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CN-122012075-A - Preparation method of all-inorganic fluorescent film for solid-state lighting

CN122012075ACN 122012075 ACN122012075 ACN 122012075ACN-122012075-A

Abstract

A preparation method of an all-inorganic fluorescent film for solid-state lighting. The method adopts an all-inorganic bonding solvent prepared from sodium silicate (16-22%), aluminum oxide (2-6%), potassium hydroxide (6-12%) and pure water, and forms a film by sequentially coating the bonding solvent and one or more fluorescent powder on a substrate, and standing and solidifying the substrate at room temperature (15-30 ℃) for 6-24 hours. By adopting an all-inorganic system and a room temperature curing process, the technical problems of poor thermal stability and damage to the fluorescent powder performance caused by high-temperature preparation of the traditional fluorescent film are effectively solved, and the prepared fluorescent film has good thermal stability and excellent luminous performance.

Inventors

  • LI YANG
  • WANG TINGTING
  • LI ZHIHAO
  • SHI MINGMING
  • ZOU JUN

Assignees

  • 上海应用技术大学

Dates

Publication Date
20260512
Application Date
20251219

Claims (10)

  1. 1. The preparation method of the all-inorganic fluorescent film for solid-state lighting adopts all-inorganic bonding solvent to solidify fluorescent powder on a substrate to form the fluorescent film, and is characterized by comprising the following steps: a) Preparing a substrate, one or more fluorescent powder and an all-inorganic bonding solvent, wherein the all-inorganic bonding solvent consists of sodium silicate, aluminum oxide, potassium hydroxide and pure water, the mass percent of the sodium silicate is 16-22%, the mass percent of the aluminum oxide is 2-6%, the mass percent of the potassium hydroxide is 6-12%, and the balance is the pure water; b) The all-inorganic bonding solvent is coated on the substrate in a spin coating, drop coating or spray coating mode, wherein the parameters in the spin coating are that the acceleration is 300-400 rpm/s, the rotating speed is 150-200 rpm, the time is 60-180 s, and the bonding solvent is fully contacted with the substrate after the coating is kept stand for 20-40 minutes at 15-30 ℃; c) Applying the fluorescent powder in a blade coating mode, wherein a 900-1100 mesh stainless steel screen is used, the pressure of a scraper is 0.1-0.5 MPa, and the thickness of single blade coating is controlled to be 0.1-0.3 mm; d) And (3) standing and curing the substrate coated with the all-inorganic bonding solvent and the fluorescent powder for 6-24 hours at 15-30 ℃, and anchoring the fluorescent powder in an inorganic network through condensation reaction of silanol groups formed by sodium silicate hydrolysis and hydroxyl groups on the surface of the substrate and participation of aluminum oxide into the formed aluminosilicate three-dimensional network to form the all-inorganic fluorescent film.
  2. 2. The method of claim 1, wherein the mass ratio of the all-inorganic bonding solvent to the phosphor in step a) is from 1:0.5 to 1:5.
  3. 3. The method according to claim 1 or 2, characterized in that the substrate is placed in the mould, which is made of silicone, epoxy or polyethylene.
  4. 4. A method according to any one of claims 1 to 3, wherein steps b) and C) are repeated at least once, each repetition followed by a rest at 15-30 ℃ for 20-40 minutes, and finally step d) is performed for final curing to form an all inorganic fluorescent film having a multi-layered composite structure.
  5. 5. The method of any one of claims 1 to 4, wherein the phosphor is selected from one or more of YAG-based phosphors, aluminate-based phosphors, nitride-based phosphors, silicate-based phosphors.
  6. 6. The method according to any one of claims 1 to 5, wherein the step c) is to knife-coat the phosphor on the bonding solvent through a screen having a mesh number of 900 to 1100 mesh.
  7. 7. An all-inorganic fluorescent film for solid state lighting, comprising: A substrate; A bonding solvent layer coated on the substrate, the bonding solvent layer being composed of sodium silicate, aluminum oxide, potassium hydroxide and pure water, wherein the sodium silicate is 16-22% by mass, the aluminum oxide is 2-6% by mass, the potassium hydroxide is 6-12% by mass, and the balance is pure water, and A phosphor layer coated on the bonding solvent layer; The fluorescent powder layer is bonded with the substrate through the bonding solvent layer by an oxyhydrogen catalytic bonding mechanism, and the all-inorganic fluorescent film is cured and formed at room temperature.
  8. 8. The all inorganic fluorescent film of claim 7, wherein the fluorescent powder is selected from one or more of YAG-based fluorescent powder, aluminate-based fluorescent powder, nitride-based fluorescent powder, silicate-based fluorescent powder.
  9. 9. The all-inorganic fluorescent film of claim 7 or 8, wherein the all-inorganic fluorescent film is a multi-layered composite structure.
  10. 10. The full inorganic fluorescent film according to any one of claims 7 to 9, wherein the substrate is an inorganic material with a surface rich in hydroxyl groups (-OH), preferably sapphire, quartz glass, fused silica or a silicon wafer after plasma or acid-base treatment, and the substrate surface should be clean, oil-free and have a water contact angle of less than 30 ° to ensure efficient condensation with silanol groups in the bonding solvent.

Description

Preparation method of all-inorganic fluorescent film for solid-state lighting Technical Field The invention relates to the technical field of solid-state lighting, in particular to a preparation method of an all-inorganic fluorescent film. Background Laser illumination has been rapidly applied to high-end scenes such as automobile headlamps, rail traffic lights, stage performance lamps, deep sea/high altitude searchlight, high-power industrial scientific research light sources and the like by virtue of the advantages of strong directivity, high brightness, long irradiation distance, long service life and the like. Fluorescent conversion materials are important components of laser illumination, and face higher challenges in the aspects of key performances such as Gao Languang laser irradiation resistance, high luminous efficiency and the like. The traditional organic fluorescent film has the problems of low heat conductivity, poor heat stability and the like, and is difficult to meet the requirements of laser illumination on high brightness and high light efficiency. The invention adopts all inorganic materials and prepares a fluorescent powder film under the room temperature preparation condition so as to solve the problems. First, conventional fluorescent conversion materials tend to have insufficient thermal stability when dealing with high-power laser irradiation, which not only accelerates material aging for high luminous flux output, but also limits the improvement of reliability of the laser illumination system. Secondly, the existing fluorescent conversion material also has obvious short plates in the aspect of heat conduction performance. Because the matrix material has low intrinsic heat conductivity, heat is difficult to diffuse rapidly, so that local temperature is excessively high, fluorescence quenching and even surface carbonization are further caused, and the light efficiency and the service life are seriously influenced. This problem is particularly acute for application scenarios requiring high power. In addition, the existing fluorescent conversion material generally depends on high-temperature sintering to realize densification, but irreversible heat damage is caused to fluorescent powder particles under the high-temperature condition, and the conditions of lattice defects, surface roughening, local phase change and the like can occur, so that the problems of reduced quantum efficiency, reduced emission intensity and the like are caused. In order to solve the problem of thermal stability of organic materials, various all-inorganic fluorescent conversion materials including fluorescent single crystals, fluorescent ceramics, fluorescent glass, etc. have been developed in the industry. However, these materials are usually prepared by a high temperature sintering process (500-1000 ℃) which causes problems that, on one hand, high temperature causes thermal damage to phosphor particles and reduces quantum efficiency, and, on the other hand, high temperature process equipment investment is large, energy consumption is high and cost is high. Therefore, the development of the fluorescent film preparation method which has the advantages of all inorganic materials and the room temperature preparation process has important significance. Thus, the preparation of inorganic bulk materials with high quantum efficiency and resistance to high power laser excitation has become a major challenge for high power laser illumination. In light of the above, the present study proposes a method for preparing an all-inorganic fluorescent film for solid-state lighting, which is simple and feasible. According to the invention, the thermal stability of the fluorescent film is improved through the selection of all inorganic components. Meanwhile, the preparation condition of room temperature has good reservation on the original luminescence property of the fluorescent powder particles. The invention provides an innovative method for preparing the fluorescent film for laser illumination. Disclosure of Invention The invention provides a preparation method of an all-inorganic fluorescent film for solid-state lighting, and aims to solve the problems of thermal damage and poor thermal stability caused by high-temperature sintering in the preparation of a traditional fluorescent powder film. In order to achieve the aim, the invention abandons a high-temperature sintering link, adopts a sintering-free process, avoids high-temperature damage of fluorescent powder particles, completely maintains the original luminescence property, simultaneously adopts an all-inorganic material system to replace organic matrixes such as organic silica gel and the like, obviously reduces the preparation cost and the process complexity, and ensures the excellent luminescence property and long-term stability of the film. The invention provides a solution for the preparation of the fluorescent film for laser illumination and has wide application pro