CN110330968B - Up-conversion luminescent material, preparation method and application thereof - Google Patents

Abstract

The present invention relates to the technical field of semiconductor materials, in particular to an up-conversion luminescent material and a preparation method and application thereof. The invention discloses a preparation method of an up-conversion luminescent material, comprising the following steps: dissolving a calcium-containing compound, an aluminum-containing compound, a first rare earth element-containing compound and a second rare earth element-containing compound in a reaction solvent, and performing a solvothermal reaction Then, calcination is performed to obtain an up-conversion luminescent material. The first rare earth element in the compound containing the first rare earth element is ytterbium or gadolinium; the second rare earth element in the compound containing the second rare earth element is thulium, erbium or holmium. In the present invention, the preparation method of the above-mentioned up-conversion light-emitting material is simple, and the up-conversion light-emitting material prepared by the solvothermal method is small in size, porous and large in specific surface area.

Description

Up-conversion luminescent material, preparation method and application thereof

technical field

The present invention relates to the technical field of semiconductor materials, in particular to an up-conversion luminescent material and a preparation method and application thereof.

Background technique

A solar cell is a semiconductor thin-film device that converts green and renewable sunlight energy into electrical energy using the photoelectric effect. It has the advantages of permanence, cleanliness, and flexibility. However, due to the limitation of the properties of semiconductor materials, solar cells can only absorb visible light, and near-infrared light cannot be absorbed and utilized, thus limiting their photoelectric conversion efficiency. Therefore, broadening the absorbable spectral range to improve the efficiency of solar cells has great theoretical research significance and practical value.

Upconversion luminescent material is a material that can convert long-wavelength near-infrared light into short-wavelength visible light. It is composed of rare earth ions and a host material. When it is applied in solar cells, it can effectively broaden the spectral response range of the cell. .

At present, the preparation of upconversion luminescent materials mostly adopts high-temperature solid-phase method and hydrothermal method, but the upconversion luminescent materials prepared by these methods are not shaped, and the size is large (2-4μm), so that the material cannot be used in solar cells; The pores are small, so that the specific surface area of the material is small, resulting in low photoelectric conversion efficiency of the up-conversion luminescent material.

SUMMARY OF THE INVENTION

The present invention provides an up-conversion luminescent material, a preparation method and application thereof, and solves the problems that the up-conversion luminescent material prepared from the current up-conversion luminescent material is not shaped, has a large size and has few pores.

Its specific technical solutions are as follows:

The present invention provides a method for preparing an up-conversion luminescent material, comprising the following steps:

Dissolving the calcium-containing compound, the aluminum-containing compound, the first rare-earth element-containing compound and the second rare-earth element-containing compound in a reaction solvent, performing a solvothermal reaction and then calcining to obtain an up-conversion luminescent material;

The first rare earth element in the first rare earth element-containing compound is ytterbium or gadolinium, more preferably ytterbium;

The second rare earth element in the second rare earth element-containing compound is thulium, erbium or holmium, more preferably thulium.

In the present invention, the molecular formula of the up-conversion luminescent material is C12A7:Re ₁ /Re ₂ , wherein Re ₁ is the first rare earth element and Re ₂ is the second rare earth element, preferably C12A7:Yb ³⁺ /Tm ³⁺ . Among them, dodecacalcium heptaaluminate (12CaO·7Al ₂ O ₃ , C12A7) has the characteristics of unique cage structure, large forbidden band width, good chemical stability, thermal stability, and excellent light transmittance. .

In the present invention, since calcium hydroxide and aluminum hydroxide are slightly soluble in water, the turbid liquid is formed after adding the reaction solvent. Therefore, before the solvothermal reaction, it also includes: ball milling, and the purpose of ball milling is to make the reactant particles become small; the ball milling time is 8-10h, preferably 8h; after the solvothermal reaction, before the calcination, it also includes: after cooling to room temperature, filtering, and drying at 90°C overnight; the calcination is completed The method further includes: grinding into powder after cooling to room temperature to obtain a powdery up-conversion luminescent material.

In the present invention, the preparation method of the above-mentioned up-conversion light-emitting material is simple, and the up-conversion light-emitting material prepared by the solvothermal method has a small particle size (400 nm-1 μm), is porous, and has a large specific surface area.

Preferably, the calcium-containing compound is calcium hydroxide;

The aluminum-containing compound is aluminum hydroxide;

The contained first rare earth element compound is ytterbium nitrate pentahydrate, ytterbium acetate tetrahydrate, ytterbium fluoride or ytterbium sulfate octahydrate, more preferably ytterbium nitrate pentahydrate;

The compound containing the second rare earth element is thulium nitrate pentahydrate, erbium nitrate pentahydrate or holmium nitrate pentahydrate, more preferably thulium nitrate pentahydrate.

Preferably, the reaction solvent is absolute ethanol and deionized water; the volume ratio of the absolute ethanol to the deionized water is 1:0-1:8, more preferably 1:1-1:8, More preferably, it is 1:8.

In the present invention, the size of the up-conversion luminescent material is controlled by adjusting the volume ratio of absolute ethanol to absolute ethanol in the reaction solvent.

Preferably, the molar ratio of the calcium element in the calcium-containing compound, the aluminum element in the aluminum-containing compound, and the first rare earth element to the second rare earth element is 12:14:(0.264-1.344):(0.024 ~0.132), more preferably 12:14:(0.806~1.344):(0.054~0.132), still more preferably 12:14:0.806:0.054.

Preferably, the temperature of the solvothermal reaction is 150-200°C, and the time is 6-24h, more preferably 180°C, 12h.

Preferably, the calcination temperature is 800-1200°C, and the time is 5h-10h, more preferably 800°C, 5h.

In the present invention, the higher the calcination temperature, the larger the particle size of C12A7, the easier to agglomerate, and the irregular shape, but the higher the calcination temperature, the greater the up-conversion luminescence intensity; the lower the calcination temperature, the more regular the shape, but the up-conversion luminescence intensity the weaker.

The present invention also provides the up-conversion luminescent material prepared by the above preparation method. The up-conversion luminescent material has a small pore size and is porous, so the specific surface area is large and the morphology is regular.

The present invention also provides the application of the above-mentioned up-conversion luminescent material in solar cells.

The present invention also provides a perovskite solar cell, comprising electrodes, a hole transport layer, a light absorption layer, an active layer, an electron transport layer and a substrate that are stacked in sequence;

The light absorption layer is the above-mentioned up-conversion light-emitting material.

The up-conversion light-emitting material of the present invention is applied in a perovskite solar cell, and can improve the photoelectric conversion efficiency.

As can be seen from the above technical solutions, the present invention has the following advantages:

The present invention provides a method for preparing an up-conversion luminescent material, comprising the following steps: dissolving a calcium-containing compound, an aluminum-containing compound, a first rare earth element-containing compound and a second rare earth element-containing compound in a reaction solvent, and performing a solvothermal reaction Then, calcination is performed to obtain an up-conversion luminescent material. The first rare earth element in the compound containing the first rare earth element is ytterbium or gadolinium; the second rare earth element in the compound containing the second rare earth element is thulium, erbium or holmium.

In the present invention, the preparation method of the above-mentioned up-conversion light-emitting material is simple, and the up-conversion light-emitting material prepared by the solvothermal method has a small pore size and is porous, so that the specific surface area is large and the morphology is regular.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

Fig. 1 is the XRD pattern of C12A7:Yb ³⁺ /Tm ³⁺ provided by Example 1 of the present invention;

Fig. 2 is the luminescence spectrum of C12A7:Yb ³⁺ /Tm ³⁺ provided by Example 1 of the present invention;

Fig. 3 is the SEM spectrum of C12A7:Yb ³⁺ /Tm ³⁺ provided by Example 5 of the present invention;

Fig. 4 is the SEM spectrum of C12A7:Yb ³⁺ /Tm ³⁺ provided in Example 6 of the present invention.

Detailed ways

The embodiments of the present invention provide an up-conversion luminescent material and a preparation method and application thereof, which are used to solve the problems that the up-conversion luminescent material prepared from the current up-conversion luminescent material is not shaped, has a large size, and has few pores.

In order to make the purpose, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the embodiments described below are only a part of the implementation of the present invention. examples, but not all examples. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

This embodiment is the preparation of the up-conversion luminescent material C12A7:Yb ³⁺ /Tm ³⁺ , and the specific preparation steps are as follows:

Step 1: Weigh 1.8782 g of calcium hydroxide, 2.3068 g of aluminum hydroxide, 0.0505 g of thulium nitrate pentahydrate and 0.7645 g of ytterbium nitrate pentahydrate, add 80 ml of solvent (absolute ethanol), and perform ball milling for 8 hours to obtain a mixed solution;

Step 2: Move the ball-milled mixed solution to the reaction kettle and keep it at 150°C for 6 hours;

Step 3: After cooling to room temperature, filter and dry at 90°C for 12 hours;

Step 4: calcining in a muffle furnace at 1200°C for 5h.

Step 5: After cooling to room temperature, grinding to obtain a powdery up-conversion luminescent material C12A7:Yb ³⁺ /Tm ³⁺ .

The C12A7:Yb ³⁺ /Tm ³⁺ prepared in this example is agglomerated and in a foam shape.

As shown in FIG. 1 , the up-conversion luminescent material prepared in this example corresponds to the standard card of C12A7 and is confirmed to be C12A7.

At the excitation wavelength of 980nm, the emission spectrum of the obtained upconversion luminescent material C12A7:Yb ³⁺ /Tm ³⁺ was studied. As shown in FIG. 2 , C12A7:Yb ³⁺ /Tm ³⁺ can perform up-conversion luminescence.

Example 2

This embodiment is the preparation of the up-conversion luminescent material C12A7:Yb ³⁺ /Tm ³⁺ . The difference between this embodiment and Embodiment 1 is only that the ball milling time of step 1 in this embodiment is 10h.

Example 3

This example is the preparation of the up-conversion luminescent material C12A7:Yb ³⁺ /Tm ³⁺ . The difference between this example and Example 1 is only that the reaction temperature in step 2 of this example is 180° C. and the time is 12h.

Example 4

This embodiment is the preparation of the up-conversion luminescent material C12A7:Yb ³⁺ /Tm ³⁺ . The difference between this embodiment and Embodiment 1 is only that the calcination temperature of step 1 of this embodiment is 800°C.

The morphology of C12A7:Yb ³⁺ /Tm ³⁺ prepared in this example is in the shape of a porous square.

When the excitation wavelength is 980 nm, the emission spectrum of the up-conversion luminescent material C12A7:Yb ³⁺ /Tm ³⁺ in this example is consistent with that of Example 1.

Example 5

This embodiment is the preparation of the up-conversion luminescent material C12A7:Yb ³⁺ /Tm ³⁺ . The difference between this embodiment and Embodiment 1 is only that the solvent in step 1 of this embodiment is anhydrous ethanol with a volume ratio of 1:1 and dehydration Ionized water, the calcination temperature in step 4 is 800°C, and the time is 5h.

Fig. 3 is the SEM spectrum of C12A7:Yb ³⁺ /Tm ³⁺ of the present embodiment. As shown in FIG. 3 , the up-conversion luminescent material has a square shape and is porous, but the size (side length) is relatively large, and the size is about 2 μm.

Example 6

This example is for the preparation of the up-conversion luminescent material C12A7:Yb ³⁺ /Tm ³⁺ . The difference between this example and Example 1 is that the volume ratio of the solvent in step 1 of this example is 1:8 absolute ethanol and deionized water. Water, the holding condition in step two is 180°C for 12h, and the calcination temperature in step four is 800°C.

As shown in FIG. 4 , the up-conversion luminescent material prepared in this example is in the shape of a square, is porous, and has a small size, with a size of about 400 nm.

Figures 3 and 4 illustrate that the size of C12A7 is significantly reduced after changing the solvent ratio.

As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand: The technical solutions described in the embodiments are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (3)

1. The perovskite solar cell is characterized by comprising an electrode, a hole transport layer, a light absorption layer, an active layer, an electron transport layer and a substrate which are sequentially stacked;

the light absorption layer is an up-conversion luminescent material;

the preparation method of the up-conversion luminescent material comprises the following steps:

dissolving a calcium-containing compound, an aluminum-containing compound, a first rare earth element-containing compound and a second rare earth element-containing compound in a reaction solvent, carrying out solvothermal reaction, and then calcining to obtain an up-conversion luminescent material;

the first rare earth element in the compound containing the first rare earth element is ytterbium or gadolinium;

the second rare earth element in the compound containing the second rare earth element is thulium, erbium or holmium;

the reaction solvent is absolute ethyl alcohol and deionized water; the volume ratio of the absolute ethyl alcohol to the deionized water is 1: 8;

the temperature of the solvothermal reaction is 180 ℃, and the time is 12 h;

the calcining temperature is 800 ℃ and the calcining time is 5 h.

2. The perovskite solar cell according to claim 1, wherein the calcium-containing compound is calcium hydroxide;

the aluminum-containing compound is aluminum hydroxide;

the first rare earth element compound is ytterbium nitrate pentahydrate, ytterbium acetate tetrahydrate, ytterbium fluoride or ytterbium sulfate octahydrate;

The second rare earth element-containing compound is thulium nitrate pentahydrate, erbium nitrate pentahydrate or holmium nitrate pentahydrate.

3. The perovskite solar cell of claim 1, wherein the molar ratio of the calcium element in the calcium-containing compound, the aluminum element in the aluminum-containing compound, and the first rare earth element to the second rare earth element is 12: 14: (0.264-1.344): (0.024-0.132).

Images