Warm-white high-color-rendering-index fluorescent ceramic for high-power LED/LD illumination, as well as preparation method and application thereof

Abstract

The invention discloses a warm-white high-color-rendering-index fluorescent ceramic for high-power LED / LD illumination, as well as a preparation method and application thereof. The fluorescent ceramichas a chemical formula of (Gd(1-x-z)LuxCez)3(Al(1-y)Gay)5O12:zCe<3+>, wherein x is the molar percentage of crystal structure stable ion Lu<3+> doped Gd<3+>, y is the molar percentage of crystal structure stable ion Ga<3+> doped Al<3+>, z is the molar percentage of Ce<3+> doped Gd<3+>, x is more than or equal to 0.05 and less than or equal to 0.15, y is more than or equal to 0.15 and less than orequal to 0.2, and z is more than or equal to 0.001 and less than or equal to 0.01; and a ceramic biscuit is molded and sintered by adopting tape casting and high-temperature solid phase reaction sintering. The transparent fluorescent ceramic material has an emission spectrum main peak of 575-580nm and half-width of 140-145nm, and realizes warm-white emission under excitation of high-power LED (350-500mA) or LD (4-10W), and has a color temperature of 2800-3000K and a color rendering index of 80-84; and the preparation process is simple, and the process is controllable.

Description

technical field [0001] The invention relates to the field of transparent fluorescent ceramic materials, in particular to a warm white high CRI fluorescent ceramic for high-power LED / LD lighting and its preparation method and application. Background technique [0002] As the fourth-generation lighting source, white LED / LD has the advantages of energy saving, environmental protection, long life and quick response. It has been applied in urban landscape lights, indoor and outdoor lighting, car lights, flat panel display backlight and other fields. At present, the packaging scheme of commercial white LED lamps is to mix more than one kind of phosphor with epoxy resin or silica gel and then coat them on the InGaN / GaN-based blue light chip. The blue light emitted by the InGaN / GaN-LED chip and the de-excited fluorescence The powder produces light of other colors which mixes to form white light. However, there are some problems in this packaging method: organic packaging materials ...

AI Technical Summary

Problems solved by technology

However, there are some problems in this packaging method: organic packaging materials have poor heat dissipation performance and heat accumulation effect, and organic materials are easy to age and deteriorate at high temperatures, resulting in light decay and color drift, which greatly reduces the service life of white LEDs.

For example, by co-doping Gd 3+ Can make Ce 3+ The luminous peak position of the ion produces a red shift, but the moving range is very limited, and the effect of improving the color temperature is not obvious

co-doped Cr 3+ 、Pr 3+ and other elements can directly complement the emission peaks in the red band, but Ce 3+ with Cr 3+ 、 Pr 3+ Energy transfer between ions will lead to Ce 3+ The luminous efficiency is significantly reduced, and the induced quenching temperature is greatly reduced

[0004] At present, the Chinese patent CN108264899 A discloses a multi-element doped transparent ceramic used for LED lighting instead of fluorescent powder, which emits white light after being excited by a blue LED chip. However, the afterglow time of this ceramic is long, which greatly limits the Its luminous efficiency makes the light loss of the device serious

Chinese patent CN 108018040 A discloses a fluorescent ceramic material with low color temperature, but its doping elements in octahedral and tetrahedral sites are limited to Mg, Ti, Si, Ge, which does not solve the problem of ceramic transparency, and there is a large amount of interface scattering , will greatly reduce the light conversion efficiency

However, in the process of preparing Ce:GAG, a GdAlO with a gadolinium-aluminum perovskite structure will be produced 3 compounds, seriously affect the optical quality of ceramics, mainly due to the Gd 3+ The introduction of the dodecahedron in the garnet produces severe distortion, which leads to the instability of the crystal structure of GAG

Images