Red-enhanced white LCD displays comprising sol-gel-based color conversion films

1. An LCD (liquid crystal display) comprising:

a color conversion film; RGB (red, green, blue) color filters; and

a backlight source providing white illumination;

wherein the color conversion film comprises at least one rhodamine-based fluorescent (RBF) compound selected to absorb illumination from the backlight source of the LCD and have a red emission peak; and wherein the at least one RBF compound is red-fluorescent and defined by Formula 1:

wherein

R 1 is COOR, NO 2 , COR, COSR, CO(N-heterocycle), CON(R) 2 , or CN;

R 2 each is independently selected from H, halide, N(R) 2 , COR, CN, CON(R) 2 , CO(N-heterocycle), NCO, NCS, OR, SR, SO 3 H, SO 3 M and COOR;

R 3 each is independently selected from H, halide, N(R) 2 , COR, CN, CON(R) 2 , CO(N-heterocycle), NCO, NCS, OR, SR, SO 3 H, SO 3 M and COOR;

R 4 -R 16 and R 4′ -R 16′ are each independently selected from H, CF 3 , alkyl, haloalkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl, benzyl, halide, NO 2 , OR, N(R) 2 , COR, CN, CON(R) 2 , CO(N-Heterocycle) and COOR;

R is H, alkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl, benzyl, —(CH 2 CH 2 O) r CH 2 CH 2 OH,—(CH 2 ) p OC(O)NH(CH 2 ) q Si(Oalkyl) 3 , —(CH 2 ) p OC(O)CH═CH 2 or —(CH 2 ) p Si(Oalkyl) 3 ;

n and m are each independently an integer between 1-4;

p and q are each independently an integer between 1-6;

r is an integer between 0-10;

M is a monovalent cation; and

X is an anion.

2. The LCD of claim 1 , wherein said color conversion film is produced at least partially by a sol gel process carried out using, to provide a matrix for the at least one RBF compound, a formulation comprising:

an ESOR (epoxy silica ormosil) solution comprising TEOS (tetraethyl orthosilicate), at least one silane precursor, and GLYMO ((3-Glycidyloxypropyl) trimethoxysilane),

a DURS (diurethane siloxane) powder comprising isocyanate-functionalized silica nanoparticles and ethylene glycol, and

a transition metal alkoxide matrix solution.

3. The LCD of claim 1 , wherein the at least one RBF compound is selected to shift some of a yellow region in the white illumination into the red transmission region of the R color filter.

4. The LCD of claim 2 , wherein ratios (wt/vol/vol (mg/ml/ml)) of the DURS/the ESOR/and the transition metal alkoxide matrix solution are 15-25/1-3/1.

5. The LCD of claim 2 , wherein the ESOR is prepared under acidic conditions.

6. The LCD of claim 2 , wherein the at least one silane precursor comprises PhTMOS (trimethoxyphenylsilane) or a TMOS (trimethoxysilane) with fluorine substituents.

7. The LCD of claim 1 , wherein the color conversion film is in an LCD panel.

8. A color conversion film prepared by a sol gel process from a formulation comprising:

an ESOR (epoxy silica ormosil) solution comprising TEOS (tetraethyl orthosilicate), at least one silane precursor, and GLYMO ((3-Glycidyloxypropyl) trimethoxysilane);

a DURS (diurethane siloxane) powder comprising isocyanate-functionalized silica nanoparticles and ethylene glycol;

a transition metal alkoxide matrix solution; and

at least one red-fluorescent rhodamine-based fluorescent (RBF) compound is defined by Formula 1 according to claim 1 .

9. The color conversion film of claim 8 , wherein the at least one silane precursor comprises PhTMOS (trimethoxyphenylsilane) or a TMOS (trimethoxysilane) with fluorine substituents.

10. The color conversion film of claim 8 , wherein the at least one RBF compound is supramolecularly encapsulated within the film or covalently embedded within the color conversion film.

11. The color conversion film of claim 8 , wherein the at least one RBF compound is bonded to the film via PMMA (poly-methyl-methacrylate) linkers.

12. An LCD, comprising at least one color conversion film of claim 8 , a backlight unit comprising a white backlight source and a LCD panel having RGB color filters.

13. The LCD of claim 12 , wherein the color conversion film is further configured to shift some of a yellow region in white illumination provided by the white backlight source into a red transmission region of the R color filter.

14. The color conversion film of claim 8 , further configured to direct self-assembly of molecules of the at least one RBF compound to yield polarization of at least part of the illumination by the color conversion film.

15. An LCD comprising at least one color conversion film of claim 14 , a backlight unit comprising a white backlight source and a LCD panel having RGB color filters, wherein the at least one color conversion film replaces at least one polarizer film in the LCD.

16. 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 have a red emission peak, wherein the backlight source of the LCD provides white illumination and the at least one RBF compound is red-fluorescent and defined by Formula 1:

wherein

R 1 is COOR, NO 2 , COR, COSR, CON(R) 2 or CN;

R 2 each is independently selected from H, halide, N(R) 2 , COR, CN, CON(R) 2 , CO(N-heterocycle), NCO, NCS, OR, SR, SO 3 H, SO 3 M and COOR;

R 3 each is independently selected from H, halide, N(R) 2 , COR, CN, CON(R) 2 , CO(N-heterocycle), NCO, NCS, OR, SR, SO 3 H, SO 3 M and COOR;

R 4 -R 16 and R 4′ -R 16′ are each independently selected from H, CF 3 , alkyl, haloalkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl, benzyl, halide, NO 2 , OR, N(R) 2 , COR, CN, CON(R) 2 , CO(N-Heterocycle) and COOR;

R is H, alkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl, benzyl, —(CH 2 CH 2 O) r CH 2 CH 2 OH, —(CH 2 ) p OC(O)NH(CH 2 ), q Si(Oalkyl) 3 , —(CH 2 ) p OC(O)CH═CH 2 or —(CH 2 ) p Si(Oalky) 3 ;

n and m are each independently an integer between 1-4;

p and q are each independently an integer between 1-6;

r is an integer between 0-10;

M is a monovalent cation;

X is an anion; and

wherein if R 2 and R 3 are hydrogens (H), then R 1 is NO 2 , COR, COSR, CON(R) 2 or CN.

17. 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 have a red emission peak, wherein the backlight source of the LCD provides white illumination and the at least one RBF compound is red-fluorescent and defined by Formula 1:

wherein

R 1 is COOZ, NO 2 , COR, COSR, or CN;

R 2 each is independently selected from H, halide, COR, CN, NCO, NCS and COOZ;

R 3 each is independently selected from H, halide, COR, CN, NCO, NCS, OR, SR, SO3H, SO 3 M and COOZ;

R 4 -R 16 and R 4′ -R 16′ are each independently selected from H, alkyl, cycloalkyl, heterocycloalkyl, aryl, benzyl, halide, NO 2 , OR, N(R) 2 , COR, CON(R) 2 , CO(N-heterocycle) and COOR;

R is H, alkyl, cycloalkyl, heterocycloalkyl, aryl, benzyl, —(CH 2 CH 2 O) r CH 2 CH 2 OH, —(CH 2 ) p OC(O)NH(CH 2 ) q Si(Oalkyl) 3 , —(CH 2 ) p OC(O)CH═CH 2 or —(CH 2 ) p Si(Oalkyl) 3 ;

Z is unsubstituted alkyl, cycloalkyl, heterocycloalkyl, aryl, benzyl, —(CH 2 CH 2 O) r CH 2 CH 2 OH, —(CH 2 ) p OC(O)NH(CH 2 ), q Si(Oalkyl) 3 , —(CH 2 ) p OC(O)CH═CH 2 or —(CH 2 ) p S i(Oalkyl) 3 ;

M is a monovalent cation;

n and m are each independently an integer between 1 -4;

p and q are each independently an integer between 1 -6;

r is an integer between 0-10;

X is an anion; and

wherein if R 2 and R 3 are hydrogens (H), then R 1 is NO 2 , COR, COSR, or CN.

18. An LCD (liquid crystal display) comprising:

A color conversion film;

RGB (red, green, blue) color filters; and

a backlight source providing white illumination;

wherein the color conversion film comprises at least one rhodamine-based fluorescent (RBF) compound selected to absorb illumination from the backlight source of the LCD and have a red emission peak;

and wherein the at least one RBF compound is red-fluorescent and defined by Formula 1:

wherein

R 1 is COOR, NO 2 , COR, COSR, CON(R) 2 or CN;

R 2 each is independently selected from H, halide, N(R) 2 , COR, CN, CON(R) 2 , CO(N-heterocycle), NCO, NCS, OR, SR, SO 3 H, SO 3 M and COOR;

R 3 each is independently selected from H, halide, N(R) 2 , COR, CN, CON(R) 2 , CO(N-heterocycle), NCO, NCS, OR, SR, SO 3 H, SO 3 M and COOR;

R 4 -R 16 and R 4′ -R 16′ are each independently selected from H, CF 3 , alkyl, haloalkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl, benzyl, halide, NO 2 , OR, N(R) 2 , COR, CN, CON(R) 2 , CO(N-Heterocycle) and COOR;

R is H, alkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl, benzyl, —(CH 2 CH 2 O) r CH 2 CH 2 OH, —(CH 2 ) p OC(O)NH(CH 2 ), q Si(Oalkyl) 3 , —(CH 2 ) p OC(O)CH═CH 2 or —(CH 2 ) p Si(Oalky) 3 ;

n and m are each independently an integer between 1-4;

p and q are each independently an integer between 1-6;

r is an integer between 0-10;

M is a monovalent cation;

X is an anion; and

wherein if R 2 and R 3 are hydrogens (H), then R 1 is NO 2 , COR, COSR, CON(R) 2 or CN.

19. An LCD (liquid crystal display) comprising:

a color conversion film;

RGB (red, green, blue) color filters; and

a backlight source providing white illumination;

wherein the color conversion film comprises at least one rhodamine-based fluorescent (RBF) compound selected to absorb illumination from the backlight source of the LCD and have a red emission peak and wherein the at least one RBF compound is red-fluorescent and defined by Formula 1:

wherein

R 1 is COOZ, NO 2 , COR, COSR or CN;

R 2 each is independently selected from H, halide, N(R) 2 , COR, CN, CON(R) 2 , CO(N-heterocycle), NCO, NCS, OR, SR, SO 3 H, SO 3 M and COOR;

R 3 each is independently selected from H, halide, N(R) 2 , COR, CN, CON(R) 2 , CO(N-heterocycle), NCO, NCS, OR, SR, SO 3 H, SO 3 M and COOR;

R 4 -R 16 and R 4′ -R 16′ are each independently selected from H, CF 3 , alkyl, haloalkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl, benzyl, halide, NO 2 , OR, N(R) 2 , COR, CN, CON(R) 2 , CO(N-Heterocycle) and COOR;

R is H, alkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl, benzyl, —(CH 2 CH 2 O) r CH 2 CH 2 OH, —(CH 2 ) p OC(O)NH(CH 2 ), q Si(Oalkyl) 3 , —(CH 2 ) p OC(O)CH═CH 2 or —(CH 2 ) p Si(Oalkyl) 3 ;

Z is unsubstituted alkyl, cycloalkyl, heterocycloalkyl, aryl, benzyl, —(CH 2 CH 2 O) r CH 2 CH 2 OH, —(CH 2 ) p OC(O)NH(CH 2 ) q Si(Oalkyl) 3 , —(CH 2 ) p OC(O)CH═CH 2 or —(CH 2 ) p Si(Oalkyl) 3 ;

n and m are each independently an integer between 1-4;

p and q are each independently an integer between 1-6;

r is an integer between 0-10;

M is a monovalent cation;

X is an anion; and

wherein if R 2 and R 3 are hydrogens (H), then R 1 is NO2, COR, COSR or CN.

20. A method comprising configuring a LCD with RGB color filters and white backlight illumination to have at least one color conversion film produced by:

preparing a hybrid sol-gel precursor formulation from:

an ESOR (epoxy silica ormosil) solution comprising TEOS (tetraethyl orthosilicate), at least one silane precursor, and GLYMO ((3-Glycidyloxypropyl) trimethoxysilane);

a DURS (diurethane siloxane) powder comprising isocyanate-functionalized silica nanoparticles and ethylene glycol; and

a transition metal alkoxide matrix solution,

mixing the prepared hybrid sol-gel precursor with at least one RBF (rhodamine-based fluorescent) compound; and

spreading the mixture and drying the spread mixture to form a film,

wherein the at least one RBF compound and/or the color conversion film production are configured to enhance a red illumination component in the white backlight illumination by shifting some of a yellow region in the white backlight illumination into a red transmission region of the R color filter wherein the at least one RBF compound is defined by Formula 1 according to claim 1 .

21. The method of claim 20 , wherein said preparing of the hybrid sol-gel precursor formulation is carried out under acidic conditions.

22. The method of claim 20 , further comprising evaporating alcohols from the mixture prior to said spreading.