Method of continuous flow synthesis and method of correcting emission spectrum of light emitting device

Patent metadata

Field	Value
Publication number	US-2016322541-A1
Application number	US-201615140501-A
Country	US
Kind code	A1
Filing date	Apr 28, 2016
Priority date	Apr 30, 2015
Publication date	Nov 3, 2016
Grant date	—

Abstract

The present application provides a method of continuous flow synthesis of core/shell quantum dots doped polymer mats (QD-MAT), including mixing a first core precursor with a second core precursor and feeding the reaction mixture into a first furnace to obtain quantum dot cores; feeding a first shell precursor and a second shell precursor into a second furnace and simultaneously injecting the quantum dot cores to obtain core/shell quantum dots; mixing the core/shell quantum dots with a polymer solution to obtain a QD-polymer composite; and introducing the QD-polymer composite to an electrospinning system to fabricate the core/shell quantum dots doped polymer mats. The present application also provides a method of correcting emission spectrum of light emitting devices with the core/shell quantum dots doped polymer mats with light diffusing properties which can be used to replace the diffuser layer of light emitting devices.

First claim

What is claimed is:

1 . A method of continuous flow synthesis of core/shell quantum dots doped polymer mats (QD-MAT), comprising:
mixing a first core precursor with a second core precursor and feeding the reaction mixture into a first furnace to obtain quantum dot cores; feeding a first shell precursor and a second shell precursor into a second furnace and simultaneously injecting the quantum dot cores to obtain core/shell quantum dots; mixing the core/shell quantum dots with a polymer solution to obtain a QD-polymer composite; and introducing the QD-polymer composite to an electrospinning system to obtain quantum dot nanofibers (QD-nanofibers) and thereby fabricating the core/shell quantum dots doped polymer mats.

2 . The method of claim 1 , wherein the temperature of the first furnace is maintained with a temperature deviation no more than about 3° C.

3 . The method of claim 1 , wherein the core/shell quantum dots have a double layer or triple layer core/shell structure.

4 . The method of claim 1 , wherein the first and second core precursors and the first and second shell precursors comprise at least one element selected from the group consisting of In, P, Zn, S, Se, N, Ga, Si, Ti, Ce, La, V, O and Cd.

5 . The method of claim 4 , wherein the core/shell quantum dots have a core/shell structure selected from the group consisting of InP/ZnS, InP/ZnSe, InN/GaN, InP/ZnS/SiO 2 , InP/ZnS/InZnS, GaP/ZnS/SiO 2 , GaP/ZnS/GaZnS, InN/GaN/SiO 2 and CdSe/ZnS.

6 . The method of claim 1 , wherein the size distribution of the core/shell quantum dots has a standard deviation of about 10% or less.

7 . The method of claim 1 , further comprising forming an additional coating around the core/shell QDs.

8 . The method of claim 7 , wherein the additional coating comprises a compound having an affinity for the polymer solution.

9 . The method of claim 7 , wherein the additional coating comprises at least one selected from the group consisting of silicon dioxide, zirconium oxide, titanium dioxide and other inorganic oxides having an affinity for the polymer solution.

10 . The method of claim 7 , wherein the additional coating is formed by micro emulsion synthesis.

11 . The method of claim 1 , wherein the polymer solution comprises at least one polymer selected from the group consisting of nylon 6.6, polyurethanes (PU), polybenzimidazole (PBI), polycarbonate (PC), polyacrylonitrile (PAN), poly(methyl methacrylate) (PMMA), polyaniline (PANI), polystyrene (PS), polyethylene terephthalate (PET), poly(vinylidene fluoride) (PVDF), polyvinyl fluoride (PVF), polyvinylchloride (PVC), poly(9-vinylcarbazole) (PVK) and polyvinylacetate (PVAc).

12 . The method of claim 1 , wherein the core/shell QDs are dispersed in a polymer solution at about 25-50° C. to obtain a QD-polymer composite with a concentration of about 0.1-5 wt % of QDs, preferably about 0.1-2 wt %, and more preferably about 0.1-1 wt %.

13 . The method of claim 12 , wherein the QD-polymer composite contains at least one solvent selected from the group consisting of toluene, N,N-dimethylforamide, acetone, chloroform and dichloromethane.

14 . The method of claim 1 , wherein the QD-nanofibers have a diameter ranging from about 0.1 μm to about 5 μm.

15 . The method of claim 1 , wherein the method is carried out in a flow reactor with a flow rate in the range of 2.9 ml/min to 15 ml/min.

16 . A method of correcting emission spectrum of a light emitting device, comprising laminating at least one layer of the QD-MATs prepared from the method of claim 1 on the light emitting device.

17 . The method of claim 16 , wherein the at least one layer of QD-MATs comprises QDs with same or different sizes.

18 . The method of claim 16 , wherein the at least one layer of QD-MATs is directly laminated on either of a diffuser or a brightness enhancement film of an LED display of the light emitting device.

19 . The method of claim 16 , wherein the at least one layer of QD-MATs is laminated on the surface of the encapsulant of an LED lighting of the light emitting device as a remote phosphor.

20 . The method of claim 16 , wherein the at least one layer of QD-MATs is doped with InP/ZnS/SiO 2 or InP/ZnS/TiO 2 core/shell QDs and Cu (Mn) doped ZnSe/SiO 2 core/shell QDs of different sizes.

Assignees

• Nano & Advanced Materials Inst Ltd

Inventors

• Liu Chenmin
• Kwok Chi Ho

Classifications

• H10H20/0361

  of wavelength conversion means · CPC title

• H10H20/8516

  having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer or wavelength conversion layer with a concentration gradient · CPC title

• C09K11/02

  Use of particular materials as binders, particle coatings or suspension media therefor · CPC title

• C09K11/883

  with zinc or cadmium · CPC title

• H10H20/8514

  characterised by their shape, e.g. plate or foil · CPC title