# US 2016/0258583 A1 · Quantum dots based optical filter

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2016/0258583 A1
- Document ID: US20160258583A1
- Status: Published application
- Kind: A1
- Application number: 14/641,052
- Filed: 2015-03-06
- Published: 2016-09-08
- Earliest claimed: 2015-03-06
- Assignees: Pixtronix, Inc.
- Applicants: Pixtronix, Inc.
- Inventors: Jianru Shi; Lu Lu; Yuhong Yao; Xiang-Dong Mi; Jignesh Gandhi; James Eakin; Waseem Mohammad; Robert Myers; Nikolay Nemchuk
- Web page: https://patentgrep.com/patent/US20160258583A1

## CPC

- C23C 16/45525: {Atomic layer deposition [ALD]}
- G02B 5/207: {comprising semiconducting materials}
- G02B 5/285: {comprising deposited thin solid films (G02B5/281 - G02B5/289 take precedence; multilayered film filters for fibre optic multiplexing G02B6/29361)}
- G02B 26/02: for controlling the intensity of light {(G02B26/004 takes precedence)}
- G02F 2/02: Frequency-changing of light, e.g. by quantum counters
- G02F 1/133521: {Interference filters}
- G02F 1/133614: {using photoluminescence, e.g. phosphors illuminated by UV or blue light}
- G02F 2202/108: quantum wells
- C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04)
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS

## Abstract

This disclosure provides devices, apparatuses and methods of providing an optical filter with quantum dot films for converting a first wavelength of light to a second wavelength of light. The optical filter includes a plurality of high refractive index layers and a plurality of low refractive index layers alternatingly disposed between the high refractive index layers. Quantum dots are dispersed in either the high refractive index layers or the low refractive index layers. In some implementations, the quantum dots are capable of absorbing blue light and emitting green light. Thus, the optical filter can be part of a red-green-blue lighting device that includes a first blue LED optically coupled with the optical filter to produce green light, a red LED and a second blue LED.

## Claims

### Claim 1

An apparatus comprising:
a substrate having first surface and a second surface opposite the first surface;
a quantum dot film on the first surface of the substrate, the quantum dot film capable of absorbing a first wavelength of light and emitting a second wavelength of light; and
an optical filter on the second surface of the substrate, the optical filter comprising:
a plurality of high refractive index layers;
a plurality of low refractive index layers alternatingly disposed between the high refractive index layers, wherein the plurality of high refractive index layers and the plurality of low refractive index layers are configured to reflect the first wavelength of light.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein the first wavelength of light corresponds to a blue wavelength and the second wavelength of light corresponds to a green wavelength.

### Claim 3 (depends on 1)

The apparatus of claim 1, wherein the quantum dot film has a thickness greater than each of the plurality of high refractive index layers and low refractive index layers.

### Claim 4 (depends on 1)

The apparatus of claim 1, wherein the quantum dot film has a thickness between about 360 nm and about 480 nm and includes SiO2.

### Claim 5 (depends on 1)

The apparatus of claim 1, wherein the first surface faces a viewing side of a display and the second surface faces a rear side of the display.

### Claim 6 (depends on 1)

The apparatus of claim 1, further comprising:
a first blue LED light source, wherein the first blue LED light source is optically coupled to the optical filter and the quantum dot film, the quantum dot film configured to convert the blue light received from the blue LED light source to green light.

### Claim 7 (depends on 6)

The apparatus of claim 6, further comprising:
a second blue LED light source; and
a red LED light source.

### Claim 8 (depends on 1)

The apparatus of claim 1, wherein an index of refraction of the high refractive index layers is between about 1.7 and about 2.6, and an index of refraction of the low refractive index layers is between about 1.0 and about 1.6.

### Claim 9 (depends on 1)

The apparatus of claim 1, wherein a thickness of each of the high refractive index layers and the low refractive index layers is between about 20 nm and about 150 nm.

### Claim 10 (depends on 9)

The optical filter of claim 9, wherein the thickness of each of the high refractive index layers is between about 40 nm and about 70 nm, and the thickness of each of the low refractive index layers is between about 70 nm and about 120 nm.

### Claim 11 (depends on 1)

The optical filter of claim 1, wherein each of the high refractive index layers includes at least one of Nb2O5 and TiO2, and each of the low refractive index layers includes at least SiO2.

### Claim 12 (depends on 1)

The apparatus of claim 1, further comprising:
a display;
a processor capable of communicating with the display, the processor being capable of processing image data; and
a memory device capable of communicating with the processor.

### Claim 13 (depends on 12)

The apparatus of claim 12, further comprising:
a driver circuit capable of sending at least one signal to the display element; and
a controller capable of sending at least a portion of the image data to the driver circuit.

### Claim 14 (depends on 12)

The apparatus of claim 12, further comprising:
an image source module capable of sending the image data to the processor, wherein the image source module includes at least one of a receiver, transceiver and transmitter.

### Claim 15 (depends on 12)

The apparatus of claim 12, further comprising:
an input device capable of receiving input data and communicating the input data to the processor.

### Claim 16

A quantum dot based optical filter, comprising:
a plurality of high refractive index layers;
a plurality of low refractive index layers alternatingly disposed between the high refractive index layers, wherein the plurality of high refractive index layers and the plurality of low refractive index layers are configured to reflect a first wavelength of light; and
a plurality of quantum dots dispersed in a plurality of layers, the plurality of layers selected from a group consisting of: the plurality of high refractive index layers and the plurality of low refractive index layers, the quantum dots capable of absorbing the first wavelength of light and emitting a second wavelength of light.

### Claim 17 (depends on 16)

The optical filter of claim 16, wherein the first wavelength of light corresponds to a blue wavelength and the second wavelength of light corresponds to a green wavelength.

### Claim 18 (depends on 17)

The optical filter of claim 17, wherein a transmission of the blue wavelength through the optical filter is less than about 5% and a transmission of the green wavelength through the optical filter is greater than about 80%.

### Claim 19 (depends on 16)

The optical filter of claim 16, wherein each of the low refractive index layers is identical or substantially identical in thickness and composition, and each of the high refractive index layers is identical or substantially identical in thickness and composition.

### Claim 20 (depends on 16)

The optical filter of claim 16, wherein the plurality of high refractive index layers include at least 3 high refractive index layers and the plurality of low refractive index layers include at least 3 low refractive index layers.

### Claim 21

An apparatus comprising:
a substrate having a first surface and a second surface opposite the first surface;
means for converting a first wavelength light to a second wavelength of light, the converting means positioned on the first surface of the substrate; and
means for reflecting the first wavelength of light, the reflecting means positioned on the second surface of the substrate, the reflecting means comprising:
a plurality of high refractive index layers; and
a plurality of low refractive index layers alternatingly disposed between the high refractive index layers, wherein the plurality of high refractive index layers and the plurality of low refractive index layers are configured to reflect the first wavelength of light.

### Claim 22 (depends on 21)

The apparatus of claim 21, wherein the first wavelength of light corresponds to a blue wavelength and the second wavelength of light corresponds to a green wavelength.

### Claim 23 (depends on 21)

The apparatus of claim 21, wherein the converting means includes a plurality of quantum dots.

### Claim 24 (depends on 21)

The apparatus of claim 21, wherein an index of refraction of the high refractive index layers is between about 1.7 and about 2.6, and an index of refraction of the low refractive index layers is between about 1.0 and about 1.6.

### Claim 25

A method of manufacturing a quantum dot based optical filter, comprising:
forming a first high refractive index layer on a substrate;
forming a first low refractive index layer on the first high refractive index layer;
forming a second high refractive index layer on the first low refractive index layer, the second high refractive index layer being identical or substantially identical in thickness and composition as the first high refractive index layer; and
forming a second low refractive index layer on the second high refractive index layer, the second low refractive index layer being identical or substantially identical in thickness and composition as the first low refractive index layer, wherein each of the high refractive index layers or each of the low refractive index layers include a plurality of quantum dots dispersed therein, the quantum dots capable of absorbing a first wavelength of light and emitting a second wavelength of light.

### Claim 26 (depends on 25)

The method of claim 25, further comprising:
forming a third high refractive index layer on the second low refractive index layer, the third high refractive index layer being identical or substantially identical in thickness and composition with the first high refractive index layer; and
forming a third low refractive index layer on the third high refractive index layer, the third low refractive index layer being identical or substantially identical in thickness and composition with the first low refractive index layer.

### Claim 27 (depends on 25)

The method of claim 25, wherein the first wavelength of light corresponds to a blue wavelength and the second wavelength of light corresponds to a green wavelength.

### Claim 28 (depends on 25)

The method of claim 25, wherein the plurality of high refractive index layers and the plurality of low refractive index layers are configured to reflect a first wavelength of light.

### Claim 29 (depends on 25)

The method of claim 25, wherein an index of refraction of the high refractive index layers is between about 1.7 and about 2.6, and an index of refraction of the low refractive index layers is between about 1.0 and about 1.6.

### Claim 30 (depends on 25)

The method of claim 25, wherein each of the high refractive index layers and the low refractive index layers are deposited using atomic layer deposition.