Nitrogenous light-emitting particle, nitrogenous light-emitting particle preparation method, nitrogenous light emitter and light emitting device

Abstract

The invention relates to a nitrogenous light-emitting particle. The nitrogenous light-emitting particle is characterized by structurally comprises an oxygen-deficient region, a transition region and an oxygen-rich region sequentially from the core of the particle to the outer surface along with progressive oxygen content increase. The oxygen-deficient region mainly comprises nitride light-emitting crystal or oxygenous solid solution thereof, the transition region mainly comprises an oxynitride material, and the oxygen-rich region mainly comprises an oxide material or an oxynitride material. The nitride light-emitting crystal or oxygenous solid solution thereof refers to Mm-m1Aa1Bb1Oo1Nn1:Rm1, the oxynitride material refers to Mm-m2Aa2Bb2Oo2Nn2:Rm2, and the oxide material or the oxynitride material refers to Mm-m3Aa3Bb3Oo3Nn3:Rm3. The nitrogenous light-emitting particle and a nitrogenous light emitter are high in chemical stability, excellent in resistance to aging and light attenuation and high in light emitting efficiency and are applicable to various light emitting devices. The preparation method is simple, convenient and reliable and is suitable for industrial batch production.

Description

technical field [0001] The invention belongs to the technical field of LED phosphors and light-emitting devices, and in particular relates to a nitrogen-containing luminescent particle that can be effectively excited by ultraviolet light, purple light or blue light, a preparation method thereof, a nitrogen-containing luminescent body and a light-emitting device. Background technique [0002] Today's semiconductor lighting electric light source represented by light-emitting diode (LED) is known as the fourth generation of lighting electric light source after incandescent lamps, fluorescent lamps and energy-saving lamps, and is called "21st century green light source". [0003] As semiconductor lighting enters the field of general lighting, it is imminent to accelerate the development of white LEDs with high color rendering, anti-aging and low light decay. The existing methods for manufacturing white LEDs mainly include: first, coating yellow phosphor (YAG) on the blue LED chi...

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Problems solved by technology

The existing methods for manufacturing white LEDs mainly include: first, coating yellow phosphor (YAG) on the blue LED chip to realize white light emission, but YAG phosphor has the disadvantages of high coloring temperature and low color rendering index, which cannot satisfy Requirements for semiconductor lighting; although the emission spectrum of YAG phosphor is very wide, the emission intensity in the red light region is very weak, resulting in the lack of red light after mixing with blue LED chips, thus affecting the correlated color temperature and color rendering of white LEDs index

The second is to apply green and red phosphors on the blue LED chips to solve the above problems, but red phosphors also have many problems, such as CaS:Eu 2+ Large light attenuation, poor chemical stability, CaMoO 4 :Eu 2+ Narrow excitation range, Y 2 o 3 :Eu 3+ and Y 2 o 2 S:Eu 3+ Weak absorption in the blue light region and low energy conversion efficiency, M 2 Si 5 N 8 :Eu 2+ The anti-light decay performance is poor, and it cannot be perfectly matched with the LED chip. These are the bottlenecks that restrict the development of white LED technology.

The third is to quote CaAlSiN 3 Although the overall performance of nitride phosphors with a crystal structure is better than that of the aforementioned YAG phosphors and ordinary red phosphors, there are still the following obvious deficiencies: ①Due to the influence of component diffusion, nucleation and preferred growth orientation during the synthesis of phosphors The internal law of the primary grain size has not been fully studied, resulting in low luminous efficiency of phosphors, so the luminous efficiency needs to be further improved; ② Phosphors will deteriorate under the combined effects of high optical density, high temperature and high humidity. It directly leads to the decline of the overall lighting effect, especially the large drift of the color coordinates, so the durability of the phosphor cannot fully meet the requirements of general lighting.

However, there are still obvious deficiencies in this method, because (Sr,Ca)AlSiN is prepared by the alloy method. 3 Red phosphor emphasizes on controlling the lower oxygen content to achieve higher consistency and phase purity, which significantly reduces the durability of the phosphor and poor practicability, which limits its application

[0006] "Reduced thermal degradation of othered-emitting Sr" published by Journal of Materials Chemistry C in 2015 2 Si 5 N 8 :Eu 2+ Phosphorviathermaltreatmentinnitrogen", for Sr 2 Si 5 N 8 :Eu 2+ The thermal degradation mechanism of the phosphor was studied, and it was believed that a layer of oxide protective film was formed on the surface of the phosphor by baking, which prevented the Eu 2+ Oxidation of , improves the thermal deterioration performance, and it is speculated that it can improve the Sr 2 Si 5 N 8 :Eu 2+ The application performance in LED, but there is no support from experimental data, and it has not fundamentally solved the problem of Sr 2 Si 5 N 8 :Eu 2+ long-term aging problems

In fact, in this system, due to the Sr 2 Si 5 N 8 :Eu 2+ The stability itself is poor, and the surface crystal structure is destroyed during the firing process, resulting in a significant decrease in the luminous intensity of the phosphor, so it has no practical application value

[0007] To sum up, there are contradictions in the existing technology in solving the problem of anti-aging and light decay of nitride phosphors and improving the luminous efficiency of phosphors. The basic rule is to improve the anti-aging and light decay of phosphors at the cost of reducing the luminous efficiency of phosphors. performance, or at the expense of reducing the anti-aging and light-fading performance of phosphors to improve the luminous efficiency of phosphors. At present, there is no comprehensive solution that can neither reduce the luminous efficiency of phosphors but also improve the anti-aging and light-fading performance of phosphors.

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