Surface defect passivated metal halide perovskite nanocrystals, their preparation and applications

A metal halide, perovskite technology, applied in chemical instruments and methods, semiconductor/solid-state device manufacturing, luminescent materials, etc. High dynamic instability and other problems, to achieve the effect of improving photoluminescence quantum yield, solving non-radiation loss, and benefiting performance

Active Publication Date: 2020-11-17
HUAZHONG UNIV OF SCI & TECH
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For NCs, there are many ligands hanging on their surface. Although these surface ligands can make NCs exist stably, these ligands are highly dynamic and unstable, which makes the ligands easy to fall off during the purification process, which eventually leads to the loss of NCs. surface defects
These surface defects will lead to non-radiative recombination, which is not conducive to the improvement of the performance of electroluminescent devices.
In order to passivate the defects on the surface of NCs, most of the strategies are to improve the surface state of NCs by introducing exogenous ligands, but the passivating groups of these exogenous ligands inevitably introduce 3-4 carbons, Therefore, to a certain extent, the electrical properties of NCs deteriorate, which is not conducive to improving the electroluminescent efficiency of NCs light-emitting diodes (LEDs).

Method used

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  • Surface defect passivated metal halide perovskite nanocrystals, their preparation and applications
  • Surface defect passivated metal halide perovskite nanocrystals, their preparation and applications
  • Surface defect passivated metal halide perovskite nanocrystals, their preparation and applications

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preparation example Construction

[0040] In some embodiments, the preparation method includes the following steps:

[0041] (1) Mix the halides, metal halides, and surface active ligands of the A-position monovalent cations in an organic solvent to obtain a metal halide perovskite nanocrystal precursor solution; wherein the A-position monovalent cations The halide is excessive relative to the metal halide, that is, the molar amount of the halide of the A-position monovalent cation is greater than the molar amount of the metal halide;

[0042] (2) mixing the precursor solution obtained in step (1) with a poor solvent to obtain the crude liquid of the metal halide perovskite nanocrystal;

[0043] (3) Mix the crude liquid obtained in step (2) with the medium solvent to obtain the precipitate, add the dispersion liquid, collect the stably dispersed supernatant to obtain the colloidal solution of the metal halide perovskite nanocrystal.

[0044] In some embodiments, the halide of the A-position monovalent cation i...

Embodiment 1

[0059] This embodiment provides a method to prepare FAPbBr using excess FABr 3 The method of NCs and its application in electroluminescent diodes include the following steps:

[0060] Preparation of FAPbBr 3 NCs solution: accurate weighing of PbBr with electronic balance 2 (0.0367g, 0.1mmol) and 0.22mmolFABr (FABr:PbBr 2 =2.2:1), add 0.5mL DMF solvent, place on a magnetic stirrer and stir until the raw materials are completely dissolved. Then, 250 μL of oleic acid and 25 μL of n-octylamine were added and mixed to obtain a precursor solution. The precursor solution was quickly added dropwise per 100 μL into a vigorously stirred 8 mL chloroform solution with a pipette gun, and green-emitting NCs were formed immediately. After stirring for 35 s, the stirring was stopped to obtain the crude NCs solution. Add 3 mL of acetonitrile to the obtained NCs crude solution, and then centrifuge at 11000 r.p.m. for 5 minutes. Discard the supernatant and disperse the pellet in 4 mL of ...

Embodiment 2

[0076] Preparation of CsPbBr 3 NCs solution: accurate weighing of PbBr with electronic balance 2 (0.0367g, 0.1mmol) and 0.2mmol CsBr, add 1mL DMSO solvent, place on a magnetic stirrer and stir until the raw materials are completely dissolved. Then, 250 μL oleic acid and 125 μL oleylamine were both added, and mixed to obtain a precursor solution. The precursor solution was quickly added dropwise per 100 μL into the vigorously stirred 8 mL toluene solution with a pipette gun, and green-emitting NCs were formed immediately. After stirring for 35 s, the stirring was stopped to obtain the crude NCs solution. Add 27 mL of ethyl acetate to the obtained NCs crude solution, and then centrifuge at 11000 r.p.m. for 5 minutes. Discard the supernatant and disperse the pellet in 4 mL of octane. Finally, the octane dispersion was centrifuged at 6000 r.p.m. for 3 minutes to remove large perovskite particles, and then the stable dispersed supernatant was collected and filtered through a 0...

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Abstract

The invention belongs to the field of optoelectronic materials, and more specifically relates to a metal halide perovskite nanocrystal with surface defect passivation, its preparation and application, and the process of preparing metal halide perovskite nanocrystal by ligand-assisted method In the process, the halide of the A-site monovalent cation is added in excess relative to the metal halide, and the excess A-site monovalent cation halide replaces part of the surface-active ligands to fill part of the defect on the surface of the perovskite nanocrystal, and realize calcium Passivation of surface defects of titanium ore nanocrystals to obtain metal halide perovskite nanocrystals with passivation of surface defects. The obtained nano crystal colloid solution has good dispersibility, can realize stable photoluminescence, high luminous efficiency and high color purity. The method has the advantages of low cost, simple operation and high repeatability. When the perovskite nanocrystals prepared by this method are applied to electroluminescent diodes, the device efficiency is greatly improved due to the reduction of surface ligands and the improvement of its electrical conductivity.

Description

technical field [0001] The invention belongs to the field of photoelectric materials, and more specifically relates to a metal halide perovskite nanocrystal with surface defect passivation, its preparation and application. Background technique [0002] With the continuous development of science and technology, future display technology will permeate all aspects of our lives, and interactive display interfaces will be ubiquitous in our lives. Display technology is regarded as the core technology that increases the convenience of people's daily life. The trend of display technology Shift from high efficiency and high resolution to high color purity for more vivid natural colors. [0003] Metal halide perovskite, taking lead halide perovskite as an example, as an emerging semiconductor material, in addition to the advantages of organic semiconductor flexibility and planar light emission, it also has high color purity, low cost, and high carrier mobility. , shallow defect energ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C09K11/06H01L51/42H01L51/50
CPCC09K11/06C09K2211/10H10K30/10H10K50/115Y02E10/549
Inventor 王磊范连伟阳妃
Owner HUAZHONG UNIV OF SCI & TECH
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