.

[0010] Optionally, the first metal includes zinc, titanium, copper, and the second metal includes silver, gold, and platinum group metal.

[0011] Optionally, the film is prepared by any one or more of spin coating, sputtering deposition.

[0012] The application further provides a preparation method of the film, comprising: preparing a film on a substrate, comprising:

[0013] mixing a solution containing a first metal and an organic solvent, and obtaining a mixed solution after reaction;

[0014] mixing and stirring the mixed solution with a stabilizer, and obtaining a metal oxide precursor solution after reaction;

[0015] mixing a solution containing a second metal with the metal oxide precursor solution, and aging to obtain a metal oxide precursor solution containing the second metal;

[0016] coating the metal oxide precursor solution containing the second metal to a surface of one side of the substrate, and then sequentially performing drying and annealing to form the film.

[0017] Optionally, the molar ratio of the solution containing the first metal to the organic solvent is (0.5-3): 50, the reaction temperature of the solution containing the first metal and the organic solvent is 20-60℃, and the reaction time is 0.5-4 hours.

[0018] Optionally, the volume of the stabilizer is 2-10% of the volume of the organic solvent, the reaction temperature of the mixed solution and the stabilizer is 20-60℃, and the reaction time is 0.5-4 hours.

[0019] Optionally, the molar ratio of the second metal in the solution containing the second metal to the organic solvent is (3-6): 2500, the reaction temperature of the solution containing the second metal and the metal oxide precursor solution is 20-60℃, and the reaction time is 9-24 hours.

[0020] Optionally, the coating method comprises spin coating,

[0021] The spin coating is accelerated from 0 to 500 r / min at 100 r / s and then maintained at 500 r / min. The total time for the spin coating to accelerate and maintain the 500 r / min speed is 5 seconds.

[0022] The spin coating is then accelerated from 500 r / min to 2000 r / min at 100 r / s, and then maintained at 2000 r / min. The total time for the spin coating to accelerate again and maintain the speed of 2000 r / min is 60 seconds.

[0023] Optionally, the drying temperature range is 100–120°C, and the drying time is 10–20 min;

[0024] The annealing temperature range is 200–350°C, and the annealing time is 10–40 min.

[0025] Optionally, the organic solvent includes any one of ethanol, methanol, and ethylene glycol methyl ether;

[0026] The stabilizer includes any one of monoethanolamine, diethanolamine, and triethanolamine;

[0027] The solution containing the second metal includes a silver nitrate solution.

[0028] Optionally, the stabilizer is added dropwise to the mixture being stirred.

[0029] Optionally, the thin film is prepared on a substrate, comprising:

[0030] Multiple sub-film layers are sequentially prepared on the substrate, wherein at least one of the sub-film layers is made of the metal oxide and the second metal.

[0031] The present invention also provides an eye protection device, including a light-emitting body and the aforementioned thin film, wherein the thin film is located on the light-emitting side of the light-emitting body.

[0032] The beneficial effects of this invention are as follows: On the one hand, the thin film provided by this invention, comprising metal oxide and second metal, is non-toxic and has good chemical stability. Therefore, the film has strong stability and can meet the requirements of long life and multi-environment application for display products using this film. On the other hand, the film can effectively absorb most of the harmful blue light in the wavelength range of 415nm to 455nm, while retaining most of the beneficial blue light in other wavelength ranges (such as blue light in the wavelength range of 460 to 500nm, which is beneficial to maintaining the color balance of transmitted light and is beneficial to the human body), and ensure the high transmittance requirements of other remaining visible light wavelengths, maintain the color balance of transmitted light, and avoid secondary damage from reflected blue light.

[0033] The thin film preparation method provided by this invention uses a solution method to prepare a thin film including a metal oxide and a second metal as a blue light absorbing film layer. The process is simple, the preparation temperature is low, and it can be prepared on a large scale at a low cost. It achieves the preparation of a blue light absorbing film layer at a low heat treatment temperature that existing absorbent blue light blocking films cannot achieve with a very simple process and extremely low cost. This reduces the transmittance of short-wavelength high-energy blue light in the incident light spectrum, reduces the damage of this part of blue light to the human eye, and can meet the needs of large-scale practical production applications.

[0034] The eye protection device provided by this invention, by employing the aforementioned thin film, improves or avoids the damage to the human eye caused by harmful blue light in the wavelength range of 415nm to 455nm in the light-emitting body, while ensuring the high transmittance requirements of other visible light residual bands and maintaining 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. Attached Figure Description

[0035] Figure 1a This is a scanning electron microscope image of the surface microstructure of the thin film in an embodiment of the present invention;

[0036] Figure 1b This is a scanning electron microscope image of the microstructure of the thin film cross-section in an embodiment of the present invention;

[0037] Figure 2a This is a cross-sectional view of a thin film structure in an embodiment of the present invention;

[0038] Figure 2b This is a cross-sectional view of another thin film in an embodiment of the present invention;

[0039] Figure 3 The ultraviolet-visible transmission spectra of thin films with different silver doping concentrations in the embodiments of the present invention are shown.

[0040] Figure 4 The ultraviolet-visible transmission spectra of films prepared at different annealing temperatures in the embodiments of the present invention;

[0041] Figure 5 The X-ray diffraction pattern of the thin film in the embodiment of the present invention;

[0042] Figure 6a The X-ray photoelectron spectrum of the thin film in the embodiment of the present invention;

[0043] Figure 6b The X-ray photoelectron spectrum of zinc was analyzed from the total X-ray photoelectron spectrum of the thin film in this embodiment of the invention.

[0044] Figure 6c The X-ray photoelectron spectrum of oxygen was analyzed from the overall X-ray photoelectron spectrum of the thin film in this embodiment of the invention.

[0045] Figure 6d The X-ray photoelectron spectrum of silver was analyzed from the total X-ray photoelectron spectrum of the thin film in this embodiment of the invention.

[0046] Figure 7 This is a graph showing the change in the absolute spectrum of the white light source before and after the thin film is applied, as described in an embodiment of the present invention.

[0047] Figure 8 This is a CIE1931 chromaticity diagram on the chromaticity diagram before and after covering the film in an embodiment of the present invention.

[0048] The reference numerals in the attached figures are:

[0049] 1. Substrate; 2. Thin film. Detailed Implementation

[0050] To enable those skilled in the art to better understand the technical solution of the present invention, the following describes in further detail a thin film, its preparation method, and an eye protection device of the present invention in conjunction with the accompanying drawings and specific embodiments.

[0051] Currently, there are three main methods for preventing blue light from harming the eyes. The first is to reflect specific wavelengths of blue light through optical path design. However, this type of reflective blue light blocking film is difficult to manufacture, has complex processes, and is costly. Furthermore, reflected blue light poses a potential secondary risk of eye damage. The second method uses down-conversion luminescent materials to convert low-wavelength blue light into higher-wavelength blue light or other light. This conversion method still shifts shorter wavelengths towards blue light, and the original brightness of blue light is increased to red light, leading to increased red light brightness and potential eye damage. The third method involves using blue light-absorbing materials to prepare blue light blocking films. Existing technologies involve incorporating organic materials or inorganic nanoparticles into a polymer substrate to create a film that absorbs blue light. However, the incorporated organic materials or polymer substrate can affect the product's lifespan due to aging, often requiring additional protective layers to extend its lifespan. In addition, most existing inorganic blue light blocking films based on semiconductors contain toxic materials such as cadmium and lead. Non-toxic blue light blocking films suffer from problems such as excessively high manufacturing temperatures and high costs, limiting their application.

[0052] To address the aforementioned problem of high-energy blue light causing eye damage, this invention provides a thin film for a display device. The thin film includes a metal oxide and a second metal, wherein the content of the metal oxide in the thin film is greater than the content of the second metal in the thin film. The metal element contained in the metal oxide is a first metal, and both the first metal and the second metal are transition elements with different atomic numbers.

[0053] Transition elements are chemical elements from Group IIIB to Group VIII in the periodic table. The atomic number is 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.

[0054] On the one hand, the thin film, including metal oxides and second metals, is non-toxic and has good chemical stability. Therefore, the thin film 2 has strong stability and can meet the requirements of long life and multi-environment application for display products using this film. On the other hand, the thin film 2 can effectively absorb most of the harmful blue light in the wavelength range of 415nm to 455nm, while retaining most of the beneficial blue light in other wavelength ranges (such as blue light in the wavelength range of 460 to 500nm, which is beneficial to maintaining the color balance of transmitted light and is beneficial to the human body). It also ensures the high transmittance requirements of the remaining wavelengths of other visible light, maintains the color balance of transmitted light, and avoids secondary damage from reflected blue light.

[0055] In some embodiments, the metal oxide and the second metal are mixed together, and the molar ratio of the second metal to the metal oxide is between 3% and 6%, wherein the atomic number of the first metal is less than that of the second metal. By controlling the molar ratio of the second metal to the metal oxide within this range, the flatness of the film layer and the absorption rate of blue light in a specific wavelength range (such as harmful blue light in the wavelength range of 415 nm to 455 nm) can be guaranteed.

[0056] In some embodiments, the average surface roughness of the film under a scanning electron microscope is between 150 and 250 nm, and the thickness of the film is between 100 nm and 2 μm.

[0057] Surface average roughness refers to the absolute value of the height difference between the highest and lowest points on a thin film within the field of view, as observed at a microscopic scale, such as using a scanning electron microscope to examine the surface and cross-sectional morphology of the film. For example... Figure 1a and Figure 1b As shown, Figure 1a This is a SEM (scanning electron microscope) image of the surface microstructure of the thin film in an embodiment of the present invention; Figure 1b This is a SEM (scanning electron microscope) image of the microstructure of the thin film cross-section in an embodiment of the present invention; from Figure 1a As can be seen, the second metal is dispersed and arranged relatively uniformly in the metal oxide. From... Figure 1b As can be seen, the film layer is relatively flat, with an average roughness between 150-250 nm.

[0058] In this embodiment, by controlling the average surface roughness of the thin film under a scanning electron microscope to be between 150 and 250 nm, the smoothness of the subsequent film layer preparation can be guaranteed, without affecting the display effect.

[0059] In some embodiments, the thin film comprises multiple sub-film layers stacked sequentially, and the material of at least one sub-film layer comprises a metal oxide and a second metal.

[0060] In some embodiments, the film has the highest absorption rate for blue light in the wavelength range of 415-455 nm, with an average cutoff rate of 57.1%; the film has an average transmittance of 87.2% for light in the wavelength range of 500-800 nm.

[0061] In some embodiments, the first metal includes zinc, titanium, and copper, and the second metal includes silver, gold, and platinum group metals.

[0062] In some embodiments, the thin film is prepared by one or more methods, such as spin coating or sputtering deposition.

[0063] In this embodiment, such as Figure 2a As shown, thin film 2 is formed on one side of substrate 1. The material of thin film 2 includes silver-doped zinc oxide, which can absorb blue light in the wavelength range of 415nm to 455nm.

[0064] On the one hand, silver-doped zinc oxide is non-toxic and has good chemical stability, so the film 2 has strong stability, which can meet the requirements of long life and multi-environment application of display products using this film. On the other hand, film 2 can effectively absorb most of the harmful blue light in the wavelength range of 415nm to 455nm, while retaining most of the beneficial blue light in other wavelength ranges (such as blue light in the wavelength range of 460 to 500nm, which is beneficial to maintaining the color balance of transmitted light and is beneficial to the human body), and ensure the high transmittance requirements of other remaining visible light wavelengths, maintain the color balance of transmitted light, and avoid secondary damage from reflected blue light.

[0065] In some embodiments, the molar ratio of silver to zinc oxide in the thin film 2 ranges from 3% to 6%. The addition of silver can effectively absorb harmful blue light in the wavelength range of 415nm to 455nm. The higher the doping concentration of silver, the higher the absorption rate of harmful blue light in the wavelength range of 415nm to 455nm. This molar ratio range of silver to zinc oxide can effectively absorb harmful blue light in the wavelength range of 415nm to 455nm while retaining most of the beneficial blue light in other wavelength ranges (such as blue light in the wavelength range of 460 to 500nm, which is beneficial to maintaining the color balance of transmitted light and is good for the human body), while ensuring the high transmittance requirements of other remaining visible light wavelengths and maintaining the color balance of transmitted light.

[0066] In some embodiments, the thickness of film 2 ranges from 100 nm to 2 μm. Compared to existing inorganic blue light blocking films, which are often very thick and thus have limited application range, film 2 in this embodiment can achieve a nanometer-level thickness, making it more suitable for the future development of flexible and large-area displays, and offering wide applicability and convenience in display and lighting applications.

[0067] In some embodiments, such as Figure 2b As shown, thin film 2 is also formed on the other side of substrate 1; the materials and thicknesses of thin films 2 formed on both sides of substrate 1 are the same. The arrangement of thin films 2 on both sides of substrate 1 further improves the cutoff rate of harmful blue light in the wavelength range of 415nm to 455nm, and also avoids the decrease in transmittance of light in other visible light bands due to the mutual influence between the two blue light absorption film layers, so that the thin film can be better applied to display devices or lighting devices.

[0068] In some embodiments, substrate 1 may be a glass substrate.

[0069] Based on the above-described structure of the thin film in this embodiment, this embodiment also provides a method for preparing the thin film, comprising: preparing the thin film on a substrate, including:

[0070] Step S01: Mix the solution containing the first metal with an organic solvent, and after the reaction, obtain a mixed liquid;

[0071] In this step, the molar ratio of the solution containing the first metal to the organic solvent is (0.5–3):50, the reaction temperature of the solution containing the first metal and the organic solvent is 20–60°C, and the reaction time is 0.5–4 hours.

[0072] In some embodiments, the solution comprising the first metal is such as zinc acetate dihydrate. The organic solvent includes any one of ethanol, methanol, and ethylene glycol methyl ether.

[0073] In some embodiments, the molar ratio of zinc acetate dihydrate to organic solvent is 1:50.

[0074] In some embodiments, the reaction temperature is preferably 25–45°C; the reaction time is preferably 2 hours.

[0075] In this step, the reaction is preferably carried out under stirring conditions. In this embodiment, there are no special requirements for the stirring rate; a stirring rate well known in the art can be used. In this embodiment, the mixed liquid is transparent and contains sediment.

[0076] There are no special requirements for the mixing method in this step; any mixing method well known in the field can be used.

[0077] Step S02: Mix the liquid mixture with the stabilizer and stir. After the reaction, a metal oxide precursor solution is obtained.

[0078] In this step, the volume of the stabilizer is 2-10% of the volume of the organic solvent, the reaction temperature of the mixture and the stabilizer is 20-60℃, and the reaction time is 0.5-4 hours.

[0079] In some embodiments, the metal oxide precursor solution is such as a zinc oxide precursor solution. The stabilizer includes any one of monoethanolamine, diethanolamine, and triethanolamine.

[0080] In some embodiments, the preferred method of mixing is to add the stabilizer dropwise to the stirred mixture. Dropwise addition promotes a more complete reaction.

[0081] In some embodiments, the reaction temperature is preferably 30°C. The reaction time is started after all the stabilizer has been added.

[0082] In this embodiment, the reaction is preferably carried out under stirring conditions. There are no special requirements for the stirring rate in this embodiment, and a stirring rate well known in the art can be used.

[0083] Step S03: Mix the solution containing the second metal with the metal oxide precursor solution and then age it to obtain a metal oxide precursor solution containing the second metal.

[0084] In this step, the solution containing the second metal, such as a silver source (including silver nitrate solution), is used. The metal oxide precursor solution, such as a zinc oxide precursor solution, is also used. Alternatively, the metal oxide precursor solution containing the second metal, such as a silver-doped zinc oxide precursor solution, can be used.

[0085] In this step, the molar ratio of the second metal in the solution containing the second metal to the organic solvent is (3-6):2500, the reaction temperature of the solution containing the second metal and the metal oxide precursor solution is 20-60℃, and the reaction time is 9-24 hours.

[0086] In this step, the molar ratio of silver in the silver source to the organic solvent is (3-6):2500, the reaction temperature of the silver source and the zinc oxide precursor solution is 20-60℃, and the reaction time is 9-24 hours.

[0087] In some embodiments, the molar ratio of silver in the silver source to the organic solvent is 3:2500. The reaction temperature is preferably 30°C, and the reaction time is preferably 20 hours.

[0088] Step S04: A metal oxide precursor solution containing a second metal is coated onto the surface of one side of the substrate, and then dried and annealed in sequence to form a thin film.

[0089] In this step, a silver-doped zinc oxide precursor solution is coated onto the surface of one side of the substrate, and then dried and annealed in sequence to form a thin film.

[0090] In some embodiments, the coating method includes spin coating, wherein the spin coating is accelerated from 0 to 500 r / min at 100 r / s and then maintained at 500 r / min, the total duration of the spin coating acceleration and the maintenance of 500 r / min speed is 5 seconds; the spin coating is then accelerated from 500 r / min to 2000 r / min at 100 r / s and then maintained at 2000 r / min speed, the total duration of the spin coating acceleration and the maintenance of 2000 r / min speed is 60 seconds.

[0091] In some embodiments, the coating method may also be spraying, dipping, etc., but spin coating is more preferred. Spin coating can better control the thickness and uniformity of the blue light absorption film.

[0092] In some embodiments, the drying temperature range is 100–120°C, and the drying time is 10–20 min; the annealing temperature range is 200–350°C, and the annealing time is 10–40 min.

[0093] In some embodiments, the drying temperature is 100°C, and the drying time is preferably 10–20 min. The annealing temperature is preferably 230–300°C, more preferably 250–270°C; the annealing time is preferably 20 min. Annealing is preferably performed in an air atmosphere. The solvent in the silver-doped zinc oxide precursor solution is removed by drying.

[0094] In some embodiments, before coating, the film preparation method further includes cleaning the glass substrate sequentially with scouring powder, deionized water, acetone and anhydrous ethanol, then drying it with nitrogen and cleaning it with ozone for 10 minutes.

[0095] In this embodiment, zinc oxide silver-doped crystals are generated during the annealing process. After annealing, the film is allowed to cool naturally to room temperature in air. If the harmful blue light blocking rate of the formed film does not meet the requirements, the above spin coating, drying, and annealing steps can be repeated until the target blue light blocking rate of the film is achieved.

[0096] In some embodiments, preparing the thin film on a substrate includes: sequentially preparing a plurality of sub-film layers on the substrate, wherein at least one sub-film layer is made of a metal oxide and a second metal. The preparation method for any sub-film layer comprising a metal oxide and a second metal is the same as the thin film preparation method described above, and will not be repeated here.

[0097] In some embodiments, such as Figure 3As shown, the specific method for preparing a thin film on the substrate is as described in Example 1: Step S01: Add 1.128g of zinc acetate dihydrate (C4H6O4Zn·2H2O, also known as zinc acetate dihydrate) to 15ml of ethanol, stir and react at 30℃ for 2 hours to obtain a transparent mixed liquid with precipitate.

[0098] Step S02: Add 985 μl of diethanolamine dropwise slowly to the mixture, stir at 30°C for 2 hours until the solution becomes transparent, and obtain the zinc oxide precursor solution;

[0099] Step S03: Add 103 μl of 1.5 mol / L silver nitrate solution to the zinc oxide precursor solution, stir at 30°C for 2 hours, and then let stand for 20 hours to obtain the silver-doped zinc oxide precursor solution.

[0100] Step S04: Clean the glass substrate in sequence with detergent, deionized water, acetone and anhydrous ethanol. Before use, dry it with nitrogen and clean it with ozone for 10 minutes.

[0101] A glass substrate (e.g., 0.7 mm thick) was placed on the spin coater's turntable. The prepared silver-doped zinc oxide precursor solution was then dropped onto the substrate surface. Spin coating was performed at an acceleration of 100 r / s from 0 to 500 r / min, held for 5 seconds, and then at an acceleration of 100 r / s from 500 r / min to 2000 r / min, held for 60 seconds. Next, the substrate with the wet film was dried at a preheated temperature of 100°C for 10 minutes. Afterward, it was annealed at 270°C for 20 minutes on a drying stage. Finally, it was removed and allowed to cool naturally to room temperature in air, thus forming a thin film on the substrate.

[0102] In some embodiments, such as Figure 3 As shown, unlike the specific embodiments described above, in the method for preparing the thin film on the substrate, step S03 of Example 2 involves adding 206 μl of a 1.5 mol / L silver nitrate solution to the zinc oxide precursor solution, stirring at 30°C for 2 hours, and then allowing it to stand for 20 hours to obtain the silver-doped zinc oxide precursor solution. The other steps and process conditions of the thin film preparation method in this embodiment are the same as in Example 1 above, and will not be repeated here.

[0103] In some embodiments, such as Figure 3 As shown, unlike the specific embodiments described above, in the method for preparing the thin film on the substrate, step S03 of Example 3 involves adding 309 μl of a 1.5 mol / L silver nitrate solution to the zinc oxide precursor solution, stirring at 30°C for 2 hours, and then allowing it to stand for 20 hours to obtain the silver-doped zinc oxide precursor solution. The other steps and process conditions of the thin film preparation method in this embodiment are the same as in Example 1 above, and will not be repeated here.

[0104] like Figure 3 As shown, by comparing the three examples of thin film preparation, we can conclude that: the higher the silver doping concentration, the better the absorption effect of the prepared thin film on harmful blue light in the wavelength range of 415nm to 455nm, and the lower the transmittance of harmful blue light in the wavelength range of 415nm to 455nm, that is, the more significant the decrease in the transmittance of harmful blue light in the wavelength range of 415nm to 455nm; at the same time, thin films with different silver doping concentrations can retain most of the beneficial blue light in other wavelength ranges (such as blue light in the wavelength range of 460 to 500nm, which is beneficial to maintaining the color balance of transmitted light and is beneficial to the human body), and ensure the high transmittance requirements of other remaining visible light wavelengths, maintaining the color balance of transmitted light.

[0105] In some embodiments, such as Figure 4 As shown, unlike any of the above specific embodiments, in the method for preparing a thin film on a substrate, in step S04 of Embodiment 4, the film is annealed at 210°C for 20 minutes on a drying table, and finally removed and allowed to cool naturally to room temperature in air to form a thin film on the substrate. The other steps and process conditions of the thin film preparation method in this embodiment are the same as in Embodiment 2 above, and will not be repeated here.

[0106] In some embodiments, such as Figure 4 As shown, unlike any of the specific embodiments described above, in step S04 of Example 5, the thin film is annealed at 260°C for 20 minutes on a drying table, and then naturally cooled to room temperature in air to form a thin film on the substrate. The other steps and process conditions of the thin film preparation method in this embodiment are the same as in Example 2 above, and will not be repeated here. The thin film prepared in this embodiment has an average cutoff rate of 57.1% for short-wavelength blue light in the wavelength range of 415–455 nm, and an average transmittance of 87.2% for light in the wavelength range of 500–800 nm.

[0107] In some embodiments, such as Figure 4 As shown, unlike any of the specific embodiments described above, in the method for preparing a thin film on a substrate, in step S04 of Example Six, the film is annealed at 300°C for 20 minutes on a drying table, and finally removed and allowed to cool naturally to room temperature in air to form a thin film on the substrate. The other steps and process conditions of the thin film preparation method in this embodiment are the same as in Example Two above, and will not be repeated here.

[0108] like Figure 4As shown, comparing Examples 4, 5, and 6 of the above-mentioned thin film preparation, it can be concluded that: in the preparation of the thin film, the annealing temperature can be changed to control the absorption peak of harmful blue light in the wavelength range of 415nm to 455nm. The lower the final annealing temperature, the better the absorption effect of the prepared thin film on harmful blue light in the wavelength range of 415nm to 455nm, the higher the absorption peak of the thin film on harmful blue light in the wavelength range of 415nm to 455nm, that is, the more significant the decrease in the transmittance of harmful blue light in the wavelength range of 415nm to 455nm; at the same time, thin films with different annealing temperatures can retain most of the beneficial blue light in other wavelength ranges (such as blue light in the wavelength range of 460 to 500nm, which is beneficial to maintaining the color balance of transmitted light and is beneficial to the human body), and ensure the high transmittance requirements of other remaining visible light wavelengths, maintaining the color balance of transmitted light.

[0109] In some embodiments, such as Figure 5 As shown, the thin film prepared in this embodiment was characterized by X-ray diffraction (XRD) to detect its crystal structure. The results showed that the film structure was hexagonal wurtzite zinc oxide doped with cubic silver nanoparticles. The thin film prepared in this embodiment was also characterized by X-ray photoelectron spectroscopy (XPS) to detect the specific valence states and contents of each element within the film. The experimental results are shown below. Figure 6a , Figure 6b , Figure 6c and Figure 6d As shown in the figure, the silver content detected by EDS is comparable to the doping amount. The silver in the film is in an elemental state, and its plasmon resonance absorption effect is good, with a good absorption effect on harmful blue light in the wavelength range of 415nm to 455nm; while the silver ions and silver oxide in the silver nitrate solution have poor absorption effect on harmful blue light in the wavelength range of 415nm to 455nm.

[0110] like Figure 5 As shown, in an X-ray diffraction pattern (i.e., an XRD pattern), the horizontal axis represents the diffraction angle, that is, the angle between the incident X-ray and the diffracted line exiting the thin film, and the vertical axis represents the intensity of the diffracted line exiting the thin film. Figures 6a to 6d As shown, in the X-ray photoelectron spectrum (i.e., XPS spectrum), the horizontal axis represents the binding energy, which is used to determine the specific valence state of the element, and the vertical axis represents the intensity of the diffraction lines emitted after passing through the thin film. Figure 6a The total X-ray photoelectron spectrum of the thin film. Figure 6b XPS spectra of zinc element analyzed from the overall spectrum of the thin film; Figure 6c XPS pattern of oxygen element analyzed from the overall spectrum of the thin film; Figure 6dThis is the XPS spectrum of silver element analyzed from the overall spectrum of the thin film.

[0111] In some embodiments, such as Figure 7 and Figure 8 As shown, using an integrating sphere and a light radiation safety measurement system, the absolute spectrum of a white light source before and after being covered with the thin film prepared in this invention was measured (before and after the white light passed through the thin film). The measurement results show that the intensity of blue light decreased significantly after being covered with the thin film, while the light in other wavelength bands (i.e., wavelengths in the range of 500–800 nm) remained almost unchanged. Figure 8 The CIE1931 chromaticity diagrams before and after the film coating show that the color temperature of the white light source decreases and the color cast is less after the film coating is applied.

[0112] In some embodiments, the light radiation of a white light source before and after covering the film is measured by the Far East OST-500 light radiation safety measurement system, according to standard IEC / TR 62778, and with reference to the white light source test report before and after covering the film by the blue light hazard testing system in Table 1 below.

[0113] Table 1

[0114]

[0115] As shown in Table 1, after the blue light hazard testing system was covered with a thin film, the blue light hazard (i.e., blue light radiance Lb) decreased from 9.264e+003 (W / m²) to 9.264e+003 (W / m²). 2 / sr) decreased to 2.257e+003 (W / m 2 The maximum permissible irradiation time has also changed from 108s to 443s.

[0116] In Table 1, blue light hazard (Lb) refers to the effective blue light radiance, which is calculated by weighting the B(λ) spectrum (the spectrum in the optical radiation safety measurement system) and expressed in watts per square meter per steradian (W / m²). 2 / sr) indicates.

[0117] The thin film preparation method in this embodiment uses a solution method to prepare a thin film including a metal oxide and a second metal as a blue light absorbing film layer. The process is simple, the preparation temperature is low, and it can be prepared on a large scale at a low cost. It achieves the preparation of a blue light absorbing film layer at a low heat treatment temperature that existing absorbent blue light blocking films cannot achieve with a very simple process and extremely low cost. This reduces the transmittance of short-wavelength high-energy blue light in the incident light spectrum, reduces the damage of this part of blue light to the human eye, and can meet the needs of large-scale practical production applications.

[0118] This invention also provides an eye protection device, including a light-emitting body and a thin film as described in any of the above embodiments, wherein the thin film is located on the light-emitting side of the light-emitting body.

[0119] The light-emitting body can be a display panel or a lighting panel, etc.

[0120] By employing the thin film in any of the above embodiments, the harmful blue light in the wavelength range of 415nm to 455nm in the light-emitting body is improved 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.

[0121] 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.

[0122] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for preparing a thin film, characterized in that, The preparation of the thin film on the substrate includes: A solution containing the first metal is mixed with an organic solvent, and the mixture is reacted to obtain a mixed liquid. The mixture is stirred with a stabilizer, and after reaction, a metal oxide precursor solution is obtained. The solution containing the second metal is mixed with the metal oxide precursor solution and then aged to obtain the metal oxide precursor solution containing the second metal. The metal oxide precursor solution containing the second metal is coated onto the surface of one side of the substrate, and then dried and annealed in sequence to form the thin film; The first metal includes zinc, titanium, and copper, and the second metal includes silver, gold, and platinum group metals.

2. The method for preparing the thin film according to claim 1, characterized in that, The molar ratio of the solution containing the first metal to the organic solvent is (0.5-3):50, the reaction temperature of the solution containing the first metal and the organic solvent is 20-60°C, and the reaction time is 0.5-4 hours.

3. The method for preparing the thin film according to claim 1, characterized in that, The volume of the stabilizer is 2-10% of the volume of the organic solvent, the reaction temperature of the mixture with the stabilizer is 20-60°C, and the reaction time is 0.5-4 hours.

4. The method for preparing the thin film according to claim 1, characterized in that, The molar ratio of the second metal in the solution containing the second metal to the organic solvent is (3-6):2500. The reaction temperature of the solution containing the second metal and the metal oxide precursor solution is 20-60°C, and the reaction time is 9-24 hours.

5. The method for preparing the thin film according to claim 1, characterized in that, The coating method includes spin coating. The spin coating is accelerated from 0 to 500 r / min at 100 r / s and then maintained at 500 r / min. The total time for the spin coating to accelerate and maintain the 500 r / min speed is 5 seconds. The spin coating is then accelerated from 500 r / min to 2000 r / min at 100 r / s, and then maintained at 2000 r / min. The total time for the spin coating to accelerate again and maintain the speed of 2000 r / min is 60 seconds.

6. The method for preparing the thin film according to claim 1, characterized in that, The drying temperature range is 100–120°C, and the drying time is 10–20 min; The annealing temperature range is 200–350°C, and the annealing time is 10–40 min.

7. The method for preparing the thin film according to any one of claims 1-6, characterized in that, The organic solvent includes any one of ethanol, methanol, and ethylene glycol methyl ether; The stabilizer includes any one of monoethanolamine, diethanolamine, and triethanolamine; The solution containing the second metal includes a silver nitrate solution.

8. The method for preparing a thin film according to claim 1, characterized in that, The stabilizer is added dropwise to the mixture being stirred.

9. The method for preparing a thin film according to any one of claims 1-6, characterized in that, The preparation of the thin film on the substrate includes: Multiple sub-film layers are sequentially prepared on the substrate, wherein at least one of the sub-film layers is made of the metal oxide and the second metal.

10. A thin film for a display device, characterized in that, The thin film is prepared by the preparation method according to any one of claims 1-9; The thin film comprises a metal oxide and a second metal, wherein the content of the metal oxide in the thin film is greater than the content of the second metal in the thin film, wherein the metal oxide contains a first metal, and both the first metal and the second metal are transition elements, and the first metal and the second metal have different atomic numbers.

11. The thin film according to claim 10, characterized in that, The metal oxide is mixed with the second metal, and the molar ratio of the second metal to the metal oxide is between 3% and 6%. The atomic number of the first metal is less than that of the second metal.

12. The thin film according to claim 11, characterized in that, The average surface roughness of the film under a scanning electron microscope is between 150 and 250 nm, and the thickness of the film is between 100 nm and 2 µm.

13. The thin film according to claim 10, characterized in that, The thin film comprises multiple sub-film layers stacked sequentially, and at least one of the sub-film layers is made of the metal oxide and the second metal.

14. The thin film according to claim 10, characterized in that, The film exhibits the highest absorption rate for blue light in the wavelength range of 415-455nm, with an average cutoff rate of 57.1%; the film also has an average transmittance of 87.2% for light in the wavelength range of 500-800nm.

15. An eye protection device, comprising a light-emitting body, characterized in that, It also includes the thin film according to any one of claims 10-14, wherein the thin film is located on the light-emitting side of the light-emitting body.

Images