Illumination source comprising nanoplatelets and display apparatus having the same

• US 10,642,139 B2
• Filed: 06/01/2018
• Issued: 05/05/2020
• Est. Priority Date: 06/02/2017
• Status: Active Grant

• Current Assignee: Nexdot
• Original Assignee: Nexdot
• Inventors: Pousthomis, Marc, D'Amico, Michele, Lin, Yu-Pu
• Primary Examiner(s): Green, Tracie Y
• Application Number:
  US15/995,447
• Publication Number:
  US 20190004369A1
• Time in Patent Office: 704 Days
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: C09K 11/025 non-luminescent particle coatings or suspension media
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 11/565 with zinc cadmium
• CPC Class Codes: C09K 11/703 with zinc or cadmium
• CPC Class Codes: C09K 11/883 with zinc or cadmium
• CPC Class Codes: C09K 2211/10 Non-macromolecular compounds
• CPC Class Codes: G02B 6/0026 Wavelength selective element, sheet or layer, e.g. filter or grating
• CPC Class Codes: G02B 6/0046 Tapered light guide, e.g. wedge-shaped light guide
• CPC Class Codes: G02F 1/133504 Diffusing, scattering, diffracting elements associated to illuminating devices G02F1/133606
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: G02F 1/133617 Illumination with ultraviolet light; Luminescent elements or materials associated to the cell
• CPC Class Codes: G02F 2201/501 Blocking layers, e.g. against migration of ions
• CPC Class Codes: G02F 2202/10 semiconductor
• CPC Class Codes: G03B 21/008 using micromirror devices
• CPC Class Codes: G03B 21/204 using secondary light emission, e.g. luminescence or fluorescence using different colours G03B33/00; if related to video signals H04N9/3197
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 33/50 : Wavelength conversion elements
• CPC Class Codes: H01L 33/501 : characterised by the materials, e.g. binder
• CPC Class Codes: H01L 33/502 : Wavelength conversion materials
• CPC Class Codes: H01L 33/505 : characterised by the shape, e.g. plate or foil
• CPC Class Codes: H10K 2102/331 : Nanoparticles used in non-emissive layers, e.g. in packaging layer
• CPC Class Codes: H10K 50/865 : comprising light absorbing layers, e.g. light-blocking layers
• CPC Class Codes: H10K 59/38 : comprising colour filters or colour changing media [CCM]
• CPC Class Codes: H10K 59/8792 : comprising light absorbing layers, e.g. black layers

Abstract

Disclosed is a color conversion layer including at least one light emitting material including at least one composite particle surrounded partially or totally by at least one surrounding medium; wherein the light emitting material is configured to emit light in response to an excitation and the at least one composite particle includes a plurality of nanoparticles encapsulated in an inorganic material; and wherein the inorganic material has a difference of refractive index compared to the at least one surrounding medium superior or equal to 0.02 at 450 nm. Also disclosed is an illumination source and a display apparatus.

Claims

1. An illumination source (15) comprising at least one light source (5) and 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 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); and

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 the nanoparticles (3) comprise at least 1% of semiconductor nanoplatelets.

2. The illumination source (15) according to claim 1, further comprising a light guide (11), wherein the at least one color conversion layer (4) is located between the light source (5) and said light guide (11).

3. The illumination source (15) according to claim 1, further comprising a reflector (16) configured to reflect the light from the light source (5) and/or from the at least one color conversion layer (4).

4. The illumination source (15) according to claim 1, wherein the light source (5) comprises at least one light-emitting diode (LED) or an array of LEDs.

11. The illumination source (15) 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).

12. The illumination source (15) 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.

13. The illumination source (15) 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_yE_zA_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.

14. The illumination source (15) 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_xN_yE_zA_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.

15. The illumination source (15) 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_xN_yE_zA_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.

16. The illumination source (15) according to claim 1, wherein the nanoparticles (3) comprised in the at least one composite particle (1) are semiconductor nanoplatelets.

17. The illumination source (15) according to claim 1, wherein the at least one surrounding medium (71) is optically transparent.

18. The illumination source (15) 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).

5. A display apparatus (8) comprising an illumination source (15) comprising at least one light source (5) and 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 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); and

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 the nanoparticles (3) comprise at least 1% of semiconductor nanoplatelets.

6. The display apparatus (8) according to claim 5, wherein the illumination source (15) further comprises a light guide (11), wherein the at least one color conversion layer (4) is located between the light source (5) and said light guide (11).

7. The display apparatus (8) according to claim 5, wherein the illumination source (15) further comprises a reflector (16) configured to reflect the light from the light source (5) and/or from the at least one color conversion layer (4).

8. The display apparatus (8) according to claim 5, wherein the light source (5) comprises at least one light-emitting diode (LED) or an array of LEDs.

9. The display apparatus (8) according to claim 5, further comprising at least one color filter (18).

10. The display apparatus (8) according to claim 9, comprising at least one layer of activation between the illumination source (15) and the at least one color filter (18).