Preparation method of zinc sulfide electroluminescent crystal material

Abstract

The invention relates to a preparation method of a zinc sulfide electroluminescent crystal material. The zinc sulfide electroluminescent crystal material comprises a matrix material, an activator and a co-activator, the method is characterized in that a matrix material is zinc sulfide, an added activating agent is copper ions, an added co-activating agent is rare earth ions, the materials are uniformly mixed to form a proportioning material, the proportioning material is subjected to hot melting at a high temperature of 1100 DEG C in a quartz tube by using a high-temperature hot melting method, and growth is guided through hydrogen sulfide airflow carrying and zinc sulfide seed crystals on the wall of the quartz tube. And preparing the zinc sulfide electroluminescent crystal which is greater than 2mm, wherein the zinc sulfide electroluminescent crystal generates green luminescence in an alternating current electric field.

Description

Technical Field

[0001] This invention belongs to the field of electroluminescent display device technology. Background Technology

[0002] Existing electroluminescence technologies are divided into high-field and low-field electroluminescence, and have been widely used in light emission, display, and lighting fields. Among them, thin-film electroluminescence, thick-film electroluminescence, and powder electroluminescence suffer from poor stability when using AC / DC emission, while organic electroluminescence and LED electroluminescence consume relatively large currents. Crystal electroluminescence can avoid the defects of existing technologies, but the crystal preparation process is complex, resulting in poor uniformity and integrity of the electroluminescent material. This invention utilizes traditional zinc sulfide electroluminescent material to achieve simple batch preparation of electroluminescent crystals through airflow seed crystal growth.

[0003] This invention discloses a method for preparing zinc sulfide electroluminescent crystal material, comprising a matrix material, an activator, and a co-activator. The matrix material is zinc sulfide, the added activator is copper ions, and the added co-activator is rare earth ions. After uniform mixing, a proportioned material is formed. The proportioned material is then melted at 1100 degrees Celsius in a quartz tube using a high-temperature hot-melt method. The material is then carried by a hydrogen sulfide gas stream and grown using zinc sulfide seed crystals placed at the temperature difference between the quartz tube walls. This process produces zinc sulfide electroluminescent crystals larger than 2 mm in diameter, which emit green light under an alternating electric field.

[0004] This invention can be widely used in the field of light-emitting display lighting, such as semiconductor lighting, display panels, mobile phone screens, and high-voltage indicators. Summary of the Invention

[0005] A method for preparing zinc sulfide electroluminescent crystal material includes a matrix material, an activator, and a co-activator. The matrix material is zinc sulfide, the activator is copper ions, and the co-activator is rare earth ions. After uniform mixing, a proportioning material 3 is formed. The proportioning material is melted at 1100 degrees Celsius in a quartz tube 2 using a high-temperature hot-melt method. The melted material is then carried by a hydrogen sulfide gas stream. The growth of the crystal is guided by zinc sulfide seed crystals 1 set at the temperature difference between the quartz tube walls, resulting in a zinc sulfide electroluminescent crystal larger than 2 mm in diameter. The zinc sulfide electroluminescent crystal emits green light under an alternating electric field.

[0006] The matrix material in this invention is high-grade pure zinc sulfide. An activator and a co-activator are added to the zinc sulfide, and the mixture is thoroughly mixed with deionized water, dried at 110 degrees Celsius, pulverized and ball-milled to form a formulated material.

[0007] The activator in this invention is copper ions, such as anhydrous copper sulfate containing copper ions. The weight ratio of the activator added is 3 x 10 copper ions per gram of matrix material. -3Copper sulfate can be dissolved and added to zinc sulfide, mixed thoroughly, and then dried; alternatively, a dry mixing method can be used. When copper ions are used as the activator and manganese ions are added simultaneously, orange electroluminescence can be produced. In this case, the weight ratio of the activator added is 3 x 10⁻⁶ copper ions per gram of matrix material. -3 Each gram of matrix material contains 1 x 10 manganese ions. -2 In this invention, copper ions exist in the electroluminescent crystal in the form of cuprous sulfide. The cuprous sulfide light-emitting line pairs deposited by lattice dislocations are a necessary condition for the electroluminescent crystal to emit light. Rare earth ions can increase the occurrence of lattice dislocations, and the number of lattice dislocations is proportional to the luminescence brightness.

[0008] The co-activator in this invention is the rare earth ion erbium, and the weight ratio of the co-activator added is: 1 x 10⁻⁶ erbium ions per gram of matrix material. -4 The co-activator can be made by diluting erbium nitrate with deionized water and then adding it to zinc sulfide, mixing thoroughly, and then drying. Adding the activator and co-activator simultaneously to zinc sulfide, mixing the liquids, and then drying and pulverizing results in better uniformity. After dry mixing, prolonged ball milling is required to achieve a uniform mixture.

[0009] The high-temperature hot-melt method in this invention involves placing the formulated material 3 at 1100 degrees Celsius and placing a seed crystal at the head wall of a quartz tube with a temperature difference of less than 5-25 degrees Celsius. The hot-melt formulated material is carried by airflow and grows on the basis of the seed crystal structure. Figure 1 This invention uses a quartz tube 2 as a sintering tube, a quartz boat or a corundum boat as a carrier for the proportioning material, a gas inlet guide tube 4 placed above the proportioning material in the quartz boat, and a gas outlet guide tube 5 placed at the outlet of the quartz tube.

[0010] In this invention, the hydrogen sulfide gas, after being dried, is placed above the hot-melted premixed material through a guide tube. The growth rate of the electroluminescent crystal can be controlled by adjusting the flow rate of the hydrogen sulfide gas. The growth state of the electroluminescent crystal material can be observed using a transparent quartz tube.

[0011] The zinc sulfide seed crystals in this invention have a hexagonal phase structure. They are prepared by using high-grade pure zinc sulfide, sintering it for 5 hours in a sulfur atmosphere at 1200 degrees Celsius, and selecting zinc sulfide particles with a complete hexagonal phase structure. Particles with a size of approximately 50-100 micrometers are selected as sulfide seed crystals. Sulfide seed crystals can be used to quickly and completely prepare electroluminescent crystal materials.

[0012] The zinc sulfide electroluminescent crystal of this invention is cold-processed into a thin sheet, with conductive electrodes on both sides and a thin-film transparent electrode on at least one side. The thin-film transparent electrode uses an ITO conductive film, and the conductive electrode can be a copper sheet. Electroluminescence is generated when an alternating current is applied. The green electroluminescence spectrum is 530-540 nm, and the orange electroluminescence spectrum is 580 nm. Attached Figure Description

[0013] Figure 1. Preparation diagram of zinc sulfide electroluminescent crystal material In the figures of this invention: 1 zinc sulfide seed crystal, 2 quartz tube, 3 mixing material, 4 gas inlet guide tube, 5 gas outlet guide tube, 6 sealing port. Specific implementation methods

[0014] A method for preparing zinc sulfide electroluminescent crystal material includes a matrix material, an activator, and a co-activator. The matrix material is superior-grade pure zinc sulfide, the added activator is copper ions, and the added co-activator is rare earth ions. After uniform mixing, a mixture 3 is formed. In a quartz tube 2, the mixture is melted at a high temperature of 1100 degrees Celsius using a high-temperature hot-melt method. Stable and accurate control of the growth temperature can make the crystal more complete. Then, carried by a hydrogen sulfide gas flow, the growth of the crystal is guided by zinc sulfide seed crystals 1 set at the temperature difference of the quartz tube wall, thus preparing a zinc sulfide electroluminescent crystal larger than 2 mm. The zinc sulfide electroluminescent crystal emits green light under an alternating electric field.

[0015] The matrix material in this invention is high-grade pure zinc sulfide. An activator and a co-activator are added to the zinc sulfide, and the mixture is thoroughly mixed with deionized water and dried at 110 degrees Celsius. The mixture is then pulverized and ball-milled to form a proportioned material. Wet mixing makes it easy to achieve uniformity.

[0016] The activator in this invention is copper ions, which can be copper sulfate, copper chloride, copper nitrate, etc. For example, anhydrous copper sulfate containing copper ions can be dissolved in deionized water. The weight ratio of the activator added is 3 x 10 copper ions per gram of matrix material. -3 Copper sulfate solution is added to zinc sulfide, mixed thoroughly, and dried at 110°C for 5 hours. Alternatively, dry mixing can be used, but this requires prolonged ball milling. A high concentration of copper ions produces green luminescence, while a low concentration produces blue luminescence. When copper ions are used as the activator and manganese ions are added simultaneously, orange electroluminescence is produced. In this case, the weight ratio of the activator added is 3 x 10⁻⁶ copper ions per gram of matrix material. -3 Each gram of matrix material contains 1 x 10 manganese ions. -2 In this invention, copper ions exist in the electroluminescent crystal as cuprous sulfide after sintering. The deposition of cuprous sulfide by lattice dislocations is a necessary condition for the electroluminescent crystal to emit light, and rare earth ions can increase the occurrence of lattice dislocations.

[0017] The co-activator in this invention is the rare earth ion erbium, and the weight ratio of the co-activator added is: 1 x 10⁻⁶ erbium ions per gram of matrix material. -4The co-activator can be erbium nitrate diluted with deionized water and added to zinc sulfide, mixed thoroughly, and then dried. Adding the activator and co-activator simultaneously to zinc sulfide, mixing the liquids, and then drying and pulverizing results in better uniformity. After dry mixing, prolonged ball milling is required to achieve a uniform mixture. Rare earth ions can also be europium, dysprosium, etc., but erbium and europium offer the best color and brightness.

[0018] The high-temperature hot-melt method in this invention involves placing the formulated material 3 at 1100 degrees Celsius. The phase transition point of zinc sulfide is 1040 degrees Celsius, and the phase transition point of zinc sulfide after copper doping is 1050 degrees Celsius. A seed crystal is placed on the wall of a quartz tube with a temperature difference of less than 5-10 degrees Celsius. The hot-melt formulated material is carried by airflow and grows on the seed crystal structure. Figure 1 The temperature at the amethyst growth site is around 1070 degrees Celsius. The growth time is directly proportional to the crystal size, typically exceeding 24 hours. The smooth walls of the quartz tube prevent impurities from growing. Without a seed crystal, the resulting electroluminescent crystal is unlikely to be large and complete. This invention uses a quartz tube 2 as the sintering tube, and a quartz boat or corundum boat as the carrier for the proportioning material. Gas enters through a guide tube 4 placed above the proportioning material in the quartz boat, and gas exits through a guide tube 5 placed at the outlet of the quartz tube.

[0019] The hydrogen sulfide gas used in this invention can be self-prepared or directly used. After drying, it is placed above the hot-melted composite material through a guide tube. The dried gas allows for more complete crystal growth. The growth rate of the electroluminescent crystal can be controlled by adjusting the flow rate of the hydrogen sulfide gas. The growth state of the electroluminescent crystal material can be observed using a transparent quartz tube.

[0020] The zinc sulfide seed crystals in this invention have a hexagonal phase structure. They are prepared using high-purity zinc sulfide with little or no added copper ions, resulting in more complete seed crystals. Sintering is performed at 1200°C in a sulfur atmosphere for at least 5 hours to select zinc sulfide particles with a complete hexagonal phase structure; cubic phase zinc sulfide cannot grow completely subsequently. Seed crystals with a particle size of approximately 50-100 micrometers are selected as the sulfide seed crystals. These sulfide seed crystals can rapidly and completely prepare electroluminescent crystal materials. The seed crystals are adhered to the quartz tube head using sodium silicate and potassium silicate; the rounded quartz tube facilitates airflow.

[0021] The zinc sulfide electroluminescent crystal of this invention is cold-processed into a thin sheet, with conductive electrodes on both sides and a thin-film transparent electrode on at least one side. The thin-film transparent electrode uses an ITO conductive film, and the conductive electrode can be a copper sheet. Electroluminescence is generated when an alternating current is applied. The green electroluminescence spectrum is 530 nm, and the orange electroluminescence spectrum is 580 nm. The advantages of this invention are:

[0022] Electroluminescent crystal materials are grown using a simple single-crystal preparation method. These materials have stable structures, high luminous intensity, and good anti-aging properties. They can be cut and shaped according to crystal orientation. In addition, the addition of rare earth materials provides advantages such as high brightness and spectral stability, making them suitable for various light-emitting display and lighting scenarios.

[0023] Having described the preferred embodiments of the present invention above, it should be understood by those skilled in the art that any changes and modifications made to the present invention without departing from its spirit and scope are within the scope of the present invention.

Claims

1. A method for preparing a zinc sulfide electroluminescent crystal material, comprising a matrix material, an activator, and a co-activator; characterized in that: The matrix material is zinc sulfide, the activator is copper ions, and the co-activator is rare earth ions. After uniform mixing, a proportioned material is formed. The proportioned material is melted at 1100 degrees Celsius in a quartz tube using a high-temperature hot-melt method. Then, it is carried by a hydrogen sulfide gas flow and grown by zinc sulfide seed crystals at the quartz tube wall to prepare zinc sulfide electroluminescent crystals larger than 2 mm. The zinc sulfide electroluminescent crystals produce green light under an alternating electric field.

2. The method for preparing a zinc sulfide electroluminescent crystal material according to claim 1, wherein the matrix material is superior pure zinc sulfide, an activator and a co-activator are added to the zinc sulfide, the mixture is thoroughly mixed with deionized water, dried at 110 degrees Celsius, pulverized and ball-milled to form a proportioned material.

3. The method for preparing a zinc sulfide electroluminescent crystal material according to claim 1, wherein the activator is copper ions, and the weight ratio of the activator added is: 3 x 10 copper ions per gram of matrix material. -3 .

4. The method for preparing a zinc sulfide electroluminescent crystal material according to claim 1, wherein the activator is copper ions and manganese ions, and the weight ratio of the activator added is: 3 x 10 copper ions per gram of matrix material. -3 Each gram of matrix material contains 1 x 10 manganese ions. -2 .

5. The method for preparing a zinc sulfide electroluminescent crystal material according to claim 1, wherein the co-activator is rare earth ion erbium, and the weight ratio of the co-activator added is: 1 x 10⁻⁶ erbium ions per gram of matrix material. -4 .

6. The method for preparing zinc sulfide electroluminescent crystal material according to claim 1, wherein the high-temperature hot-melt method involves placing the proportioned material at 1100 degrees and placing a seed crystal on the wall of a quartz tube with a temperature difference of less than 5-10 degrees, and the hot-melted proportioned material is carried by airflow to grow on the basis of the seed crystal structure.

7. In the method for preparing zinc sulfide electroluminescent crystal material according to claim 1, after the hydrogen sulfide gas is dried, it is placed above the hot-melted proportioned material through a guide tube, and the growth rate of the electroluminescent crystal is controlled by adjusting the flow rate of the hydrogen sulfide gas.

8. The method for preparing zinc sulfide electroluminescent crystal material according to claim 1, wherein the zinc sulfide seed crystal has a hexagonal phase structure, using high-grade pure zinc sulfide, sintering in a sulfur atmosphere at 1200 degrees Celsius for 5 hours, selecting zinc sulfide particles with a complete hexagonal phase structure, and selecting particles with a particle size of about 50-100 micrometers as zinc sulfide seed crystals.

9. The method for preparing a zinc sulfide electroluminescent crystal material according to claim 1, wherein the zinc sulfide electroluminescent crystal is cold-processed into a thin sheet, covered with a thin-film transparent electrode, and electroluminescence is generated by applying alternating current.

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