CN114864840B - A method for preparing a blue light perovskite light-emitting diode - Google Patents

Abstract

The invention discloses a preparation method of a blue light perovskite light-emitting diode, which comprises the following steps: preparing a passivating agent TMBBr, preparing a TMB ₂PbBr₄ solution, synthesizing CsPbBr ₃ powder, preparing a quasi-two-dimensional blue-light perovskite PEA _xPA_2‑x(CsPbBr₃)_n‑1PbBr₄: TMBBr precursor solution, and preparing a three-dimensional mixed halogen perovskite light-emitting diode device. The present disclosure refers to sodium bis (trifluoromethylsulfonyl) imide as an interface modification layer for nickel oxide (NiO _x) that provides superior spectral stability and device performance by introducing 4- (trifluoromethyl) benzamide hydrobromide in a quasi-two-dimensional perovskite precursor solution.

Description

A method for preparing a blue light perovskite light-emitting diode

Technical Field

The invention relates to the preparation of a perovskite light-emitting diode device, and in particular to a method for preparing a highly efficient and stable quasi-two-dimensional blue light perovskite light-emitting diode device, which is applied to the technical field of novel display device manufacturing.

Background technique

Metal halide perovskite (MHP) has excellent optical and electrical properties such as high luminescence color purity, easily adjustable band gap, and high carrier mobility. It is an ideal light-emitting layer material for light-emitting diodes (LEDs).

In recent years, the development of perovskite light-emitting diodes (PeLEDs) has been very rapid. The stability and external quantum efficiency (EQE) of green and red PeLEDs have been greatly improved. The device life can reach up to 115min (@7200cdm ^-2 ), and the EQE has exceeded 20%. The device performance is comparable to that of traditional OLEDs. However, the stability and EQE of blue PeLEDs are still very backward. The device life is less than one hundredth of that of green and red PeLEDs, and the EQE is only about 10%, which seriously limits the application of PeLEDs in full-color display and white light lighting.

The general structural formula of perovskite is ABX ₃ , where X is a halogen anion such as Cl ^- , Br ^- , or I ^- , A is a monovalent cation such as FA ⁺ , MA ⁺ , or Cs ⁺ , and B is a divalent cation such as Pb ²⁺ . Currently, three strategies are used to realize blue light PeLEDs:

1) By adjusting the ratio of Cl/Br in the mixed-halogen perovskite (ABCl _x Br _3-x ), the emission peak can be adjusted from sky blue (490nm) to dark blue and even ultraviolet (410nm). However, the mixed-halogen perovskite film has poor morphology. Under light, heat and other environments, ion migration will occur, leading to phase separation, which will broaden the blue light perovskite emission peak and red-shift the peak position.

2) Use divalent cations such as Cu ²⁺ , Ni ³⁺ , and Mn ²⁺ to replace Pb ²⁺ , so that the perovskite lattice is distorted, the band gap becomes larger, and the spectrum is blue-shifted to achieve blue light emission. However, this doped perovskite film not only has a low PLQY, but also has extremely poor stability.

3) The crystal dimension of perovskite is regulated by introducing long-chain organic cations to separate octahedral inorganic layers of different numbers to form a perovskite structure with multiple quantum wells, i.e., quasi-two-dimensional perovskite, which increases the exciton binding energy and widens the band gap, thereby blue-shifting the luminescence spectrum and achieving blue light emission.

Summary of the invention

In order to solve the problems of the prior art, the purpose of the present invention is to overcome the shortcomings of the existing technology and provide a method for preparing a blue light perovskite light-emitting diode. The method adopts a strategy of efficient and stable quasi-two-dimensional blue light perovskite light-emitting diode devices, and for the first time quotes sodium bis(trifluoromethanesulfonyl)imide (SBTI) as an interface modification layer of nickel oxide (NiO _x ). By introducing 4-(trifluoromethylbenformamide bromide) (TMBBr) into the quasi-two-dimensional perovskite precursor solution, the device has excellent spectral stability and good device performance.

In order to achieve the above object, the present invention adopts the following technical scheme:

A method for preparing a blue light perovskite light-emitting diode comprises the following steps:

a. Preparation of passivating agent TMBBr:

Dissolve 0.9 g of trifluoromethylbenzamide in at least 25 mL of ethanol, cool to below 10° C. using an ice-water bath, slowly drop at least 2 mL of hydrobromic acid having a mass percentage concentration of not less than 48%, keep the temperature of the mixed solution below 10° C. during the addition of hydrobromic acid, and react for at least two hours; after the reaction, centrifuge the product solution at a speed of not less than 7800 r.p.m., pour out the supernatant, add at least 20 mL of n-hexane to dissolve the precipitate, and then shake and wash away the unreacted product with at least 5 mL of deionized water; then centrifuge the mixed solution at a speed of 7800 r.p.m. for at least 30 seconds until stratification occurs, and rotary evaporate the n-hexane solution of the upper product at not less than 50° C. to obtain a white product, namely TMBBr powder;

b. Preparation of TMB ₂ PbBr ₄ solution:

The above TMBBr powder was mixed with PbBr ₂ at a molar mass ratio of 2:1, and the solvent was dimethyl sulfoxide (DMSO) to obtain a TMB ₂ PbBr ₄ solution;

c. Synthesis of CsPbBr ₃ powder:

5 mmol _PbBr2 is dissolved in hydrobromic acid having a mass percentage concentration of not less than 48% and stirred for at least 10 minutes, and then at least 1.5 mL of a CsBr aqueous solution having a molar concentration of not less than 3.4 M is added dropwise to obtain an orange solution; then the precipitate is centrifuged from the orange solution, and thoroughly washed with ether and ethanol at least 3 times, and then dried at not less than 60°C for at least 12 hours to obtain _CsPbBr3 powder;

d. Preparation of quasi-two-dimensional blue perovskite PEA _x PA _2-x (CsPbBr ₃ ) _n-1 PbBr ₄ :TMBBr precursor solution:

According to the ratio of the molar concentration of the target prepared mixed solution, CsPbBr ₃ powder, PABr powder and PEA ₂ PbBr ₄ powder are dissolved in DMSO, and the molar concentration of CsPbBr ₃ in the obtained mixed solution is not less than 0.15M, the molar concentration of PABr is not less than 0.15M, and the molar concentration of PEA ₂ PbBr ₄ is not less than 0.015M, and then at least 10μLTMB ₂ PbBr ₄ solution is added to the mixed solution, and stirred at least 12h in a glove box under a nitrogen environment at not less than 50°C, and filtered for use;

e. Preparation of three-dimensional mixed halogen perovskite light-emitting diode devices:

A three-dimensional mixed-halogen perovskite light-emitting diode device consisting of a substrate, an ITO anode, a hole transport layer, an interface modification layer, a perovskite light-emitting layer, an electron transport layer, an electron injection layer/electrode modification layer, and a cathode Al layer is formed from bottom to top; wherein the hole transport layer, the interface modification layer, the perovskite light-emitting layer, the electron transport layer, and the electron injection layer/electrode modification layer constitute a light-emitting unit.

Preferably, in the step e, the substrate and the ITO anode are made of ITO conductive glass, and the thickness of the ITO film is 100-150 nm.

Preferably, in the step e, the hole transport layer is a nickel oxide (NiO _x ) film, and the thickness of the NiO _x film is 35-40 nm.

Preferably, in the step e, the interface modification layer is SBTI, and the thickness of SBTI is 3-5 nm.

Preferably, in the step e, the perovskite light-emitting layer is a perovskite thin film, which is a quasi-two-dimensional blue light perovskite PEA _x PA _2-x (CsPbBr ₃ ) _n-1 PbBr ₄ :TMBBr, and the thickness of the perovskite light-emitting layer is 35 to 40 nm;

Preferably, in step e, the perovskite light-emitting layer adopts a perovskite thin film, the luminescence efficiency of the perovskite thin film is not less than 52.3%, the emission wavelength is 485-487nm, and the half maximum width (FWHM) is 22-24nm.

Preferably, in the step e, the material of the electron transport layer is 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, i.e., 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene, TPBi, and the thickness of the TPBi film is 30 to 35 nm.

Preferably, in the step e, the electron injection layer/electrode modification layer is made of lithium fluoride (LiF), and the film thickness of the lithium fluoride is not less than 1 nm.

Preferably, in the step e, the thickness of the cathode Al layer is not less than 100 nm.

Preferably, in the step e, preparing a three-dimensional mixed halogen blue perovskite light-emitting device with an upright structure comprises the following steps:

(1) Cleaning of glass substrate containing ITO transparent electrode:

First, the ITO glass substrate is wiped with a dust-free cloth soaked in detergent, and then continuously ultrasonically cleaned with deionized water, acetone, and isopropyl alcohol for at least 15 minutes each, and then the glass substrate is dried and treated with oxygen plasma gas for at least 15 minutes.

(2) Preparation of hole transport layer:

Spin coating a NiO _x ethanol solution having a concentration of not less than 12 mg/mL on the ITO glass substrate after the cleaning treatment in step (1), with a rotation speed of at least 4000 rpm and a spin coating time of at least 40 s. After the spin coating is completed, annealing is performed at a temperature of not less than 300° C. for 40 min to form a NiO _x film;

(3) Preparation of interface modification layer:

Spin coating a SBTI solution dissolved in ethanol on the NiO _x film, wherein the concentration of the SBTI solution is not less than 1 mg/mL, the rotation speed is at least 4000 rpm, and the spin coating time is at least 40 seconds. After the spin coating is completed, annealing is performed at a temperature not less than 100° C. for at least 10 minutes to prepare an interface modification layer;

(4) Preparation of perovskite light-emitting layer:

After the interface modification layer is treated with oxygen plasma gas, a blue light perovskite solution is spin-coated, wherein the blue light perovskite is a quasi-two-dimensional blue light perovskite PEA _x PA _2-x (CsPbBr ₃ ) _n-1 PbBr ₄ :TMBBr, which is dissolved in DMSO at a concentration of 0.15 mol/L, the rotation speed is not less than 3000 rpm, the spin coating time is at least 60 s, and at 25 s after the start of spin coating, at least 250 μL of anti-solvent toluene is drop-coated, and after the spin coating is completed, annealing is performed at a temperature not less than 150° C. for at least 2 min to obtain a device part having a perovskite light-emitting layer;

(5) Preparation of electron transport layer:

The device with the perovskite light-emitting layer was transferred to a vacuum evaporation chamber and heated to 5 × 10 ^-4 Pa under vacuum. 30-35nm TPBi is deposited at a speed of 1000 nm to obtain an electron transport layer;

(6) Preparation of electron injection layer/electrode modification layer:

After the TPBi of the electron transport layer is deposited, Depositing LiF at a rate of at least 1 nm to obtain an electron injection layer/electrode modification layer;

(7) Anode:

Finally The Al electrode is deposited at a speed of at least 100 nm to obtain a blue light perovskite light-emitting diode device.

Compared with the prior art, the present invention has the following obvious outstanding substantial features and significant advantages:

1. Oxygen vacancies and other defects in the device film will cause fluorescence quenching of the perovskite film, reducing the crystallinity of the perovskite crystal and the stability of the perovskite film; the interface modification layer SBTI introduced in the present invention not only passivates the surface defects of NiO _x and suppresses the fluorescence quenching of the light-emitting layer, but also reduces the injection barrier of holes, which is conducive to the effective injection of holes into the perovskite light-emitting layer, making the injection of holes and electrons more balanced, improving the external quantum efficiency of the quasi-two-dimensional blue light perovskite device, and improving the stability of the device; and the introduction of SBTI improves the film quality of the perovskite, forming a continuous and dense small-grain film, and increasing the probability of radiation recombination;

2. The present invention introduces TMBBr into the PEA _x PA _2-x (CsPbBr ₃ ) _n-1 PbBr ₄ perovskite precursor solution. The C=O and NH functional groups in TMBBr can effectively passivate the defects on the surface and grain boundary of the perovskite grains, inhibit the non-radiative recombination of the perovskite crystals, improve the photoluminescence quantum yield (PLQY) of the film, and achieve a stable electroluminescence peak of blue light PeLEDs at 487nm and a maximum EQE of 8.6%.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic diagram of the structure of a quasi-two-dimensional blue perovskite light-emitting diode device, wherein: 1-substrate, 2-ITO anode, 3-hole transport layer, 4-interface modification layer, 5-perovskite light-emitting layer, 6-electron transport layer, 7-electron injection layer/electrode modification layer, 8-cathode Al.

Figure 2 is a single carrier diagram of the quasi-two-dimensional blue light perovskite modified by SBTI.

Figure 3 is a diagram of the external quantum efficiency of a quasi-two-dimensional blue perovskite light-emitting device.

FIG4 is a device lifetime diagram of a quasi-two-dimensional blue perovskite light-emitting device.

Detailed ways

The above scheme is further described below in conjunction with specific implementation examples. It should be noted that these embodiments are only used to illustrate the present invention and do not limit the scope of the present invention. After reading the content of the present invention, any modifications and substitutions made by those skilled in the art to the present invention fall within the scope defined by the claims attached to this application. The preferred embodiments of the present invention are described in detail as follows:

Example 1

In this embodiment, a method for preparing a blue light perovskite light emitting diode comprises the following steps:

a. Preparation of passivating agent TMBBr:

Dissolve 0.9 g of trifluoromethylbenzamide in at least 25 mL of ethanol, cool to below 10° C. using an ice-water bath, slowly drop at least 2 mL of hydrobromic acid having a mass percentage concentration of not less than 48%, keep the temperature of the mixed solution below 10° C. during the addition of hydrobromic acid, and react for at least two hours; after the reaction, centrifuge the product solution at a speed of not less than 7800 r.p.m., pour out the supernatant, add at least 20 mL of n-hexane to dissolve the precipitate, and then shake and wash away the unreacted product with at least 5 mL of deionized water; then centrifuge the mixed solution at a speed of 7800 r.p.m. for at least 30 seconds until stratification occurs, and rotary evaporate the n-hexane solution of the upper product at not less than 50° C. to obtain a white product, namely TMBBr powder;

b. Preparation of TMB ₂ PbBr ₄ solution:

The above TMBBr powder was mixed with PbBr ₂ at a molar mass ratio of 2:1, and the solvent was dimethyl sulfoxide (DMSO) to obtain a TMB ₂ PbBr ₄ solution;

c. Synthesis of CsPbBr ₃ powder:

5 mmol of _PbBr2 is dissolved in hydrobromic acid having a mass percentage concentration of not less than 48% and stirred for at least 10 minutes, and then at least 1.5 mL of a CsBr aqueous solution having a molar concentration of not less than 3.4 M is added dropwise to obtain an orange solution; then the precipitate is centrifuged from the orange solution, and thoroughly washed with ether and ethanol at least 3 times, and then dried at not less than 60°C for at least 12 hours to obtain a _CsPbBr3 powder;

d. Preparation of quasi-two-dimensional blue perovskite PEA _x PA _2-x (CsPbBr ₃ ) _n-1 PbBr ₄ :TMBBr precursor solution:

According to the ratio of the molar concentration of the target prepared mixed solution, CsPbBr ₃ powder, PABr powder and PEA ₂ PbBr ₄ powder are dissolved in DMSO, and the molar concentration of CsPbBr ₃ in the obtained mixed solution is not less than 0.15M, the molar concentration of PABr is not less than 0.15M, and the molar concentration of PEA ₂ PbBr ₄ is not less than 0.015M, and then at least 10μLTMB ₂ PbBr ₄ solution is added to the mixed solution, and stirred at least 12h in a glove box under a nitrogen environment at not less than 50°C, and filtered for use;

e. Preparation of three-dimensional mixed halogen perovskite light-emitting diode devices:

From bottom to top, a three-dimensional mixed halogen perovskite light-emitting diode device consisting of a substrate 1, an ITO anode 2, a hole transport layer 3, an interface modification layer 4, a perovskite light-emitting layer 5, an electron transport layer 6, an electron injection layer/electrode modification layer 7, and a cathode Al layer 8 is formed; wherein the hole transport layer 3, the interface modification layer 4, the perovskite light-emitting layer 5, the electron transport layer 6, and the electron injection layer/electrode modification layer 7 constitute a light-emitting unit. See FIG1 .

In the step e, preparing a three-dimensional mixed halogen blue perovskite light-emitting device with an upright structure comprises the following steps:

(1) Cleaning of glass substrate containing ITO transparent electrode:

First, the ITO glass substrate is wiped with a dust-free cloth soaked in detergent, and then continuously ultrasonically cleaned with deionized water, acetone and isopropanol for 15 minutes each, and then the glass substrate is dried and treated with oxygen plasma gas for 15 minutes to obtain an anode for standby use;

(2) Preparation of hole transport layer:

A NiO _x ethanol solution with a concentration of 12 mg/mL was spin-coated on the ITO glass substrate after the cleaning treatment in step (1) at a rotation speed of 4000 rpm for 40 seconds. After the spin coating, the solution was annealed at 300° C. for 40 minutes to obtain a NiO _x film.

(3) Preparation of interface modification layer:

The NiO _x film was spin-coated with an SBTI solution dissolved in ethanol, the concentration of the SBTI solution was 1 mg/mL, the rotation speed was 4000 rpm, the spin coating time was 40 s, and after the spin coating was completed, it was annealed at 100°C for 10 min to obtain an interface modification layer;

(4) Preparation of perovskite light-emitting layer:

After the interface modification layer is treated with oxygen plasma gas, a blue light perovskite solution is spin-coated, wherein the blue light perovskite is a quasi-two-dimensional blue light perovskite PEA _x PA _2-x (CsPbBr ₃ ) _n-1 PbBr ₄ :TMBBr, which is dissolved in DMSO at a concentration of 0.15 mol/L. The rotation speed is 3000 rpm, and the spin coating time is 60 s. At 25 s after the start of spin coating, 250 μL of anti-solvent toluene is drop-coated. After the spin coating is completed, the device is annealed at 150° C. for 2 min to obtain a device part with a perovskite light-emitting layer.

(5) Preparation of electron transport layer:

The device with the perovskite light-emitting layer was transferred to a vacuum evaporation chamber and heated to 5 × 10 ^-4 Pa under vacuum. 30-35nm TPBi is deposited at a speed of 1000 nm to obtain an electron transport layer;

(6) Preparation of electron injection layer/electrode modification layer:

After the electron transport layer TPBi is deposited, LiF was deposited at a speed of 1 nm to obtain an electron injection layer/electrode modification layer;

(7) Anode:

Finally The Al electrode was deposited at a speed of 100 nm to a thickness of 100 nm, thereby obtaining a blue light perovskite light-emitting diode device.

Experimental test analysis

The single electron single hole characterization of the quasi-two-dimensional blue light PeLEDs of Example 1 was performed, and the single electron single hole diagram of the quasi-two-dimensional blue light PeLEDs was obtained, as shown in Figure 2. For this type of blue light perovskite device, the electron injection capacity is much higher than the hole injection energy, which causes a large number of carriers to recombine at the interface between the transport layer and the perovskite layer, greatly reducing the device performance. After the SBTI is introduced as the interface modification layer in this embodiment, the hole injection capacity is effectively improved, which is conducive to the hole and electron injection balance and the radiation recombination probability.

The device performance test of the quasi-two-dimensional blue PeLEDs of Example 1 was carried out, and the external quantum efficiency and lifetime of the quasi-two-dimensional blue PeLEDs were obtained. Different from the traditional blue perovskite, the C=O and N-H in the organic molecule TMBBr we introduced modified the defects in the perovskite, effectively inhibited the non-radiative recombination, and improved the device performance, so that the EQE of the device reached 8.6%, as shown in Figure 2, and the lifetime of the device reached 52min, as shown in Figure 3, which shows that this method is an effective solution for preparing high-efficiency quasi-two-dimensional blue PeLEDs devices. Figure 4 is a device lifetime diagram of the quasi-two-dimensional blue perovskite light-emitting device. This embodiment uses SBTI as the interface modification layer, and the inventive concept of TMBBr passivating the perovskite light-emitting layer makes the device have excellent spectral stability and good device performance.

The above embodiment of the present invention introduces the interface modification layer SBTI, which not only passivates the surface defects of NiO _x and suppresses the fluorescence quenching of the light-emitting layer, but also reduces the injection barrier of holes, which is beneficial to the effective injection of holes into the perovskite light-emitting layer, making the injection of holes and electrons more balanced, improving the external quantum efficiency of the quasi-two-dimensional blue light perovskite device, and improving the stability of the device; and the introduction of SBTI improves the film formation quality of the perovskite, forms a continuous and dense small-grain film, and increases the probability of radiative recombination; the above embodiment introduces TMBBr into the PEA _x PA _2-x (CsPbBr ₃ ) _n-1 PbBr ₄ perovskite precursor solution, and the C＝O and NH functional groups in TMBBr can effectively passivate the defects on the surface and grain boundaries of the perovskite grains, suppress the non-radiative recombination of the perovskite crystals, improve the photoluminescence quantum yield (PLQY) of the film, and achieve a stable electroluminescence peak of blue light PeLEDs at 487nm and a maximum EQE of 8.6%.

The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made according to the purpose of the invention of the present invention. Any changes, modifications, substitutions, combinations or simplifications made according to the spirit and principle of the technical solution of the present invention should be equivalent replacement methods. As long as they meet the purpose of the invention of the present invention and do not deviate from the technical principles and inventive concepts of the present invention, they belong to the protection scope of the present invention.

Claims (10)

1. The preparation method of the blue perovskite light-emitting diode is characterized by comprising the following steps of:

a. preparation of passivating agent TMBBr:

Dissolving 0.9g of trifluoromethyl formamide in at least 25mL of ethanol, cooling to below 10 ℃ by using an ice water bath, slowly dripping at least 2mL of hydrobromic acid with the mass percent concentration not lower than 48%, keeping the temperature of the mixed solution below 10 ℃ during dripping the hydrobromic acid, and reacting for at least two hours; after the reaction is finished, centrifuging the product solution at a speed not lower than 7800r.p.m., pouring out supernatant, adding at least 20mL of n-hexane into the precipitate for dissolution, and uniformly shaking with at least 5mL of deionized water to wash out unreacted substances; centrifuging the mixed solution at a speed of 7800r.p.m for at least 30 seconds until layering occurs, and rotationally evaporating the n-hexane solution of the upper product at a temperature of not less than 50 ℃ to obtain a white product, namely TMBBr powder;

b. Preparation of TMB ₂PbBr₄ solution:

mixing TMBBr powder and PbBr ₂ in a molar mass of 2:1, wherein a solvent is dimethyl sulfoxide (DMSO) to obtain TMB ₂PbBr₄ solution;

c. synthesis of CsPbBr ₃ powder:

5mmol of PbBr ₂ is dissolved in hydrobromic acid with the mass percent concentration not lower than 48% and stirred for at least 10 minutes, and then 1.5mL of CsBr aqueous solution with the molar concentration not lower than 3.4M is added dropwise to obtain orange solution; centrifuging the precipitate from the orange solution, thoroughly washing the precipitate with diethyl ether and ethanol for at least 3 times, and drying at 60 ℃ or higher for at least 12 hours to obtain CsPbBr ₃ powder;

d. Preparation of a quasi-two-dimensional blue perovskite PEA _xPA_2-x(CsPbBr₃)_n-1PbBr₄: TMBBr precursor solution:

According to the molar concentration ratio of the mixed solution prepared by the aim, csPbBr ₃ powder, PABr powder and PEA ₂PbBr₄ powder are dissolved in DMSO, the molar concentration of CsPbBr ₃ in the obtained mixed solution is not lower than 0.15M, the molar concentration of PABr is not lower than 0.15M, the molar concentration of PEA ₂PbBr₄ is not lower than 0.015M, at least 10 mu L of TMB ₂PbBr₄ solution is added into the mixed solution, and the mixed solution is stirred for at least 12 hours at the temperature of not lower than 50 ℃ in a glove box in a nitrogen environment and is filtered for later use;

e. preparing a three-dimensional mixed halogen perovskite light-emitting diode device:

A three-dimensional mixed halogen perovskite light-emitting diode device composed of a substrate (1), an ITO anode (2), a hole transport layer (3), an interface modification layer (4), a perovskite light-emitting layer (5), an electron transport layer (6), an electron injection layer/electrode modification layer (7) and a cathode Al layer (8) is formed from bottom to top; the light-emitting unit comprises a hole transport layer (3), an interface modification layer (4), a perovskite light-emitting layer (5), an electron transport layer (6) and an electron injection layer/electrode modification layer (7).

2. The method for manufacturing a Lan Guanggai-titanium-ore light-emitting diode according to claim 1, wherein: in the step e, the substrate (1) and the ITO anode (2) are made of ITO conductive glass, and the thickness of an ITO film is 100-150 nm.

3. The method for manufacturing a Lan Guanggai-titanium-ore light-emitting diode according to claim 1, wherein: in the step e, the hole transport layer (3) is a nickel oxide NiO _x film, and the thickness of the NiO _x film is 35-40 nm.

4. The method for manufacturing a Lan Guanggai-titanium-ore light-emitting diode according to claim 1, wherein: in the step e, the interface modification layer (4) is SBTI, and the thickness of the SBTI is 3-5 nm.

5. The method for manufacturing a Lan Guanggai-titanium-ore light-emitting diode according to claim 1, wherein: in the step e, the perovskite light-emitting layer (5) adopts a perovskite film and is a quasi-two-dimensional blue perovskite

PEA _xPA_2-x(CsPbBr₃)_n-1PbBr₄: TMBBr, and the thickness of the perovskite luminescent layer (5) is 35-40 nm.

6. The method for manufacturing a Lan Guanggai-titanium-ore light-emitting diode according to claim 1, wherein: in the step e, the perovskite light-emitting layer (5) adopts a perovskite film, the light-emitting efficiency of the perovskite film is not lower than 52.3%, the emission wavelength is 485-487 nm, and the full width at half maximum FWHM is 22-24 nm.

7. The method for manufacturing a Lan Guanggai-titanium-ore light-emitting diode according to claim 1, wherein: in the step e, the material of the electron transport layer (6) is Chinese name 1,3,5-Tris (1-phenyl-1H-benzimidazol-2-yl) benzene, namely 1,3,5-Tris (1-phenyl-1H-benzimidazol-2-yl) benzene, TPBi, and the thickness of the thin film of the TPBi is 30-35 nm.

8. The method for manufacturing a Lan Guanggai-titanium-ore light-emitting diode according to claim 1, wherein: in the step e, the electron injection layer/electrode modification layer (7) adopts lithium fluoride LiF, and the film thickness of the lithium fluoride is not less than 1nm.

9. The method for manufacturing a Lan Guanggai-titanium-ore light-emitting diode according to claim 1, wherein: in the step e, the thickness of the cathode Al layer (8) is not less than 100nm.

10. The method for manufacturing a Lan Guanggai-titanium-ore light-emitting diode according to claim 1, wherein: in the step e, the method comprises the following steps:

(1) Cleaning a glass substrate containing an ITO transparent electrode:

Firstly, wiping an ITO glass substrate by using dust-free cloth stained with detergent, sequentially carrying out continuous ultrasonic cleaning treatment on the ITO glass substrate by using deionized water, acetone and isopropanol for at least 15min, drying the glass substrate, and carrying out surface treatment on the glass substrate by using oxygen plasma gas for at least 15min;

(2) Preparation of hole transport layer:

Spin-coating NiO _x ethanol solution with concentration not lower than 12mg/mL on the ITO glass substrate subjected to the cleaning treatment in the step (1), wherein the rotating speed is at least 4000r.p.m., the spin-coating time is at least 40s, and annealing is performed for 40min at the temperature not lower than 300 ℃ after the spin-coating is completed, so as to form a NiO _x film;

(3) Preparation of an interface modification layer:

Spin-coating an SBTI solution dissolved in ethanol on the NiO _x film, wherein the concentration of the SBTI solution is not lower than 1mg/mL, the rotating speed is at least 4000r.p.m., the spin-coating time is at least 40s, and annealing is carried out for at least 10min at the temperature of not lower than 100 ℃ after the spin-coating is finished, so as to prepare an interface modification layer;

(4) Preparation of perovskite light-emitting layer:

after oxygen plasma gas treatment is carried out on the interface modification layer, carrying out spin coating on Lan Guanggai titanium ore solution, wherein blue titanium ore is quasi-two-dimensional blue titanium ore PEA _xPA_2-x(CsPbBr₃)_n-1PbBr₄: TMBBr, the concentration is 0.15mol/L, the rotating speed is not lower than 3000r.p.m., the spin coating time is at least 60s, 25s after the spin coating is started, at least 250 mu L of anti-solvent toluene is dripped, and annealing is carried out for at least 2min at the temperature of not lower than 150 ℃ after the spin coating is finished, so that a device part with a perovskite light-emitting layer is obtained;

(5) Preparation of an electron transport layer:

Transferring the device part with perovskite light-emitting layer to vacuum evaporation chamber under vacuum degree lower than 5×10 ^-4 Pa to Depositing 30-35nm TPBi at a rate to obtain an electron transport layer;

(6) Preparation of electron injection layer/electrode modification layer:

After the TPBi of the electron transport layer is deposited, the electron transport layer is then deposited to be not lower than LiF is deposited at a speed of at least 1nm, and an electron injection layer/electrode modification layer is obtained;

(7) Anode:

finally by Al electrode with a thickness of at least 100nm, thereby obtaining a blue perovskite light emitting diode device.