Method for preparing CdSe/CdS nuclear shell semiconductor quantum dots at normal temperature

A technology for semiconductors and quantum dots, which is applied in the field of preparing CdSe/CdS core-shell semiconductor quantum dots, can solve problems such as unfavorable solubility of quantum dots and decrease in conductivity of nanoparticles, and achieves mild reaction conditions, simple process and wide application prospects. Effect

Inactive Publication Date: 2015-12-16
FUDAN UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The presence of insulating long-chain organic ligands reduces the conductivity of nanoparticles and is not conducive to the solubility of quantum dots in polar solvents

Method used

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  • Method for preparing CdSe/CdS nuclear shell semiconductor quantum dots at normal temperature
  • Method for preparing CdSe/CdS nuclear shell semiconductor quantum dots at normal temperature
  • Method for preparing CdSe/CdS nuclear shell semiconductor quantum dots at normal temperature

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Embodiment 1

[0020] 1.1 Synthesis of 2nm CdSe quantum dots by oil phase method. Synthesis of 2nmCdSe quantum dots. 256mg CdO, 3.5mL oleylamine and 40mL octadecene were heated to 220°C and kept at 220°C until the solution was colorless and clear. Then the solution was reduced to 120°C and vacuum was applied for 1 hour. In N 2 Under the conditions, 2mL TOP dissolved with 316mg Se powder was injected into the precursor solution of Cd. React for 10 minutes and cool down. Wash and finally dissolve in n-hexane solution.

[0021] 1.2S 2- Surface treatment quantum dot particles

[0022] 1.2.1(NH 4 ) 2 S surface treatment. At room temperature, use (NH 4 ) 2 S (40%-48% aqueous solution) formamide solution treats CdSe quantum dots to exchange semiconductor nanoparticles into formamide. Wash the CdSe / CdS core-shell semiconductor nanoparticles with acetone to remove excess S 2- , And finally dissolved in formamide.

[0023] 1.2.2K 2 S surface treatment. At room temperature, use K 2 S formamide solutio...

Embodiment 2

[0026] 2.1 Synthesis of 3nm CdSe quantum dots by oil phase method. 3nmCdSe quantum dot synthesis. 77mgCdO, 757μL oleylamine, 30mL octadecene in N 2 Heat to 250°C and keep until the solution becomes clear. Cool down to 120°C and vacuum for 1h. Under N2 conditions, heat the solution to 240°C and keep it for 3 minutes. Add 1mL of oleylamine, 1mL of oleic acid and 4mL of octadecene mixture and inject it at a rate of 1mL / min. The reaction was kept at 240°C for 30 minutes. Reduce to room temperature, wash, and finally dissolve in n-hexane solution.

[0027] 2.2.1(NH 4 ) 2 S surface treatment. At room temperature, use (NH 4 ) 2 S (40%-48% aqueous solution) formamide solution treats CdSe quantum dots to exchange semiconductor nanoparticles into formamide. Wash the CdSe / CdS core-shell semiconductor nanoparticles with acetone to remove excess S 2- , And finally dissolved in formamide.

[0028] 2.2.2K 2 S surface treatment. At room temperature, use K 2 S formamide solution treats CdSe...

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Abstract

The invention belongs to the technical field of inorganic materials, and particularly relates to a method for preparing CdSe/CdS nuclear shell semiconductor quantum dots at a normal temperature. According to the method, a formamide solution of ammonium sulfide or potassium sulphide is used for treating CdSe nano particles at the normal temperature, and CdSe/CdS nuclear shell semiconductor nano particles are obtained; meanwhile, S2- replaces organic long carbon chain ligands on the surfaces of the CdSe nano particles, and the nano particles are dissolved in formamide polar solvent; afterwards, illumination is conducted for two days under the air condition, and fluorescence of the semiconductor nano particles is enhanced; (NH4)2S is used for treating CdSe nano particles of 2 nm so that the quantum yield can be increased to 39.8%, and the quantum yield of CdSe nano particles of 3 nm can be increased to 9.4%; K2S is used for treating the CdSe nano particles of 2 nm so that the quantum yield can be increased to 26.1%, and the quantum yield of the CdSe nano particles of 3 nm can be increased to 3.3%. The method is simple, the reaction condition is moderate, the prepared CdSe/CdS nuclear shell semiconductor quantum dots can be dissolved in the polar solvent, and the quantum yield is high. Broad application prospects can be achieved in the fields of photodiodes, fluorescent marks and the like.

Description

technical field [0001] The invention belongs to the technical field of inorganic materials, and in particular relates to a method for preparing CdSe / CdS core-shell semiconductor quantum dots. Background technique [0002] The optical properties of CdSe / CdS core-shell nano-quantum dots are closely related to the particle size and shape, so the optical properties can be adjusted by adjusting the size and shape of the nano-particles, which makes it suitable for field effect transistors, solar cells, Photodetectors have a wide range of applications. Moreover, its unique chemical structure of type I makes electrons and holes concentrated in the core, making it exhibit more excellent fluorescence characteristics. [0003] The traditional preparation of CdSe / CdS core-shell nanoparticles is to add the precursor solution of Cd and S to the organic phase solution of the CdSe core under high temperature conditions, so that a layer of CdS shell grows on the surface of the core. In ord...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K11/88C09K11/02
Inventor 董安钢杨东刘丽敏汲丽胡建华汪碧微
Owner FUDAN UNIV
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