Modifications of the sol-gel films and production processes thereof
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. The color conversion films may comprise at least one of: polydimethylsiloxane hydroxy terminated, dendritic polyol or polyvinylpyrrolidone.
1. A hybrid sol-gel formulation comprising:
an epoxy silica ormosil solution comprising TEOS (tetraethyl orthosilicate), at least one silane precursor other than TEOS, and GLYMO ((3-Glycidyloxypropyl) trimethoxysilane);
a nanoparticles powder comprising isocyanate-functionalized silica nanoparticles and ethylene glycol;
a transition metal alkoxide matrix solution; and
at least one rhodamine-based fluorescent (RBF) compound;
wherein the formulation further comprises at least one of: polydimethylsiloxane hydroxy terminated, dendritic polyol or polyvinylpyrrolidone.
2. The sol-gel formulation of claim 1 , wherein the GLYMO is polymerized.
3. The sol-gel formulation of claim 1 , wherein the at least one silane precursor comprises at least one of: PhTMOS (trimethoxyphenylsilane), a TMOS (trimethoxysilane) with fluorine substituents, F 1 TMOS (trimethoxy(3,3,3-trifluoropropyl)silane), F 2 TMOS (tridecafluoro- 1,1,2,2 -tetrahydrooctyl)trimethoxysilane, 1,2-bis(triethoxysilyl)ethane, trimethoxy(propyl)silane, octadecyltrimethoxysilane, fluorotriethoxysilane, and ammonium(propyl)trimethoxysilane.
4. The formulation of claim 3 , wherein the RBF compound is defined by the following formula:
5. The formulation of claim 3 , wherein the RBF compound is defined by the following formula:
6. The formulation of claim 3 , wherein the RBF compound is defined by the following formula:
7. The formulation of claim 1 , wherein the RBF compound is a red-fluorescent RBF compound and the at least one silane precursor comprises PhTMOS.
8. The formulation of claim 1 , wherein the RBF is a red-fluorescent RBF compound and the at least one silane precursor comprises a TMOS with fluorine substituents.
9. The formulation of claim 1 , wherein the RBF is a green-fluorescent RBF compound and the at least one silane precursor comprises F 1 TMOS.
10. A color conversion film for a LCD (liquid crystal display) having RGB (red, green, blue) color filters, the color conversion film prepared from the formulation of claim 3 by a sol-gel process, wherein the RBF compound is selected to absorb illumination from a backlight source of the LCD and have at least one of a R emission peak and a G emission peak.
11. A LCD comprising the color conversion film of claim 8 .
12. The LCD of claim 11 , wherein the color conversion film is in the LCD panel.
13. A method comprising:
preparing a hybrid sol-gel precursor formulation from:
a solution comprising tetraethyl orthosilicate (TEOS), at least one silane precursor, and (3-Glycidyloxypropyl) trimethoxysilane (GLYMO);
a nanoparticles powder comprising isocyanate-functionalized silica nanoparticles and ethylene glycol;
a transition metal alkoxide matrix solution, and
mixing the hybrid sol-gel precursor with at least one RBF compound; and
spreading the mixture on a substrate and drying the spread mixture to form a film;
wherein the GLYMO is polymerized before preparing the epoxy silica ormosil solution.
14. The method of claim 13 , wherein at least one of the following is added to the epoxy silica ormosil solution: polydimethylsiloxane hydroxy terminated, dendritic polyol and polyvinylpyrrolidone.
15. The method of claim 13 , wherein the substrate is treated prior to the spreading of the mixture.
16. The method of claim 15 , wherein the substrate is treated by covalently bonding (aminopropyl)triethoxysilane (APTES).
17. The method of claim 13 , further comprising associating the film with any of: a diffuser, a prism film and a polarizer film in a display backlight unit.
18. A hybrid sol-gel formulation comprising:
an epoxy silica ormosil solution comprising TEOS (tetraethyl orthosilicate), at least one silane precursor other than TEOS, and GLYMO ((3-Glycidyloxypropyl) trimethoxysilane);
a nanoparticles powder comprising non-functionalized silica nanoparticles and ethylene glycol;
a transition metal alkoxide matrix solution; and
at least one rhodamine-based fluorescent (RBF) compound.