IP Library Granted Patent US 11,121,290
Granted Patent B2
US 11,121,290 · App. 16/307,137 · Granted Sep 14, 2021

Barrier free stable quantum dot film

Inventors: Chi Ho Kwok (Hong Kong, HK); Chi Hin Wong (Hong Kong, HK); Wing Yin Yung (Hong Kong, HK); Chenmin Liu (Hong Kong, HK)
Assignee: Nano and Advanced Materials Institute Limited
H01L33/507C09J4/00C09J5/00C09J11/04C09J133/12C09K11/883H01L33/504H01L33/505B82Y20/00B82Y40/00C09J2203/326C09J2433/00C09J2467/008H01L2933/0041
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Quick Facts
Patent No.
US 11,121,290
App. No.
16/307,137
Granted
Sep 14, 2021
Kind
B2
Abstract

A barrier free quantum dot particles film includes a free standing layer comprising shielded quantum dot particles; wherein the shielded quantum dot particles are formed by shielding quantum dot particles by at least one shielding method; wherein the shielded quantum dot particles are characterized in resisting at least one condition selected from the group consisting of high temperature, high humidity and water; and wherein the shielded quantum dot particles are dispersed in an acrylate adhesive. A method of fabricating a barrier free quantum dot particles free standing film is also disclosed. The method of fabrication of shielded quantum dot particles film on a light emitting diode (LED) lens is also disclosed.

Claims (25)

1. A method of fabricating a barrier free quantum dot particles layer film, comprising:

shielding quantum dot particles by at least one of a shielding method to form shielded quantum dot particles; and

dispersing the shielded quantum dot particles in an adhesive comprising an acrylate adhesive, a silicone adhesive, a thermoplastic adhesive, or an UV cured adhesive to form a free standing quantum dot particles layer;

wherein the shielded quantum dot particles are resistant to at least one of condition selected from the group consisting of high temperature, high humidity and water;

wherein the quantum dot particles are shielded by at least one of a house shielding method, a ligand shielding method and a jacket shielding method; and

wherein the house shielding method comprises encapsulating the quantum dot particles by swelling and shrinking of carrier polymers in a solvent; wherein the swelling is carried out by heating the carrier polymers; wherein the shrinking is carried out by cooling of the carrier polymers; wherein the encapsulating of quantum dot particles is controlled by sonicating and further evaporating excess solvent from the carrier polymers; wherein encapsulation efficiency of the carrier polymers is within a range of 5 to 20%; and wherein the house shielding method is characterized in providing moisture resistance property to the shielded quantum dot particles.

2. The method according to claim 1 , wherein the film comprises a step of sandwiching a free standing quantum dot particles layer of quantum dot particles between at least two outer layers; wherein each of the at least two outer layers is a film selected from the group consisting of polyethylene terephthalate (PET) film, a polyethylene naphthalate (PEN) film and a polyacrylonitrile (PAN) film.

3. The method according to claim 2 , wherein a water vapor transmission rate (WVTR) and an oxygen transmission rate (OTR) for each of the at least two outer layers is within a range of 1-10 g/m 2 d and 50-200 cm 3 /m 2 d, respectively.

4. The method according to claim 1 , wherein the quantum dot particles are made of a material selected from the group consisting of CdSe, ZnS, CdZnS, MAPbX3 (MA=methylammonium; X=Cl, Br, I), and combinations thereof; wherein size of quantum dot particles is within a range of 4 nm to 8 nm; and wherein the quantum dot particles are hydrophobized with hydrophobic ligand comprising one or more of C3-C21 aliphatic, branched, cyclic and aromatic thiol.

5. The method according to claim 1 , wherein the house shielding method comprises adding crosslinked polymer beads as quantum dot carriers; wherein the crosslinked polymer beads comprises at least one of polystyrene and polymethyl methacrylate; wherein the crosslinking of polymer beads are crosslinked by a crosslinker selected from the group consisting of divinylbenzene, N,N′-Methylene-bis-acrylamide, and ethylene glycol di-methacrylate crosslinker; and wherein a size of the crosslinker is within a range of 100 nm to 5 μm; and wherein the amount of the crosslinker in a dispersion is within a range of 1 to 5% wt.

6. The method according to claim 1 , wherein the ligand shielding method comprises encapsulating the quantum dot particles with a surfactant ligand co-system in a form of liquid, grease or paste; wherein the surfactant ligand co-system comprises a surfactant and a ligand; and wherein the ligand shielding method provides surface rigidity and extra stability to the quantum dot particles.

7. The method according to claim 6 , wherein the surfactant is selected from one of the following:

a block copolymer selected from the group consisting of poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol), poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol), and polystyrene-block-poly(acrylic acid);

a copolymer selected from the group consisting of poly(methyl methacrylate-co-methacrylic acid), and poly(styrene)-co-methacrylic acid; and

a non-ionic surfactant selected from the group consisting of polyethylene glycol oleyl ether, polyoxyethylene (5) nonylphenylether, and polyethylene-block-poly(ethylene glycol);

wherein the surfactant is present in an amount within a range of 1-10% wt;

wherein the ligand is selected from the group consisting of Pluronic P123, octanethiol, C3-C21 aliphatic thiols, branched thiols, cyclic thiols, aromatic thiol, C3-C21 aliphatic amines, branched amines, cyclic amines and aromatic amines; and

wherein the ligand is present in an amount within a range of 1-10% wt.

8. The method according to claim 1 , wherein the jacket shielding method comprises core/shell shielding the quantum dot particles with a multi-shell coating on metal-alloyed cores of the quantum dot particles; wherein the multi shell coating comprises a coating layer of 1-5 shells; wherein a total size of the shielded quantum dot particles ranges from 8 nm to 20 nm, a size of the metal-alloyed core ranges from 4 nm to 8 nm, and a thickness of the multi-shell coating ranges from 2 nm to 6 nm; and wherein the jacket shielding method provides thermal resistant properties to the shielded quantum dot particles; and wherein the metal-alloyed core is made of at least one metal alloy selected from the group consisting of CdSe, ZnSe, CdZnSeS, CdTe and MAPbX3 (MA=methylammonium; X=Cl, Br, I), and the multi-shell coating is made of at least one of ZnS and CdZnS.

9. The method according to claim 1 , wherein the shielded quantum dot particles free standing film is fabricated on a light emitting diode (LED) lens by a method comprising:

a first step of spraying a free standing layer of shielded quantum dot particles on a surface of LED lens;

a second step of enabling a blue light to enter the LED lens without changing the light path;

a third step of exciting the shielded quantum dot particles by blue light;

a fourth step of mixing the shielded quantum dot particles as white light for display, and

a fifth step of mixing the shielded quantum dot particles with UV or thermal curable adhesive and then spraying on the surface of the LED lens.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 17, 2026
From: NANO AND ADVANCED MATERIALS INSTITUTE LIMITED
To: HONG KONG APPLIED SCIENCE AND TECHNOLOGY RESEARCH INSTITUTE COMPANY LIMITED
Reel/Frame 075402/0553 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 6, 2018
From: KWOK, CHI HO; WONG, CHI HIN; YUNG, WING YIN; LIU, CHENMIN
To: NANO AND ADVANCED MATERIALS INSTITUTE LIMITED
Reel/Frame 047686/0087 →
Continuity (2)
Provisional Application 62707558 · Nov 8, 2017
Related Publication 20210234076A1 · Jul 29, 2021