Quantum dot surface purification method for improving luminous efficiency of perovskite LED

A technology of luminous efficiency and quantum dots, used in semiconductor devices, electrical components, circuits, etc., can solve the problems of complex operation, can not improve device performance well, achieve good crystallinity, simple surface treatment method, reduce ligands effect of quantity

Active Publication Date: 2016-10-12
NANJING UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The surface state treatment of perovskite quantum dots has always been a difficult problem. It has been reported (Li G, Rivarola F W R, Davis N J L K, et al. Highly Efficient Perovskite Nanocrystal Light‐Emitting Diodes Enabled by a Universal Crosslinking Method[J]. Advanced Materials, 2016.) Introduce an aluminum source on the surface of the quantum dot film, and use ALD to make the ligands on the surface of the quantum dot form a cross-linked structure through Al, but this only treats the surface of the film and cannot improve the performance of the device. complex

Method used

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  • Quantum dot surface purification method for improving luminous efficiency of perovskite LED

Examples

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Embodiment 1

[0029] 1) Dissolve 2.5g of Cs(st) in 40mL of octadecene, heat and stir to dissolve completely, and make a cesium precursor solution;

[0030] 2) Add 0.198g of PbBr 2 Dissolve in a mixed solution of 1.5mL oleic acid, 1mL oleylamine and 15mL octadecene, repeatedly evacuate-fill with argon, cycle for 10min, exhaust oxygen and water, and ensure that the reaction system is protected by an inert atmosphere;

[0031] 3) Heat and stir at 120°C, continue heating for 10 minutes until the reactants are fully dissolved, then raise the temperature to 170°C;

[0032] 4) Take 0.55g of the cesium precursor solution in step 1), quickly inject it into the mixed solution, react for 5s, and quickly ice-bath to room temperature to obtain the CsPbBr3 quantum dot stock solution;

[0033] 5) In CsPbX 3 Add 20mL acetone and 20mL ethyl acetate to the stock solution of quantum dots, centrifuge at 10000rpm / 1min, pour off the supernatant, and take the precipitate;

[0034] 6) Dissolve the precipitate i...

Embodiment 2

[0038] Using the same process as in Example 1, the difference is that step 6) in Example 1 is not operated, and the precipitate obtained in step 5) is directly combined with step 7), and other conditions remain the same.

Embodiment 3

[0040] The same process as in Example 1 was adopted, except that step 6) was repeated before step 7) in Example 1, and other conditions remained the same.

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Abstract

The invention discloses a quantum dot surface purification method for improving the luminous efficiency of a perovskite LED. The method comprises the steps of: (1) adding a flocculant to a CsPbX3 quantum dot solution, carrying out centrifuging and then taking sediments; (2) dispersing the sediments into an organic solvent, adding a purification solvent, carrying out centrifuging again and taking the sediments; and (3) dispersing the sediments obtained in the step (2) into the organic solvent again and obtaining purified CsPbX3 quantum dots. Surface purification is carried out on the perovskite quantum dots by screening different solvents and cycle indexes; the number of ligands on the surfaces of the quantum dots is reduced; and the charge injection rate can be improved while the photoluminescence quantum yield is ensured, so that an QLED with high luminous efficiency is obtained; the photoluminescence quantum yield of the purified QLED is kept over 90%; and the external quantum efficiency is improved to 3.2% from 0.9%.

Description

technical field [0001] The invention relates to a quantum dot surface purification method for improving the luminous efficiency of a perovskite LED, belonging to the field of material synthesis. Background technique [0002] In the past two years, perovskite materials have developed rapidly in the field of optoelectronics due to their advantages such as high carrier mobility, pure luminous color, high photoelectric conversion efficiency, and strong room temperature photoluminescence characteristics. The EQE of organic-inorganic hybrid perovskite LEDs has increased from 0.76% to 8.53% within one year. It can be seen that perovskite materials have great potential in the display field, but their poor stability has hindered their application development. Compared with organic-inorganic hybrid perovskite, all-inorganic perovskite material has higher stability, and it will have greater application value in the field of optoelectronics. But the EQE of the reported all-inorganic pe...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01L33/00H01L33/06
CPCH01L33/005H01L33/06
Inventor 曾海波许蕾梦宋继中李建海薛洁董宇辉陈嘉伟王涛
Owner NANJING UNIV OF SCI & TECH
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