Preparation method of novel cerium (III) activated germanate blue fluorescent powder
By preparing the new cerium (III) activated germanate blue phosphor, the problem that traditional plant lighting sources cannot meet the different growth needs of plants is solved, and efficient blue light emission and versatile applications are achieved.
Patent Information
- Application Number
- CN202510134922.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-07
- Publication Date
- 2025-05-09
AI Technical Summary
Traditional plant lighting sources cannot effectively meet the different growth needs of plants for blue, red and near-infrared light, resulting in inefficient plant growth.
A new cerium (III) activated germanate blue phosphor is used to prepare a new cerium (III) activated germanate blue phosphor with the chemical formula Sr2(1-x)Ga2GeO7:2xCe3+. The high-efficiency blue phosphor is prepared by specific raw material ratios, grinding and high-temperature solid phase treatment.
This phosphor is not only suitable for blue LEDs in plant growth applications, but also for contactless optical temperature measurements, with versatility and good economic benefits.
Smart Images
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of luminescent materials, and in particular relates to a method for preparing a novel cerium (III) activated germanate blue phosphor. Background Art
[0002] In nature, plant growth is inseparable from light, and photosynthesis is usually carried out by obtaining sunlight. This makes plant growth limited by natural conditions. With the continuous development of science and technology, people began to use traditional plant lighting sources such as incandescent lamps, halogen lamps, fluorescent lamps and high-pressure sodium lamps, but there are significant disadvantages such as uncontrollable spectrum, high energy consumption and high operating costs. In contrast, LED, as a new light source, provides many advantages, including high electro-optical conversion efficiency, customizable spectrum, compact size and long service life, and has become the first choice for factory production due to its small size, high efficiency and low cost. LEDs used for general lighting are made of ultraviolet chips that excite Y3Al5O12:Ce3+ (YAG:Ce) yellow phosphor, or excite a combination of red, green and blue phosphors to emit white light. However, due to the different requirements of plant growth for blue, red and near-infrared light, some traditional LED lighting has been difficult to meet the different growth needs of plants. Blue light irradiation can significantly increase the photosynthetic rate and chlorophyll in plant leaves. In addition, blue light regulates plant morphogenesis by affecting the synthesis and distribution of plant hormones. For example, blue light can inhibit the elongation of plant stems and promote the growth of leaves, making plants denser and stronger. Moreover, blue light irradiation can induce plants to synthesize and accumulate a series of secondary metabolites, such as flavonoids and phenolic substances, which are important for plants to resist adversity, diseases and pests. Therefore, it is of great significance to find new blue phosphors to meet the different growth needs of plants and improve the economic benefits of my country's agriculture. Summary of the invention
[0003] Based on the existing problems that need to be solved, this technology provides a new method for preparing cerium (III) activated germanate blue phosphor. The specific method is as follows: A method for preparing a novel cerium (III) activated germanate blue phosphor, wherein the chemical formula of the phosphor is Sr 2(1-x) Ga2GeO7:2xCe 3+ , including the following steps: (1) Strontium carbonate, gallium oxide, germanium dioxide and cerium oxide are weighed according to the calculated raw material ratio, the formula Sr:Ga:Ge:O:Ce=2(1-x):2:1:7:2x, where x represents the doping concentration of Ce3+ (0-0.8); (2) Place the weighed items into an agate grinding bowl and grind thoroughly for 15-20 minutes to ensure that the sample is fully ground; (3) The ground mixture is then placed in a small crucible and buried in a large crucible filled with carbon powder, which acts as a reducing agent to help reduce Ce4+ to Ce3+; (4) Then, the entire assembly is heated to 1300°C in a muffle furnace and kept at this temperature for 5-7 hours until the entire assembly cools down to room temperature by itself and is taken out; (5) Finally, the solid obtained by the high-temperature solid phase method is placed in an agate grinding bowl, the calcined solid is crushed, and fully ground for 5-7 minutes until there is no abrasive feeling, thereby obtaining a blue phosphor.
[0004] The beneficial effects of the present invention are: (1) The phosphor of the present invention is easy to prepare, the raw materials are easy to obtain, easy to operate, low-cost, pollution-free, and easy to industrialize; (2) The phosphor of the present invention is not only suitable for blue LEDs in plant growth applications, but can also be used for non-contact optical temperature measurement in practical applications. It is a multifunctional phosphor with good economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Figure 1 The SEM image (a), element mapping (b) and EDS spectrum (c) of the blue phosphor prepared in Example 3; Figure 2 is the optical band gap of the blue phosphor prepared in Example 1; Figure 3 is the optical band gap of the blue phosphor prepared in Example 3; Figure 4 is the optical band gap of the blue phosphor prepared in Example 10; Figure 5 is the PL spectrum of the blue phosphor prepared in Example 2; Figure 6 is the PL spectrum of the blue phosphor prepared in Example 3; Figure 7 is the PL spectrum of the blue phosphor prepared in Example 4; Figure 8 is the PL spectrum of the blue phosphor prepared in Example 6; Fig. 9 is the PL spectrum of the blue phosphor prepared in Example 8; Fig.10 is a PL spectrum diagram of the blue phosphor prepared in Example 10; Fig.11 is a diffuse reflection spectrum of the blue phosphor prepared in Example 1; Fig.12 is a diffuse reflectance spectrum of the blue phosphor prepared in Example 3; Fig.13 is a diffuse reflectance spectrum of the blue phosphor prepared in Example 10; Fig.14 It is the attenuation curve diagram of the blue phosphor prepared in Examples 1, 2, 3, 4, 6, 8 and 10. DETAILED DESCRIPTION
[0006] The following examples are provided to further illustrate the present invention, but not to limit the present invention. Unless otherwise specified, the experimental materials and reagents in the present invention are all products purchased from the conventional market in the field of the present technology.
[0007] Example 1 Weigh 0.5027g of strontium carbonate, 0.3191g of gallium oxide, and 0.1781g of germanium dioxide respectively. Grind the above raw materials in an agate mortar, grind for 15 minutes, put the ground mixture into a small crucible, and bury it in a large crucible filled with carbon powder as a reducing agent to help reduce Ce4+ to Ce3+, and then perform high-temperature solid phase treatment, heat from room temperature to 1300℃ at a rate of 10℃ / min in a normal pressure air atmosphere, keep 1300℃ for 6 hours, wait for it to cool naturally, take it out, and grind for 7 minutes to obtain blue phosphor.
[0008] Example 2 Weigh 0.5000g of strontium carbonate, 0.3190g of gallium oxide, 0.1781g of germanium dioxide, and 0.0029g of cerium oxide respectively. Grind the above raw materials in an agate mortar, grind for 15 minutes, put the ground mixture into a small crucible, and bury it in a large crucible filled with carbon powder as a reducing agent to help reduce Ce4+ to Ce3+, and then perform high-temperature solid phase treatment, heat from room temperature to 1300℃ at a rate of 10℃ / min in a normal pressure air atmosphere, keep 1300℃ for 6 hours, wait for it to cool naturally, take it out, and grind for 7 minutes to obtain blue phosphor.
[0009] Example 3 Weigh 0.4973g of strontium carbonate, 0.3189g of gallium oxide, 0.1780g of germanium dioxide, and 0.0059g of cerium oxide respectively. Grind the above raw materials in an agate mortar, grind for 15 minutes, put the ground mixture into a small crucible, and bury it in a large crucible filled with carbon powder as a reducing agent to help reduce Ce4+ to Ce3+, and then perform high-temperature solid phase treatment, heat from room temperature to 1300℃ at a rate of 10℃ / min in a normal pressure air atmosphere, keep 1300℃ for 6 hours, wait for it to cool naturally, take it out, and grind for 7 minutes to obtain blue phosphor.
[0010] Example 4 Weigh 0.4918g of strontium carbonate, 0.3186g of gallium oxide, 0.1779g of germanium dioxide, and 0.0117g of cerium oxide respectively. Grind the above raw materials in an agate mortar, grind for 15 minutes, put the ground mixture into a small crucible, and bury it in a large crucible filled with carbon powder as a reducing agent to help reduce Ce4+ to Ce3+, and then perform high-temperature solid phase treatment, heat from room temperature to 1300℃ at a rate of 10℃ / min in a normal pressure air atmosphere, keep 1300℃ for 6 hours, wait for it to cool naturally, take it out, and grind for 7 minutes to obtain blue phosphor.
[0011] Example 5 Weigh 0.4864g of strontium carbonate, 0.3183g of gallium oxide, 0.1777g of germanium dioxide, and 0.0115g of cerium oxide respectively. Grind the above raw materials in an agate mortar, grind for 15 minutes, put the ground mixture into a small crucible, and bury it in a large crucible filled with carbon powder as a reducing agent to help reduce Ce4+ to Ce3+, and then perform high-temperature solid phase treatment, heat from room temperature to 1300℃ at a rate of 10℃ / min in a normal pressure air atmosphere, keep 1300℃ for 6 hours, wait for it to cool naturally, take it out, and grind for 7 minutes to obtain blue phosphor.
[0012] Example 6 Weigh 0.4810g of strontium carbonate, 0.3181g of gallium oxide, 0.1776g of germanium dioxide, and 0.0234g of cerium oxide respectively. Grind the above raw materials in an agate mortar, grind for 15 minutes, put the ground mixture into a small crucible, and bury it in a large crucible filled with carbon powder as a reducing agent to help reduce Ce4+ to Ce3+, and then perform high-temperature solid phase treatment, heat from room temperature to 1300℃ at a rate of 10℃ / min in a normal pressure air atmosphere, keep 1300℃ for 6 hours, wait for it to cool naturally, take it out, and grind for 7 minutes to obtain blue phosphor.
[0013] Example 7 Weigh 0.4756g of strontium carbonate, 0.3178g of gallium oxide, 0.1774g of germanium dioxide, and 0.0292g of cerium oxide respectively. Grind the above raw materials in an agate mortar, grind for 15 minutes, put the ground mixture into a small crucible, and bury it in a large crucible filled with carbon powder as a reducing agent to help reduce Ce4+ to Ce3+, and then perform high-temperature solid phase treatment, heat from room temperature to 1300℃ at a rate of 10℃ / min in a normal pressure air atmosphere, keep 1300℃ for 6 hours, wait for it to cool naturally, take it out, and grind for 7 minutes to obtain blue phosphor.
[0014] Example 8 Weigh 0.4702g of strontium carbonate, 0.3175g of gallium oxide, 0.1773g of germanium dioxide, and 0.0350g of cerium oxide respectively. Grind the above raw materials in an agate mortar, grind for 15 minutes, put the ground mixture into a small crucible, and bury it in a large crucible filled with carbon powder as a reducing agent to help reduce Ce4+ to Ce3+, and then perform high-temperature solid phase treatment, heat from room temperature to 1300℃ at a rate of 10℃ / min in a normal pressure air atmosphere, keep 1300℃ for 6 hours, wait for it to cool naturally, take it out, and grind for 7 minutes to obtain blue phosphor.
[0015] Example 9 Weigh 0.4648g of strontium carbonate, 0.3173g of gallium oxide, 0.1771g of germanium dioxide, and 0.0407g of cerium oxide respectively. Grind the above raw materials in an agate mortar, grind for 15 minutes, put the ground mixture into a small crucible, and bury it in a large crucible filled with carbon powder as a reducing agent to help reduce Ce4+ to Ce3+, and then perform high-temperature solid phase treatment, heat from room temperature to 1300℃ at a rate of 10℃ / min in a normal pressure air atmosphere, keep 1300℃ for 6 hours, wait for it to cool naturally, take it out, and grind for 7 minutes to obtain blue phosphor.
[0016] Example 10 Weigh 0.4594g of strontium carbonate, 0.3170g of gallium oxide, 0.1770g of germanium dioxide, and 0.0466g of cerium oxide respectively. Grind the above raw materials in an agate mortar, grind for 15 minutes, put the ground mixture into a small crucible, and bury it in a large crucible filled with carbon powder as a reducing agent to help reduce Ce4+ to Ce3+, and then perform high-temperature solid phase treatment, heat from room temperature to 1300℃ at a rate of 10℃ / min in a normal pressure air atmosphere, keep 1300℃ for 6 hours, wait for it to cool naturally, take it out, and grind for 7 minutes to obtain blue phosphor.
[0017] The description of the above embodiments is intended to help understand the technical solutions and core essences involved in the present invention. It should be pointed out that technicians in this technical field can make several improvements and modifications to the present invention without departing from the principles of the present invention. These improvements and modifications are also covered by the protection scope of the claims of the present invention.
[0018] Preferably, Example 3 is the best solution. After testing, its optical properties in various aspects are better able to meet various conditions of plant lighting compared with other cerium (III) doping concentrations, and its performance is the best.
Claims
1. A method for preparing a novel cerium (III) activated germanate blue phosphor, characterized in that: The chemical formula of the blue phosphor is Sr 2(1-x) Ga2GeO7:2xCe 3+ Where x represents the doping concentration of Ce3+ (0 to 0.8), including the following steps: (1) Strontium carbonate, gallium oxide, germanium dioxide and cerium oxide are weighed according to the calculated raw material ratio, the formula Sr:Ga:Ge:O:Ce=2(1-x):2:1:7:2x, where x represents the doping concentration of Ce3+ (0-0.8); (2) Place the weighed items into an agate grinding bowl and grind thoroughly for 15-20 minutes to ensure that the sample is fully ground; (3) The ground mixture is then placed in a small crucible and buried in a large crucible filled with carbon powder, which acts as a reducing agent to help reduce Ce4+ to Ce3+; (4) Then, the entire assembly is heated to 1300°C in a muffle furnace and kept at this temperature for 5-7 hours until the entire assembly cools down to room temperature by itself and is taken out; (5) Finally, the solid obtained by the high-temperature solid phase method is placed in an agate grinding bowl, the calcined solid is crushed, and fully ground for 5-7 minutes until there is no abrasive feeling, thereby obtaining a blue phosphor.
2. Use of the novel cerium (III) activated germanate blue phosphor as claimed in claim 1 in a light-emitting device.
3. The use according to claim 2, characterized in that: The novel cerium (III) activated germanate blue phosphor is not only suitable for blue LEDs in plant growth applications, but also can be used for non-contact optical temperature measurement in practical applications. It is a multifunctional phosphor with good economic benefits.