CN108682743A - A kind of preparation method of the titania-doped quantum dot of holmium ytterbium magnesium and its application in perovskite battery - Google Patents

Abstract

The invention relates to a method for preparing quantum dots doped with holmium, ytterbium and magnesium, comprising the following steps: 1) preparation of titanium dioxide precursor; 2) preparation of quantum dots: Ho(NO ₃ ) ₃ ·5H ₂ O, Yb (NO ₃ ) ₃ 5H ₂ O and Mg(NO ₃ ) ₂ 6H ₂ O were added to the titanium dioxide precursor solution to obtain a mixed solution C, which was dried and annealed to obtain quantum dots of holmium, ytterbium and magnesium doped titanium dioxide The quantum dots of holmium, ytterbium and magnesium doped with titanium dioxide can be used as electron transport materials in the preparation of perovskite batteries. The prepared perovskite batteries can convert near-infrared light into visible light with high conversion efficiency.

Description

A preparation method of quantum dots doped with holmium, ytterbium, magnesium and titanium dioxide and its application in perovskite Application in battery

technical field

The invention belongs to the technical field of solar cells, and in particular relates to the preparation of Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots and its application in perovskite cells.

Background technique

In recent years, perovskite solar cells have become a research hotspot in the field of solar cells because of their high efficiency, low cost, and simple preparation methods. The conversion efficiency of perovskite cells has increased rapidly, reaching 22.1% by 2017 (Science, 2017, 356:1376). However, perovskite solar cells can only absorb a small part of the solar spectrum (280–800 nm) and cannot absorb near-infrared light, and the energy loss of incident light is large, which hinders further improvement of cell efficiency. One way to solve this problem is to use up-conversion luminescent materials to convert near-infrared light into visible light that the battery can absorb, thereby improving the conversion efficiency of the battery. At present, people mainly use rare earth ions doping NaYF ₄ to prepare electron transport materials for solar cells. However, the poor conductivity of NaYF ₄ will hinder the transport of electrons (Inorg. Chem., 2014, 53:8045). In perovskite solar cells, TiO ₂ is a commonly used electron transport material. If the electron transport material is prepared by doping TiO ₂ with rare earth elements, it will not affect the electron transport and can convert the near-infrared light in sunlight. Visible light is absorbed by the perovskite cell, thereby improving cell efficiency.

Contents of the invention

The object of the present invention is to provide a preparation method of Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots, the Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ prepared by this method can Convert near-infrared light into visible light with high conversion efficiency. The Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ prepared by this method was used as an electron transport material to prepare a perovskite solar cell, which expanded the absorption of near-infrared light by the perovskite cell and improved the battery performance. photoelectric conversion efficiency.

The invention discloses a preparation method of Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots, comprising the following steps:

1) Preparation of _TiO2 precursor:

Mix n-butyl titanate and acetylacetone evenly, then add isopropanol to obtain solution A, wherein the volume ratio of n-butyl titanate, acetylacetone and isopropanol is (7~8): ( 2~3) :100;

Nitric acid and water are added in isopropanol, mix uniformly, obtain solution B, wherein the volume ratio of nitric acid, water, isopropanol is (7~8): (2~3):100;

Mix solution B and solution A according to the volume ratio of solution A and solution B (2~3):1 to obtain the _TiO2 precursor solution.

2) Preparation of quantum dots: Ho(NO ₃ ) ₃ 5H ₂ O, Yb(NO ₃ ) ₃ 5H ₂ O and Mg(NO ₃ ) ₂ 6H ₂ O were added to the TiO ₂ precursor solution to obtain a mixed Solution C, dry the mixed solution C at 90~110ºC, and then anneal at 450~550ºC for 30~90 min to obtain Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots;

The molar ratios of Ho to Ti, Yb to Ti, and Mg to Ti in the mixed solution C are 0.5-1.5:100, 1-5:100, and 1-4:100, respectively.

The specific method of mixing solution B and solution A in the step 1) is: adding solution B to solution A drop by drop, and stirring for 6 hours.

The prepared Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots can be used as electron transport materials and can be applied to perovskite batteries.

A preparation method of a perovskite battery adding the Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots, comprising the following steps:

1) FTO glass sheet treatment: the etched FTO glass sheet is cleaned and treated with ultraviolet light to obtain a clean FTO glass sheet.

2) Preparation of dense layer: add 0.05~0.1 ml titanium acetylacetonate to 0.5~1.5 ml n-butanol solution and mix to obtain a dense layer precursor, drop the dense layer precursor solution on the clean FTO glass sheet obtained in step 1) , spin coating and annealing to obtain a dense layer/FTO.

3) Preparation of the electron transport layer: mix TiO ₂ and absolute ethanol at a mass ratio of 1:6 to obtain a TiO ₂ slurry, drop the TiO ₂ slurry on the dense layer, spin-coat, and anneal to obtain an electron transport layer/dense layer/FTO.

4) Prepare the modification layer: drop the mixed solution C on the electron transport layer, spin coat and anneal to prepare the Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ modification layer/electron transport layer/dense layer/ FTO.

5) Perovskite absorption layer: Dissolve 0.5~1.5 mmol FAI, 1~1.5 mmol PbI ₂ , 0.1~0.5 mmol MABr, 0.1~0.5 mmol PbBr ₂ in a mixed solution of 1mL DMF and DMSO, then add 40-50µl CsI solution, mixed evenly to obtain a perovskite precursor solution, drop the perovskite precursor solution on the modified layer of Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ , spin coating, drop chlorine Benzene, heated to obtain perovskite absorption layer/modification layer/electron transport layer/dense layer/FTO.

6) Preparation of hole transport layer: Dissolve 70~80 mg spiro-oMeTAD in 1 mL chlorobenzene, then add 28.8 ul 4-tert-pyridine and 17.5 ul bis(trifluoromethanesulfonyl) at a concentration of 520 mg/ml Acetonitrile solution of lithium imide, mixed uniformly to obtain hole transport layer solution, hole transport layer/perovskite absorption layer/modification layer/electron transport layer/dense layer/FTO.

7) A layer of Au electrode is thermally evaporated on the hole transport layer to obtain a perovskite battery of Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ electron transport material, that is, Au/hole transport layer/calcium Titanium absorption layer/modification layer/electron transport layer/dense layer/FTO.

The specific method of cleaning the etched FTO glass described in step 1) is: put the etched FTO glass piece into the conductive glass cleaning solution, acetone and isopropanol in sequence, and ultrasonically clean it for 20 min each.

The implementation parameters of the spin coating are: when the dense layer is prepared in step 2), the rotation speed is 3500 rpm; when the electron transport layer is prepared in step 3), the rotation speed is 4000 rpm; when the modification layer is prepared in step 4), , the rotation speed is 5000 rpm; when the perovskite absorbing layer is prepared in step 5), the rotation speed is 1000 rpm 10s and 6000 rpm 20s; when the hole transport layer is prepared in step 6), the speed is 4000 rpm.

The implementation parameters of the annealing are: when the dense layer is prepared in step 2), the annealing temperature is 500°C and the time is 30-60 minutes; when the electron transport layer is prepared in step 3), the annealing temperature is 450°C and the time is 30-60 minutes; When preparing the modification layer in step 4), the annealing temperature is 500ºC and the time is 30-120 min; when preparing the perovskite absorbing layer in step 5), the annealing temperature is 500ºC and the time is 30-60 min; in step 6), the hole When the transport layer was prepared, the annealing temperature was 100ºC and the time was 60 min.

The volume ratio of DMF to DMSO in step 5) is 4:1.

The prepared Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dot perovskite battery includes sequentially stacked FTO glass, dense layer, electron transport layer, modification layer, perovskite absorption layer, hole transport layer, Au electrode; the Au electrode is 80 nm thick.

The present invention has the following advantages:

1) The present invention uses this preparation method to prepare Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots. Due to the addition of Mg ²⁺ , Ho ³⁺ -Yb ³⁺ doped TiO ₂ The conversion luminescence performance is enhanced. By changing the doping amount of magnesium nitrate and changing the luminous intensity of the upper electron transport material, the optimal doping amount of Mg ²⁺ corresponding to the strongest luminous intensity can be obtained.

2) The Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots prepared by the present invention are used as electron transport materials to prepare perovskite solar cells. Since Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots can convert near-infrared light into visible light that perovskite can absorb, it expands the spectral response range of perovskite cells and improves cell conversion efficiency.

Description of drawings

Fig. 1 is the Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dot energy transfer schematic diagram described in Example 1;

Figure 2 is the X-ray diffraction pattern (XRD) of the Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots described in Example 1;

Fig. 3 is the ultraviolet-visible-infrared absorption spectrogram of Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots described in Example 1;

Fig. 4 is the conversion luminescence diagram of the quantum dots of Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ described in Example 1 and Comparative Example 1;

Fig. 5 is the perovskite cell structure schematic diagram of Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots described in Example 2;

6 is a current-voltage curve corresponding to the highest efficiency of the perovskite battery described in Example 2 and Comparative Example 2.

Detailed ways

Embodiments of the present invention will be described in detail below in conjunction with examples, but the following examples are only used to illustrate the present invention, and should not limit the scope of the present invention. The room temperature is 25±5°C.

In the present invention, n-butyl titanate, acetylacetone, isopropanol, Ho(NO ₃ ) ₃ ·5H ₂ O, Yb(NO ₃ ) ₃ ·5H ₂ O, Mg(NO ₃ ) ₂ ·6H ₂ O , Conductive glass cleaning fluid (Shenzhen Regres Technology Co., Ltd.), acetone, absolute ethanol, chlorobenzene, formamidine iodide (FAI), lead iodide (PbI ₂ ), methylamine bromide (MABr), lead bromide (PbBr ₂ ), dimethylformamide (DMF), dimethylsulfoxide (DMSO), CsI solution, spiro-oMeTAD, chlorobenzene, 4-tert-pyridine, lithium bis(trifluoromethanesulfonyl)imide , Acetonitrile all belong to commercially available products.

The TiO ₂ slurry mentioned in the present invention is commercial TiO ₂ purchased from Dyesol, model 30NR-D.

Example 1:

A method for preparing quantum dots on Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ , comprising the steps of:

1) Preparation of TiO2 precursor:

Mix 0.75 ml of n-tetrabutyl titanate and 0.225 ml of acetylacetone at room temperature for 1 hour, and then add 10 ml of iso-propyl alcohol to obtain solution A;

Add 0.045 ml of nitric acid and 0.105 ml of deionized water into 5 ml of isopropanol, mix and stir for 1 hour to obtain solution B;

Solution B was added dropwise to solution A and magnetically stirred for 6 h to obtain the _TiO2 precursor solution.

2) Preparation of quantum dots: Ho(NO ₃ ) ₃ 5H ₂ O, Yb(NO ₃ ) ₃ 5H ₂ O and Mg(NO ₃ ) ₂ 6H ₂ O were added to the TiO ₂ precursor solution to obtain a mixed Solution C, the molar ratios of Ho and Ti, Yb and Ti, Mg and Ti in the mixed solution C are 0.5~1.5:100, 1~5:100, 1~4:100 respectively;

Dry the mixed solution C at 100°C for 12 hours (remove the solvent), and then anneal at 500°C for 30-90 minutes to obtain Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots, denoted Ho ³⁺ -Yb ³⁺ -Mg ²⁺ : TiO ₂ .

Comparative example 1

The difference between this comparative example and Example 1 is that the addition of Mg(NO ₃ ) ₂ ·6H ₂ O is omitted, and the quantum dot material is recorded as Ho ³⁺ -Yb ³⁺ :TiO ₂ .

The optical properties of the quantum dots described in Example 1 and Comparative Example 1 are detected:

1. The schematic diagram of quantum dot energy transfer of Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ described in this example is shown in Figure 1. TiO ₂ is used as the host material, and Ho ³⁺ is the activator as the luminescence center , Yb ³⁺ is a sensitizer that can absorb energy and transfer it to the activator Ho ³⁺ .

2. Detect the X-ray diffraction of the prepared Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots. As shown in Figure 2, the characteristic peaks at 25.9º, 38.7º, 48.6º and 62.9º are respectively It is attributed to the (101), (004), (200) and (204) crystal planes of TiO ₂ anatase phase TiO ₂ , and the characteristic peak at 54.9º corresponds to the (211) crystal plane of TiO ₂ rutile phase, which indicates that The _TiO2 prepared by the present invention is a mixed phase of anatase and rutile phases.

3. Detect the ultraviolet-visible-infrared light absorption of the quantum dots of Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ described in this embodiment, as shown in Figure 3, due to the ² F of Yb ³⁺ ions The energy level transition of _7/2 → ² F _5/2 and the energy level transition of Ho ^{3+ 5} I ₇ → ⁵ F ₅ , the quantum dots of Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ can absorb near infrared light.

4. Under the excitation of a 980 nm laser as the excitation light source, the conversion luminescence of the Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots described in this example was detected, as shown in Figure 4, at 547 nm The upconversion luminescence peaks at 663 nm and 663 nm are assigned to the energy level transitions of ⁵ F ₄ , ⁵ S ₂ → ⁵ I ₈ and ⁵ F ₅ → ⁵ I ₈ of Ho ³⁺ , respectively. It can be seen from the figure that due to the addition of Mg ²⁺ , the Ho ³⁺ -Yb ³⁺ -Mg ^{2+ doped} TiO ₂ quantum dots described in Example 1 are more ³⁺ doped TiO ₂ quantum dots, the conversion luminescence intensity is enhanced.

Example 2

In this example, the mixed solution C prepared in Example 1 is used to participate in the preparation of the perovskite battery of this example, and the specific preparation method is as follows:

1) FTO glass sheet treatment: clean the FTO glass sheet and treat it with ultraviolet light for 20 min to obtain a clean FTO glass sheet; the specific method of FTO glass cleaning is: etching (that is, using Zn powder and dilute hydrochloric acid The FTO glass slices were etched), and the FTO glass slices were placed in conductive glass cleaning solution, acetone and isopropanol in sequence, and ultrasonically cleaned for 20 minutes each.

2) Preparation of a dense layer: Add 0.072 ml of titanium acetylacetonate to 1 ml of n-butanol and mix evenly to obtain a dense layer precursor. Drop the dense layer precursor solution on the clean FTO glass sheet obtained in step 1), and mix at 3500 spin coating at a speed of 30 s per minute, and then annealed at 500ºC for 30-60 min to obtain a dense layer/FTO;

3) Preparation of the electron transport layer: TiO ₂ and absolute ethanol were mixed at a mass ratio of 1:6 to obtain a TiO ₂ slurry, and the TiO ₂ slurry was dropped on the dense layer, and spin-coated at 4000 rpm for 30 s, Then anneal at 450ºC for 30-60 min to prepare electron transport layer/dense layer/FTO;

4) Preparation of the modification layer: drop the mixed solution C obtained in Example 1 on the electron transport layer, spin-coat at a speed of 5000 rpm for 30 s, and then anneal at 500ºC for 30-120 min to obtain Ho ^{3 +} -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dot modification layer/electron transport layer/dense layer/FTO;

5) Preparation of perovskite absorbing layer: 1 mmol of formamidine iodide (FAI), 1.1 mmol of lead iodide (PbI ₂ ), 0.2 mmol of methylamine bromide (MABr), 0.2 mmol of lead bromide (PbBr ₂ ) were dissolved in 1 mL In the mixed solution of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (DMF:DMSO=4:1, volume ratio), add 42 μl of 1.5 M CsI solution (solvent is DMSO), Mix and stir evenly to obtain a perovskite precursor solution, drop the perovskite precursor solution on the modified layer of Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ , at 1000 rpm for 10s and 6000 rpm for 20s Spin coating under the bottom, and drop 100 ul of chlorobenzene 10s before the end of the spin, then place the sample on a heating plate at 100ºC and heat for 60 min to obtain perovskite absorption layer/modification layer/electron transport layer/dense layer/FTO;

6) Preparation of hole transport layer: Dissolve 72.3 mg spiro-oMeTAD in 1 mL chlorobenzene, then add 28.8 ul 4-tert-pyridine and 17.5 ul bis(trifluoromethanesulfonyl)imide at a concentration of 520 mg/ml Lithium acetonitrile solution, mixed evenly to obtain a hole transport layer solution, drop the hole transport layer on the perovskite absorption layer, and spin-coat at a speed of 4000 rpm for 30s to obtain a hole transport layer/perovskite absorption layer /modification layer/electron transport layer/dense layer/FTO;

7) Electrode preparation: a layer of Au electrode is vacuum thermally evaporated on the hole transport layer to obtain a perovskite battery of Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ electron transport material, that is, Au/hole transport layer/perovskite absorption layer/modification layer/electron transport layer/dense layer/FTO; the thickness of the Au electrode is 80 nm.

The structural schematic diagram of the perovskite battery, as shown in Figure 5, 1-FTO, 2-dense layer, 3-electron transport layer, 4-Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots The modification layer, 5-perovskite absorption layer, 6-hole transport layer, 7-Au electrode.

Comparative example 2

The difference from Example 2 is that the preparation of this comparative example omits the preparation of the modified layer described in Example 2, that is, the perovskite absorption layer is directly prepared on the electron transport layer, and the obtained battery is recorded as Au/hole transport layer/ Perovskite absorbing layer/electron transport layer/dense layer/FTO.

The photoelectric performance of the battery of embodiment 2 and comparative example 2 is detected:

1. The photovoltaic characteristic parameters of the perovskite cells described in Example 2 and Comparative Example 2 were tested, and the test results are shown in Table 1.

The photovoltaic characteristic parameter of the perovskite cell described in table 1 embodiment 2 and comparative example 2

Compared with the perovskite battery described in Comparative Example 2, the short-circuit current of the battery based on Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ was increased from 21.2 mA/cm ² to 22.6 mA/cm ² , and the photoelectric conversion The efficiency (PCE) increased from 15.2% to 16.3%.

2. Detect the current density of the perovskite solar cells described in Example 2 and Comparative Example 2, and draw a current-voltage curve, as shown in FIG. 6 . 6 is the current-voltage curve corresponding to the highest efficiency of the perovskite solar cell described in Example 2 and Comparative Example 2. The current-voltage curve is tested under the illumination of AM1.5 standard solar simulator (illuminance is 100 mW/cm ² ). The highest efficiency of the perovskite battery of Comparative Example 2 was 15.7%, and the highest efficiency of the battery of Example 2 reached 16.8%.

Although the invention has been illustrated and described by specific embodiments, it should be appreciated that many other changes and modifications can be made without departing from the spirit and scope of the invention, therefore, it is meant All changes and modifications included in the scope of the present invention in the claims belong to the protection scope of the present invention.

Claims (9)

1. a Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO _2The preparation method of the quantum dot is characterized in that, comprising the following steps: 1) Preparation of _TiO2 precursor: Mix n-butyl titanate and acetylacetone evenly, then add isopropanol to obtain solution A, wherein the volume ratio of n-butyl titanate, acetylacetone and isopropanol is (7~8): ( 2~3) :100, Add nitric acid and water into isopropanol and mix well to obtain solution B, wherein the volume ratio of nitric acid, water, and isopropanol is (7~8): (2~3):100, According to the volume ratio of A solution and B solution (2 ~ 3): 1, solution B is mixed with solution A to obtain _TiO Precursor solution; 2) Preparation of quantum dots: Ho(NO ₃ ) ₃ 5H ₂ O, Yb(NO ₃ ) ₃ 5H ₂ O and Mg(NO ₃ ) ₂ 6H ₂ O were added to the TiO ₂ precursor solution to obtain a mixed Solution C, dry the mixed solution C at 90~110ºC, and then anneal at 450~550ºC for 30~90 min to obtain Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots; The molar ratios of Ho to Ti, Yb to Ti, and Mg to Ti in the mixed solution C are 0.5-1.5:100, 1-5:100, and 1-4:100, respectively. 2. The preparation method of Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots as claimed in claim 1, characterized in that the specific way of mixing solution B and solution A in step 1) is: Solution B was added dropwise to solution A and stirred for 6 hours. 3. Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots prepared by the preparation method according to claim 1 or claim 2. 4. add the described Ho of claim 3 3 ⁺ -Yb ³⁺ -Mg ²⁺ doping _TiO The preparation method of the quantum dot of the perovskite cell, it is characterized in that, comprises the following steps: 1) FTO glass sheet treatment: Clean the etched FTO glass sheet and treat it with ultraviolet light to obtain a clean FTO glass sheet; 2) Preparation of dense layer: add 0.05~0.1 ml titanium acetylacetonate to 0.5~1.5 ml n-butanol solution and mix to obtain a dense layer precursor, drop the dense layer precursor solution on the clean FTO glass obtained in step 1) , spin coating and annealing to obtain a dense layer/FTO; 3) Preparation of the electron transport layer: mix TiO ₂ and absolute ethanol at a mass ratio of 1:6 to obtain a TiO ₂ slurry, drop the TiO ₂ slurry on the dense layer, spin-coat, and anneal to obtain an electron transport layer/dense Layer/FTO; 4) Prepare the modification layer: drop the mixed solution C on the electron transport layer, spin coat and anneal to prepare the Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ modification layer/electron transport layer/dense layer/ FTO; 5) Perovskite absorption layer: Dissolve 0.5~1.5 mmol FAI, 1~1.5 mmol PbI ₂ , 0.1~0.5 mmol MABr, 0.1~0.5 mmol PbBr ₂ in 1 mL of the mixed solution of DMF and DMSO, then add 40-50 µl CsI solution, mixed evenly to obtain a perovskite precursor solution, drop the perovskite precursor solution on the modified layer of Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ , spin coating, drop chlorine Benzene, heated to obtain perovskite absorption layer/modification layer/electron transport layer/dense layer/FTO; 6) Preparation of hole transport layer: Dissolve 70~80 mg spiro-oMeTAD in 1 mL of chlorobenzene, then add 28.8 ul of 4-tert-pyridine and 17.5 ul of bis(trifluoromethanesulfonyl) sulfide at a concentration of 520 mg/ml Acetonitrile solution of lithium amide, mixed evenly to obtain hole transport layer solution, hole transport layer/perovskite absorption layer/modification layer/electron transport layer/dense layer/FTO; 7) Thermally evaporate a layer of Au electrode on the hole transport layer to obtain a perovskite battery of Ho3+-Yb3+-Mg2+ doped TiO2 electron transport material, that is, Au/hole transport layer/perovskite absorption layer/modification layer /electron transport layer/dense layer/FTO. 5. The method for preparing the perovskite battery of Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots as claimed in claim 4, characterized in that the FTO glass etched in step 1) The specific method of cleaning is as follows: put the etched FTO glass sheet into conductive glass cleaning solution, acetone and isopropanol in sequence, and ultrasonically clean it for 20 min each. 6. as claimed in claim 4 Ho ³⁺ -Yb ³⁺ -Mg ₂ ⁺ doping TiO The preparation method of the quantum dot of the perovskite cell, it is characterized in that, the implementation parameter of described spin coating is: step 2 ) during the preparation of the dense layer, the rotation speed was 3500 rpm; during the preparation of the electron transport layer in step 3), the rotation speed was 4000 rpm; during the preparation of the modification layer in step 4), the rotation speed was 5000 rpm; step 5) When preparing the perovskite absorbing layer, the rotation speed was 1000 rpm for 10s and 6000 rpm for 20s; in step 6), when preparing the hole transport layer, the speed was 4000 rpm. 7. as claimed in claim 4 Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doping TiO _2The preparation method of the quantum dot of the perovskite cell, it is characterized in that, The implementation parameters of the annealing are: when the dense layer is prepared in step 2), the annealing temperature is 500°C and the time is 30-60 minutes; when the electron transport layer is prepared in step 3), the annealing temperature is 450°C and the time is 30-60 minutes; When preparing the modification layer in step 4), the annealing temperature is 500ºC and the time is 30-120 min; when preparing the perovskite absorbing layer in step 5), the annealing temperature is 500ºC and the time is 30-60 min; in step 6), the hole When the transport layer was prepared, the annealing temperature was 100ºC and the time was 60 min. 8. The method for preparing a perovskite battery of Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped TiO ₂ quantum dots as claimed in claim 4, characterized in that the volume of DMF and DMSO in step 5) The ratio is 4:1. 9. use the arbitrary described preparation method of claim 4-8 to prepare Ho ³⁺ -Yb ³⁺ -Mg ²⁺ doped _TiO The perovskite cell of the quantum dot, it is characterized in that, comprise the FTO that stacks up successively Glass, dense layer, electron transport layer, modification layer, perovskite absorption layer, hole transport layer, Au electrode; the thickness of the Au electrode is 80 nm.