Eu (III)-doped tantalate red fluorescent powder, preparation method thereof and application of Eu (III)-doped tantalate red fluorescent powder in pixelated LED

Abstract

The invention relates to Eu (III) doped tantalate red fluorescent powder, a preparation method thereof and application of the Eu (III) doped tantalate red fluorescent powder in pixelated LEDs, and belongs to the technical field of inorganic luminescent materials. The invention discloses Eu (III) doped tantalate red fluorescent powder, which is mainly Eu < 3 + > doped tantalate red fluorescent powder (the chemical composition is Sr2Lu1-xTaO6: xEu < 2 + >, and x is greater than or equal to 0.05 and less than or equal to 0.25). According to the Eu (III) doped tantalate red fluorescent powder, the oxide Sr2LuTaO6 is used as a fluorescent powder matrix, Eu < 3 + > is added for doping, so that strong red light emission is achieved, the Eu (III) doped tantalate red fluorescent powder is stable in structure and excellent in thermal stability, the color rendering performance of a white light LED can be remarkably improved, and pixelated LEDs (representing high luminous intensity, high brightness and high brightness) can be achieved. The high-efficiency pixelated white-light LED is expected to be realized when the high-efficiency pixelated white-light fluorescent powder is combined with green-light or yellow-light fluorescent powder in the prior art.

Description

Technical Field

[0001] The invention belongs to the technical field of inorganic luminescent materials, and relates to Eu(III)-doped tantalate red phosphor and a preparation method thereof, and application thereof in pixelated LEDs. Background Art

[0002] With the rapid development of light-emitting diode (LED) technology, especially the efficient application of InGaN chips, LED has gradually become one of the most efficient light-emitting devices. In this technical background, the development of red phosphor has become one of the key technologies to improve the performance of LED devices. Rare earth-doped luminescent materials, especially Eu 3+ Doped red phosphors have become an important research direction in the current solid-state lighting and display fields due to their excellent optical properties and thermal stability. White light LEDs (WLEDs), as the core technology of solid-state lighting, are known as the fourth generation of green lighting sources due to their advantages such as energy saving, environmental protection and long life, and have wide application potential. At present, the common light-conversion white light LEDs on the market mainly generate white light by exciting YAG yellow phosphors with blue light InGaN chips. However, traditional WLEDs lack red light emission, resulting in a low color rendering index (Ra<80) and a high correlated color temperature (CCT>4500K), which has certain limitations in high-end applications such as artistic lighting and medical lighting.

[0003] Pixelated LEDs are becoming a key technology in the field of high-resolution display and fine lighting. By closely arranging multiple LED pixels and enabling independent control, pixelated LEDs can provide higher display resolution and color accuracy. However, the performance of pixelated LEDs is highly dependent on the phosphor materials used, especially in achieving high color rendering index and low color temperature, the quality of red phosphor is crucial. Therefore, in response to this demand, the development of efficient Eu 3+ Tantalate-doped red phosphors have become an effective way to solve the above problems. This type of phosphor can emit efficient red light under the excitation of blue light, thus making up for the lack of red light in traditional WLEDs. By applying this red phosphor in pixelated LEDs, its color rendering, luminous efficiency and overall visual performance can be significantly improved to meet the stringent requirements of high-end display and fine lighting fields. With the continuous advancement of LED technology, Eu 3+ Doped tantalate red phosphors not only help improve the performance of white light LEDs, but also play a key role in pixelated LEDs, providing strong support for the further development of display and lighting technologies.

[0004] Rare earth-doped luminescent materials have important applications in solid-state lighting and display technologies, especially trivalent europium ions (Eu 3+) plays a central role in the development of red phosphors due to its unique optical properties. 3+ The 4f electronic structure of the ion enables it to emit sharp red light through 4f-4f transitions under lower energy excitation, usually in the wavelength range of 610 to 630 nm. This spectral characteristic makes Eu 3+ Doping materials have become an indispensable part of high color rendering lighting and high color saturation display technology. Oxide matrix has high chemical and thermal stability. 3+ The research on doped red phosphors has received extensive attention. Compared with traditional sulfide or nitride matrices, oxide materials not only show better stability under high temperature conditions, but also have a more environmentally friendly preparation process. For example, oxide matrices such as Y2O3, Y2O2S and Gd2O3 have been widely used in Eu 3+ Under doping, it shows good luminous efficiency and high emission intensity, so it is widely used in LED and display backlight sources. However, traditional oxide red phosphors still have certain limitations in achieving white light LED applications with lower color temperature (CCT < 4500K) and high color rendering index (Ra > 80).

[0005] The researchers turned their attention to Eu 3+ Doped strontium aluminates have excellent optical properties and a wide range of potential applications. These materials have long performed well in terms of high quantum efficiency and long-lasting afterglow luminescence, especially in fluorescent lamps, light-emitting diodes (LEDs) and plasma displays, showing important application value. In the strontium aluminate family, there are many possible crystal phases, including SrAl2O4, Sr4Al 14 O 25 、SrAl 12 O 19 and Sr3Al2O6. These materials are widely used in optoelectronic devices due to their different crystal structures and luminescence properties. However, the monoclinic SrAl4O7 phase is relatively less studied, although it has unique unit cell parameters in the C2 / c space group: β=106.502°. Early studies synthesized SrAl4O7 by spray drying amorphous precursors and determined its stability region. In order to achieve photoluminescence in SrAl4O7, different research teams have tried to dope various elements to regulate the optical properties of the material and explore its potential in practical applications. For example, Eu 2+ With Dy 3+The co-doping of Eu and SrAl4O7 not only successfully achieved long-lasting afterglow luminescence, but also significantly enhanced the overall luminescence performance of the material. This feature makes SrAl4O7 material show a wide range of application prospects in the fields of luminous signs, display backlights, etc. Based on the previous work, a single-phase SrAl4O7 sample was successfully synthesized by conventional solid-phase reaction method, and further prepared Eu-doped 3+ The study found that Eu doped 3+ The SrAl4O7 sample exhibits efficient red light emission under blue light excitation. This discovery not only proves the application potential of this material in solid-state lighting and display backlight sources, but also provides an efficient and stable material solution for the next generation of optoelectronic devices. 3+ With further research and optimization of doped SrAl4O, this new luminescent material is expected to show excellent performance in more diverse application scenarios.

[0006] Eu 3+ There are many methods for synthesizing doped compounds, including the Czochralski method, floating zone method, spray drying, solvothermal method, sol-gel method, and combustion method. Although these methods are effective, they usually require complex equipment and processes. The conventional solid-phase reaction method has become an alternative method worthy of exploration due to its simple process and easy large-scale production. However, there are currently few reports on the synthesis of Sr2LuTaO6 by solid-phase reaction. Existing literature has studied the structure of Sr2LuTaO6 in detail and confirmed its crystal structure (10.1016 / j.ceramint.2019.05.053). These studies have laid an important foundation for the further development of luminescent materials. In addition, studies have reported the synthesis of Sr2LuTaO6 by doping with trivalent rare earth ions (such as Sm 3+ ) achieved luminescence in Sr2LuTaO6 (https: / / doi.org / 10.1016 / j.jlumin.2021.117901; https: / / doi.org / 10.1007 / s10854-019-01260-w).

[0007] Therefore, further research is needed on Eu 3+ As an activator, Eu 3+ The role and progress of doped tantalate red phosphors. Summary of the invention

[0008] In view of this, one of the objects of the present invention is to provide Eu (III) doped tantalate red phosphor; the second object of the present invention is to provide a method for preparing Eu (III) doped tantalate red phosphor; the third object of the present invention is to provide the application of Eu (III) doped tantalate red phosphor in pixelated LED; the fourth object of the present invention is to provide a white light LED light-emitting device.

[0009] In order to achieve the above object, the present invention provides the following technical solutions:

[0010] 1. Eu(III)-doped tantalate red phosphor, wherein the Eu(III)-doped tantalate red phosphor is Eu 3+ Doped red phosphor, wherein the chemical composition of the red phosphor is Sr2Lu 1-x TaO6, wherein 0.05≤x≤0.25, the Sr2Lu 1-x TaO6 neutralizes doped Eu 3+ The molar ratio is (1-x):x.

[0011] Preferably, the tantalate red phosphor is Eu 3+ The luminous center.

[0012] 2. A method for preparing the above-mentioned Eu(II)-doped tantalate red phosphor, the preparation method comprising the following steps:

[0013] (1) According to the general formula Sr2Lu 1-x TaO6:xEu 2+ , accurately weighing strontium source, lutetium source, tantalum source and europium source as raw materials in a stoichiometric ratio of 0.05≤x≤0.25, adding flux, and fully grinding and mixing to obtain a raw material mixture;

[0014] (2) The raw material mixture obtained in step (1) is calcined at 1100-1450° C. for 4-10 hours to obtain Eu(II)-doped tantalate red phosphor.

[0015] Preferably, the strontium source is at least one of strontium carbonate or other compounds that can be converted into strontium oxide;

[0016] The lutetium source is at least one of lutetium trioxide or other compounds that can be converted into lutetium trioxide.

[0017] Preferably, the flux is at least one of boron trioxide or compounds that can be converted into boron trioxide, and the amount of the flux is 1-10% of the molar amount of the raw material, wherein the mixture is formed by mixing a strontium source, a lutetium source, a tantalum source and the flux.

[0018] Preferably, the tantalum source is tantalum pentoxide or at least one of compounds that can be converted into tantalum pentoxide.

[0019] 3. Application of the above Eu(III) doped tantalate red phosphor in pixelated LEDs.

[0020] 4. A white light LED light emitting device, comprising an InGaN semiconductor chip, a green fluorescent material and the above-mentioned Eu(III)-doped tantalate red fluorescent powder.

[0021] Preferably, the peak wavelength of the light emission of the InGaN semiconductor chip is 365-395 nm, and the chemical composition of the green phosphor is Ba2SiO4:Eu 2+ ;

[0022] The green fluorescent material in the white light LED luminescent device and the Eu(III)-doped tantalate red fluorescent powder as claimed in any one of claims 1 to 5 are uniformly dispersed in UV quick-drying resin glue and covered on the surface of the InGaN semiconductor chip by coating or dispensing.

[0023] The beneficial effects of the present invention are as follows: the present invention discloses a Eu(III)-doped tantalate red phosphor, which is mainly composed of Eu 3+ Doped tantalate red phosphor (chemical composition is Sr2Lu 1-x TaO6:xEu 2+ , 0.05≤x≤0.250). The present invention uses oxide Sr2LuTaO6 as the phosphor matrix and adds Eu 3+ Doping is performed to achieve strong red light emission. The Eu(III)-doped tantalate red phosphor of the present invention has a stable structure and excellent thermal stability, which can not only significantly improve the color rendering performance of white light LEDs, but also realize pixelated LEDs (showing high luminous intensity. It is combined with green or yellow phosphors in the prior art to achieve efficient pixelated white light LEDs).

[0024] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0026] Figure 1a is the Eu(III)-doped tantalate red phosphor (Sr2Lu 0.95 TaO6:0.05Eu 3+ ) is the XRD pattern of a, b is the Eu(III)-doped tantalate red phosphor (Sr2Lu 0.95 TaO6:0.05Eu 3+ )’s excitation and emission spectra;

[0027] Figure 2 a is the Eu(III)-doped tantalate red phosphor (Sr2Lu 0.9 TaO6:0.10Eu 3 + ) is the XRD pattern of Example 2, and b is the XRD pattern of the Eu(III)-doped tantalate red phosphor (Sr2Lu 0.9 TaO6:0.10Eu 3+ )’s excitation and emission spectra;

[0028] Figure 3 a is the Eu(III)-doped tantalate red phosphor (Sr2Lu 0.85 TaO6:0.15Eu 3+ ) is the XRD pattern of a, b is the Eu(III)-doped tantalate red phosphor (Sr2Lu 0.85 TaO6:0.15Eu 3+ )’s excitation and emission spectra;

[0029] Figure 4 a is the Eu(III)-doped tantalate red phosphor (Sr2Lu 0.8 TaO6:0.20Eu 3 + ) is the XRD pattern of a, b is the Eu(III)-doped tantalate red phosphor (Sr2Lu 0.8 TaO6:0.20Eu 3+ )’s excitation and emission spectra;

[0030] Figure 5 a is the Eu(III)-doped tantalate red phosphor (Sr2Lu 0.75 TaO6:0.25Eu 3+ ) is the XRD pattern of a, b is the Eu(III)-doped tantalate red phosphor (Sr2Lu 0.75 TaO6:0.25Eu 3+ )’s excitation and emission spectra;

[0031] Figure 6 A pixelated LED light-emitting device made of the red phosphor prepared in Example 5 and an InGaN semiconductor chip, wherein the size of a is 2×2 mm, and the size of b is 0.5×0.5 mm;

[0032] Figure 7 This is the temperature-dependent emission spectrum of the red phosphor prepared in Example 5 in the pixelated LED light-emitting device. DETAILED DESCRIPTION

[0033] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0034] Example 1

[0035] A Eu(III)-doped tantalate red phosphor (Sr2Lu 0.95 TaO6:0.05Eu 3+ ), the specific preparation method is as follows:

[0036] Take 2mmol SrCO3, 0.5mmol Lu2O3, 0.5mmol Ta2O5, 0.05mmol Eu2O3 and 1%mmol B2O3, mix them thoroughly and place them in a high temperature box furnace, heat them to 1350℃ and sinter them for 6h, take them out after cooling, grind them into powder, and get Eu(III) doped tantalate red phosphor (Sr2Lu 0.95 TaO6:0.05Eu 3+ ).

[0037] The Eu(III)-doped tantalate red phosphor (Sr2Lu 0.95 TaO6:0.05Eu 3+ ) completely matches the standard card, and its XRD pattern is as follows Figure 1 As shown in a, the excitation and emission spectra are Figure 1 As shown in b, by monitoring the sample at a wavelength of 615 nm, multiple narrow-band excitation peaks can be observed. When the excitation spectrum of the sample is measured using the optimal excitation wavelength of 319 nm, it can be clearly seen that there are multiple narrow-band emission peaks in the range of 550 to 750 nm.

[0038] Example 2

[0039] A Eu(III)-doped tantalate red phosphor (Sr2Lu 0.9 TaO6:0.10Eu 3+ ), the specific preparation method is as follows:

[0040] Take 2mmol SrCO3, 0.5mmol Lu2O3, 0.5mmol Ta2O5, 0.1mmol Eu2O3 and 1%mmol B2O3, mix them thoroughly and place them in a high-temperature box furnace, heat them to 1450℃ and sinter them for 6h, take them out after cooling, grind them into powder, and obtain the red phosphor of this embodiment.

[0041] The Eu(III)-doped tantalate red phosphor (Sr2Lu 0.9 TaO6:0.10Eu 3+ ) completely matches the standard card, and its XRD pattern is as follows Figure 2 As shown in a, the excitation and emission spectra are Figure 2 As shown in b, by monitoring the sample at a wavelength of 615 nm, multiple narrow-band excitation peaks can be observed. When the excitation spectrum of the sample is measured using the optimal excitation wavelength of 319 nm, it can be clearly seen that there are multiple narrow-band emission peaks in the range of 550 to 750 nm.

[0042] Example 3

[0043] A Eu(III)-doped tantalate red phosphor (Sr2Lu 0.85 TaO6:0.15Eu 3+ ), the specific preparation method is as follows:

[0044] Take 2mmol SrCO3, 0.5mmol Lu2O3, 0.5mmol Ta2O5, 0.15mmol Eu2O3 and 1%mmol B2O3, mix them thoroughly and place them in a high temperature box furnace, heat them to 1450℃ and sinter them for 6h, take them out after cooling, grind them into powder, and get Eu(III) doped tantalate red phosphor (Sr2LuTaO6:0.15Eu 3+ ).

[0045] The Eu(III)-doped tantalate red phosphor (Sr2Lu 0.85 TaO6:0.15Eu 3+ ) completely matches the standard card, and its XRD pattern is as follows Figure 3 As shown in a, the excitation and emission spectra are Figure 3As shown in b, by monitoring the sample at a wavelength of 615 nm, multiple narrow-band excitation peaks can be observed. When the excitation spectrum of the sample is measured using the optimal excitation wavelength of 319 nm, it can be clearly seen that there are multiple narrow-band emission peaks in the range of 550 to 750 nm.

[0046] Example 4

[0047] A Eu(III)-doped tantalate red phosphor (Sr2Lu 0.8 TaO6:0.20Eu 3+ ), the specific preparation method is as follows:

[0048] Take 2mmol SrCO3, 0.5mmol Lu2O3, 0.5mmol Ta2O5, 0.20mmol Eu2O3 and 1%mmol B2O3, mix them thoroughly and place them in a high temperature box furnace, heat them to 1450℃ and sinter them for 6h, take them out after cooling, grind them into powder, and get Eu(III) doped tantalate red phosphor (Sr2Lu 0.8 TaO6:0.20Eu 3+ ).

[0049] The Eu(III)-doped tantalate red phosphor (Sr2Lu 0.8 TaO6:0.20Eu 3+ ) completely matches the standard card, and its XRD pattern is as follows Figure 4 As shown in a, the excitation and emission spectra are Figure 4 As shown in b, by monitoring the sample at a wavelength of 615 nm, multiple narrow-band excitation peaks can be observed. When the excitation spectrum of the sample is measured using the optimal excitation wavelength of 319 nm, it can be clearly seen that there are multiple narrow-band emission peaks in the range of 550 to 50 nm.

[0050] Example 5

[0051] A Eu(III)-doped tantalate red phosphor (Sr2Lu 0.8 TaO6:0.20Eu 3+ ), the specific preparation method is as follows: weigh 2mmol SrCO3, 0.5mmol Lu2O3, 0.5mmol Ta2O5, 0.20mmol Eu2O3 and 1%mmol B2O3 as raw materials, mix them thoroughly and place them in a high-temperature box furnace, heat them to 1450℃ and sinter them for 6h, take them out after cooling, grind them into powder, and obtain Eu(III)-doped tantalate red phosphor (Sr2LuTaO6:0.20Eu 3+ ).

[0052] The Eu(III)-doped tantalate red phosphor (Sr2Lu 0.8 TaO6:0.20Eu 3+ ) completely matches the standard card, and its XRD pattern is as follows Figure 5 As shown in a, the excitation and emission spectra are Figure 5 As shown in b, by monitoring the sample at a wavelength of 615 nm, multiple narrow-band excitation peaks can be observed. When the excitation spectrum of the sample is measured using the optimal excitation wavelength of 319 nm, it can be clearly seen that there are multiple narrow-band emission peaks in the range of 550 to 750 nm.

[0053] Example 6

[0054] The Eu(III)-doped tantalate red phosphor (Sr2Lu 0.8 TaO6:0.20Eu 3+ ) to make pixelated LEDs, the specific method is:

[0055] First, the Eu(III)-doped tantalate red phosphor (Sr2Lu 0.8 TaO6:0.20Eu 3+ ) is evenly mixed with a transparent resin, and the mixture is precisely coated on the surface of the purple LED chip to form a uniform red light emitting layer.

[0056] Then, these Sr2Lu 0.8 TaO6:0.20Eu 3+ The LED chips with phosphor are processed into independent pixel arrays. Each pixel can emit pure red light under the excitation of purple light, thus achieving high-resolution display effects. Finally, the pixelated LED array is encapsulated with a transparent epoxy resin coating to ensure its excellent optical properties and avoid damage to the pixelated LED array by air humidity, so as to improve the long-term stability of the device. Figure 6 A pixelated LED light-emitting device made of the red phosphor prepared in Example 5 and an InGaN semiconductor chip, wherein the size of a is 2×2 mm, and the size of b is 0.5×0.5 mm; Figure 7 The temperature-dependent emission spectrum of the red phosphor prepared in Example 5 in the pixelated LED light-emitting device is shown in FIG. 1 . It can be seen that the Eu(III)-doped tantalate red phosphor prepared in the present invention can be used in the pixelated LED to obtain stable light emission.

[0057] Similarly, the Eu(III)-doped tantalate red phosphor prepared in the above-mentioned Examples 2 to 5 replaces the Eu(III)-doped tantalate red phosphor (Sr2Lu1-x TaO6:xEu 3+ , 0.05≤x≤0.25) is used to prepare pixelated LEDs. Performance tests have also shown that the Eu(III)-doped tantalate red phosphors prepared by the present invention emit pure red light, achieving high-resolution display performance.

[0058] In summary, the present invention discloses a Eu(III)-doped tantalate red phosphor, which is mainly composed of Eu 3+ Doped tantalate red phosphor (chemical composition is Sr2Lu 1-x TaO6:xEu 2+ , wherein 0.05≤x≤0.25). The present invention uses oxide Sr2LuTaO6 as the phosphor matrix and adds Eu 3+ Doping is performed to achieve strong red light emission. The Eu(III)-doped tantalate red phosphor of the present invention has a stable structure and excellent thermal stability, which can not only significantly improve the color rendering performance of white light LEDs, but also realize pixelated LEDs (showing high luminous intensity. It is combined with green or yellow phosphors in the prior art to achieve efficient pixelated white light LEDs).

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. Eu(III)-doped tantalate red phosphor, characterized in that: The Eu(III)-doped tantalate red phosphor is Eu 3+ Doped red phosphor, wherein the chemical composition of the red phosphor is Sr2Lu 1-x TaO6, wherein 0.05≤x≤0.25, the Sr2Lu 1-x TaO6 neutralizes doped Eu 3+ The molar ratio is (1-x):x.

2. The Eu(III)-doped tantalate red phosphor according to claim 1, characterized in that: The tantalate red phosphor is Eu 3+ The luminous center.

3. The method for preparing the Eu(II)-doped tantalate red phosphor according to any one of claims 1 to 2, characterized in that: The preparation method comprises the following steps: (1) According to the general formula Sr2Lu 1-x TaO6:xEu 2+ , accurately weighing strontium source, lutetium source, tantalum source and europium source as raw materials in a stoichiometric ratio of 0.05≤x≤0.25, adding flux, and fully grinding and mixing to obtain a raw material mixture; (2) The raw material mixture obtained in step (1) is calcined at 1100-1450° C. for 4-10 hours to obtain Eu(II)-doped tantalate red phosphor.

4. The preparation method according to claim 3, characterized in that: The strontium source is at least one of strontium carbonate or other compounds that can be converted into strontium oxide; The lutetium source is at least one of lutetium trioxide or other compounds that can be converted into lutetium trioxide.

5. The preparation method according to claim 3, characterized in that: The flux is at least one of boron trioxide or compounds that can be converted into boron trioxide, and the amount of the flux is 1-10% of the molar amount of the raw material, wherein the mixture is formed by mixing a strontium source, a lutetium source, a tantalum source and the flux.

6. The preparation method according to claim 3, characterized in that: The tantalum source is at least one of tantalum pentoxide and a compound that can be converted into tantalum pentoxide.

7. Use of the Eu(III)-doped tantalate red phosphor according to any one of claims 1 to 2 in a pixelated LED.

8. A white light LED lighting device, characterized in that: The white light LED luminescent device comprises an InGaN semiconductor chip, a green fluorescent material and the Eu(III)-doped tantalate red fluorescent powder as claimed in any one of claims 1 to 2.

9. The white light LED lighting device according to claim 8, characterized in that: The peak wavelength of the InGaN semiconductor chip is 365-395 nm, and the chemical composition of the green phosphor is Ba2SiO4:Eu 2+ ; The green fluorescent material in the white light LED luminescent device and the Eu(III)-doped tantalate red fluorescent powder as claimed in any one of claims 1 to 5 are uniformly dispersed in UV quick-drying resin glue and covered on the surface of the InGaN semiconductor chip by coating or dispensing.

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