CN108384536A - Er3+/Yb3+Codope calcium aluminum fluoride green up conversion luminescent material and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of inorganic luminescent materials, and in particular relates to an Er ³⁺ /Yb ³⁺ co-doped calcium fluoroaluminate green up-conversion luminescent material excited by near-infrared light and a preparation method thereof. The present invention adopts high-temperature solid-phase method to prepare Er ³⁺ /Yb ³⁺ co-doped calcium fluoroaluminate, and mixes high-purity Er ₂ O ₃ , Yb ₂ O ₃ , Al ₂ O ₃ , CaF ₂ and CaCO ₃ raw materials in proportion After uniformity, sintering to obtain Er ³⁺ /Yb ³⁺ co-doped calcium fluoroaluminate luminescent material. The luminescent material emits green light at about 550 nanometers when excited by near-infrared light at 980 nanometers, and has a high up-conversion luminous efficiency; the luminescent material involved in the present invention has good stability, is environmentally friendly, and has low cost, and can be widely used in The field of three-dimensional display, biomolecular fluorescent labeling probe, optical fiber amplifier, etc.; the preparation method of the invention is easy to operate and industrialized production, and the production cost is low.

Description

Er3+/Yb3+ co-doped calcium fluoroaluminate green up-conversion luminescent material and preparation method thereof

technical field

The invention belongs to the technical field of inorganic luminescent materials, and specifically relates to a calcium fluoroaluminate green up-conversion luminescent material co-doped with Er ³⁺ /Yb ³⁺ and a preparation method thereof.

Background technique

The up-conversion luminescent material doped with rare earth ions converts near-infrared light invisible to human eyes into visible light that people can see. It has a large Stokes shift and is not disturbed by background light. It can be widely used in three-dimensional display and laser anti-counterfeiting , bioimaging, biodetection, drug carriers, and novel photodynamic therapy of cancer. At present, most high-efficiency upconversion luminescent materials use fluoride, sulfide, and halide substrates with low phonon energy, but these substrates have poor thermal stability, are prone to deliquescence, and are not resistant to radiation, and the preparation process is also complicated. Therefore, to a certain extent, the popularization and application of up-conversion luminescent materials in many special fields is limited.

Contents of the invention

Aiming at the problems existing in the prior art, the purpose of the present invention is to prepare a calcium fluoroaluminate green up-conversion luminescent material with good stability and capable of near-infrared light excitation. The luminescent material emits narrow-band green light under near-infrared light excitation. , can overcome the defect of poor thermal stability of fluoride, and is beneficial to expand the application field of up-conversion luminescent materials.

In the visible light range, Er ³⁺ ions have green light generated by ² H _11/2 / ⁴ S _3/2 → ⁴ I _15/2 transition (near 530nm and 550nm) and ⁴ F _9/2 → ⁴ I _15/2 The transition (near 660nm) produces two emission bands in red. By changing the doping concentration of Yb ³⁺ ions, the up-conversion emission intensity of green light and red light can be adjusted, and emission with different red-green ratios can be obtained.

The present invention uses calcium fluoroaluminate with a wide band gap as the doped matrix material. Because of its good chemical stability and temperature stability, and its large forbidden band width combined with the excellent stability of oxides and the low phonon energy of fluorides, it is very suitable as a matrix for luminescent materials.

The invention is prepared by a high-temperature solid phase method. The concrete steps of preparation method of the present invention are as follows:

(1) Weigh high-purity Er ₂ O ₃ , Yb ₂ O ₃ , Al ₂ O ₃ , CaF ₂ and CaCO ₃ raw materials respectively according to the stoichiometric ratio, place them in an agate mortar, grind them with absolute ethanol as a dispersant, Grinding is drying after the raw materials are fully mixed;

(2) Pre-burn the dried raw materials at 800-900°C for 1-3 hours, and then grind for 1-2 hours;

(3) Calcining the fully mixed raw materials at 1150-1300° C. for 6-10 hours in an air atmosphere;

(4) After grinding, the Er ³⁺ /Yb ³⁺ co-doped calcium fluoroaluminate upconversion luminescent material (Ca ₁₂ Al ₁₄ O ₃₂ F ₂ :Er,Yb) excited by near-infrared light is obtained

The beneficial effects of the present invention are:

1. The present invention adopts the traditional high-temperature solid-phase method, has a simple preparation process, can be produced on a large scale, and has a good market application prospect.

2. The excitation range of the Er ³⁺ /Yb ³⁺ co-doped calcium fluoroaluminate prepared in the present invention is mainly concentrated in the vicinity of 980 nanometers in the near-infrared range, and this wavelength has strong tissue penetration ability and no damage to biological tissues , No background fluorescence interference, these characteristics make it have great application potential in three-dimensional display, laser anti-counterfeiting, biological imaging, biological detection, drug carrier and new cancer photodynamic therapy.

3. The up-conversion luminescent material of the present invention has the following advantages:

(1) The up-conversion calcium fluoroaluminate luminescent material of the present invention can emit green light with a main peak at 550 nanometers under excitation at 980 nanometers, with high luminous purity and stable performance.

(2) The substrate of the up-conversion luminescent material of the present invention has good thermal stability and radiation resistance, which is beneficial to expand the application of the up-conversion luminescent material in special fields, such as the application in space and under high temperature conditions.

(3) The raw materials of the up-conversion luminescent material of the present invention are abundant in nature, cheap in price, low in production cost and pure in the phase of the prepared sample.

(4) The preparation process of the present invention is simple, the output is efficient, the repeatability is good, and no pollutants are discharged during the preparation process, and it is an environmentally friendly phosphorescent material

Description of drawings

Fig. 1 is the X-ray powder diffraction pattern of the sample Ca _11.98 Al ₁₄ O ₃₂ F ₂ :Er _0.002 /Yb _0.018 prepared in Example 1 of the present invention.

Fig. 2 is an up-conversion luminescence spectrum diagram obtained under the excitation of 980 nm near-infrared light for the prepared sample Ca _11.98 Al ₁₄ O ₃₂ F ₂ :Er _0.002 /Yb _0.018 in Example 1 of the present invention.

Detailed ways

According to the steps given in the summary of the invention, Er ³⁺ /Yb ³⁺ co-doped calcium fluoroaluminate green up-conversion luminescent materials with various doping concentrations can be obtained.

Example 1

(1) Weighing CaCO ₃ (99.99%) 1.1771g, Al ₂ O ₃ (99.99%) 0.71372g, CaF ₂ (99.99%) 0.07808g, Er ₂ O ₃ (99.99%) 0.00459g, Yb ₂ O ₃ ( 99.99%) 0.04256g, placed in a mortar, ground with ethanol as a dispersant, ground to make the raw materials fully mixed and then dried;

(2) pre-burning the dried raw materials at 850°C for 2 hours, and then grinding for 1 hour;

(3) calcining the fully mixed raw materials at 1200° C. for 10 hours in an air atmosphere;

(4) After grinding, the Er ³⁺ /Yb ³⁺ co-doped calcium fluoroaluminate upconversion luminescent material (Ca _11.98 Al ₁₄ O ₃₂ F ₂ :Er _0.002 /Yb _0.018 ) excited by near-infrared light is obtained

Example 2

(1) Weighing CaCO ₃ (99.99%) 1.1963g, Al ₂ O ₃ (99.99%) 0.71372g, CaF ₂ (99.99%) 0.07808g, Er ₂ O ₃ (99.99%) 0.00459g, Yb ₂ O ₃ ( 99.99%) 0.047g, placed in a mortar, ground with ethanol as a dispersant, ground to make the raw materials fully mixed and then dried;

(2) pre-burning the dried raw materials at 900°C for 2 hours, and then grinding for 1 hour;

(3) calcining the fully mixed raw materials at 1250° C. for 6 hours in an air atmosphere;

(4) After grinding, the Er ³⁺ /Yb ³⁺ co-doped calcium fluoroaluminate upconversion luminescent material (Ca _11.996 Al ₁₄ O ₃₂ F ₂ : Er _0.002 /Yb _0.002 ) excited by near-infrared light is obtained

Example 3

(1) Weighing CaCO ₃ (99.99%) 2.3494g, Al ₂ O ₃ (99.99%) 1.42744g, CaF ₂ (99.99%) 0.15616g, Er ₂ O ₃ (99.99%) 0.00918g, Yb ₂ O ₃ ( 99.99%) 0.0946g, placed in a mortar, and ground with ethanol as a dispersant, the grinding is drying after the raw materials are fully mixed;

(2) pre-burning the dried raw materials at 850°C for 2 hours, and then grinding for 1 hour;

(3) calcining the fully mixed raw materials at 1300° C. for 10 hours in an air atmosphere;

(4) After grinding, the Er ³⁺ /Yb ³⁺ co-doped calcium fluoroaluminate upconversion luminescent material (Ca _11.978 Al ₁₄ O ₃₂ F ₂ :Er _0.002 /Yb _0.02 ) excited by near-infrared light was obtained

Example 4

(1) Weighing CaCO ₃ (99.99%) 1.1867g, Al ₂ O ₃ (99.99%) 0.71372g, CaF ₂ (99.99%) 0.07808g, Er ₂ O ₃ (99.99%) 0.00459g, Yb ₂ O ₃ ( 99.99%) 0.0236g, placed in a mortar, and ground with ethanol as a dispersant, the grinding is drying after the raw materials are fully mixed;

(2) pre-burning the dried raw materials at 900°C for 2 hours, and then grinding for 1 hour;

(3) calcining the fully mixed raw materials at 1200° C. for 8 hours in an air atmosphere;

(4) After grinding, an Er ³⁺ /Yb ³⁺ co-doped calcium fluoroaluminate upconversion luminescent material (Ca _11.988 Al ₁₄ O ₃₂ F ₂ :Er _0.002 /Yb _0.010 ) excited by near-infrared light is obtained.

Claims (2)

1. Er ³⁺ /Yb ³⁺ co-doped calcium fluoroaluminate green upconversion luminescent material excited by near-infrared light, characterized in that: the chemical formula of the material is Ca _12-xy Al ₁₄ O ₃₂ F ₂ :Er _x / Yb _y , where x is the molar ratio of erbium ion doping, y is the molar ratio of ytterbium ion doping, 0.001≤x≤0.005, 0.01≤y≤0.05. 2. The preparation method of the Er3 ⁺ / ^Yb3+ co-doped calcium fluoroaluminate green up-conversion luminescent material excited by near-infrared light according to claim 1 can adopt a high-temperature solid-phase method, which is characterized in that, specifically comprising Follow the steps below: (1) According to the stoichiometric ratio of each element in the chemical formula Ca _12-xy Al ₁₄ O ₃₂ F ₂ :Er _x /Yb _y , weigh high-purity Er ₂ O ₃ , Yb ₂ O ₃ , Al ₂ O ₃ , CaF ₂ and CaCO ₃ raw materials, put them in an agate mortar, use absolute ethanol as a dispersant to grind, grind to make the raw materials fully mixed and then dry; (2) Pre-fire the dried raw materials for 1-2 times in air atmosphere, the sintering temperature is 800-900°C, the pre-sintering time is 1-3 hours, and after natural cooling, grind for 1-2 hours; (3) Calcining the fully mixed raw materials at 1150-1300°C for 6-10 hours in an air atmosphere; (4) After uniform grinding, the Er ³⁺ /Yb ³⁺ co-doped calcium fluoroaluminate green upconversion luminescent material (Ca ₁₂ Al ₁₄ O ₃₂ F ₂ :Er/Yb) excited by near-infrared light was obtained.