CN103224790B - Material for conversion of ultraviolet light and emission of near-infrared light and its preparation method and use - Google Patents

Abstract

The invention discloses a material for converting ultraviolet light and emitting near-infrared light, a preparation method and an application. Its general chemical formula is MR _2-2x Yb _2x (MoO ₄ ) ₄ , where R is Er ³⁺ , Eu ³⁺ , La ³⁺ , Y ³⁺ , Ce ³⁺ , Tm ³⁺ , Pr ³⁺ , Nd One or more of ³⁺ , Sm ³⁺ , Gd ³⁺ , Tb ³⁺ , Dy ³⁺ , Ho ³⁺ and Lu ³⁺ ; M is one of Ca ²⁺ , Sr ²⁺ and Ba ²⁺ One or more; x is the mole percentage of Yb ³⁺ doping, 0.0001≤x≤1.0. The invention adopts a high-temperature solid-phase method or a chemical synthesis method, and the prepared material emits near-infrared light of 950nm to 1100nm under the excitation of ultraviolet light of 250nm to 400nm, and can be used as a light conversion material for silicon-based solar cells to improve the photoelectric conversion of the battery efficiency and performance stability.

Description

Material, preparation method and application of ultraviolet light conversion and near-infrared light emission

technical field

The invention relates to a preparation method and application of a luminescent material, in particular to a preparation method and application of a material capable of converting ultraviolet light to emit near-infrared light, and belongs to the field of luminescent materials in luminescence physics.

Background technique

Since the beginning of the 21st century, non-renewable energy resources have become increasingly depleted and more difficult to exploit, and the harm to the environment caused by the mining process has become increasingly prominent. Pollution-free and clean renewable energy has attracted much attention, objectively making solar energy the focus of development and utilization, among which the most dynamic is the research field of solar cells.

A solar cell is a device that converts sunlight energy directly into electrical energy due to the photovoltaic effect. It is a semiconductor photodiode. When the sun shines on the photodiode, the photodiode will convert the sun's light energy into electrical energy, generating current. Among them, silicon is the most commonly used semiconductor material and plays an absolute leading role in the photovoltaic industry. However, the forbidden band width of crystalline silicon is about 1.12eV, and the effective response spectrum of silicon solar cells to incident light ranges from 400 to 1100nm, which does not exactly match the spectral distribution of sunlight, resulting in short Ultraviolet and blue-green light with wavelengths are difficult to be absorbed by solar cells. This spectral mismatch phenomenon will lead to a great loss of sunlight energy. Therefore, a new type of luminescent material that can adjust the solar spectrum is developed to improve the photoelectric conversion efficiency of crystalline silicon solar cells. It is one of the focal issues of widespread concern at present.

Down-conversion luminescence refers to the phenomenon of absorbing one high-energy photon of ultraviolet light and emitting two or more low-energy photons. It can convert the short-wavelength light in sunlight into long-wavelength light, which can greatly eliminate the phenomenon of spectral mismatch, improve the utilization rate of sunlight, and indirectly improve the photoelectric conversion efficiency of monocrystalline silicon solar cells. Because the infrared emission of Yb ³⁺ ions is located at 1000nm, which is very matched with the forbidden band width of single crystal silicon, it is often used as dopant ions for down-conversion materials. However, Yb ³⁺ ions have relatively weak absorption in the ultraviolet to visible region, or almost no absorption. At present, the most studied method is to sensitize by co-doping trivalent rare earth ions (such as: Tb ³⁺ , Pr ³⁺ , Er ³⁺ , etc.) agent to improve its absorption in the ultraviolet to visible region, thereby increasing the utilization rate of solar energy. P. Vergeer et al. reported in Phys. Rev. B, 71 (2005): Co-doping rare earth Tb ³⁺ /Yb ³⁺ ion pairs in oxide powders realized quantum tailoring emission from visible light to near-infrared light; Li Kaiyu reported in Luminescence Journal, 5 (2012): Pr ³⁺ , Yb ³⁺ co-doped YPO ₄ powder was successfully prepared, and the down-converted near-infrared luminescence under 450nm light excitation was realized.

However, although these sensitizing ions have absorption in the ultraviolet to visible region, their absorption is linear and the absorption intensity is relatively weak. However, the light conversion material prepared by the present invention transfers energy to doped rare earth ions through inter-band absorption transfer while utilizing Yb ³⁺ ion emission, so that broadband absorption can be realized, which not only improves its absorption in the ultraviolet to visible light region , and at the same time weaken the thermal effect of silicon-based solar cells, which is expected to be applied in improving the conversion efficiency of crystalline silicon solar cells.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies in the prior art, and provide a light conversion material for silicon-based solar cells that realizes the conversion of ultraviolet light and emits near-infrared light.

Another object of the present invention is to provide a preparation method of the above-mentioned ultraviolet light conversion and emission near-infrared light material, the preparation process is simple and the production cost is low.

In order to achieve the above object, the technical solution adopted in the present invention is: provide a kind of material that converts ultraviolet light and emits near-infrared light, and it emits near-infrared light of 950nm～1100nm under the excitation of ultraviolet light of 250nm～400nm; The general chemical formula is MR _2-2x Yb _2x (MoO ₄ ) ₄ , where R is Er ³⁺ , Eu ³⁺ , La ³⁺ , Y ³⁺ , and Ce ³⁺ , thulium ion Tm ³⁺ , praseodymium ion Pr ³⁺ , neodymium ion Nd ³⁺ , samarium ion Sm ³⁺ , gadolinium ion Gd ³⁺ , terbium ion Tb ³⁺ , dysprosium ion Dy ³⁺ , holmium ion Ho ³⁺ , lutetium One of the ions Lu ³⁺ or any combination thereof; M is one of the alkaline earth metal ions Ca ²⁺ , strontium ions Sr ²⁺ , barium ions Ba ²⁺ or any combination thereof; x is Yb ^{3 +} Mole percent of doping, 0.0001≤x≤1.0.

The preparation method of the above-mentioned material for converting ultraviolet light and emitting near-infrared light adopts a high-temperature solid-phase method, and includes the following steps:

1. According to the stoichiometric ratio of each element in the chemical formula MR _2-2x Yb _2x (MoO ₄ ) ₄ , where 0.0001≤x≤1.0, weigh the compound containing ytterbium ion Yb ³⁺ , the compound containing ion R , and the compound containing ion R Compounds of M and compounds containing molybdenum ions Mo ⁶⁺ are ground and mixed uniformly to obtain a mixture; the ions R are rare earth erbium ions Er ³⁺ , europium ions Eu ³⁺ , lanthanum ions La ³⁺ , and yttrium ions Y ^{3 +} , cerium ions Ce ³⁺ , thulium ions Tm ³⁺ , praseodymium ions Pr ³⁺ , neodymium ions Nd ³⁺ , samarium ions Sm ³⁺ , gadolinium ions Gd ³⁺ , terbium ions Tb ³⁺ , dysprosium ions Dy ³⁺ , One of holmium ion Ho ³⁺ , lutetium ion Lu ³⁺ or any combination thereof; the ion M is one of alkaline earth metal ion calcium ion Ca ²⁺ , strontium ion Sr ²⁺ , barium ion Ba ²⁺ species or any combination of them;

2. Calcining the mixture obtained in step 1 in an air atmosphere for 1-2 times; the calcination temperature is 200-600° C., and the calcination time is 1-12 hours;

3. Naturally cool the mixture obtained in step 2, grind and mix evenly, and then calcinate in the air atmosphere, the calcining temperature is 600-850°C, and the calcining time is 1-12 hours;

4. Naturally cool the mixture obtained in step 3, grind and mix evenly, and then calcinate in air atmosphere, the calcining temperature is 850-1000°C, the calcining time is 1-12 hours, and naturally cool to room temperature to obtain an ultraviolet light conversion Materials that emit near-infrared light.

A preferred solution for the above-mentioned high-temperature solid-phase method to prepare the material for converting ultraviolet light into near-infrared light is as follows: the calcination temperature in step 2 is 250-550° C., and the calcination time is 2-10 hours. The calcination temperature in step 3 is 650-800° C., and the calcination time is 2-10 hours. The calcination temperature in step 4 is 850-950° C., and the calcination time is 2-10 hours.

The preparation method of a material that converts ultraviolet light and emits near-infrared light described in the technical solution of the present invention also includes the use of a chemical synthesis method, specifically as follows:

1. According to the stoichiometric ratio of each element in the chemical formula MR _2-2x Yb _2x (MoO ₄ ) ₄ , where 0.0001≤x≤1.0, weigh the compound containing ytterbium ion Yb ³⁺ , the compound containing ion R, and the compound containing ion M Compounds are dissolved in dilute nitric acid solution to obtain various transparent solutions; complexing agent citric acid or oxalic acid is added according to 0.5-2.0wt% of the mass of each reactant, and stirred at a temperature of 50-100°C ; The ion R is rare earth erbium ion Er ³⁺ , europium ion Eu ³⁺ , lanthanum ion La ³⁺ , yttrium ion Y ³⁺ , cerium ion Ce ³⁺ , thulium ion Tm ³⁺ , praseodymium ion Pr ³⁺ , One of neodymium ions Nd ³⁺ , samarium ions Sm ³⁺ , gadolinium ions Gd ³⁺ , terbium ions Tb ³⁺ , dysprosium ions Dy ³⁺ , holmium ions Ho ³⁺ , lutetium ions Lu ³⁺ , or any combination thereof The ion M is one of alkaline earth metal ion calcium ion Ca ²⁺ , strontium ion Sr ²⁺ , barium ion Ba ²⁺ or any combination thereof; respectively weigh the compound containing ytterbium ion Yb ³⁺ , containing Compounds of rare earth ions R, compounds containing alkaline earth metal ions M;

2. According to the stoichiometric ratio of each element in the chemical formula MR _2-2x Yb _2x (MoO ₄ ) ₄ , where 0.0001≤x≤1.0, weigh the compound containing molybdenum ion Mo ⁶⁺ and dissolve it in deionized water or ethanol solution , add complexing agent citric acid or oxalic acid according to 0.5～2.0wt% of reactant mass, stir under the temperature condition of 50～100 ℃;

3. Slowly mix the various solutions obtained in steps 1 and 2, stir at a temperature of 50-100°C for 1-2 hours, let stand, and dry to obtain a fluffy precursor;

4. The precursor is calcined in a muffle furnace at a temperature of 850-1000° C. for 1-15 hours, and naturally cooled to room temperature to obtain a material that realizes ultraviolet light conversion and emits near-infrared light.

The compound containing ion R described in the present invention is one or any combination of oxides, fluorides, and nitrates of R; the compound containing ytterbium ion Yb ³⁺ is ytterbium oxide, ytterbium fluoride, and ytterbium nitrate One or any combination of them; the compound containing ion M is one of the oxides, fluorides, carbonates, sulfates, nitrates of M or any combination of them; the compound containing molybdenum ion Mo ⁶⁺ It is one of molybdenum oxide and ammonium molybdate or any combination thereof.

The technical solution of the present invention provides an application of a material for converting ultraviolet light and emitting near-infrared light, which is used as a light conversion material for silicon-based solar cells.

Compared with the prior art, the present invention has the following beneficial effects:

1. The material for ultraviolet light conversion and near-infrared light emission of the present invention has a main emission peak at 960nm to 1100nm, and its energy perfectly matches the forbidden band width of silicon, which can effectively improve the photoelectric conversion efficiency of silicon-based solar cells, and is a potential silicon-based solar cell. Rare earth light conversion materials for solar cells.

2. The ultraviolet light conversion and emission near-infrared light material of the present invention has strong absorption in the ultraviolet region (250nm-400nm), which can improve the utilization rate of solar energy and at the same time reduce the thermal effect of solar cells.

3. Since the present invention is calcined in an air atmosphere, there is no need to provide a reducing atmosphere, the preparation process is simple, there is no pollution, the environment is friendly, and the synthesized light conversion material has stable performance.

Description of drawings

Fig. 1 is the X-ray powder diffraction pattern of sample BaGd _1.999 Yb _0.001 (MoO ₄ ) ₄ prepared in Example 1 of the present invention;

Fig. 2 is the excitation spectrum of the sample BaGd _1.999 Yb _0.001 (MoO ₄ ) ₄ prepared in Example 1 of the present invention under monitoring at a wavelength of 1000 nm;

Fig. 3 is the fluorescence spectrogram of the sample BaGd _1.999 Yb _0.001 (MoO ₄ ) ₄ prepared in Example 1 of the present invention under excitation at a wavelength of 355 nm;

Fig. 4 is the excitation spectrum of the sample BaGd _1.7 Yb _0.3 (MoO ₄ ) ₄ prepared in Example 2 of the present invention under monitoring at a wavelength of 1000 nm;

Fig. 5 is a fluorescence spectrum diagram of the sample BaGd _1.7 Yb _0.3 (MoO ₄ ) ₄ prepared in Example 2 of the present invention under excitation at a wavelength of 355 nm;

Fig. 6 is the X-ray powder diffraction pattern of the sample BaEu _1.99 Yb _0.01 (MoO ₄ ) ₄ prepared in Example 3 of the present invention;

Fig. 7 is the X-ray powder diffraction pattern of the sample BaY _1.9 Yb _0.1 (MoO ₄ ) ₄ prepared in Example 4 of the present invention;

Fig. 8 is an X-ray powder diffraction pattern of the sample BaLa _1.6 Yb _0.4 (MoO ₄ ) ₄ prepared in Example 5 of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Example 1

According to the stoichiometric ratio of each element in the chemical formula BaGd _1.999 Yb _0.001 (MoO ₄ ) ₄ , weigh barium carbonate BaCO ₃ : 0.387 grams, gadolinium oxide Gd ₂ O ₃ : 1.812 grams, ytterbium oxide Yb ₂ O ₃ : 0.001 grams, Ammonium molybdate (NH ₄ ) ₆ MO ₇ O ₂₄ -4H ₂ O: 3.531 grams, ground in an agate mortar and mixed evenly, then calcined for the first time in an air atmosphere at a temperature of 250°C for 2 hours, and then Cool to room temperature and remove the sample. After the first calcination of the raw materials, the mixture was thoroughly mixed and ground again, and the second sintering was carried out at 650°C in an air atmosphere. The sintering time was 6 hours, cooled to room temperature, and the samples were taken out. After the raw material is calcined for the second time, the mixture is fully mixed and ground evenly again, and then sintered for the third time in an air atmosphere at 850°C, the sintering time is 6 hours, cooled to room temperature, taken out and fully ground to obtain the sample .

Referring to accompanying drawing 1, it is the X-ray powder diffraction spectrum of the sample prepared by the technical scheme of this embodiment; Compared with the standard card 36-0192, the position and relative intensity of the diffraction peak are completely consistent with the standard card, indicating that the prepared in this example The samples are pure phase.

Referring to accompanying drawing 2, it is the excitation spectrum of the sample prepared according to the technical solution of this embodiment under 1000nm wavelength monitoring; referring to accompanying drawing 3, it is the emission spectrum diagram of the sample prepared according to the technical solution of this embodiment under the excitation of 355nm wavelength. It can be seen from the figure that near-infrared luminescence in the 960nm-1100nm band appears in the emission spectrum, and the prepared material effectively converts ultraviolet light into near-infrared luminescence.

Example 2

According to the stoichiometric ratio of each element in the chemical formula BaGd _1.7 Yb _0.3 (MoO ₄ ) ₄ , weigh barium carbonate BaCO ₃ : 0.395 grams, gadolinium oxide Gd ₂ O ₃ : 0.616 grams, ytterbium oxide Yb ₂ O ₃ : 0.118 grams, Ammonium molybdate (NH ₄ ) ₆ MO ₇ O ₂₄ -4H ₂ O: 1.412 grams, ground in an agate mortar and mixed evenly, and then calcined for the first time in an air atmosphere at a temperature of 350°C for 6 hours, and then Cool to room temperature and remove the sample. After the first calcination of the raw materials, the mixture was thoroughly mixed and ground again, and the second sintering was carried out at 750°C in an air atmosphere. The sintering time was 5 hours, cooled to room temperature, and the samples were taken out. After the raw materials are calcined for the second time, the mixture is fully mixed and ground evenly again, and then sintered for the third time in an air atmosphere at 900°C, the sintering time is 9 hours, cooled to room temperature, taken out and fully ground to obtain the sample .

The X-ray powder diffraction pattern of the sample prepared by the technical scheme of this embodiment is consistent with that of the sample prepared in Example 1.

Referring to accompanying drawing 4, it is the excitation spectrum of the sample prepared according to the technical scheme of this embodiment under the monitoring of 1000nm wavelength; referring to accompanying drawing 5, it is the emission spectrum diagram of the sample prepared according to the technical scheme of this embodiment under the excitation of 355nm wavelength. It can be seen from the figure that near-infrared luminescence in the 960nm~1100nm band appears in the emission spectrum, and the prepared material effectively converts ultraviolet light into near-infrared luminescence.

Example 3

According to the stoichiometric ratio of each element in the chemical formula BaEu _1.99 Yb _0.01 (MoO ₄ ) ₄ , weigh barium carbonate BaCO ₃ : 0.395 grams, europium oxide Eu ₂ O ₃ : 0.71 grams, ytterbium oxide Yb ₂ O ₃ : 0.0039 grams, Ammonium molybdate (NH ₄ ) ₆ MO ₇ O ₂₄ -4H ₂ O: 1.412 grams, ground in an agate mortar and mixed evenly, then calcined for the first time in an air atmosphere at a temperature of 400°C for 8 hours, and then Cool to room temperature and remove the sample. After the first calcination of the raw materials, the mixture was fully mixed and ground again, and the second sintering was carried out at 700°C in an air atmosphere. The sintering time was 7 hours, cooled to room temperature, and the samples were taken out. After the raw materials are calcined for the second time, the mixture is fully mixed and ground evenly again, and then sintered for the third time in an air atmosphere at 880°C, the sintering time is 9 hours, cooled to room temperature, taken out and fully ground to obtain the sample .

Referring to accompanying drawing 6, it is the X-ray powder diffraction pattern of the sample prepared by the technical scheme of this embodiment, and its excitation spectrum and emission spectrum are similar to accompanying drawings 2 and 3 respectively.

Example 4

According to the stoichiometric ratio of each element in the chemical formula BaY _1.9 Yb _0.1 (MoO ₄ ) ₄ , weigh barium carbonate BaCO ₃ : 0.395 grams, yttrium oxide Y ₂ O ₃ : 0.429 grams, ytterbium oxide Yb ₂ O ₃ : 0.039 grams, Ammonium molybdate (NH ₄ ) ₆ MO ₇ O ₂₄ -4H ₂ O: 1.412 grams, ground in an agate mortar and mixed evenly, then calcined for the first time in an air atmosphere at a temperature of 450°C for 9 hours, and then Cool to room temperature and remove the sample. After the first calcination of the raw materials, the mixture was thoroughly mixed and ground again, and the second sintering was carried out at 720°C in an air atmosphere. The sintering time was 8 hours, cooled to room temperature, and the samples were taken out. After the raw materials are calcined for the second time, the mixture is fully mixed and ground evenly again, and then sintered for the third time in an air atmosphere at 890°C, the sintering time is 10 hours, cooled to room temperature, taken out and fully ground to obtain the sample .

Referring to accompanying drawing 7, it is the X-ray powder diffraction pattern of the sample prepared by the technical scheme of this embodiment, and its excitation spectrum and emission spectrum are similar to accompanying drawings 2 and 3 respectively.

Example 5

According to the stoichiometric ratio of each element in the chemical formula BaLa _1.6 Yb _0.4 (MoO ₄ ) ₄ , weigh barium carbonate BaCO ₃ : 0.395 grams, lanthanum oxide La ₂ O ₃ : 0.521 grams, ytterbium oxide Yb ₂ O ₃ : 0.157 grams, Ammonium molybdate (NH ₄ ) ₆ MO ₇ O ₂₄ -4H ₂ O: 1.412 grams, ground in an agate mortar and mixed evenly, then calcined for the first time in an air atmosphere at a temperature of 500°C for 10 hours, and then Cool to room temperature and remove the sample. After the first calcination of the raw materials, the mixture was thoroughly mixed and ground again, and then sintered for the second time at 750°C in an air atmosphere. The sintering time was 7 hours, cooled to room temperature, and the samples were taken out. After the raw material is calcined for the second time, the mixture is fully mixed and ground again, and then sintered for the third time in an air atmosphere at 900°C. The sintering time is 8 hours, cooled to room temperature, taken out and fully ground to obtain the sample.

Referring to accompanying drawing 8, it is the X-ray powder diffraction pattern of the sample prepared by the technical scheme of this embodiment, and its excitation spectrum and emission spectrum are similar to accompanying drawings 4 and 5 respectively.

Example 6

According to the stoichiometric ratio of each element in the chemical formula BaErYb(MoO ₄ ) ₄ , weigh barium carbonate BaCO ₃ : 0.395 grams, erbium oxide Er ₂ O ₃ : 0.383 grams, ytterbium oxide Yb ₂ O ₃ : 0.394 grams, ammonium molybdate (NH ₄ ) ₆ MO ₇ O ₂₄ -4H ₂ O: 1.412 grams, and citric acid of 1.8wt% of the total mass of the above medicines, weighed barium carbonate BaCO ₃ , erbium oxide Er ₂ O ₃ and ytterbium oxide Yb ₂ Dissolve O ₃ in an appropriate amount of dilute nitric acid solution, dissolve the weighed ammonium molybdate (NH ₄ ) ₆ MO ₇ O ₂₄ -4H ₂ O in deionized water or ethanol solution, add appropriate amount of deionized water and Stir the citric acid at 70°C; then slowly mix the above solutions and continuously stir for 1.5 hours; let stand and dry to obtain a fluffy precursor; place the precursor in a muffle furnace for calcination at a sintering temperature of 920°C, The calcination time is 10 hours, cooled to room temperature, taken out and fully ground to obtain the sample. Its XRD is consistent with accompanying drawing 1, and its excitation spectrum and emission spectrum are similar to accompanying drawing 4 and accompanying drawing 5 respectively.

Example 7

According to the stoichiometric ratio of each element in the chemical formula BaBi _0.6 Yb _1.4 (MoO ₄ ) ₄ , weigh barium carbonate BaCO ₃ : 0.395 grams, bismuth oxide Bi ₂ O ₃ : 0.279 grams, ytterbium oxide Yb ₂ O ₃ : 0.552 grams, Ammonium molybdate (NH ₄ ) ₆ MO ₇ O ₂₄ -4H ₂ O: 1.412 grams, ground in an agate mortar and mixed evenly, then calcined for the first time in an air atmosphere at a temperature of 550°C for 10 hours, and then Cool to room temperature and remove the sample. After the first calcination of the raw materials, the mixture was fully mixed and ground again, and the second sintering was carried out at 780°C in an air atmosphere. The sintering time was 9 hours, cooled to room temperature, and the samples were taken out. After the raw material is calcined for the second time, the mixture is fully mixed and ground again, and then sintered for the third time at 930°C in an air atmosphere. The sintering time is 10 hours, cooled to room temperature, taken out and fully ground to obtain the sample. Its XRD is consistent with accompanying drawing 1, and excitation spectrum and emission spectrum are similar to accompanying drawing 2 and accompanying drawing 3 respectively.

Example 8

According to the stoichiometric ratio of each element in the chemical formula BaDy _0.2 Yb _1.8 (MoO ₄ ) ₄ , weigh barium carbonate BaCO ₃ : 0.395 grams, dysprosium oxide Dy ₂ O ₃ : 0.074 grams, ytterbium oxide Yb ₂ O ₃ : 0.709 grams, Ammonium molybdate (NH ₄ ) ₆ MO ₇ O ₂₄ -4H ₂ O: 1.412 grams, and the citric acid of 1.8wt% of the total mass of the above medicines, the weighed barium carbonate BaCO ₃ , dysprosium oxide Dy ₂ O ₃ and oxide Ytterbium Yb ₂ O ₃ was dissolved in an appropriate amount of dilute nitric acid solution, and the weighed ammonium molybdate (NH ₄ ) ₆ MO ₇ O ₂₄ -4H ₂ O was dissolved in deionized water or ethanol solution, and an appropriate amount of deionized Ionized water and citric acid were stirred at 70°C; then the above solution was slowly mixed and stirred continuously for 2 hours; left to stand and dried to obtain a fluffy precursor; the precursor was calcined in a muffle furnace at a sintering temperature of 950 ℃, the calcination time is 10 hours, cooled to room temperature, taken out and fully ground to obtain the sample. Its XRD is consistent with accompanying drawing 1, and excitation spectrum and emission spectrum are similar to accompanying drawing 4 and accompanying drawing 5 respectively.

Claims (9)

1. A material that converts ultraviolet light to emit near-infrared light, characterized in that: it emits near-infrared light from 950nm to 1100nm under the excitation of ultraviolet light from 250nm to 400nm; the general chemical formula of the material is MR _2-2x Yb _2x (MoO ₄ ) ₄ , where R is Er ³⁺ , Eu 3+ , La ³⁺ , Y ³⁺ , Ce ³⁺ , Tm ³⁺ , Tm ³⁺ , praseodymium One of ion Pr ³⁺ , neodymium ion Nd ³⁺ , samarium ion Sm ³⁺ , gadolinium ion Gd ³⁺ , terbium ion Tb ³⁺ , dysprosium ion Dy ³⁺ , holmium ion Ho ³⁺ , lutetium ion Lu ³⁺ Or any combination of them; M is one of alkaline earth metal ion calcium ion Ca ²⁺ , strontium ion Sr ²⁺ , barium ion Ba ²⁺ or any combination thereof; x is the mole percentage of Yb ³⁺ doping, 0.0001 ≤ x < 1.0. 2. A preparation method of a material that converts ultraviolet light as claimed in claim 1 and emits near-infrared light, adopts a high-temperature solid-phase method, and is characterized in that it comprises the steps: (1) According to the stoichiometric ratio of each element in the chemical formula MR _2-2x Yb _2x (MoO ₄ ) ₄ , wherein 0.0001≤x<1.0, respectively weigh the compound containing ytterbium ion Yb ³⁺ , the compound containing ion R , and the compound containing Compounds of ion M and compounds containing molybdenum ions Mo ⁶⁺ are ground and mixed uniformly to obtain a mixture; the ions R are rare earth erbium ions Er ³⁺ , europium ions Eu ³⁺ , lanthanum ions La ³⁺ , and yttrium ions Y ³⁺ , cerium ion Ce ³⁺ , thulium ion Tm ³⁺ , praseodymium ion Pr ³⁺ , neodymium ion Nd ³⁺ , samarium ion Sm ³⁺ , gadolinium ion Gd ³⁺ , terbium ion Tb ³⁺ , dysprosium ion Dy ³⁺ One of holmium ion Ho ³⁺ , lutetium ion Lu ³⁺ or any combination thereof; the ion M is alkaline earth metal ion calcium ion Ca ²⁺ , strontium ion Sr ²⁺ , barium ion Ba ²⁺ one or any combination of them; (2) Calcining the mixture obtained in step (1) for 1 to 2 times in an air atmosphere; the calcination temperature is 200-600° C., and the calcination time is 1-12 hours; (3) Cool the mixture obtained in step (2) naturally, grind and mix evenly, then calcinate in air atmosphere, the calcining temperature is 600-850°C, and the calcining time is 1-12 hours; (4) Cool the mixture obtained in step (3) naturally, grind and mix it evenly, then calcinate in air atmosphere, the calcining temperature is 850-1000°C, the calcining time is 1-12 hours, and naturally cool to room temperature to obtain a Ultraviolet light is converted to materials that emit near-infrared light. 3 . The method for preparing a material that converts ultraviolet light and emits near-infrared light according to claim 2 , wherein the calcination temperature in step (2) is 250-550° C., and the calcination time is 2-10 hours. 4 . The method for preparing a material that converts ultraviolet light and emits near-infrared light according to claim 2 , wherein the calcination temperature in step (3) is 650-800° C., and the calcination time is 2-10 hours. 5 . The method for preparing a material that converts ultraviolet light and emits near-infrared light according to claim 2 , wherein the calcination temperature in step (4) is 850-950° C., and the calcination time is 2-10 hours. 6. according to the preparation method of a kind of ultraviolet light conversion emission material of near-infrared light described in claim 2, it is characterized in that: the described compound containing ion R is the oxide, fluoride, nitrate in R One or any combination thereof; the compound containing ytterbium ion Yb ³⁺ is one of ytterbium oxide, ytterbium fluoride, ytterbium nitrate or any combination thereof; the compound containing ion M is M oxide, fluoride, One of carbonate, sulfate, nitrate or any combination thereof; the compound containing molybdenum ions Mo ⁶⁺ is one of molybdenum oxide and ammonium molybdate or any combination thereof. 7. A preparation method of a material that converts ultraviolet light as claimed in claim 1 and emits near-infrared light, adopts a chemical synthesis method, and is characterized in that it comprises the steps: (1) According to the stoichiometric ratio of each element in the chemical formula MR _2-2x Yb _2x (MoO ₄ ) ₄ , where 0.0001≤x<1.0, weigh the compound containing ytterbium ion Yb ³⁺ , the compound containing ion R, the compound containing ion R The compounds of M are respectively dissolved in dilute nitric acid solution to obtain various transparent solutions; the complexing agent citric acid or oxalic acid is added according to 0.5-2.0wt% of the mass of each reactant, and the temperature is 50-100°C. Stirring; the ions R are rare earth erbium ions Er ³⁺ , europium ions Eu ³⁺ , lanthanum ions La ³⁺ , yttrium ions Y ³⁺ , cerium ions Ce ³⁺ , thulium ions Tm ³⁺ , praseodymium ions Pr ³⁺ , neodymium ions Nd ³⁺ , samarium ions Sm ³⁺ , gadolinium ions Gd ³⁺ , terbium ions Tb ³⁺ , dysprosium ions Dy ³⁺ , holmium ions Ho ³⁺ , lutetium ions Lu ³⁺ , or any of them combination; the ion M is one of alkaline earth metal ion calcium ion Ca ²⁺ , strontium ion Sr ²⁺ , barium ion Ba ²⁺ or any combination thereof; respectively weigh the compound containing ytterbium ion Yb ³⁺ , Compounds containing rare earth ions R, compounds containing alkaline earth metal ions M; (2) According to the stoichiometric ratio of each element in the chemical formula MR _2-2x Yb _2x (MoO ₄ ) ₄ , where 0.0001≤x<1.0, weigh the compound containing molybdenum ion Mo ⁶⁺ and dissolve it in deionized water or ethanol solution In, add complexing agent citric acid or oxalic acid according to 0.5～2.0wt% of reactant mass, stir under the temperature condition of 50～100 ℃; (3) Slowly mix the various solutions obtained in steps (1) and (2), stir at a temperature of 50-100°C for 1-2 hours, let stand, and dry to obtain a fluffy precursor; (4) The precursor is calcined in a muffle furnace at a temperature of 850-1000° C. for 1-15 hours, and naturally cooled to room temperature to obtain a material that realizes ultraviolet light conversion and emits near-infrared light. 8. The preparation method of a kind of material that converts ultraviolet light and emits near-infrared light according to claim 7, characterized in that: the compound containing ion R is the oxide, fluoride, and nitrate of R One or any combination thereof; the compound containing ytterbium ion Yb ³⁺ is one of ytterbium oxide, ytterbium fluoride, ytterbium nitrate or any combination thereof; the compound containing ion M is M oxide, fluoride, One of carbonate, sulfate, nitrate or any combination thereof; the compound containing molybdenum ions Mo ⁶⁺ is one of molybdenum oxide and ammonium molybdate or any combination thereof. 9. An application of the material for converting ultraviolet light and emitting near-infrared light as claimed in claim 1, characterized in that it is used as a light conversion material for silicon-based solar cells.