Color conversion films with plasmon enhanced fluorescent dyes

• US 10,059,876 B2
• Filed: 01/26/2017
• Issued: 08/28/2018
• Est. Priority Date: 11/16/2015
• Status: Active Grant

• Current Assignee: Moleculed Ltd.
• Original Assignee: StoreDot Ltd.
• Inventors: Szwarcman, Daniel, Kuks, Evgenia Liel
• Primary Examiner(s): Jarrell, Noble E
• Application Number:
  US15/415,886
• Publication Number:
  US 20170137705A1
• Time in Patent Office: 579 Days
• Field of Search: None
• CPC Class Codes: C09B 11/24 Phthaleins containing amino groups ; Phthalanes; Fluoranes; Phthalides; Rhodamine dyes; Phthaleins having heterocyclic aryl rings; Lactone or lactame forms of triarylmethane dyes
• CPC Class Codes: C09B 69/008 Dyes containing a substituent, which contains a silicium atom
• CPC Class Codes: C09B 69/103 containing a diaryl- or triarylmethane dye
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/1007 Non-condensed systems
• CPC Class Codes: C09K 2211/1048 with oxygen
• CPC Class Codes: C09K 2211/1088 containing oxygen as the only heteroatom
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/1336 Illuminating devices
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: G02F 2202/30 Metamaterials
• CPC Class Codes: G02F 2202/36 Micro- or nanomaterials
• CPC Class Codes: G02F 2203/05 wavelength dependent
• CPC Class Codes: G02F 2203/10 plasmon

Abstract

Color conversion films for a LCD (liquid crystal display) having RGB (red, green, blue) color filters, as well as such displays, formulations, precursors and methods are provided, which improve display performances with respect to color gamut, energy efficiency, materials and costs. The color conversion films absorb backlight illumination and convert the energy to green and/or red emission at high efficiency, specified wavelength ranges and narrow emission peaks. For example, rhodamine-based fluorescent compounds are used in matrices produced by sol gel processes and/or UV (ultraviolet) curing processes which are configured to stabilize the compounds and extend their lifetime—to provide the required emission specifications of the color conversion films. Film integration and display configurations further enhance the display performance with color conversion films utilizing various color conversion elements. Fluorescent emission may be enhanced by plasmon resonance of coupled nanoparticles.

Claims

1. A color conversion film for a LCD (liquid crystal display) having RGB (red, green, blue) color filters, the color conversion film comprising at least one rhodamine-based fluorescent (RBF) compound selected to absorb illumination from a backlight source of the LCD and having at least one of a R emission peak and a G emission peak,

wherein the at least one RBF compound is defined by Formula 1:

2. The color conversion film according to claim 1, wherein the PR elements are metallic nanoparticles ranging in diameter between 10-100 nm.

3. The color conversion film of claim 1, wherein the PR elements are coated or sputtered on the color conversion film.

4. The color conversion film of claim 1, wherein the PR elements are islands or perforations on at least part of the color conversion film.

5. The color conversion film of claim 1, wherein the PR elements are configured as a hyperbolic metamaterial.

6. The color conversion film of claim 1, produced at least partially by a sol gel process and/or a UV (ultraviolet) curing process.

7. The LCD comprising the color conversion film of claim 1.

8. A method comprising:

preparing at least one color conversion film comprising at least one RBF compound selected to absorb illumination from a backlight source of the LCD and having at least one of a R emission peak and a G emission peak,

wherein the at least one RBF compound is defined by Formula I;

9. The method of claim 8, further comprising using linkers for the electromagnetic coupling.

10. The method of claim 8, further comprising designing PR elements to enhance a plasmon field thereof.

11. The method of claim 8, further comprising embedding the at least one RBF compound in a matrix enclosed within the PR elements being plasmonic nanostructure shells.

12. The method of claim 8, further comprising coating or sputtering the PR elements on the at least one color conversion film.

13. The method of claim 8, wherein the at least one color conversion film is prepared by at least one corresponding sol-gel process and/or UV curing process.