White light device with high color rendering index as well as preparation method and application of white light device

Abstract

The invention discloses a high-color-rendering-index white light device and a preparation method and application thereof, yellow YAG and wide-band red and green nitride fluorescent powder improve the color rendering index of an LED, a flexible polymer is used as a packaging material, and the high-color-rendering-index white light LED device applied to a lighting source is prepared; red fluorescent powder and green fluorescent powder are added on the basis of yellow fluorescent powder, and a white light LED device with the color rendering index of 96.9 is obtained. The color rendering index is high, meanwhile, the mass ratio of the 6901A silica gel to the 6901B silica gel is adjusted, the fluorescent powder is packaged, and the flexible fluorescent powder composite light-emitting film with the maximum deformation displacement and the optimal fracture stress is obtained and used for device preparation. The color rendering index of the device can be effectively improved, and the adopted packaging film can still show excellent mechanical properties when subjected to stretching and cyclic physical deformation. Wide application prospects are realized in the fields of high-performance white light LED lighting devices, wearable equipment and flexible display.

Description

Technical Field

[0001] This invention belongs to the field of white LED device technology, specifically relating to a high color rendering index white light device, its preparation method, and its application. Background Technology

[0002] White light-emitting diodes (LEDs) are gradually replacing traditional lighting sources due to their numerous outstanding characteristics such as energy saving, environmental friendliness, high efficiency, and long lifespan, and are hailed as the next generation of mainstream lighting sources. The performance of white LEDs is closely related to the phosphors used. The most common method for achieving white LEDs is based on a blue LED chip combined with yellow phosphors. However, due to the lack of red light components in the emission spectrum, the resulting white light suffers from defects such as low color rendering index (CRI), excessively high correlated color temperature (CRT), and low spectral continuity. Simultaneously, there is a spectral gap in the 480-520 nm region between the blue light emitted by the blue LED chip and the yellow light spectrum of the YAG phosphor, known as the "cyan gap." The presence of the cyan gap in the spectrum causes discontinuity in the visible light emission spectrum and also reduces the CRI of the white light device. Therefore, this patent compensates for these deficiencies by adding broadband red and green phosphors, significantly improving the color rendering performance of the device.

[0003] Furthermore, silicone, as a widely used inorganic polymer material, shines in numerous application fields due to its excellent physical properties and chemical stability. It can withstand both high and low temperatures, effectively solving the problem of shortened lifespan in white LEDs and preventing breakage or deformation. In addition, silicone's excellent insulation and good chemical stability make it a preferred material in the electronics industry, providing a solid foundation for the corrosion resistance and long lifespan of products. Mixing phosphors with silicone can prepare flexible luminescent films for white light devices, retaining the advantages of LEDs in lighting while fully utilizing the excellent mechanical properties of flexible silicone, potentially highlighting its comprehensive advantages in flexible light-emitting devices. However, the mechanical properties of flexible phosphor luminescent films and their optimal ratio still require systematic experimental verification. Therefore, the development of high color rendering index white light devices based on flexible luminescent films is crucial and has broad application prospects. Summary of the Invention

[0004] Technical problem to be solved: This invention addresses the core technical problems of white light in existing technologies, such as low color rendering, excessively high correlated color temperature, and low spectral continuity.

[0005] Purpose of the invention: This application provides a high color rendering index white light device, its preparation method, and its application. Yellow YAG phosphor and broad-band red and green nitride phosphors are used as luminescent materials, and a flexible polymer is innovatively used as the encapsulation material. This method can significantly improve the light color performance, thereby developing a high color rendering index white LED device. In addition, the flexible polymer material has excellent flexibility and processability, and can be well adapted to LED chips of different shapes and sizes, further improving the applicability of the device.

[0006] To achieve the above objectives, this application provides the following technical solution: A method for fabricating a high color rendering index white light device, the specific steps of which are as follows: S1, Preparation of yellow-red-green composite phosphor gel: S11. Preparation of gel without red and green phosphors: Weigh 0.444 g of yellow phosphor and add it to 2 g of E625A silica gel and 2 g of E625B silica gel mixed gel according to the mass ratio, and stir the mixture evenly. S12. Preparation of gels with different proportions of red phosphor: Weigh yellow phosphor, red phosphor and green phosphor according to the mass ratio, with the mass ratio of red phosphor increasing, and add them in groups to a mixed silica gel with a mass ratio of E625A silica gel:E625B silica gel=1:1. Stir the mixture evenly. S13. Preparation of gels with different proportions of green phosphor: Weigh yellow phosphor, red phosphor and green phosphor according to the mass ratio, with the mass ratio of green phosphor increasing, and add them in groups to a mixed silica gel with a mass ratio of E625A silica gel:E625B silica gel=1:1. Stir the mixture evenly. S2, Testing light and color performance: The prepared yellow-red-green composite phosphor gel was uniformly coated on the blue LED chip and heated on a 225℃ heating stage for 30 s. After the gel solidified, it was placed in an integrating sphere. Using a spectroradiometer, the color temperature was controlled at 5100-5300 K, and the spectral distribution and color rendering index were observed. The yellow, red, and green phosphor films with the optimal mass ratio were obtained for the preparation of high color rendering index white LED devices. S3, Preparation of silicone film: A mixture of 6901A and 6901B silicone with a mass ratio of 10:0.5-5 was prepared. The mixture was added to a centrifuge tube and thoroughly stirred until homogeneous. The mixture was then vibrated in an ultrasonic disperser for 15 minutes to remove air bubbles, yielding a mixed gel. 5-8 mL of the mixed gel was then poured into a glass petri dish, maintaining a film thickness of 0.5-1.5 mm. The film was allowed to stand at room temperature for 1 hour to form a film. The film was then removed for testing and characterization. The optimal mass ratio of 6901A and 6901B silicone films with the best mechanical properties was obtained for the fabrication of high color rendering index white LED devices. S4, Preparation of flexible phosphor composite luminescent film: Weigh and mix 6901A and 6901B silica gels in the optimal mass ratio, then add yellow, red, and green phosphors in the optimal mass ratio; stir evenly and then oscillate in an ultrasonic disperser for 15 min to remove air bubbles, thus obtaining a mixed phosphor gel; then, take 5-8 mL of the mixed phosphor gel and pour it into a glass petri dish, control the film thickness at 0.5-1.5 mm, and let it stand at room temperature for 1 h to form a film, thus obtaining a phosphor film with the optimal ratio. The film is then removed for testing and characterization. S5, Measure the mechanical properties of the film: The prepared silicone film and phosphor film are tested for mechanical properties using a tensile testing machine; S6, Preparation of white LED device: The prepared phosphor film with the optimal ratio is attached to the blue LED chip to obtain a white LED device with a high color rendering index. The spectral distribution and color rendering index are observed by placing it in an integrating sphere and using a spectroradiometer.

[0007] Furthermore, the yellow phosphor is a yellow rare-earth yttrium aluminum garnet phosphor, YAG, specifically Y3Al5O. 12 :Ce 3 + .

[0008] Furthermore, the red phosphor is AlSiN3:Eu 2+ SrSiN3:Eu 2+ CaSiN3:Eu 2+ One or more of the following, the green phosphor being BaSi2O2N2:Eu 2+ .

[0009] Further, in S12, the first group contains 0.234 g of yellow phosphor, 0.047 g of red phosphor, 0.164 g of green phosphor, 2 g of E625A silica gel, and 2 g of E625B silica gel; the second group contains 0.22 g of yellow phosphor, 0.067 g of red phosphor, 0.156 g of green phosphor, 2 g of E625A silica gel, and 2 g of E625B silica gel; the third group contains 0.212 g of yellow phosphor, 0.085 g of red phosphor, 0.148 g of green phosphor, 2 g of E625A silica gel, and 2 g of E625B silica gel; the fourth group contains 0.202 g of yellow phosphor, 0.101 g of red phosphor, 0.141 g of green phosphor, 2 g of E625A silica gel, and 2 g of E625B silica gel. g; Group 5: 0.193g yellow phosphor, 0.116g red phosphor, 0.135g green phosphor, 2g E625A silica gel and 2g E625B silica gel.

[0010] Further, in S13, the first group contains 0.278 g of yellow phosphor, 0.139 g of red phosphor, 0.0278 g of green phosphor, 2 g of E625A silica gel, and 2 g of E625B silica gel; the second group contains 0.247 g of yellow phosphor, 0.123 g of red phosphor, 0.074 g of green phosphor, 2 g of E625A silica gel, and 2 g of E625B silica gel; the third group contains 0.222 g of yellow phosphor, 0.111 g of red phosphor, 0.156 g of green phosphor, 2 g of E625A silica gel, and 2 g of E625B silica gel; the fourth group contains 0.202 g of yellow phosphor, 0.101 g of red phosphor, 0.141 g of green phosphor, 2 g of E625A silica gel, and 2 g of E625B silica gel. g; Group 5: 0.185g yellow phosphor, 0.093g red phosphor, 0.167g green phosphor, 2g E625A silica gel and 2g E625B silica gel.

[0011] Furthermore, in S2, a spectroradiometer is used to control the color temperature at 5200 K and observe the spectral distribution and color rendering index.

[0012] Furthermore, the oscillation frequency of the ultrasonic disperser in S3 and S4 is 40 kHz.

[0013] A high color rendering index white light device prepared by any of the above methods is obtained by adjusting the proportions of yellow, red, and green phosphors in a flexible polymer and using a blue LED chip to excite the yellow, red, and green phosphors. This makes the white light emitted by the LED device closer to the full spectrum of natural light, ultimately resulting in a high color rendering index white light device. Application of a high color rendering index white light device prepared by any of the above methods in high-performance white LED lighting devices, wearable devices and flexible display technology.

[0014] Explanation of the principle: This method for obtaining high color rendering index (CRI) white LED lighting devices by encapsulating broadband yellow, red, and green phosphors in a flexible polymer involves first mixing phosphors of different mass fractions with the polymer, stirring thoroughly, and then coating the mixture onto a blue LED chip. The color performance is measured to optimize the mass ratio of yellow, red, and green phosphors. Based on the optimal phosphor ratio, a flexible composite luminescent film is used to prepare a white LED device with a high CRI. Therefore, this invention not only significantly improves the color performance of traditional white LED devices, but also provides a phosphor composite luminescent film with excellent mechanical properties, aligning with the application trend of flexible light-emitting devices. Furthermore, it can be applied to various flexible light-emitting devices, demonstrating good versatility.

[0015] This application provides a high color rendering index white light device, its fabrication method, and its application. Compared with the prior art, it has the following advantages: 1. Compared to blue light chip-excited YAG:Ce 3+ This invention proposes a method for preparing traditional white LEDs using yellow phosphors. It utilizes yellow YAG phosphors and broad-band red and green nitride phosphors to improve the color rendering performance of white LED devices. These phosphors are used together as luminescent materials to significantly improve the color rendering index of white LED devices. Furthermore, a flexible polymer with excellent mechanical properties is used as the encapsulation material to obtain a high color rendering index white LED device for use in lighting sources. 2. When only 10% yellow phosphor is used, the color rendering index (CRI) of the white LED device is 68.7 at a color temperature of 5200 K. When the phosphor content is 10% and the ratio of yellow, red, and green phosphors is 10:5:7, the CRI of the LED device using the flexible phosphor composite light-emitting film reaches as high as 96.9 at a color temperature of 5200 K, which is 41% higher than that of the traditional white LED device using yellow phosphor. 3. In the mechanical tensile test, the Young's modulus of the pure polymer film was 4.23 MPa, and the fracture energy was 449.37 KJ / m. 3 The flexible phosphor composite luminescent film has a Young's modulus of 5.41 MPa and a fracture energy of 570.53 KJ / m. 3 The stiffness of the flexible phosphor composite luminescent film is higher than that of the pure polymer film, indicating that the flexible phosphor composite luminescent film has greater stiffness and is less prone to deformation. It can absorb more energy during the fracture process and has better toughness. 4. In the mechanical tensile cycle test, the flexible phosphor composite light-emitting film has almost no energy dissipation compared with the pure polymer film, indicating that the flexible phosphor composite light-emitting film is relatively rigid, has strong resistance to deformation, and has good stability, making it suitable for applications that require maintaining shape stability and structural precision. 5. By incorporating three phosphors, a high color rendering index and excellent mechanical recovery properties can be obtained. The high color rendering index white LED device fabrication process disclosed in this invention is simple, and the phosphor composite light-emitting film is expected to promote the development of flexible light-emitting devices, with broad application prospects and market demand in the fields of white light lighting devices, wearable devices and flexible displays.

[0016] Attached image description: Figure 1 The following are statistical charts of the color rendering index of devices encapsulated with different proportions of yellow, red and green phosphor films in Embodiments 1, 2 and 3 of this application, where (a) is a statistical chart of the color rendering index of devices with different proportions of red phosphor films and (b) is a statistical chart of the color rendering index of devices with different proportions of green phosphor films. Figure 2 The images show the mechanical tensile test results of silicone films prepared in different proportions of silicone mixtures in Examples 1, 2 and 3 of this application, where (a) is a stress-strain diagram and (b) is an integral area statistical diagram of different silicone ratios. Figure 3 The images show the mechanical tensile test results of the silicone film and phosphor film prepared in Examples 1, 2 and 3 of this application, where (a) is a stress-strain diagram and (b) is a statistical diagram of average Young's modulus and average fracture energy. Figure 4 The stress and strain curves of the silicone film and phosphor film prepared in Examples 1, 2 and 3 of this application are obtained by continuous cyclic stretching at 50% strain for ten cycles without interval after each cycle. Among them, (a) is the strain curve of the silicone film and (b) is the strain curve of the phosphor film. Figure 5 The stress and strain curves of the silicone film and phosphor film prepared in Examples 1, 2 and 3 of this application are obtained under the condition of continuous cyclic stretching at 50% strain for ten cycles, with an interval of 60 s after each cycle. Among them, (a) is the strain curve of the silicone film and (b) is the strain curve of the phosphor film. Figure 6 The stress and strain curves of the silicone film and phosphor film prepared in Examples 1, 2 and 3 of this application are obtained under continuous tensile cycles at strains of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% and 90%, with no interval between each cycle. Among them, (a) is the strain curve of the silicone film and (b) is the strain curve of the phosphor film. Figure 7This is a statistical chart of energy dissipation data obtained by tensile cycling under strains of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90% for the silicone film and phosphor film prepared in Examples 1, 2, and 3 of this application, with no interval between each cycle. Figure 8 The stress and strain curves of the silicone film and phosphor film prepared in Examples 1, 2 and 3 of this application under tensile cycles at strains of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% and 90%, with an interval of 60 s after each cycle, are shown. (a) is the strain curve of the silicone film and (b) is the strain curve of the phosphor film. Figure 9 This is a statistical chart of energy dissipation data obtained by tensile cycling under strains of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90% for the silicone film and phosphor film prepared in Examples 1, 2, and 3 of this application, with a 60-second interval after each cycle. Figure 10 The images show the structural schematic diagram, the spectrum of the white LED device with a mass ratio of yellow, red, and green phosphors of 10:5:7, and the actual light emission diagram of the device in Embodiments 1, 2, and 3 of this application. (a) is the structural schematic diagram, (b) is the spectrum of the yellow, red, and green phosphors with a mass ratio of 10:5:7, and (c) is the actual light emission diagram of the device. Detailed Implementation

[0017] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0018] Example 1: This example provides a method for fabricating a high color rendering index white light device. The specific steps of the fabrication method are as follows: S1, Preparation of gel without red and green phosphors: Weigh 0.444 g of yellow phosphor and add it to 2 g of E625A silica gel and 2 g of E625B silica gel mixed gel according to the mass ratio, and stir the mixture evenly. S2, Test the light and color performance: The prepared phosphor gel was evenly coated on the blue LED chip and heated on a 225℃ heating stage for 30 s. After the gel solidified, it was placed in an integrating sphere and the color temperature was controlled at 5200 K using a spectroradiometer to observe the spectral distribution and color rendering index. S3, Preparation of silicone film: A mixture of 6901A silicone and 6901B silicone with a mass ratio of 10:0.5-5 was prepared. The mixture was added to a centrifuge tube and thoroughly stirred until homogeneous. The mixture was then vibrated in an ultrasonic disperser for 15 minutes to remove air bubbles, yielding a mixed gel. 5-8 mL of the mixed gel was then poured into a glass petri dish, maintaining a film thickness of 0.5-1.5 mm. The film was allowed to stand at room temperature for 1 hour to form a film. The film was then removed for testing and characterization. A film with the optimal mass ratio of 10 g of 6901A silicone and 3 g of 6901B silicone, yielding the best mechanical properties, was used for the preparation of high color rendering index white LED devices. S4, Preparation of flexible phosphor composite luminescent film: Weigh 10 g of 6901A silica gel and 3 g of 6901B silica gel in the optimal mass ratio, mix them, and add 0.444 g of yellow phosphor. After stirring evenly, oscillate in an ultrasonic disperser for 15 min to remove air bubbles and obtain a mixed phosphor gel. Then, take 5-8 mL of the mixed phosphor gel and pour it into a glass petri dish, control the film thickness at 0.5-1.5 mm, and let it stand at room temperature for 1 h to form a film, thus obtaining a phosphor film. Remove the film for testing and characterization. S5, Measure the mechanical properties of the film: The prepared silicone film and phosphor film are tested for mechanical properties using a tensile testing machine; S6, Fabrication of white LED device: The prepared phosphor film with the optimal ratio is attached to the blue LED chip to obtain a white LED device with a high color rendering index. The spectral distribution and color rendering index are observed using a spectroradiometer in an integrating sphere. Example 2: This example provides a method for fabricating a high color rendering index white light device. The specific steps of the fabrication method are as follows: S1, Prepare gels with different proportions of red phosphor: Weigh yellow phosphor, red phosphor and green phosphor according to the mass ratio, with the mass ratio of red phosphor increasing, and add them in groups to a mixed gel of E625A silica gel and E625B silica gel in a mass ratio of E625A silica gel:E625B silica gel=1:1, and stir the blend evenly. The composition of the first group consists of 0.234 g of yellow phosphor, 0.047 g of red phosphor, 0.164 g of green phosphor, 2 g of E625A silica gel, and 2 g of E625B silica gel. The second group consists of 0.22 g of yellow phosphor, 0.067 g of red phosphor, 0.156 g of green phosphor, 2 g of E625A silica gel, and 2 g of E625B silica gel. The third group consists of 0.212 g of yellow phosphor, 0.085 g of red phosphor, 0.148 g of green phosphor, 2 g of E625A silica gel, and 2 g of E625B silica gel. The fourth group consists of 0.202 g of yellow phosphor, 0.101 g of red phosphor, 0.141 g of green phosphor, 2 g of E625A silica gel, and 2 g of E625B silica gel. The fifth group consists of 0.193 g of yellow phosphor, 0.116 g of red phosphor, 0.135 g of green phosphor, and 2 g of E625A silica gel. g and E625B silicone 2 g; S2, Testing optical color performance: The prepared yellow-red-green composite phosphor gel was uniformly coated on the blue LED chip and heated on a 225℃ heating stage for 30 s. After the gel solidified, it was placed in an integrating sphere. Using a spectroradiometer, the color temperature was controlled at 5200 K, and the spectral distribution and color rendering index were observed. The optimal mass ratio of yellow, red, and green phosphor films with a mass ratio of 10:5:7 was obtained for the preparation of high color rendering index white LED devices. S3, Preparation of silicone film: A mixture of 6901A silicone and 6901B silicone with a mass ratio of 10:0.5-5 was prepared. The mixture was added to a centrifuge tube and thoroughly stirred until homogeneous. The mixture was then vibrated in an ultrasonic disperser for 15 minutes to remove air bubbles, yielding a mixed gel. 5-8 mL of the mixed gel was then poured into a glass petri dish, maintaining a film thickness of 0.5-1.5 mm. The film was allowed to stand at room temperature for 1 hour to form a film. The film was then removed for testing and characterization. A film with the optimal mass ratio of 10 g of 6901A silicone and 3 g of 6901B silicone, yielding the best mechanical properties, was used for the preparation of high color rendering index white LED devices. S4, Preparation of flexible phosphor composite luminescent film: Weigh 10 g of 6901A silica gel and 3 g of 6901B silica gel in the optimal mass ratio and mix them. Then add 0.202 g of yellow phosphor, 0.101 g of red phosphor and 0.141 g of green phosphor in the optimal mass ratio. After stirring evenly, shake in an ultrasonic disperser for 15 min to remove air bubbles and obtain a mixed phosphor gel. Then, take 5-8 mL of the mixed phosphor gel and pour it into a glass petri dish. Control the film thickness at 0.5-1.5 mm and let it stand at room temperature for 1 h to form a film. Obtain the phosphor film with the optimal ratio. Remove the film for testing and characterization. S5, Measure the mechanical properties of the film: The prepared silicone film and phosphor film are tested for mechanical properties using a tensile testing machine; S6, Preparation of white LED device: The prepared phosphor film with the optimal ratio is attached to the blue LED chip to obtain a white LED device with a high color rendering index. The spectral distribution and color rendering index are observed by placing it in an integrating sphere and using a spectroradiometer.

[0019] Example 3: This example provides a method for fabricating a high color rendering index white light device. The specific steps of the fabrication method are as follows: S1, Prepare gels with different proportions of green phosphor: Weigh yellow phosphor, red phosphor and green phosphor according to the mass ratio, with the mass ratio of green phosphor increasing, and add them in groups to a mixed gel of E625A silica gel and E625B silica gel in a mass ratio of E625A silica gel:E625B silica gel=1:1, and stir the blend evenly. The composition of the first group consists of 0.278 g of yellow phosphor, 0.139 g of red phosphor, 0.0278 g of green phosphor, 2 g of E625A silica gel, and 2 g of E625B silica gel; the second group consists of 0.247 g of yellow phosphor, 0.123 g of red phosphor, 0.074 g of green phosphor, 2 g of E625A silica gel, and 2 g of E625B silica gel; the third group consists of 0.222 g of yellow phosphor, 0.111 g of red phosphor, 0.156 g of green phosphor, 2 g of E625A silica gel, and 2 g of E625B silica gel; the fourth group consists of 0.202 g of yellow phosphor, 0.101 g of red phosphor, 0.141 g of green phosphor, 2 g of E625A silica gel, and 2 g of E625B silica gel; the fifth group consists of 0.185 g of yellow phosphor, 0.093 g of red phosphor, 0.167 g of green phosphor, and 2 g of E625A silica gel. g and E625B silicone 2 g; S2, Testing optical color performance: The prepared yellow-red-green composite phosphor gel was uniformly coated on the blue LED chip and heated on a 225℃ heating stage for 30 s. After the gel solidified, it was placed in an integrating sphere. Using a spectroradiometer, the color temperature was controlled at 5200 K, and the spectral distribution and color rendering index were observed. The optimal mass ratio of yellow, red, and green phosphor films with a mass ratio of 10:5:7 was obtained for the preparation of high color rendering index white LED devices. S3, Preparation of silicone film: A mixture of 6901A silicone and 6901B silicone with a mass ratio of 10:0.5-5 was prepared. The mixture was added to a centrifuge tube and thoroughly stirred until homogeneous. The mixture was then vibrated in an ultrasonic disperser for 15 minutes to remove air bubbles, yielding a mixed gel. 5-8 mL of the mixed gel was then poured into a glass petri dish, maintaining a film thickness of 0.5-1.5 mm. The film was allowed to stand at room temperature for 1 hour to form a film. The film was then removed for testing and characterization. A film with the optimal mass ratio of 10 g of 6901A silicone and 3 g of 6901B silicone, yielding the best mechanical properties, was used for the preparation of high color rendering index white LED devices. S4, Preparation of flexible phosphor composite luminescent film: Weigh 10 g of 6901A silica gel and 3 g of 6901B silica gel in the optimal mass ratio and mix them. Then add 0.202 g of yellow phosphor, 0.101 g of red phosphor and 0.141 g of green phosphor in the optimal mass ratio. After stirring evenly, shake in an ultrasonic disperser for 15 min to remove air bubbles and obtain a mixed phosphor gel. Then, take 5-8 mL of the mixed phosphor gel and pour it into a glass petri dish. Control the film thickness at 0.5-1.5 mm and let it stand at room temperature for 1 h to form a film. Obtain the phosphor film with the optimal ratio. Remove the film for testing and characterization. S5, Measure the mechanical properties of the film: The prepared silicone film and phosphor film are tested for mechanical properties using a tensile testing machine; S6, Preparation of white LED device: The prepared phosphor film with the optimal ratio is attached to the blue LED chip to obtain a white LED device with a high color rendering index. The spectral distribution and color rendering index are observed by placing it in an integrating sphere and using a spectroradiometer.

[0020] Figure 1 The figures show the color rendering index (CRI) statistics of devices encapsulated with different proportions of yellow, red, and green phosphor films in Embodiments 1, 2, and 3 of this application. (a) shows the CRI statistics of devices with different proportions of red phosphor films, and (b) shows the CRI statistics of devices with different proportions of green phosphor films. Figure 1 As shown in the figure, the device encapsulated with a single yellow phosphor film has the lowest color rendering index, approximately 68.7. Appropriately increasing the proportion of red and green phosphors improves the color rendering index. When the mass ratio of yellow, red, and green phosphors in the encapsulation is 10:5:7, the device has the highest color rendering index, approximately 96.9.

[0021] Figure 2The figures show the mechanical tensile test results of silicone films prepared in different proportions of silicone mixtures in Examples 1, 2 and 3 of this application. (a) is a stress-strain diagram and (b) is a statistical diagram of the integrated area of ​​different silicone ratios. As can be seen from the figures, as the mass ratio of 6901B silicone increases, the fracture strain of the silicone film increases. The silicone film prepared when the mass ratio of 6901A and 6901B silicone is 10:3 has the largest fracture strain and the largest integrated area, thus exhibiting the best mechanical properties.

[0022] Figure 3 These are the tensile test results of the silicone film and phosphor film prepared in Examples 1, 2, and 3 of this application, where (a) is a stress-strain diagram and (b) is a statistical diagram of average Young's modulus and average fracture energy; Figure 3 As shown in (a), the average fracture strain of the three groups of silicone films in the mechanical tensile test was 185%, while the average fracture strain of the phosphor films was 116%, indicating that the addition of phosphor reduced the stretchability of the flexible light-emitting films. Figure 3 As shown in (b), the Young's modulus of the phosphor film is 582.9 kPa, which is higher than that of the silicone film (330.5 kPa), indicating that the phosphor film has greater stiffness and is less prone to deformation. The fracture energy of the phosphor film is 570.53 kJ / m. 3 It is higher than the 449.37 kJ / m of the silicone film. 3 This indicates that the phosphor film can absorb more energy during the fracture process and has better toughness.

[0023] like Figure 4 As shown, the stress and strain curves of the silicone film (a) and phosphor film (b) prepared in Examples 1, 2, and 3, after being subjected to ten consecutive cyclic stretching cycles at 50% strain, with no interval between each cycle, are presented. Figure 4 It can be seen that phosphor films still have similar elasticity and low dissipation properties to silicone films.

[0024] like Figure 5 As shown, the stress and strain curves of (a) silicone film and (b) phosphor film prepared in Examples 1, 2, and 3 were obtained under 50% strain after ten consecutive cyclic stretching cycles with a 60-second interval between each cycle. The results show that when a 60-second cycle interval is introduced, the stress of both the silicone film and the phosphor film under 50% strain increases, while the stress decay rate decreases with each cycle. This indicates that the introduction of the interval provides conditions for the recovery of the entropy structure of the molecular chains and promotes the recovery of the network structure inside the elastomer.

[0025] like Figure 6As shown, the stress and strain curves of (a) silicone film and (b) phosphor film prepared in Examples 1, 2 and 3 under continuous tensile cycles at strains of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% and 90%, with no interval between each cycle.

[0026] like Figure 7 As shown, the dissipation energy of both the silicone film and the phosphor film increases with increasing strain. Furthermore, at all strain levels, the phosphor film exhibits higher dissipation energy than the silicone film. Specifically, at 90% strain, the silicone film's dissipation energy is 0.604 kJ / m. 3 The dissipation energy of the phosphor film is 3.267 kJ / m. 3 .

[0027] like Figure 9 As shown, the dissipation energy of both the silicone film and the phosphor film increases with increasing strain. Furthermore, at all strain levels, the phosphor film exhibits higher dissipation energy than the silicone film. Specifically, at 90% strain, the dissipation energy of the silicone film is 0.823 kJ / m. 3 The dissipation energy of the phosphor film is 8.496 kJ / m. 3 ; The above description is only a preferred embodiment of the present invention. It should be noted that, under the premise of following the principles of the present invention, improved experimental schemes should also be considered within the scope of protection of the present invention.

[0028] The embodiments selected in the above materials are for ease of understanding and not for limiting the process method. Those skilled in the art can easily modify the process flow or transfer it to other cases without inventive change. If these modifications also fall under the category of similar claims or similar technology of this invention, then the intent of this invention also includes these modifications.

Claims

1. A method for fabricating a high color rendering index white light device, characterized in that, The specific steps of the preparation method are as follows: S1, Preparation of yellow-red-green composite phosphor gel: S11. Preparation of gel without red and green phosphors: Weigh 0.444 g of yellow phosphor and add it to 2 g of E625A silica gel and 2 g of E625B silica gel mixed gel according to the mass ratio, and stir the mixture evenly. S12. Preparation of gels with different proportions of red phosphor: Weigh yellow phosphor, red phosphor and green phosphor according to the mass ratio, with the mass ratio of red phosphor increasing, and add them in groups to a mixed silica gel with a mass ratio of E625A silica gel:E625B silica gel=1:

1. Stir the mixture evenly. S13. Preparation of gels with different proportions of green phosphor: Weigh yellow phosphor, red phosphor and green phosphor according to the mass ratio, with the mass ratio of green phosphor increasing, and add them in groups to a mixed silica gel with a mass ratio of E625A silica gel:E625B silica gel=1:

1. Stir the mixture evenly. S2, Testing light and color performance: The prepared yellow-red-green composite phosphor gel was uniformly coated on the blue LED chip and heated on a 225℃ heating stage for 30 s. After the gel solidified, it was placed in an integrating sphere. Using a spectroradiometer, the color temperature was controlled at 5100-5300 K, and the spectral distribution and color rendering index were observed. The yellow, red, and green phosphor films with the optimal mass ratio were obtained for the preparation of high color rendering index white LED devices. S3, Preparation of silicone film: A mixture of 6901A and 6901B silicone with a mass ratio of 10:0.5-5 was prepared. The mixture was added to a centrifuge tube and thoroughly stirred until homogeneous. The mixture was then vibrated in an ultrasonic disperser for 15 minutes to remove air bubbles, yielding a mixed gel. 5-8 mL of the mixed gel was then poured into a glass petri dish, maintaining a film thickness of 0.5-1.5 mm. The film was allowed to stand at room temperature for 1 hour to form a film. The film was then removed for testing and characterization. The optimal mass ratio of 6901A and 6901B silicone films with the best mechanical properties was obtained for the fabrication of high color rendering index white LED devices. S4, Preparation of flexible phosphor composite luminescent film: Weigh and mix 6901A and 6901B silica gels in the optimal mass ratio, then add yellow, red, and green phosphors in the optimal mass ratio; stir evenly and then oscillate in an ultrasonic disperser for 15 min to remove air bubbles, thus obtaining a mixed phosphor gel; then, take 5-8 mL of the mixed phosphor gel and pour it into a glass petri dish, control the film thickness at 0.5-1.5 mm, and let it stand at room temperature for 1 h to form a film, thus obtaining the phosphor film with the optimal ratio. The film is then removed for testing and characterization. S5, Measure the mechanical properties of the film: The prepared silicone film and phosphor film are tested for mechanical properties using a tensile testing machine; S6, Preparation of white LED device: The prepared phosphor film with the optimal ratio is attached to the blue LED chip to obtain a white LED device with a high color rendering index. The spectral distribution and color rendering index are observed by placing it in an integrating sphere and using a spectroradiometer.

2. The method for fabricating a high color rendering index white light device according to claim 1, characterized in that: The yellow phosphor is a yellow rare-earth yttrium aluminum garnet phosphor, YAG, specifically Y3Al5O. 12 :Ce 3+ .

3. The method for fabricating a high color rendering index white light device according to claim 1, characterized in that: The red phosphor is AlSiN3:Eu 2+ SrSiN3:Eu 2+ CaSiN3:Eu 2+ One or more of the following, the green phosphor being BaSi2O2N2:Eu 2+ .

4. The method for fabricating a high color rendering index white light device according to claim 1, characterized in that: The S12 composition includes: Group 1: 0.234 g yellow phosphor, 0.047 g red phosphor, 0.164 g green phosphor, 2 g E625A silica gel, and 2 g E625B silica gel; Group 2: 0.22 g yellow phosphor, 0.067 g red phosphor, 0.156 g green phosphor, 2 g E625A silica gel, and 2 g E625B silica gel; Group 3: 0.212 g yellow phosphor, 0.085 g red phosphor, 0.148 g green phosphor, 2 g E625A silica gel, and 2 g E625B silica gel; Group 4: 0.202 g yellow phosphor, 0.101 g red phosphor, 0.141 g green phosphor, 2 g E625A silica gel, and 2 g E625B silica gel; Group 5: 0.193 g yellow phosphor, 0.116 g red phosphor, 0.135 g green phosphor, and 2 g E625A silica gel. g and E625B silicone 2 g.

5. The method for fabricating a high color rendering index white light device according to claim 1, characterized in that: The S13 composition includes: Group 1: 0.278 g yellow phosphor, 0.139 g red phosphor, 0.0278 g green phosphor, 2 g E625A silica gel, and 2 g E625B silica gel; Group 2: 0.247 g yellow phosphor, 0.123 g red phosphor, 0.074 g green phosphor, 2 g E625A silica gel, and 2 g E625B silica gel; Group 3: 0.222 g yellow phosphor, 0.111 g red phosphor, 0.156 g green phosphor, 2 g E625A silica gel, and 2 g E625B silica gel; Group 4: 0.202 g yellow phosphor, 0.101 g red phosphor, 0.141 g green phosphor, 2 g E625A silica gel, and 2 g E625B silica gel; Group 5: 0.185 g yellow phosphor, 0.093 g red phosphor, 0.167 g green phosphor, and 2 g E625A silica gel. g and E625B silicone 2 g.

6. The method for fabricating a high color rendering index white light device according to claim 1, characterized in that: In S2, a spectroradiometer is used to control the color temperature at 5200 K and observe the spectral distribution and color rendering index.

7. The method for fabricating a high color rendering index white light device according to claim 1, characterized in that: The oscillation frequency of the ultrasonic disperser in S3 and S4 is 40 kHz.

8. A high color rendering index white light device prepared by any one of the preparation methods of claims 1-7, characterized in that: By adjusting the proportions of yellow, red, and green phosphors in a flexible polymer, and using a blue LED chip to excite the yellow, red, and green phosphors, the white light emitted by the LED device is made closer to the full spectrum of natural light, ultimately resulting in a high color rendering index white light device.

9. The application of a high color rendering index white light device prepared by any one of the preparation methods of claims 1-7 in high-performance white LED lighting devices, wearable devices and flexible display technology.

Images