A kind of silicate fluorescent ceramics with full spectrum emission and preparation method thereof

Abstract

The invention provides a silicate fluorescent ceramic with full spectrum emission, which has the chemical formula shown in formula (I): Ca 3‑x‑y‑z‑ m Ce x PR y mn z Na m sc 2 Si 3 o 12 (I); wherein, 0.001≤x≤0.2, 0≤y≤0.1, 0.03≤z≤0.4, 0≤m≤0.3; the silicate fluorescent ceramic has a garnet crystal structure, belongs to the cubic crystal system, and has a space group for Ia3d. The silicate fluorescent ceramic provided by the present invention has stable physical and chemical properties, and its emission wavelength range is wide under the effective excitation of blue light, and the spectrum covers blue-green light, yellow light, red light and deep red light. This single fluorescent ceramic can Realize the production of white light LED with low color temperature and high color rendering, and overcome the reabsorption problem caused by the mixing of multi-color phosphor powder. It can be used for high-power blue LED or LD-pumped white LED to meet high-end display and lighting.

Description

technical field [0001] The invention relates to the technical field of luminescent materials, in particular to a silicate fluorescent ceramic with full-spectrum emission and a preparation method thereof. Background technique [0002] White LEDs are considered to be the fourth-generation lighting sources that are expected to replace traditional lighting due to their advantages of energy saving, environmental protection, long life, small size, and short response time. At present, there are mainly two schemes for synthesizing white light LEDs. One is to use red, green, and blue primary color LEDs to synthesize white light through the principle of color mixing; the other is to use one or more phosphors to emit blue or ultraviolet light from LEDs. light is converted to white light. The former scheme is only used in the field of large-screen display because of its complicated control circuit and high manufacturing cost. At present, the commercialized white light LED mainly adopt...

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Problems solved by technology

But due to the activated ion Ce 3+ replace Ca 2+ There is a charge mismatch at the lattice site, Ce 3+ The concentration of ions entering the host lattice is very low, resulting in weak absorption of excitation light by the phosphor. People try to enhance the absorption by increasing the thickness of the phosphor, but the light extraction efficiency of the device is significantly reduced due to the multiple scattering of light in the phosphor. , which greatly limits its application in high-power white LEDs

On the other hand, current fluorescent ceramics mainly focus on rare earth aluminates with garnet structure, such as Re 3 al 3 o 12 (Re=Lu, Y, Tb and Gd), and they all emit light from a single active ion. The white LED synthesized by it also has problems such as low color rendering index and high color temperature due to the lack of red light components.

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