阅读说明：本技术 一种近红外荧光粉以及含该荧光粉的发光装置 (Near-infrared fluorescent powder and light-emitting device containing same ) 是由 刘荣辉 刘元红 陈晓霞 马小乐 高慰 陈明月 于 2018-11-30 设计创作，主要内容包括：本发明属于发光材料技术领域,尤其涉及一种近红外荧光粉,并进一步公开其制备方法,以及含该荧光粉的发光装置。本发明所述近红外荧光粉包括组成式为A<Sub>x</Sub>R<Sub>p</Sub>O<Sub>r</Sub>的无机化合物,该化合物以A<Sub>x</Sub>R<Sub>p</Sub>O<Sub>r</Sub>结构为基质,通过掺杂特定的稀土离子或过渡金属离子,制备的荧光粉的激发峰位于350-750nm,在紫外光、蓝光或红光激发下呈现宽带发射,发射主峰位于700-1600nm。通过离子取代等方式构筑固溶体,由于晶体场劈裂的影响,可制得不同发射波长的近红外荧光粉材料,不仅显著提升了荧光粉的发光强度,且实现了光谱的可调控性,进一步扩大其应用范围。(The invention belongs to the technical field of luminescent materials, and particularly relates to near-infrared fluorescent powder, and further discloses a preparation method thereof and a luminescent device containing the fluorescent powder. The near-infrared fluorescent powder comprises a composition formula A x R p O r The compound of (A) x R p O r The structure is a substrate, the excitation peak of the prepared fluorescent powder is positioned at 350-750nm by doping specific rare earth ions or transition metal ions, broadband emission is realized under the excitation of ultraviolet light, blue light or red light, and the emission main peak is positioned at 700-1600 nm. The solid solution is constructed by ion substitution and other modes, and near-infrared fluorescent powder materials with different emission wavelengths can be prepared due to the influence of crystal field splitting, so that the luminous intensity of the fluorescent powder is remarkably improved, and the spectrum can be adjustedControlling property and further expanding the application range.)

1. A near-infrared phosphor is characterized in that the phosphor comprises a compound represented by a chemical formula A_xR_pO_r:D_yThe inorganic compound of (1), wherein,

the element A is one or two of Sc, Y, La, Lu, Ga or Gd elements;

the R element comprises Ga element, and one of Al, B or In element can be selectively added;

the D element comprises a Cr element, and one of Ce, Eu, Tb, Bi, Dy, Yb, Pr, Nd or Er elements can be selectively added;

and the parameters x, p, r and y satisfy the following conditions: x is more than or equal to 0.8 and less than or equal to 1.2, p is more than or equal to 0.8 and less than or equal to 1.2, r is more than or equal to 2 and less than or equal to 4, and y is more than or equal to 0.0001 and less than or equal to 0.25.

2. The near-infrared phosphor of claim 1, wherein the a element and the R element are not Ga elements at the same time.

3. The near-infrared phosphor of claim 1 or 2, wherein the parameters x, p, r, and y satisfy the following condition: (x + y): p: r is 1: 1: 3.

4. the near-infrared phosphor of any one of claims 1 to 3, wherein a molar content ratio of Ga element in the R element is 30% or more.

5. A near-infrared phosphor as claimed in any one of claims 1 to 4, wherein said element A is Sc.

6. A near-infrared phosphor as claimed in any one of claims 1 to 5, wherein said D element is a Cr element.

7. A method for preparing the near-infrared phosphor of any one of claims 1 to 6, comprising the steps of:

(1) taking compounds corresponding to selected A, R and D elements as raw materials, and uniformly mixing according to a selected stoichiometric ratio; the resulting mixture;

(2) sintering the obtained mixture at the temperature of 1200-1500 ℃ in air or protective atmosphere for 2-10h to obtain a roasted product; and carrying out post-treatment of crushing, grinding, grading and screening and washing on the obtained roasted product to obtain the required near-infrared fluorescent powder.

8. The method of claim 7, wherein the A, R compound and the D element compound comprise an oxide, a carbonate and/or a nitrate.

9. A light-emitting device comprising a light source and a luminescent material, wherein the luminescent material comprises the near-infrared phosphor of any one of claims 1 to 6.

10. The light-emitting device according to claim 9, wherein the light source is a semiconductor chip having an emission peak wavelength range of 350-500 nm.

Technical Field

The invention belongs to the technical field of luminescent materials, and particularly relates to near-infrared fluorescent powder, and further discloses a preparation method thereof and a luminescent device containing the fluorescent powder.

Background

In recent years, with the rapid development of the application of the near infrared spectrum technology in the fields of face recognition, iris recognition, security monitoring, laser radar, health detection, 3D sensing and the like, the near infrared LED has become an international research focus due to a series of advantages of good directivity, low power consumption, small volume and the like.

At present, the main implementation mode of the near-infrared LED is a method adopting a near-infrared semiconductor chip, and the core technology of the near-infrared chip is monopolized abroad and has the problems of high cost, immature technology and the like. Therefore, the near-infrared LED of the blue-light chip composite near-infrared luminescent material is provided, and the realization mode of the composite package has the advantages of simple preparation process, low cost, high luminous efficiency and the like, and is widely concerned internationally. Therefore, the development of new near-infrared luminescent materials with different wave bands for infrared LEDs is urgent and the application demand for realizing the diversification thereof is urgent.

The near-infrared fluorescent powder with the peak wavelength of 780-1700nm can be used in food detection, face recognition, iris recognition, security monitoring, laser radar, health detection, 3D sensing and other fields, has the most extensive practical application value, and can meet the requirements of different applications. Since the perovskite-type composite oxide has a stable crystal structure, it can be partially substituted with other ions having similar radii while keeping the crystal structure substantially unchanged. Therefore, the perovskite system doped with rare earth ions and transition metal ions is taken as a research object, and a solid solution is constructed through ion substitution to prepare the wide-spectrum or multi-spectrum near-infrared fluorescent powder with the emission main peak in the range of 780-cozy 1700nm, so that the adjustability and controllability are realized; the crystal grains with good and controllable appearance are obtained by improving the reaction conditions, thereby reaching the application standard and having wider application prospect.

For example, Chinese patent CN107573937A discloses a structure such as MBO₃:Cr³⁺The borate fluorescent powder, wherein M is Sc, Al, Lu, Gd or Y element, can be effectively excited by blue light (420-520nm), and can emit near infrared light in the range of 700-920 nm. When M is Al, Lu, Gd, or Y, the emission spectrum is similar to that when M is Sc. In addition, the patent is mainly dedicated to the study of MBO₃:Cr³⁺The influence of the reaction temperature and the reaction time was examined for the preparation method of (1), but the spectral properties thereof were not examined.

And as non-patent document Photopharmaceuticals Properties of a ScBO₃:Cr³⁺Phosphorand Its Applications for Broadband Near-infrared LEDs》[J]RSC Adv,2018,8,12035-12042 discloses a near-infrared fluorescent powder ScBO₃:Cr³⁺The fluorescent powder shows near-infrared broadband emission with a main peak at 800nm under the excitation of a blue light chip, and the quantum efficiency is 65%. The near-infrared fluorescent powder and the blue light chip are used for packaging, the output power of near-infrared light is 26mW, and the energy conversion efficiency is only 7 percent.

As can be seen, the known near-infrared powder MBO developed in the prior art₃:Cr³⁺The emission main peak is mostly positioned around 800nm, the emission wavelength range is narrow, the luminous intensity is low, the emission wavelength has no controllability, and the application range and the application effect of the fluorescent powder are limited.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to provide a near-infrared phosphor, which has the advantages of broad-spectrum or multi-spectrum emission, adjustable spectrum and high luminous efficiency, and can meet the material performance requirements in the fields of facial recognition, iris recognition, security monitoring, laser radar, health detection, 3D sensing and the like.

The second technical problem to be solved by the present invention is to provide a light emitting device capable of realizing high-efficiency near-infrared light emission under excitation of blue light or red light, so as to solve the problems of poor stability and low light emitting efficiency of the existing near-infrared light emitting material and light emitting device.

In order to solve the technical problem, the near-infrared phosphor disclosed by the invention comprises a phosphor with a chemical formula A_xR_pO_r:D_yThe inorganic compound of (1), wherein,

the element A is one or two of Sc, Y, La, Lu or Gd elements;

the R element comprises Ga element, and one of Al, B or In element can be selectively added;

the D element comprises a Cr element, and one of Ce, Eu, Tb, Bi, Dy, Yb, Pr, Nd or Er elements can be selectively added;

and the parameters x, p, r and y satisfy the following conditions: x is more than or equal to 0.8 and less than or equal to 1.2, p is more than or equal to 0.8 and less than or equal to 1.2, r is more than or equal to 2 and less than or equal to 4, and y is more than or equal to 0.0001 and less than or equal to 0.25.

Preferably, the element A and the element R are not Ga at the same time.

Preferably, the parameters x, p, r and y satisfy the following conditions: (x + y): p: r is 1: 1: 3.

more preferably, in the R element, the molar content of Ga element in the R element is not less than 30%.

More preferably, the element A is Sc element.

More preferably, the D element is a Cr element.

The invention also discloses a method for preparing the near-infrared fluorescent powder, which comprises the following steps:

(1) taking compounds corresponding to selected A, R and D elements as raw materials, and uniformly mixing according to a selected stoichiometric ratio; the resulting mixture;

(2) sintering the obtained mixture at the temperature of 1200-1500 ℃ in air or protective atmosphere for 2-10h to obtain a roasted product; and carrying out post-treatment of crushing, grinding, grading and screening and washing on the obtained roasted product to obtain the required near-infrared fluorescent powder.

Further, the A, R and the compound corresponding to the element D comprise oxide, carbonate and/or nitrate.

The invention also discloses a light-emitting device which comprises a light source and a light-emitting material, wherein the light-emitting material comprises the near-infrared fluorescent powder.

The light source is a semiconductor chip with the emission peak wavelength range of 350-500 nm.

The near-infrared fluorescent powder comprises a composition formula A_xR_pO_rIn the perovskite type A_xR_pO_rThe structure is a substrate, the excitation peak of the prepared fluorescent powder is positioned at 350-750nm by doping selected rare earth ions or transition metal ions, broadband or multispectral emission is presented under the excitation of ultraviolet light, blue light or red light, and the emission main peak is positioned at 780-1600 nm. The solid solution is constructed by ion substitution and other modes, and near-infrared fluorescent powder materials with different emission wavelengths can be prepared due to the influence of crystal field splitting, so that the luminous intensity of the fluorescent powder is remarkably improved, the adjustability of a spectrum is realized, and the application range of the fluorescent powder is further expanded. The near-infrared fluorescent powder can promote the high-efficiency emission of doped ions in an energy transfer mode through ion co-doping, further improves the luminous intensity of the near-infrared fluorescent powder, and can achieve a better application effect.

The near-infrared luminescent material can be used for preparing a luminescent device, the luminescent device can emit broadband near-infrared light under the excitation of a blue light chip and an ultraviolet chip, and the adjustable and controllable effect of a spectrum can be realized by compounding various fluorescent powders. The light-emitting device can meet the requirements of various fields such as light effect communication, face iris recognition, security monitoring, anti-counterfeiting, laser radar, food detection, digital medical treatment, 3D sensing and the like; and the defects of high cost and poor stability of a light-emitting device directly using a near-infrared chip are avoided, and the method becomes a new way for generating near-infrared light.

Drawings

In order that the present disclosure may be more readily and clearly understood, the following detailed description of the present disclosure is provided in connection with specific embodiments thereof and the accompanying drawings, in which,

FIG. 1 is a graph of excitation and emission spectra of a phosphor sample prepared in comparative example 1 of the present invention, with a detection wavelength of 810nm for the left side curve and an excitation wavelength of 460nm for the right side curve;

FIG. 2 is a graph of the excitation and emission spectra of a phosphor sample prepared in example 1, with the detection wavelength of the left curve at 835nm and the excitation wavelength of the right curve at 460 nm.

Detailed Description

Comparative example

In the near-infrared phosphor of this embodiment, the composition formula of the compound contained in the near-infrared phosphor is Sc_0.98BO₃:Cr_0.02。

According to formula Sc_0.98BO₃:Cr_0.02The Sc is accurately weighed according to the stoichiometric ratio of₂O₃、H₃BO₃And Cr₂O₃Uniformly mixing to obtain a mixture; calcining the obtained mixture for 8h at 1300 ℃ in the air atmosphere, and cooling to obtain a calcined product; and carrying out post-treatment such as crushing, grinding, grading, screening and washing on the obtained roasted product to obtain a near-infrared luminescent material sample.

The obtained near-infrared luminescent material sample is subjected to excitation test, and the excitation and emission spectrograms of the obtained sample are shown in figure 1. As can be seen, the emission peak of the phosphor is at 810nm, and the relative luminous intensity is 100.