Narrowband green light-emitting transparent fluorescent composite ceramic and preparation method and application thereof

Abstract

The invention discloses a narrow-band green-light-emitting transparent fluorescent composite ceramic, and relates to the field of luminescent materials. The chemical structure of the composite ceramic is yAl2O3-LaMgAl11O19: xMn < 2 + >, x is more than or equal to 0 and less than or equal to 0.5, and y is more than or equal to 0 and less than or equal to 32wt%; the narrow-band green-emitting fluorescent ceramic can be excited by blue laser, has excellent luminescence performance, has the advantages of simple preparation process, batch preparation, good stability and the like, and can be possibly applied to laser-driven wide-color-gamut display devices.

Description

Technical Field

[0001] The invention belongs to the technical field of solid luminescent materials, and in particular relates to a narrow-band green light emitting transparent fluorescent composite ceramic and a preparation method and application thereof. Background Art

[0002] With the widespread application of high-quality projection display technology in theaters, commerce, education and other fields, the development of a new generation of light source technology has become increasingly necessary. Traditional display light sources, such as halogen lamps, high-pressure sodium lamps and mercury lamps, usually have shortcomings in system efficiency, color quality, service life and stability. In addition, the widely used light-emitting diodes (LEDs) face the problem of "efficiency droop" under high input power, making it difficult to meet the needs of high-brightness displays, and are therefore being replaced by emerging laser diodes (LDs). At present, LDs are superior to LEDs in terms of high luminous efficiency, monochromaticity, directionality and system compactness. However, the "all-laser" solution still faces serious challenges, such as the "green gap" phenomenon and significant laser speckle. As an alternative, it is particularly important to combine high-power blue LDs with fluorescent conversion materials.

[0003] The quality of laser-driven fluorescent conversion materials is crucial to the final display performance. Among various fluorescent conversion materials, fluorescent ceramics have become the only choice for laser-driven fluorescent conversion materials due to their resistance to laser irradiation, excellent heat dissipation performance, and adjustable microstructure (such as pores, secondary phases or grain size). Currently, the light conversion materials used in laser-driven display devices are mainly commercial broadband emission Ce 3+ Doped garnet structure luminescent ceramics (luminescence half-peak width is about 100nm), such as Y3Al5O 12 :Ce 3+ (YAG:Ce 3+ ) and Lu3Al5O 12 :Ce 3+ (LuAG:Ce 3+ ). The achievable color gamut of these materials is about 80%, and there is a significant light loss (about 63%) after the filter. Therefore, it is urgent to develop new narrow-band green light conversion materials with convenient preparation, ultra-narrow emission band (half-peak width ≤ 30nm), high quantum efficiency and excellent stability to break through the bottleneck problem of laser-driven wide color gamut display technology. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a narrow-band green light emitting transparent fluorescent composite ceramic suitable for laser-driven wide color gamut display devices. Under the excitation of a 450nm high-power blue laser, the fluorescent composite ceramic material can realize ultra-wide color gamut laser-driven projection display.

[0005] The technical solution of the present invention is as follows:

[0006] The present invention provides a narrow-band green light emitting transparent fluorescent composite ceramic, which is a multiphase fluorescent ceramic, and its chemical structural formula is yAl2O3-LaMgAl 11 O 19 :xMn 2+ , where 0≤x≤0.5, 0≤y≤32wt%.

[0007] The present invention also provides a method for preparing a narrow-band green light emitting transparent fluorescent composite ceramic, comprising the following steps:

[0008] S1, target narrow-band green fluorescent ceramic yAl2O3-LaMgAl 11 O 19 :xMn 2+ To proportion the components, weigh powders La2O3, MgO, Al2O3 and MnCO3;

[0009] S2. Grind the powder raw materials evenly, granulate, sieve, and then press into ceramic green sheets. Then heat to above 600°C and keep warm for 10 hours for pre-sintering. Then transfer to a vacuum sintering furnace, keep warm at above 1700°C for 4 hours under vacuum, and cool naturally to obtain narrow-band green light emitting transparent fluorescent composite ceramics.

[0010] The present invention also provides the application of the narrow-band green light emitting transparent fluorescent composite ceramic in a laser driven wide color gamut display device.

[0011] Furthermore, under the excitation of 450nm blue laser, the narrow-band green light emitting transparent fluorescent composite ceramic effectively provides a narrow-band green light band spectrum.

[0012] The present invention further provides a laser driven wide color gamut display device, comprising a blue laser, the narrow-band green light emitting transparent fluorescent composite ceramic as claimed in claim 1, and a red light LD as light sources.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. The narrow-band green light emitting transparent fluorescent composite ceramic yAl2O3-LaMgAl 11 O 19 :xMn 2+ , where 0≤x≤0.5, 0≤y≤32wt%, exhibits narrow-band green light emission under 450nm laser excitation, and has the advantages of simple preparation process, batch preparation, and stable spectrum. It is possible to solve the problem of lack of "narrow-band green light" materials and be widely used in laser-driven wide color gamut display devices;

[0015] 2. The narrow-band green light emitting transparent fluorescent composite ceramic provided by the present invention effectively realizes a narrow-band green light band spectrum, and at the same time introduces a red light LD chip as a light source, and the corresponding display device color gamut can reach 100.8% Rec.2020 (ultra-high-definition display standard). BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 yAl2O3-LaMgAl in Examples 1 to 5 11 O 19 :xMn 2+ X-ray diffraction pattern of fluorescent ceramics; wherein x=0.3, y=0wt%, 8wt%, 16wt%, 24wt% and 32wt%;

[0017] Figure 2 0wt% Al2O3-LaMgAl in Example 1 11 O 19 :0.3Mn 2+ SEM images of fluorescent ceramics;

[0018] Figure 3 yAl2O3-LaMgAl in Examples 1 to 5 11 O 19 :0.3Mn 2+ Steady-state emission spectra of fluorescent ceramics (excitation wavelength: 450 nm), where y = 0 wt%, 8 wt%, 16 wt%, 24 wt% and 32 wt%;

[0019] Figure 4 24wt% Al2O3-LaMgAl in Example 4 11 O 19 :0.3Mn 2+ Scanning electron microscope images of fluorescent ceramics and corresponding element distribution images;

[0020] Figure 5 24wt% Al2O3-LaMgAl in Example 4 11 O 19 :0.3Mn 2+ High-resolution transmission electron micrographs of fluorescent ceramics;

[0021] Figure 6 In Example 6, 24 wt% Al2O3-LaMgAl 11 O 19 :0.3Mn 2+ Electroluminescence spectrum of a prototype light source made by coupling a fluorescent ceramic with a blue laser (wavelength of 450nm) and a red laser diode (wavelength of 642nm);

[0022] Figure 7In Example 6, 24 wt% Al2O3-LaMgAl 11 O 19 :0.3Mn 2+ CIE color gamut diagram of the prototype light source prepared by fluorescent ceramics coupled with a blue laser (wavelength of 450nm) and a red laser diode (wavelength of 642nm).

[0023] Figure 8 yAl2O3-LaMgAl in Examples 7 and 8 11 O 19 :xMn 2+ X-ray diffraction pattern of fluorescent ceramics; wherein y=0, x=0, 0.1, 0.2, 0.3, 0.4 and 0.5 mol;

[0024] Fig. 9 yAl2O3-LaMgAl in Examples 7 and 8 11 O 19 :xMn 2+ Steady-state emission spectra of fluorescent ceramics (excitation wavelength: 450 nm), where y=0, x=0, 0.1, 0.2, 0.3, 0.4 and 0.5 mol. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings and preferred embodiments.

[0026] Example 1

[0027] This embodiment provides a method for preparing a narrow-band green light emitting transparent fluorescent composite ceramic. The prepared transparent fluorescent composite ceramic is a complex phase fluorescent ceramic, and its chemical structure is yAl2O3-LaMgAl 11 O 19 :xMn 2+ , where x is 0.3 and y is 0. The specific steps are as follows:

[0028] S1. Analytical pure La2O3, MgO, Al2O3 and MnCO3 powders were prepared according to the chemical formula yAl2O3-LaMgAl 11 O 19 :xMn 2+ Proportion the components and weigh them accurately;

[0029] S2. After the powder raw materials are evenly ground, granulated, sieved, and then pressed into a ceramic blank, then heated to above 600°C and kept warm for 10 hours for pre-sintering, then transferred to a vacuum sintering furnace, kept warm at above 1700°C for 4 hours under vacuum, and cooled naturally to obtain a transparent fluorescent composite ceramic LaMgAl 11 O 19 :0.3Mn 2+.

[0030] like Figure 1 As shown, the LaMgAl prepared according to the above method 11 O 19 :0.3Mn 2+ X-ray diffraction data of the transparent ceramics showed that they were phase pure.

[0031] like Figure 2 As shown, scanning electron microscopy of LaMgAl 11 O 19 :0.3Mn 2+ The transparent ceramic particles were found to be flake-shaped and about 50 μm in size.

[0032] like Figure 3 As shown, the fluorescence spectrometer FLS1000 was used to measure the fluorescence of LaMgAl under 450nm blue light irradiation. 11 O 19 :0.3Mn 2 + The steady-state emission spectrum of transparent ceramics shows a narrow-band emission with a central wavelength in green light.

[0033] Example 2

[0034] The difference from Example 1 is that:

[0035] The chemical structure is yAl2O3-LaMgAl 11 O 19 :xMn 2+ , wherein x is 0.3, y is 8wt% of transparent fluorescent composite ceramics; analytically pure La2O3, MgO, Al2O3 and MnCO3 powders are prepared according to the chemical formula 8wt% Al2O3-LaMgAl 11 O 19 :0.3Mn 2+ The remaining steps are the same as in Example 1.

[0036] like Figure 1 As shown, the 8wt% Al2O3-LaMgAl 11 O 19 :0.3Mn 2+ X-ray diffraction data of the fluorescent ceramics showed that they were two phases.

[0037] like Figure 3 As shown, the FLS1000 fluorescence spectrometer was used to measure the 8wt% Al2O3-LaMgAl 11 O 19 :0.3Mn 2+ The steady-state emission spectrum of fluorescent ceramics shows a narrow-band emission with a central wavelength in green light.

[0038] Example 3

[0039] The difference from Example 1 is that the obtained chemical structure is yAl2O3-LaMgAl 11 O 19 :xMn 2+ , wherein x is 0.3, y is 16wt% of transparent fluorescent composite ceramics; analytically pure La2O3, MgO, Al2O3 and MnCO3 powders are prepared according to the chemical formula 16wt% Al2O3-LaMgAl 11 O 19 :0.3Mn 2+ The remaining steps are the same as in Example 1.

[0040] like Figure 1 As shown, the 16wt% Al2O3-LaMgAl 11 O 19 :0.3Mn 2+ X-ray diffraction data of the fluorescent ceramics showed that it was two phases;

[0041] like Figure 3 As shown, the FLS1000 fluorescence spectrometer was used to measure the 16wt% Al2O3-LaMgAl 11 O 19 :0.3Mn 2+ The steady-state emission spectrum of fluorescent ceramics shows a narrow-band emission with a central wavelength in green light.

[0042] Example 4

[0043] The difference from Example 1 is that the obtained chemical structure is yAl2O3-LaMgAl 11 O 19 :xMn 2+ , wherein x is 0.3, y is 24wt% of transparent fluorescent composite ceramics; analytically pure La2O3, MgO, Al2O3 and MnCO3 powders are prepared according to the chemical formula 24wt% Al2O3-LaMgAl 11 O 19 :0.3Mn 2+ The remaining steps are the same as in Example 1.

[0044] like Figure 1 As shown, the 24wt% Al2O3-LaMgAl 11 O 19 :0.3Mn 2+ X-ray diffraction data of the fluorescent ceramics showed that they were two phases.

[0045] like Figure 3 As shown, the FLS1000 fluorescence spectrometer was used to measure the fluorescence intensity of 24wt% Al2O3-LaMgAl under 450nm blue light irradiation. 11 O 19 :0.3Mn 2+ The steady-state emission spectrum of fluorescent ceramics shows a narrow-band emission with a central wavelength in green light.

[0046] like Figure 4 As shown, the corresponding EDS element surface scan of the scanning electron microscope confirmed that its chemical composition is La, Mg, Al, O; and it presents a uniform two-phase distribution.

[0047] like Figure 5 As shown, high-resolution transmission electron microscopy can observe 24wt% Al2O3-LaMgAl 11 O 19 :0.3Mn 2+ The clear lattice fringes of the two phases of the composite ceramics indicate the crystalline properties of the prepared fluorescent ceramics. The measured interplanar spacings are and They correspond to the (110) and (-120) planes of Al2O3 and LaMgAl 11 O 19 (101) crystal plane.

[0048] Example 5

[0049] The difference from Example 1 is that the obtained chemical structure is yAl2O3-LaMgAl 11 O 19 :xMn 2+ , wherein x is 0.3, y is 32wt% of transparent fluorescent composite ceramics; analytically pure La2O3, MgO, Al2O3 and MnCO3 powders are prepared according to the chemical formula 32wt% Al2O3-LaMgAl 11 O 19 :0.3Mn 2+ The remaining steps are the same as in Example 1.

[0050] like Figure 1 As shown, the 32wt% Al2O3-LaMgAl 11 O 19 :0.3Mn 2+ X-ray diffraction data of the fluorescent ceramics showed that it was two phases;

[0051] like Figure 3 As shown, the FLS1000 fluorescence spectrometer was used to measure the fluorescence intensity of 32wt% Al2O3-LaMgAl under 450nm blue light irradiation. 11 O 19 :0.3Mn2+ The steady-state emission spectrum of fluorescent ceramics shows a narrow-band emission with a central wavelength in green light.

[0052] Example 6

[0053] In this embodiment, the narrow-band fluorescent transparent ceramic 24wt% Al2O3-LaMgAl 11 O 19 :0.3Mn 2+ It is used in laser-driven wide color gamut display, providing blue and red light sources at the same time, including blue laser, red LD chip and commercial filter. Under 450nm blue light excitation, the fluorescent ceramic exhibits narrow-band green light emission, effectively realizing the green light band spectrum;

[0054] like Figure 6 and Figure 7 As shown, using 24wt% Al2O3-LaMgAl 11 O 19 :0.3Mn 2+ Fluorescent transparent ceramics are coupled with a blue laser (wavelength of 450nm) and a red laser diode (wavelength of 642nm) to obtain a high-quality light source, and the corresponding display system color gamut is 100.8% Rec.2020; it can be seen that the fluorescent ceramics of the present invention can achieve narrow-band green light emission, thereby obtaining high-quality, wide-color gamut white light.

[0055] Example 7

[0056] The difference from Example 1 is that:

[0057] The chemical structure is yAl2O3-LaMgAl 11 O 19 :xMn 2+ , wherein x is 0 and y is 0, a transparent fluorescent composite ceramic; analytically pure La2O3, MgO, Al2O3 and MnCO3 powders are prepared according to the chemical formula 0wt% Al2O3-LaMgAl 11 O 19 The remaining steps are the same as in Example 1.

[0058] like Figure 8 As shown, 0wt% Al2O3-LaMgAl 11 O 19 X-ray diffraction data of the ceramic showed that it was a single phase.

[0059] like Fig. 9 As shown, the FLS1000 fluorescence spectrometer was used to measure the 0wt% Al2O3-LaMgAl 11 O 19The steady-state emission spectrum of the ceramic shows no obvious luminescence signal due to the absence of activation centers.

[0060] Example 8

[0061] The difference from Example 1 is that:

[0062] The chemical structure is yAl2O3-LaMgAl 11 O 19 :xMn 2+ , wherein x is 0.5 and y is 0, a transparent fluorescent composite ceramic; analytically pure La2O3, MgO, Al2O3 and MnCO3 powders are prepared according to the chemical formula 0wt% Al2O3-LaMgAl 11 O 19 :0.5Mn 2+ The remaining steps are the same as in Example 1.

[0063] like Figure 8 As shown, 0wt% Al2O3-LaMgAl 11 O 19 :0.5Mn 2+ X-ray diffraction data of the fluorescent ceramics showed that they were single phase.

[0064] like Fig. 9 As shown, the FLS1000 fluorescence spectrometer was used to measure the 0wt% Al2O3-LaMgAl 11 O 19 :0.5Mn 2+ The steady-state emission spectrum of fluorescent ceramics shows a narrow-band emission with a central wavelength in green light.

[0065] also, Figure 8 and Fig. 9 In addition to the values ​​of y and x listed in the above embodiment, yAl2O3-LaMgAl 11 O 19 :xMn 2+ X-ray diffraction patterns and steady-state emission spectra of fluorescent ceramics.

[0066] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A narrow-band green light emitting transparent fluorescent composite ceramic, characterized in that: It is a composite fluorescent ceramic with the chemical structure of yAl2O3-LaMgAl 11 O 19 :xMn 2+ , where 0≤x≤0.5, 0≤y≤32wt%.

2. The method for preparing the narrow-band green light emitting transparent fluorescent ceramic according to claim 1, characterized in that: The steps include: S1, target narrow-band green fluorescent ceramic yAl2O3-LaMgAl 11 O 19 :xMn 2+ To proportion the components, weigh powders La2O3, MgO, Al2O3 and MnCO3; S2. Grind the powder raw materials evenly, granulate, sieve, and then press into ceramic green sheets. Then heat to above 600°C and keep warm for 10 hours for pre-sintering. Then transfer to a vacuum sintering furnace, keep warm at above 1700°C for 4 hours under vacuum, and cool naturally to obtain narrow-band green light emitting transparent fluorescent composite ceramics.

3. Apply the narrow-band green light emitting transparent fluorescent composite ceramic as claimed in claim 1 to a laser driven wide color gamut display device.

4. The use according to claim 3, characterized in that Under the excitation of 450nm blue laser, the narrow-band green light emitting transparent fluorescent composite ceramic effectively provides a narrow-band green light band spectrum.

5. A laser driven wide color gamut display device, characterized in that: The light source comprises a blue laser, the narrow-band green light emitting transparent fluorescent composite ceramic as claimed in claim 1 and a red light LD.

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