A method of controlling the size distribution of pbs or pbse quantum dots

A technology of size distribution and quantum dots, which is applied in the field of compound semiconductor nanomaterial preparation, can solve the problems of difficult to find suitable reactivity and low chemical yield, and achieve the effect of low cost, simple operation process and low environmental requirements

Inactive Publication Date: 2018-09-21
HUAZHONG UNIV OF SCI & TECH +1
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] Aiming at the defects of the prior art, the object of the present invention is to provide a method for controlling the size distribution of PbSe quantum dots, which aims to solve the problem that the traditional method of controlling the size distribution of quantum dots is usually to maintain supersaturation by subsequent injection of molecular precursors. The chemical yield of the reaction is low and the problem of finding molecular precursors with suitable reactivity is difficult

Method used

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  • A method of controlling the size distribution of pbs or pbse quantum dots
  • A method of controlling the size distribution of pbs or pbse quantum dots
  • A method of controlling the size distribution of pbs or pbse quantum dots

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example 1

[0044] (1) Weigh 0.417g of lead chloride and 5ml of OLA in a two-necked reaction flask, and vacuumize the mixture.

[0045](2) Heat the mixture to 140°C for 30min, then raise the temperature of the mixture to 190°C, inject 0.3ml of CdSe quantum dot solution (concentration: 125mg / mL) with a particle size of 3.26nm, and keep for 30s. Take a small amount of reaction solution immediately after 30s, and measure its optical absorption in a fluorescence spectrometer, and its absorption spectrum is as follows: figure 2 Shown in a.

[0046] (3) Then immediately lower the temperature to 160°C. After the temperature reaches 160°C, quickly inject 0.7mL of CdSe quantum dot solution (concentration: 40mg / mL) with a particle size of 1.95nm, and take a small amount of reaction solution immediately after 4min, and measure it with a fluorescence spectrometer Its optical absorption, its absorption spectrum as figure 2 Shown in b.

[0047] (4) Then continue to inject 1mL particle diameter and...

example 5

[0059] (1) Weigh 0.834g of lead chloride and 10ml of OLA in a two-necked reaction flask, and vacuumize the mixture.

[0060] (2) Heat the mixture to 140°C for 30min, then raise the temperature of the mixture to 190°C, inject 1ml of CdS quantum dot solution (containing about 0.25mmol S) with a particle size of 5.27nm quickly, and keep for 40s. Take a small amount of reaction solution immediately after 40s, and measure its optical absorption in a fluorescence spectrometer, and its absorption spectrum is as follows: Image 6 Shown in a.

[0061] (3) Then immediately lower the temperature to 160°C. After the temperature reaches 160°C, quickly inject 1.25mL of CdS quantum dot solution (containing about 0.125mmol S) with a particle size of 1.45nm, take a small amount of reaction solution immediately after 5min, and measure it with a fluorescence spectrometer Its optical absorption, its absorption spectrum as Image 6 Shown in b.

[0062] (4) Then continue to inject 1.5mL of CdS q...

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Abstract

The invention discloses a method for controlling PbS or PbSe quantum dot size distribution. The method comprises the following steps that: (1) first, CdSe (or CdS) quantum dots with larger sizes are injected into a precursor of lead, and PbSe (or PbS) quantum dots with larger sizes are obtained through a cation exchange reaction at the moment; (2) then, CdSe (or CdS) quantum dots with smaller sizes are continuously injected, and the PbSe (or PbS) quantum dots with smaller sizes are obtained through the cation exchange reaction at the moment; (3) finally, the size distribution of the PbSe (or PbS) quantum dots becomes narrower and narrower under the action of Ostwald ripening effect, so that the size distribution of the PbSe (or PbS) quantum dots is controlled. Through the method, various sizes of the PbSe (or PbS) quantum dots with extremely good size distribution can be obtained; moreover, the PbSe (or PbS) quantum dots are specifically stable in air; the method is low in cost, easy to operate, and not strict in environment requirement.

Description

technical field [0001] The invention belongs to the technical field of preparation of compound semiconductor nanometer materials, and in particular relates to a method for controlling the size distribution of PbS or PbSe quantum dots. Background technique [0002] Semiconductor quantum dots are quasi-zero-dimensional nanomaterials. When the particle size enters the nanoscale, size confinement will cause size effects, quantum confinement effects, macroscopic quantum tunneling effects, and surface effects, thus deriving nanosystems different from The low-dimensional physical properties of macroscopic and microscopic systems exhibit many physical and chemical properties different from macroscopic materials. [0003] Because the various characteristics of quantum dots are closely related to the size of quantum dots, for example, the half-width of the absorption spectrum and emission spectrum of quantum dots will become narrower as the size distribution of quantum dots becomes sm...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01G21/21C01B19/00B82Y30/00B82Y40/00
CPCB82Y30/00B82Y40/00C01B19/007C01G21/21C01P2002/85C01P2004/04C01P2004/32C01P2004/52C01P2004/64
Inventor 张建兵张长旺张志明夏勇黄震张道礼
Owner HUAZHONG UNIV OF SCI & TECH
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