Preparation method of narrow-band near-infrared photoelectric detector based on double perovskite nanocrystals

Abstract

The invention is applicable to the technical field of near-infrared photoelectric detection, and provides a preparation method of a narrow-band near-infrared photoelectric detector based on double perovskite nanocrystalline, and the prepared narrow-band near-infrared photoelectric detector comprises a transparent conductive substrate, an electron transport layer, a perovskite light absorption layer, a light conversion layer and a metal electrode which are sequentially stacked from bottom to top; the light conversion layer is composed of Cs2NaYbCl6: Er < 3 + > / Sb < 3 + > / K < + > DPNPs; the perovskite light absorption layer is an MAPbI3 perovskite thin film, and the absorption spectrum range of the perovskite light absorption layer covers the up-conversion emission spectrum of the light conversion layer; the electron transport layer is a SnO2 thin film; and the transparent conductive substrate is etched FTO (Fluorine-doped Tin Oxide) conductive glass. The device is simple in structure, can realize high-sensitivity and high-response-speed detection on near-infrared light of 808 nm, 980 nm, 1550 nm and the like under zero bias voltage, has excellent environmental stability, and solves the problems of low efficiency, poor stability and complex preparation of the existing narrow-band near-infrared detector.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of near-infrared photoelectric detection, and particularly relates to a preparation method of a narrow-band near-infrared photoelectric detector based on double perovskite nanocrystals. BACKGROUND

[0002] In recent years, the application of near-infrared (NIR) photoelectric detection technology is very wide, such as biothermal imaging instruments in daily life, biological tracking, sports watches, and the like, and unmanned aerial vehicles, missile guidance, production automation and the like in military and national defense all play an important role. The near-infrared detector (NIR PD) with wavelength selectivity has a broad application prospect in the fields of infrared imaging, environmental monitoring, medical detection, optical communication and the like. The development of NIR I-II zone multi-band selective PDs with easy integration, high sensitivity and low pump threshold has important significance for the development of the fields of encryption communication and biological analysis. At present, the application of wavelength-selective photoelectric detection technology focuses on integrating a plurality of semiconductor materials with different band gaps and different light response capabilities to near-infrared light, but this not only increases the preparation cost and design complexity of the device, but also seriously affects its stability.

[0003] Rare earth ions (RE 3+ ) doped upconversion nanocrystals (UCNPs) have large Stokes / anti-Stokes displacement and excellent optical stability. After absorbing near-infrared photons, they are converted into ultraviolet / visible light photons, which are absorbed by narrow-band semiconductor materials. UCNPs are considered as an excellent photosensitive material due to their advantages such as narrow-band near-infrared wavelength selective absorption characteristics, and provide a solution for the development of a new generation of wavelength-selective photoelectric detectors. However, in practical applications, firstly, the UCNPs need to face the problems of low fluorescence efficiency and high pump threshold; secondly, due to the ionic nature of perovskite, it is relatively unstable under external environmental stimulation. In a humid environment, perovskite can absorb moisture and undergo hydrolysis reaction, resulting in material structure damage and performance degradation; exposed to oxygen, perovskite materials are easily oxidized, affecting their photoelectric properties; long-term light exposure can also cause photodegradation of perovskite materials, reducing the detection rate and stability of PDs; this inherent instability brings challenges to the long-term application of narrow-band near-infrared detectors, which may hinder their commercialization. Therefore, it is of great scientific significance and social value to explore and develop stable narrow-band near-infrared photoelectric detectors. SUMMARY

[0004] The purpose of the embodiments of the present application is to provide a preparation method of a narrow-band near-infrared photoelectric detector based on double perovskite nanocrystals, aiming at solving the problems proposed in the above background.

[0005] The present invention is implemented as follows: a narrowband near-infrared photodetector based on double perovskite nanocrystals includes a transparent conductive substrate, an electron transport layer, a perovskite light-absorbing layer, a light conversion layer and a metal electrode stacked sequentially from bottom to top; The light conversion layer is composed of Cs2NaYbCl6:Er 3+ / Sb 3+ / K + Composed of dual perovskite nanoparticles (DPNPs); The perovskite light-absorbing layer is a MAPbI3 perovskite thin film, whose absorption spectrum covers the upconversion emission spectrum of the light conversion layer. The electron transport layer is a SnO2 thin film; The transparent conductive substrate is etched FTO conductive glass.

[0006] Another objective of this invention is to provide a method for fabricating a narrowband near-infrared photodetector based on double perovskite nanocrystals, comprising the following steps: Step 1: Preparation of Cs2NaYbCl6:Er 3+ / Sb 3+ / K + DPNPs; Using a hot-injection method, with cesium acetate, sodium acetate, potassium acetate, ytterbium acetate, erbium acetate, and antimony acetate as precursors, oleic acid and oleylamine as ligands, and octadecene as solvent, the reaction was carried out at 240°C under an inert atmosphere, followed by centrifugation purification to obtain Cs₂NaYbCl₆:Er 3+ / Sb 3+ / K + DPNPs dispersion; Step 2: Prepare the perovskite light-absorbing layer precursor solution; Lead iodide and methylammonium iodide were dissolved in a mixed solvent of N,N-dimethylformamide and N,N-dimethyl sulfoxide; Step 3: Device fabrication; Step 3.1: Spin-coat the electron transport layer material onto the cleaned and ozone-treated transparent conductive substrate, and anneal to form the electron transport layer; Step 3.2: In an inert atmosphere, spin-coat the precursor solution onto the electron transport layer, introduce an antisolvent, and anneal to form a perovskite light-absorbing layer; Step 3.3: Spin-coating or drop-coating Cs2NaYbCl6:Er onto the perovskite light-absorbing layer. 3+ / Sb 3+ / K + DPNPs dispersion forms a light conversion layer; Step 3.4: Deposit metal electrodes on the light conversion layer.

[0007] In a further technical solution, step 1 includes the following specific steps: First, weigh out 0.9 mmol of C2H3NaO2, 0.1 mmol of potassium acetate (C2H3KO2), 0.845 mmol of Yb(CH3COO)3, 0.15 mmol of erbium acetate (Er(CH3COO)3), 0.005 mmol of antimony acetate (Sb(CH3COO)3), and 2 mmol of C2H3CsO2, and then put them into a clean, dry three-necked flask with a capacity of 100 mL. Add 2 mL of oleic acid (OA), 2 mL of oleylamine (OAm) and 15 mL of octadecene (ODE) respectively, and place a magnetic rotor in the flask; Place the three-necked flask in a heating mantle, set the target temperature to 140℃, the rotation speed to 500 rad / min, and start the vacuum pump; after the flask reaches 140℃, time for 1 hour; after that, turn off the vacuum pump, open the nitrogen valve, and adjust the target temperature to 240℃; when the flask reaches 240℃, quickly use a 1 mL syringe to draw 0.6 mL of benzoyl chloride solution, and after the reaction continues for 2 minutes, remove the flask from the heating mantle and quickly place it in ice water to cool; After the solution is cooled to below 40 °C, the reaction solution is transferred to a centrifuge tube using a dropper. After balancing, the tube is placed in a centrifuge at 10000 rad / min for 10 min. After the first centrifugation, the supernatant is removed, 15 mL of n-hexane is added, and the centrifuge tube is placed in a shaker to fully dissolve the precipitate in the hexane. After complete dissolution, the centrifuge tube is balanced again, and a second centrifugation is performed under the same conditions as the first. After the second centrifugation, the supernatant is discarded, and 15 mL of n-hexane is added and shaken. The resulting solution is Cs₂NaYbCl₆:Er 3+ / Sb 3+ / K + DPNPs dispersion.

[0008] In a further technical solution, step 2 includes the following specific steps: First, 1 mmol of lead iodide (PbI2) and 1 mmol of methyl ammonium iodide (MAI) were placed in a small vial, and 300 µL of the polar solvent N,N-dimethyl sulfoxide (DMSO) and 700 µL of N,N-dimethylformamide (DMF) were added as solvents and mixed thoroughly. After standing for 2 h until the solution was completely clear, the MAPbI3 precursor solution was obtained.

[0009] The method for fabricating a narrowband near-infrared photodetector based on double perovskite nanocrystals provided in this invention has the following beneficial effects: (1) High-performance optical conversion layer: through Er3+ Sb 3+ and K + Synergistic co-doping of Sb in Cs₂NaYbCl₆ lattice 3+ As a bridging ion, Yb promoted 3+ To Er 3+ Energy transfer, K + The introduction of [a specific technology] further shortened the Yb [structure] by adjusting the lattice spacing. 3+ With Er 3+ The distance, and suppressed the interaction with Er 3+ Cross-relaxation between ions significantly improves upconversion luminescence efficiency.

[0010] (2) High sensitivity and low pump threshold: The efficient upconversion luminescence enables the visible light-sensitive perovskite absorber layer to generate more photogenerated carriers, thus achieving microampere-level photocurrents under zero or low bias voltages, realizing high-sensitivity detection under a low pump threshold. The device achieves a responsivity of 83.1 mA / W under 980 nm illumination and a specific detectivity of 2.27 × 10⁻⁶. 13 Jones.

[0011] (3) Excellent stability: The all-inorganic double perovskite nanocrystal light conversion layer exhibits excellent environmental stability (moisture and oxygen resistance). It is combined with the relatively less stable MAPbI3 layer through a discrete structure, rather than being mixed or alloyed, effectively isolating the direct influence of environmental factors on the light-absorbing layer. Tests show that after the device is placed in a 20% humidity environment for 120 days, the photocurrent still maintains more than 98% of its initial value.

[0012] (4) Simple structure and cost advantage: The device adopts a simple stacked structure, avoiding the complex integration process of multi-band semiconductor materials. The synthesis method of the light conversion layer material is mature and inexpensive, which is conducive to large-scale preparation and application. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of a narrowband near-infrared photodetector; Figure 2 Cs2NaYbCl6 DPNPs (left) and Cs2NaYbCl6:Er 3+ / Sb 3+ / K + Microscopic image of DPNPs (right); Figure 3 Cs2NaYbCl6:Er 3+ / Sb 3+ DPNPs and Cs2NaYbCl6:Er 3+ / Sb 3+ / K +Upconversion emission spectra of DPNPs; Figure 4 K doping + The boost factor of green and red light emission in the post-upconversion emission spectrum; Figure 5 The IT diagram for a narrowband near-infrared photodetector; Figure 6 For the responsivity and detectivity of narrowband near-infrared photodetectors; Figure 7 This represents the response time of the narrowband near-infrared photodetector at 980 nm. Figure 8 The linear dynamic range of the narrowband near-infrared photodetector; Figure 9 Stability testing for narrowband near-infrared photodetectors. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0015] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0016] Example 1: Synthesis of Cs2NaYbCl6DPNPs; First, weigh out 1 mmol of sodium acetate (C2H3NaO2), 1 mmol of ytterbium acetate (Yb(CH3COO)3), and 2 mmol of cesium acetate (C2H3CsO2), and then place them into a clean, dry 100 mL three-necked flask. Add 2 mL of OA, 2 mL of OAM, and 15 mL of ODE, and place a magnetic rotor inside the flask. Place the three-necked flask in a heating mantle, set the target temperature to 140 °C, the rotation speed to 500 rad / min, and start the vacuum pump. After the flask reaches 140 °C, time for 1 h. After that, turn off the vacuum pump, open the nitrogen valve, and adjust the target temperature to 240 °C. When the flask reaches 240 °C, quickly use a 1 mL syringe to draw 0.6 mL of benzoyl chloride solution. After the reaction continues for 2 min, remove the flask from the heating mantle and quickly place it in ice water to cool (ensuring the mouth of the flask is above the water surface), while gently shaking to promote rapid cooling. After cooling the solution to below 40 °C, transfer the reaction solution to a centrifuge tube using a dropper. Balance the solution and place it in a centrifuge at 10000 rad / min for 10 min. After the first centrifugation, precipitate is visible on the bottom and walls of the tube, along with a supernatant. Remove the supernatant, add 15 mL of n-hexane, and place the centrifuge tube in a shaker to fully dissolve the precipitate in the hexane. After complete dissolution, balance the centrifuge tube again and perform a second centrifugation under the same conditions as the first. After the second centrifugation, discard the supernatant and add 15 mL of n-hexane, shaking. Transfer the resulting solution to a brand new small glass vial for subsequent experiments and characterization.

[0017] Example 2: Cs2NaYbCl6:Er 3+ / Sb 3+ / K + Synthesis of DPNPs; First, weigh out 0.9 mmol of C2H3NaO2, 0.1 mmol of C2H3KO2, 0.845 mmol of Yb(CH3COO)3, 0.15 mmol of Er(CH3COO)3, 0.005 mmol of Sb(CH3COO)3, and 2 mmol of C2H3CsO2, and then place them into a clean, dry 100 mL three-necked flask. Add 2 mL of oleic acid (OA), 2 mL of oleylamine (OAm), and 15 mL of octadecene (ODE), and place a magnetic rotor inside the flask. Place the three-necked flask in a heating mantle, set the target temperature to 140 °C, the rotation speed to 500 rad / min, and start the vacuum pump. After the flask reaches 140 °C, time for 1 hour. After that, turn off the vacuum pump, open the nitrogen valve, and adjust the target temperature to 240 °C. When the flask reaches 240 °C, quickly use a 1 mL syringe to draw 0.6 mL of benzoyl chloride solution. After the reaction continues for 2 min, remove the flask from the heating mantle and quickly place it in ice water to cool (ensuring the mouth of the flask is above the water surface), while gently shaking to promote rapid cooling. After the solution cools to below 40 °C, use a dropper to transfer the reaction solution to a centrifuge tube. After balancing, place the tube in a centrifuge, set the speed to 10000 rad / min, and the centrifuge time to 10 min. After the first centrifugation, precipitate is visible on the bottom and walls of the tube, accompanied by a supernatant. Remove the supernatant, add 15 mL of n-hexane, and place the centrifuge tube in a shaker to fully dissolve the precipitate in the n-hexane. After complete dissolution, balance the centrifuge tube again and perform a second centrifugation under the same conditions as the first. After the second centrifugation, discard the supernatant and add 15 mL of n-hexane and shake. Transfer the resulting solution to a brand new small glass bottle for subsequent experiments and characterization.

[0018] Example 3: Preparation of MAPbI3 precursor; First, 1 mmol of PbI2 and 1 mmol of MAI were placed in a vial, and 300 µL of the polar solvent N,N-dimethyl sulfoxide and 700 µL of N,N-dimethylformamide were added as solvents and mixed thoroughly. After standing for 2 hours until the solution was completely clear, the MAPbI3 precursor solution was obtained.

[0019] Example 4: Detector structure design; First, a commercially available etched FTO conductive glass (2cm x 2cm, 5mm etching width, 500nm depth) was placed in a beaker for cleaning. Detergent and water were added to the beaker to remove surface dust and debris, and plastic wrap was used to cover the surface to prevent dust from falling into the beaker and causing recontamination. After ultrasonically vibrating the beaker for 20 minutes, the cleaning solvent was replaced with anhydrous ethanol to remove aqueous solvents and residues from the FTO surface. This process was repeated for 30 minutes of vibration. Then, anhydrous ethanol was replaced with acetone to remove oily stains. After another 30 minutes of vibration, the acetone was recovered. Next, deionized water was added to cover the top of the FTO to remove any remaining methanol, acetone, and other cleaning solvents. After vibrating for 30 minutes, the deionized water was discarded. The plastic wrap was then punctured and placed in a 60℃ oven for 5 hours to dry the surface moisture before use. Before spin coating, the cleaned FTO conductive glass was placed in an instrument for ozone treatment for 30 minutes to add hydrophilic groups to the surface and increase solution adhesion. Subsequently, a tin dioxide solution diluted with deionized water (SnO2:H2O=1:3) was spin-coated onto an ozone-treated FTO substrate at 5000 rpm / min for 30 s, followed by annealing at 150 °C for 30 min as an electron transport layer. The SnO2-coated FTO and the synthesized MAPbI3 precursor solution were then placed in a glove box to ensure an inert gas environment throughout the synthesis process. The FTO substrate was placed on a spin coater, and 100 µL of the MAPbI3 precursor was dissolved and placed on the FTO. The spin coater was turned on and rotated at a low speed of 600 rpm / min for 12 s, followed by a high speed of 4000 rpm / min for 30 s. At the 21st s mark, 400 µL of chlorobenzene was spin-coated onto the surface. After spin coating, the substrate was annealed at 60 °C for 5 minutes, followed by annealing at 100 °C for 10 minutes, resulting in the growth of a 50 µm thick MAPbI3 perovskite film on the FTO surface.

[0020] The device structure for fabricating a stable narrowband near-infrared photodetector is as follows: Figure 1 As shown, it includes a transparent conductive substrate, an electron transport layer, a perovskite light-absorbing layer, a light conversion layer, and a metal electrode stacked sequentially from bottom to top; The light conversion layer is composed of Cs2NaYbCl6:Er 3+ / Sb 3+ / K + DPNPs constitute; The perovskite light-absorbing layer is a MAPbI3 perovskite thin film, whose absorption spectrum covers the upconversion emission spectrum of the light conversion layer. The electron transport layer is a SnO2 thin film; The transparent conductive substrate is etched FTO conductive glass.

[0021] Since the absorption spectrum of the MAPbI3 layer ranges from 365 to 725 nm, covering the entire emission wavelength range of DPNPs, the MAPbI3 layer absorbs visible light from DPNPs, generating a large number of electron-hole pairs within the layer. Ultimately, electrons are transferred to the silver electrode to form a photocurrent. The Cs2NaYbCl6:Er electrode was selected as the photocurrent source. 3+ / Sb 3+ / K + The integration of DPNPs with MAPbI3 thin films to fabricate near-infrared photodetectors is due to the presence of DPNPs in Cs2NaYbCl6:Er 3+ Appropriate amount of Sb co-doped in DPNPs 3+ and K + Yb can be passivated 3+ and Na + The vacancy defects suppress nonradiative recombination and enhance Er 3+ It emits green and red light. Simultaneously, K... + Doping will increase [NaCl6] 5- The dimensions of the octahedron, and the compression of adjacent [(Er / Yb)Cl6] 3- The size of the octahedron, thus shortening Yb 3+ and Er 3+ The distance between them improves energy transfer efficiency. This synergistic structural optimization results in green and red light emission being significantly higher than that of Cs2NaYbCl6:Er 3+ / Sb 3+ DPNPs enhance the MAPbI3 film by 2500% and 800%, enabling it to absorb more visible light, generate more electron-hole pairs, and ultimately achieve higher photocurrent, thus improving the performance of the near-infrared photodetector.

[0022] Example 5: Cs2NaYbCl6:Er 3+ / Sb 3+ / K + Structural characterization of DPNPs; To investigate Cs2NaYbCl6:Er 3+ / Sb 3+ / K + The optical properties of DPNPs were improved, and various aspects were characterized. Based on Examples 1-4 above, intrinsic Cs2NaYbCl6 DPNPs and Cs2NaYbCl6:Er were further improved. 3+ / Sb 3+ / K + DPNPs were subjected to transmission electron microscopy (TEM) testing, and the microscopic images are as follows: Figure 2 As shown, at the 50 nm scale, a significant difference can be observed, with the size increasing from the original 27.9 nm to 40.3 nm. This is attributed to K.+ (1.33 Å) partially replaced Na + (1.02 Å), which triggers lattice expansion of the nanocrystals, resulting in an increase in size.

[0023] Example 6: Cs2NaYbCl6:Er 3+ / Sb 3+ / K + Optical characterization of DPNPs Cs2NaYbCl6:Er 3+ / Sb 3+ / K + The upconversion emission of DPNPs at 525 nm and 551 nm corresponds to 4 I 15 / 2 → 2 H 11 / 2 , 4 S 3 / 2 661 nm is 4 F 9 / 2 → 4 I 15 / 2 Transition. Doping with K + Afterwards, the location of the launch peak was... Figure 3 No changes were observed in the concentration of Cs2NaYbCl6:15%Er 3+ / 0.5%Sb 3+ DPNPs at 10%K + After doping, such as Figure 4 The red and green light emission was enhanced by 2460% and 730%, respectively. The increase in the difference between green and red light emission is due to the green light emission ( 4 S 3 / 2 → 4 I 15 / 2 This can be achieved through two types of energy transfer, namely... 4 I 15 / 2 → 4 I 11 / 2 (ET1) and 4 I 11 / 2 → 4 F 7 / 2 → 4 S 3 / 2 (ET2), this path only requires two Yb... 3+ -Er 3+ Energy transfer forms a short and efficient energy transmission path. However, red light emission ( 4 F 9 / 2 → 4 I 15 / 2 First, we need to start from the green light level ( 4 S 3 / 2 Relaxation to red light level (4 F 9 / 2 This leads to lower efficiency. Meanwhile, when Yb 3+ At higher concentrations, red light emission depends on Er. 3+ -Yb 3+ Cross-relaxation (CR) causes the response speed of red light emission to be slower than that of direct green light emission. Furthermore, due to the introduction of K... + It can expand Er 3+ -Er 3+ The spacing between them reduces the occurrence of cross relaxation. 2 H 11 / 2 , 4 S 3 / 2 ; 4 I 9 / 2 ]→[ 4 F 9 / 2 ; 4 F 9 / 2 This ultimately resulted in different enhancements in the emission of red and green light.

[0024] Example 7: Detector performance characterization; Figure 5 The photocurrent versus time (IT) curves of this device under 0 V bias illumination at 808 nm, 980 nm, and 1550 nm are shown. The photocurrent values ​​at 808 nm, 980 nm, and 1550 nm are 1.93 μA, 2.16 μA, and 1.89 μA, respectively, with an extremely low dark current of 6.8 × 10⁻¹³ A. The differences in photocurrent magnitude are attributed to variations in upconversion luminescence intensity, indicating excellent photodetector performance. Figure 6 As shown, the responsivity and specific detectivity at 808 nm, 980 nm, and 1550 nm are 58.4 mA / W and 2.27 × 10⁻⁶, respectively. 13 Jones, 83.1 mA / W and 2.27 × 10 13 Jones, and 49.7 mA / W and 2.07×10 13 Jones. Figure 7 In the above, the response times at 980 nm are 230 ms and 185 ms, respectively, indicating that the device has an extremely fast optical response. Figure 8 As shown, the fabricated detector has a linear dynamic range of 51 dB, indicating its excellent performance in detecting weak light signals. Figure 9 After 120 days of placement, the photocurrent still maintains 98% of its initial value, indicating that it has excellent long-term stability.

[0025] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A narrow-band near-infrared photodetector based on double perovskite nanocrystals, characterized in that, The transparent conductive substrate, the electron transport layer, the perovskite light-absorbing layer, the light conversion layer and the metal electrode are sequentially stacked from bottom to top. The light conversion layer is composed of Cs2NaYbCl6:Er 3+ / Sb 3+ / K + DPNPs The perovskite light-absorbing layer is a MAPbI3 perovskite film, and the absorption spectrum range covers the up-conversion emission spectrum of the light conversion layer. The electron transport layer is a SnO2 film. The transparent conductive substrate is etched FTO conductive glass.

2. A method for preparing a narrow-band near-infrared photodetector based on double perovskite nanocrystals, the narrow-band near-infrared photodetector based on double perovskite nanocrystals according to claim 1, characterized in that, The method comprises the following steps: Step 1 : Preparation of Cs2NaYbCl6:Er 3+ / Sb 3+ / K + DPNPs; Cs2NaYbCl6:Er was prepared by hot-injection method using cesium acetate, sodium acetate, potassium acetate, ytterbium acetate, erbium acetate and antimony acetate as precursors, oleic acid and oleylamine as ligands, octadecene as solvent, and then purified by centrifugation under inert atmosphere at 240℃, followed by centrifugation purification, to obtain Cs2NaYbCl6:Er 3+ / Sb 3+ / K + DPNPs dispersion; Step 2: preparing a perovskite light-absorbing layer precursor solution; Lead iodide and methylammonium iodide are dissolved in a mixed solvent of N,N-dimethylformamide and N,N-dimethyl sulfoxide; Step 3: device preparation; Step 3.1: spin-coating an electron transport layer material on the transparent conductive substrate after cleaning and ozone treatment, and annealing to form an electron transport layer; Step 3.2: spin-coating the precursor solution on the electron transport layer in an inert atmosphere, introducing an anti-solvent, and annealing to form a perovskite light-absorbing layer; Step 3.3: Spin or drop coating Cs2NaYbCl6:Er on the perovskite light absorbing layer 3+ / Sb 3+ / K + DPNPs dispersion, forming a light conversion layer; Step 3.4: evaporating a metal electrode on the light conversion layer.

3. The method of claim 2, wherein the method further comprises: The step 1 comprises the following specific steps: First, 0.9 mmol of C2H3NaO2, 0.1 mmol of C2H3KO2, 0.845 mmol of Yb(CH3COO)3, 0.15 mmol of Er(CH3COO)3, 0.005 mmol of Sb(CH3COO)3 and 2 mmol of C2H3CsO2 are weighed, and then put into a clean and dry three-neck flask with a capacity of 100 mL; 2 mL of OA, 2 mL of OAm and 15 mL of ODE are added respectively, and a magnetic rotor is placed in the flask; The three-neck flask is placed in a heating jacket, the target temperature is set to 140℃, the rotation speed is 500 rad / min, and the vacuum pump is started; after the flask is heated to 140℃, timing is started for 1 h; when the time is up, the vacuum pump is turned off, the nitrogen valve is opened, and the target temperature is adjusted to 240℃; when the flask reaches 240℃, 0.6 mL of benzoyl chloride solution is quickly taken out using a 1 mL syringe, the reaction continues for 2 min, then the flask is taken out of the heating jacket and quickly placed in ice water for cooling; After the solution is cooled to below 40℃, the reaction solution is transferred to a centrifuge tube using a dropper; After mass balancing, the centrifuge is set to a rotation speed of 10000 rad / min and a centrifugation time of 10 min; after the first centrifugation is completed, the supernatant is removed, 15 mL of n-hexane is added, and the centrifuge tube is placed in a shaker to fully dissolve the precipitate in n-hexane. After complete dissolution, the centrifuge tube is again made up to volume, centrifuged a second time under the same conditions as the first time; after the second centrifugation, the supernatant is decanted and 15 mL of n-hexane is added and shaken; the resulting solution is Cs2NaYbCl6:Er 3+ / Sb 3+ / K + DPNPs dispersion.

4. The method of claim 2, wherein the method further comprises: The step 2 comprises the following specific steps: First, 1 mmol of PbI2 and 1 mmol of MAI are put into a vial, 300 µL of polar solvent N,N-dimethyl sulfoxide and 700 µL of N,N-dimethylformamide are added as solvents, and the solution is mixed thoroughly, and after being still for 2 h until the solution is completely clear, a MAPbI3 precursor solution is obtained.

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