Color conversion layer and display apparatus having the same

1. A color conversion layer ( 4 ) comprising at least one light emitting material ( 7 ) comprising at least one composite particle ( 1 ) surrounded partially or totally by at least one surrounding medium ( 71 );

wherein said at least one light emitting material ( 7 ) is configured to emit a secondary light in response to an excitation and the at least one composite particle ( 1 ) comprises a plurality of nanoparticles ( 3 ) encapsulated in an inorganic material ( 2 );

wherein said inorganic material ( 2 ) has a difference of refractive index compared to the at least one surrounding medium ( 71 ) superior or equal to 0.02 at 450 nm; and

wherein a loading charge of nanoparticles ( 3 ) in a composite particle ( 1 ) is at least 10%,

said loading charge being the mass ratio between the mass of nanoparticles comprised in a composite particle and the mass of said composite particle.

2. The color conversion layer ( 4 ) according to claim 1 , wherein the inorganic material ( 2 ) limits or prevents the diffusion of outer molecular species or fluids (liquid or gas) into said inorganic material ( 2 ).

3. The color conversion layer ( 4 ) according to claim 1 , wherein the at least one composite particle ( 1 ) in the at least one surrounding medium ( 71 ) is configured to scatter light.

4. The color conversion layer ( 4 ) according to claim 1 , wherein the at least one composite particle ( 1 ) in the at least one surrounding medium ( 71 ) is configured to serve as a waveguide.

5. The color conversion layer ( 4 ) according to claim 1 , wherein the color conversion layer ( 4 ) absorbs at least 70% of incident light on a thickness less or equal to 5 pm, wherein the incident light has a wavelength ranging from 370 to 470 nm.

6. The color conversion layer ( 4 ) according to claim 1 , wherein the nanoparticles ( 3 ) comprised in the at least one composite particle ( 1 ) are semiconductor nanocrystals comprising a material of formula M x N y E z A w , wherein: M is selected from the group consisting of Zn, Cd, Hg, Cu, Ag, Au, Ni, Pd, Pt, Co, Fe, Ru, Os, Mn, Tc, Re, Cr, Mo, W, V, Nd, Ta, Ti, Zr, Hf, Be, Mg, Ca, Sr, Ba, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Cs or a mixture thereof; N is selected from the group consisting of Zn, Cd, Hg, Cu, Ag, Au, Ni, Pd, Pt, Co, Fe, Ru, Os, Mn, Tc, Re, Cr, Mo, W, V, Nd, Ta, Ti, Zr, Hf, Be, Mg, Ca, Sr, Ba, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Cs or a mixture thereof; E is selected from the group consisting of O, S, Se, Te, C, N, P, As, Sb, F, Cl, Br, I, or a mixture thereof; A is selected from the group consisting of O, S, Se, Te, C, N, P, As, Sb, F, Cl, Br, I, or a mixture thereof; and x, y, z and w are independently a decimal number from 0 to 5; x, y, z and w are not simultaneously equal to 0; x and y are not simultaneously equal to 0; z and w may not be simultaneously equal to 0.

7. The color conversion layer ( 4 ) according to claim 1 , wherein the nanoparticles ( 3 ) comprised in the at least one composite particle ( 1 ) are semiconductor nanocrystals comprising at least one shell ( 34 ) comprising a material of formula M x N y E z A w , wherein: M is selected from the group consisting of Zn, Cd, Hg, Cu, Ag, Au, Ni, Pd, Pt, Co, Fe, Ru, Os, Mn, Tc, Re, Cr, Mo, W, V, Nd, Ta, Ti, Zr, Hf, Be, Mg, Ca, Sr, Ba, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Cs or a mixture thereof; N is selected from the group consisting of Zn, Cd, Hg, Cu, Ag, Au, Ni, Pd, Pt, Co, Fe, Ru, Os, Mn, Tc, Re, Cr, Mo, W, V, Nd, Ta, Ti, Zr, Hf, Be, Mg, Ca, Sr, Ba, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Cs or a mixture thereof; E is selected from the group consisting of O, S, Se, Te, C, N, P, As, Sb, F, Cl, Br, I, or a mixture thereof; A is selected from the group consisting of O, S, Se, Te, C, N, P, As, Sb, F, Cl, Br, I, or a mixture thereof; and x, y, z and w are independently a decimal number from 0 to 5; x, y, z and w are not simultaneously equal to 0; x and y are not simultaneously equal to 0; z and w may not be simultaneously equal to 0.

8. The color conversion layer ( 4 ) according to claim 1 , wherein the nanoparticles ( 3 ) comprised in the at least one composite particle ( 1 ) are semiconductor nanocrystals comprising at least one crown ( 37 ) comprising a material of formula M x N y E z A w , wherein: M is selected from the group consisting of Zn, Cd, Hg, Cu, Ag, Au, Ni, Pd, Pt, Co, Fe, Ru, Os, Mn, Tc, Re, Cr, Mo, W, V, Nd, Ta, Ti, Zr, Hf, Be, Mg, Ca, Sr, Ba, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Cs or a mixture thereof; N is selected from the group consisting of Zn, Cd, Hg, Cu, Ag, Au, Ni, Pd, Pt, Co, Fe, Ru, Os, Mn, Tc, Re, Cr, Mo, W, V, Nd, Ta, Ti, Zr, Hf, Be, Mg, Ca, Sr, Ba, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Cs or a mixture thereof; E is selected from the group consisting of O, S, Se, Te, C, N, P, As, Sb, F, Cl, Br, I, or a mixture thereof; A is selected from the group consisting of O, S, Se, Te, C, N, P, As, Sb, F, Cl, Br, I, or a mixture thereof; and x, y, z and w are independently a decimal number from 0 to 5; x, y, z and w are not simultaneously equal to 0; x and y are not simultaneously equal to 0; z and w may not be simultaneously equal to 0.

9. The color conversion layer ( 4 ) according to claim 1 , wherein the nanoparticles ( 3 ) comprised in the at least one composite particle ( 1 ) are semiconductor nanoplatelets.

10. The color conversion layer ( 4 ) according to claim 1 , wherein the at least one surrounding medium ( 71 ) is optically transparent.

11. The color conversion layer ( 4 ) according to claim 1 , wherein the at least one surrounding medium ( 71 ) has a thermal conductivity at standard conditions of at least 0.1 W/(m·K).

12. The color conversion layer ( 4 ) according to claim 1 , wherein the at least one surrounding medium ( 71 ) is a solid host material or a fluid.

13. A display apparatus ( 230 ) comprising:

a. at least one light source ( 231 );

b. a rotating wheel ( 233 ) comprising at least two zones, wherein at least one zone comprises at least one color conversion layer ( 4 ) comprising at least one light emitting material ( 7 ) comprising at least one composite particle ( 1 ) surrounded partially or totally by at least one surrounding medium ( 71 );

wherein said at least one light emitting material ( 7 ) is configured to emit a secondary light in response to an excitation and the at least one composite particle ( 1 ) comprises a plurality of nanoparticles ( 3 ) encapsulated in an inorganic material ( 2 );

wherein said inorganic material ( 2 ) has a difference of refractive index compared to the at least one surrounding medium ( 71 ) superior or equal to 0.02 at 450 nm; and

wherein a loading charge of nanoparticles ( 3 ) in a composite particle ( 1 ) is at least 10%, said loading charge being the mass ratio between the mass of nanoparticles comprised in a composite particle and the mass of said composite particle; and

c. a modulating optical system ( 236 );

wherein the light source ( 231 ) is configured to provide excitation for the at least one color conversion layer ( 4 ) and wherein the modulating optical system ( 236 ) is configured to reflect the light emitted by the rotating wheel ( 233 ).

14. The display apparatus ( 230 ) according to claim 13 , wherein the inorganic material ( 2 ) limits or prevents the diffusion of outer molecular species or fluids (liquid or gas) into said inorganic material ( 2 ).

15. The display apparatus ( 230 ) according to claim 13 , wherein the at least one composite particle ( 1 ) in the at least one surrounding medium ( 71 ) is configured to scatter light.

16. The display apparatus ( 230 ) according to claim 13 , wherein the at least one composite particle ( 1 ) in the at least one surrounding medium ( 71 ) is configured to serve as a waveguide.

17. The display apparatus ( 230 ) according to claim 13 , wherein the color conversion layer ( 4 ) absorbs at least 70% of incident light on a thickness less or equal to 5 pm, wherein the incident light has a wavelength ranging from 370 to 470 nm.

18. The display apparatus ( 230 ) according to claim 13 , wherein the nanoparticles ( 3 ) comprised in the at least one composite particle ( 1 ) are semiconductor nanocrystals comprising a material of formula M x N y E z A w , wherein: M is selected from the group consisting of Zn, Cd, Hg, Cu, Ag, Au, Ni, Pd, Pt, Co, Fe, Ru, Os, Mn, Tc, Re, Cr, Mo, W, V, Nd, Ta, Ti, Zr, Hf, Be, Mg, Ca, Sr, Ba, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Cs or a mixture thereof; N is selected from the group consisting of Zn, Cd, Hg, Cu, Ag, Au, Ni, Pd, Pt, Co, Fe, Ru, Os, Mn, Tc, Re, Cr, Mo, W, V, Nd, Ta, Ti, Zr, Hf, Be, Mg, Ca, Sr, Ba, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Cs or a mixture thereof; E is selected from the group consisting of O, S, Se, Te, C, N, P, As, Sb, F, Cl, Br, I, or a mixture thereof; A is selected from the group consisting of O, S, Se, Te, C, N, P, As, Sb, F, Cl, Br, I, or a mixture thereof; and x, y, z and w are independently a decimal number from 0 to 5; x, y, z and w are not simultaneously equal to 0; x and y are not simultaneously equal to 0; z and w may not be simultaneously equal to 0.

19. The display apparatus ( 230 ) according to claim 13 , wherein the nanoparticles ( 3 ) comprised in the at least one composite particle ( 1 ) are semiconductor nanocrystals comprising at least one shell ( 34 ) comprising a material of formula M x N y E z A w , wherein: M is selected from the group consisting of Zn, Cd, Hg, Cu, Ag, Au, Ni, Pd, Pt, Co, Fe, Ru, Os, Mn, Tc, Re, Cr, Mo, W, V, Nd, Ta, Ti, Zr, Hf, Be, Mg, Ca, Sr, Ba, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Cs or a mixture thereof; N is selected from the group consisting of Zn, Cd, Hg, Cu, Ag, Au, Ni, Pd, Pt, Co, Fe, Ru, Os, Mn, Tc, Re, Cr, Mo, W, V, Nd, Ta, Ti, Zr, Hf, Be, Mg, Ca, Sr, Ba, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Cs or a mixture thereof; E is selected from the group consisting of O, S, Se, Te, C, N, P, As, Sb, F, Cl, Br, I, or a mixture thereof; A is selected from the group consisting of O, S, Se, Te, C, N, P, As, Sb, F, Cl, Br, I, or a mixture thereof; and x, y, z and w are independently a decimal number from 0 to 5; x, y, z and w are not simultaneously equal to 0; x and y are not simultaneously equal to 0; z and w may not be simultaneously equal to 0.

20. The display apparatus ( 230 ) according to claim 13 , wherein the nanoparticles ( 3 ) comprised in the at least one composite particle ( 1 ) are semiconductor nanocrystals comprising at least one crown ( 37 ) comprising a material of formula M x N y E z A w , wherein: M is selected from the group consisting of Zn, Cd, Hg, Cu, Ag, Au, Ni, Pd, Pt, Co, Fe, Ru, Os, Mn, Tc, Re, Cr, Mo, W, V, Nd, Ta, Ti, Zr, Hf, Be, Mg, Ca, Sr, Ba, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Cs or a mixture thereof; N is selected from the group consisting of Zn, Cd, Hg, Cu, Ag, Au, Ni, Pd, Pt, Co, Fe, Ru, Os, Mn, Tc, Re, Cr, Mo, W, V, Nd, Ta, Ti, Zr, Hf, Be, Mg, Ca, Sr, Ba, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Cs or a mixture thereof; E is selected from the group consisting of O, S, Se, Te, C, N, P, As, Sb, F, Cl, Br, I, or a mixture thereof; A is selected from the group consisting of O, S, Se, Te, C, N, P, As, Sb, F, Cl, Br, I, or a mixture thereof; and x, y, z and w are independently a decimal number from 0 to 5; x, y, z and w are not simultaneously equal to 0; x and y are not simultaneously equal to 0; z and w may not be simultaneously equal to 0.

21. The display apparatus ( 230 ) according to claim 13 , wherein the nanoparticles ( 3 ) comprised in the at least one composite particle ( 1 ) are semiconductor nanoplatelets.

22. The display apparatus ( 230 ) according to claim 13 , wherein the at least one surrounding medium ( 71 ) is optically transparent.

23. The display apparatus ( 230 ) according to claim 13 , wherein the at least one surrounding medium ( 71 ) has a thermal conductivity at standard conditions of at least 0.1 W/(m·K).

24. The display apparatus ( 230 ) according to claim 13 , wherein the at least one surrounding medium ( 71 ) is a solid host material or a fluid.

25. The display apparatus ( 230 ) according to claim 13 , wherein the modulating optical system ( 236 ) is configured to reflect the light emitted by the rotating wheel ( 233 ) to a screen.

26. The display apparatus ( 230 ) according to claim 13 , further comprising a screen ( 238 ).

27. The display apparatus ( 230 ) according to claim 13 , wherein the modulating optical system ( 236 ) is a digital micromirror device.