Solid polymer composition

Abstract

The present invention relates in a first aspect to a solid polymer component comprising luminescent crystals of 3-500 nm size, surfactant and a hardened/cured polymer. In a second aspect of the invention, a luminescent component comprises a first element comprising the solid polymer component according to the first aspect and an encapsulation enclosing the first element. In a third aspect of the invention, a luminescent component comprises a first film comprising the solid polymer composition of the first aspect. A fourth aspect of the invention relates to a light emitting device comprising the luminescent component according to the second or third aspect of the invention and a light source.

Claims

1. A solid polymer composition comprising: (i) luminescent crystals of 3-500 nm size, said luminescent crystals being selected from compounds of formula (I)
[M.sup.1A.sup.1].sub.aM.sup.2.sub.bX.sub.c  (I), wherein: cation A.sup.1, which is mandatory, is an organic cation, cation M.sup.2 is a metal cation and cation M.sup.1, if present, is an alkali metal cation; and A.sup.1 represents one or more cations selected from the group consisting of ammonium, formamidinium, guanidinium, imidazolium, pyridinium, pyrrolidinium, protonated thiourea, M.sup.1 represents one or more alkaline metals selected from Cs, Rb, K, Na, Li, M.sup.2 represents one or more metals selected from the group consisting of Ge, Sn, Pb, Sb, and Bi, X represents one or more anions selected from the group consisting of chloride, bromide, iodide, cyanide, thiocyanate, isothiocyanate and sulfide, a represents 1-4, b represents 1-2, c represents 3-9; and (ii) a surfactant selected from the group of non-ionic, anionic, cationic and zwitter-ionic surfactants, and (iii) a hardened/cured polymer, said polymer being an acrylate comprising or consisting of units of formula (III): ##STR00021## wherein: R.sup.9 represents H or CH.sub.3, R.sup.10 represents a cyclic C.sub.5-25 alkyl, or a cyclic C.sub.5-25 alkenyl group, or a C.sub.6-26 aryl group, each optionally substituted with one or more cyclic, linear or branched C.sub.1-20 alkyl, phenyl or phenoxy, n represents 0 or 1, and X represents a spacer from the group of alkoxylates comprising 1-40 carbon atoms and 1-10 oxygen atoms.

2. The solid polymer composition according to claim 1, wherein the weight ratio of luminescent crystals:matrix (polymer+surfactant) is in the range of 0.00001-0.2; and/or the weight ratio surfactant:luminescent crystals is in the range of 100-0.01.

3. The solid polymer composition according to claim 1, wherein in formula (I) of the luminescent crystals A.sup.1 represents formamidinium, and M.sup.1 is not present.

4. The solid polymer composition according to claim 1, wherein the surfactant is a zwitter-ionic surfactant.

5. A luminescent component, comprising a first element comprising a first solid polymer composition according to claim 1, wherein luminescent crystals of the first solid polymer composition emit light of a first wavelength in response to excitation by light with a wavelength shorter than the first wavelength, and an encapsulation enclosing the first element, wherein the encapsulation comprises an encapsulation polymer or inorganic matrix.

6. The luminescent component according to claim 5, further comprising a second element comprising a second solid polymer composition comprising (i) luminescent crystals of 3-500 nm size, said luminescent crystals being selected from compounds of formula (I); (ii) a second surfactant; and a second a hardened/cured polymer, wherein luminescent crystals of the second solid polymer composition are of a different chemical composition and/or a different size than the luminescent crystals of the first solid polymer composition, emit light of a second wavelength different to the first wavelength in response to excitation by light with a wavelength shorter than each of the first and second wavelength, wherein the encapsulation encloses the second element.

7. The luminescent component according to claim 6, comprising N further elements with N≥1, each further element comprising a further solid polymer composition comprising (i) luminescent crystals of 3-500 nm size, said luminescent crystals being selected from compounds of formula (I); (ii) a further surfactant; and a further hardened/cured polymer wherein the luminescent crystals of the further solid polymer composition are of a different chemical composition and/or a different size than the luminescent crystals of the first solid polymer composition, the luminescent crystals of the second solid polymer composition, and any luminescent crystals of the N−1 other solid polymer compositions, emit light of a further wavelength in response to excitation by light with a wavelength shorter than the further wavelength, wherein the further wavelength is different from the first wavelength, is different from the second wavelength, and is different from any of the N−1 other further wavelengths.

8. The luminescent component according to claim 6, wherein the first element and the second element are arranged spaced within the encapsulation.

9. The luminescent component of claim 7, wherein the polymer of the further solid polymer composition is not dissolvable in the encapsulation polymer or inorganic matrix, and vice versa.

10. The luminescent component according to claim 6, wherein the luminescent crystals of the first solid polymer composition, and the luminescent crystals of the second solid polymer composition, independently are of size between 3 nm and 100 nm.

11. The luminescent component of claim 6, wherein the polymer of the second solid polymer composition is not dissolvable in the encapsulation polymer or inorganic matrix, and vice versa.

12. The luminescent component according to claim 5, wherein the encapsulation polymer is a polymer selected from the list of acrylate polymers, carbonate polymers, sulfone polymers, epoxy polymers, vinyl polymers, urethane polymers, ester polymers, styrene polymers, silicone polymers, olefin polymers, cyclic olefin copolymers, and halogenated vinyl polymers.

13. The luminescent component of claim 12, wherein the encapsulation polymer has a water vapor permeability of less than 5 g mm m.sup.−2 day.sup.−1.

14. The luminescent component according to claim 5, wherein the encapsulation comprises luminescent crystals according to formula (I).

15. The luminescent component according to claim 14, wherein the luminescent crystals comprised in the encapsulation are of different chemical composition and/or size than the luminescent crystals of the first solid polymer composition and emit light of a wavelength different to the first wavelength in response to excitation by light with a wavelength shorter than the first wavelength.

16. The luminescent component according to claim 5, comprising one or more barrier films each having a water vapor transmission rate of less than 0.1 g m.sup.−2 day.sup.−1.

17. The luminescent component of claim 16, wherein a material of each barrier film is selected from the group consisting of polyvinylidene chlorides, cyclic olefin copolymers, high-density polyethylene, metal oxides, silicon oxide, silicon nitride; optionally in the form of organic/inorganic multilayers.

18. The luminescent component of claim 5, wherein the polymer of the first solid polymer composition is not dissolvable in the encapsulation polymer or inorganic matrix, and vice versa.

19. A luminescent component, comprising a first film comprising a first solid polymer composition according to claim 1, wherein the luminescent crystals of the first solid polymer composition emit light with a first wavelength in response to excitation by light with a wavelength shorter than the first wavelength.

20. The luminescent component according to claim 19, wherein the luminescent crystals of the first solid polymer composition emit red light in response to excitation by light with a shorter wavelength, comprising a second film, comprising a second solid polymer composition comprising (i) luminescent crystals of 3-500 nm size, said luminescent crystals being selected from compounds of formula (I); (ii) a second surfactant; and a second a hardened/cured polymer wherein the luminescent crystals of the second solid polymer composition emit green light in response to excitation by light with a shorter wavelength.

21. The luminescent component according to claim 20, wherein a thickness of the first film is between 3 μm and 500 μm and/or wherein a thickness of the second film is between 30 μm and 500 μm.

22. The luminescent component according to claim 20, further comprising a substrate and at least one barrier film having a water vapor transmission rate of less than 0.1 g m.sup.−2 day.sup.−1, wherein one of the first and the second film is arranged between the substrate and the other of the first and the second film, and wherein the first and the second film are arranged between the substrate and the at least one barrier film.

23. The luminescent component according to claim 20, comprising a substrate, wherein the first film is supported by the substrate, and wherein the second film is supported by the substrate, and wherein the substrate is one of an organic substrate or an inorganic substrate.

24. The luminescent component according to claim 23, further comprising at least a first and a second barrier film each having a water vapor transmission rate of less than 0.1 g m.sup.−2 day.sup.−1, wherein the substrate is arranged between the first film and the second film, and wherein the first film is arranged between a first of the barrier films and the substrate, and the second film is arranged between a second of the barrier films and the substrate.

25. The luminescent component according to claim 23, further comprising at least one barrier film having a water vapor transmission rate of less than 0.1 g m.sup.−2 day.sup.−1, wherein the first film and the second film are arranged on a common surface of the substrate, wherein the first film and the second film are arranged spaced or adjacent, and wherein the first film and the second film are arranged between the substrate and the at least one barrier film.

26. The luminescent component according to claim 25, comprising multiple first films of the first solid polymer composition, multiple second films of the second solid polymer composition, wherein the multiple first films and the multiple second films are arranged on the common surface of the substrate, and wherein the multiple first films and the multiple second films are arranged between the substrate and the at least one barrier film.

27. The luminescent component according to claim 26, wherein the multiple first films and the multiple second films are arranged alternating on the common surface of the substrate in one of a spaced or an adjacent arrangement.

28. The luminescent component according to claim 19, wherein the luminescent crystal weight per area of film is between 0.05 g/m.sup.2 and 3.0 g/m.sup.2.

29. The luminescent component according to claim 19, comprising one or more barrier films each having a water vapor transmission rate of less than 0.1 g m.sup.−2 day.sup.−1.

30. The luminescent component of claim 29, wherein a material of each barrier film is selected from the group consisting of polyvinylidene chlorides, cyclic olefin copolymers, high-density polyethylene, metal oxides, silicon oxide, silicon nitride; optionally in the form of organic/inorganic multilayers.

31. A light emitting device, comprising a luminescent component according to claim 5, a light source for emitting blue light, wherein the light source is arranged for exciting the luminescent component, and wherein the light emitting device is one of a Liquid Crystal Display, an Organic Light Emitting Diode or a Light Emitting Diode.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be better understood and objects other than those set forth above will become apparent from the following detailed description of embodiments thereof. Such description makes reference to the annexed drawings, wherein:

(2) FIG. 1a illustrates a schematic perspective view of a luminescent component according to an embodiment of the second aspect of the present invention;

(3) FIG. 1b illustrates a schematic perspective view of a luminescent component according to a further embodiment of the second aspect of the present invention;

(4) FIG. 1c illustrates a schematic perspective view of a luminescent component according to a further embodiment of the second aspect of the present invention;

(5) FIG. 2 illustrates a light emitting device according to an embodiment of the fourth aspect of the present invention;

(6) FIG. 3 illustrates a light emitting device according to another embodiment of the fourth aspect of the present invention;

(7) FIG. 4 illustrates a light emitting device according to another embodiment of the fourth aspect of the present invention;

(8) FIGS. 5 to 7 each shows a perspective view of a luminescent component according to an embodiment of the third aspect of the present invention;

(9) FIG. 8 illustrates a schematic block diagram of a light emitting device according to an embodiment of the third aspect of the present invention;

(10) FIG. 9 illustrates a schematic block diagram of a light emitting device according to an embodiment of the fourth aspect of the present invention;

(11) FIG. 10 shows an X-ray diffraction pattern of a preferred starting material FAPbBr.sub.3;

(12) FIG. 11 shows a TEM image of FAPbBr.sub.3 luminescent crystals for a solid polymer composition according to an embodiment of the present invention;

(13) FIG. 12 shows a TEM image of Cs.sub.0.85FA.sub.0.15PbBr.sub.3 luminescent crystals for a solid polymer composition according to an embodiment of the present invention; and

(14) FIG. 13 shows a TEM image of Cs.sub.0.5FA.sub.0.5PbBr.sub.3 luminescent crystals for a solid polymer composition according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

(15) FIG. 1a illustrates a schematic perspective view of a luminescent component according to an embodiment of the second aspect of the present invention. The luminescent component 104 comprises an encapsulation 103, e.g. made from a non-opaque polymer. In the present embodiment, the encapsulation 103 is of a thin film shape whereby the length (x-axis) and width (y-axis) are of much greater size than the thickness in z-direction. However, the encapsulation 103 may take a different shape if needed.

(16) First elements 101, second elements 102, and first further elements if are embedded in the encapsulation 103, only one of each is shown in a cut mode in FIG. 1a.

(17) The first element 101 comprises a first solid polymer composition comprising luminescent crystals 111, a polymer 112 and surfactants. The luminescent crystals 111 of the first solid polymer composition are selected from compounds of formula (I) introduced above. These luminescent crystals 111 have a size between 3 nm and 500 nm. In response to excitation by blue light BL as indicated by the arrow, these luminescent crystals 111 emit red light RD, for example.

(18) The second element 102 comprises a second solid polymer composition comprising luminescent crystals 121, a polymer 122, and surfactants. The luminescent crystals 121 of the second solid polymer composition are selected from compounds of formula (I) introduced above. These luminescent crystals 221 have a size between 3 nm and 500 nm. In response to excitation by the blue light BL, these luminescent crystals 121 emit green light GR, for example.

(19) Generally, different further elements nf with n∈[1,N] may be comprised in the encapsulation 103 including a first further element 1f, preferably a second further element 2f, . . . an Nth further element Nf. Each further element nf comprises a further solid polymer composition comprising luminescent crystals n1f, a polymer n2f, and surfactants.

(20) Presently, only first further elements 1f are included in the encapsulation 103. Each first further element if comprises luminescent crystals 11f, a polymer 12f and surfactants. The luminescent crystals 11f of the first further elements 1f are selected from compounds of formula (I) introduced above. These luminescent crystals 11f have a size between 3 nm and 500 nm. In response to excitation by the blue light BL, these luminescent crystals 11f emit yellow light YL, for example.

(21) In one embodiment of the invention there can also be multiple further elements nf emitting multiple different colors.

(22) The luminescent crystals of the first, second and further solid polymer component 111, 121, n1f are separated from each other by means of the separated elements 101, 102, nf. In this embodiment, the encapsulation 103 builds the separation. Hence, the first, second and further luminescent elements 101, 102, nf are stable, also in a long-term.

(23) As is indicated in FIG. 1a, once such luminescent component is exposed to radiation of a shorter wavelength than the emitted wavelength, and in particular to blue radiation BL, the luminescent crystals of the first, second and first further solid polymer composition 111, 121, 11f are excited and emit red, green and yellow light RD, GR, YL, respectively. Together with a portion of the blue light BL passing the luminescent component 104 the output of the luminescent component is a mixture of these colors and can be tuned by the amount of first, second and first further elements 101, 102, 11f in the luminescent component.

(24) In case the luminescent component 104 of FIG. 1a comprises first and second elements 101 and 102 emitting red and green light only, the luminescent component 104 may in combination with a light source emitting the blue light BL represent a backlight film that can be used in an LCD given that the combination of red, green and blue light emitted result in white light. An intensity proportion of the red, green and blue light emitted preferably is in the range of a ⅓ each.

(25) FIG. 1b illustrates a schematic perspective view of a luminescent component 104 according to an embodiment of the second aspect of the invention as shown in FIG. 1a. The embodiment of FIG. 1b distinguishes from the embodiment of FIG. 1a in that the luminescent component 104 comprises multiple first elements 101 only that are embedded in the encapsulation 103. The first elements 101 comprise each luminescent crystal of the first solid polymer composition only.

(26) FIG. 1c illustrates a schematic perspective view of a luminescent component 104 according to a further embodiment of the second aspect of the invention. The encapsulation 103 of this further embodiment comprises additional luminescent crystals 133.

(27) These luminescent crystals 133 are of different chemical composition and/or size than the luminescent crystals 111 of the first solid polymer composition and emit light of a wavelength different to the first wavelength in response to excitation by light with a wavelength shorter than the first wavelength.

(28) In addition, the luminescent crystals 133 enclosed by the encapsulation 103 might be different in composition and/or in size to the luminescent crystals 121 of the second and or/to the luminescent crystals (11f) of the first further solid polymer composition.

(29) The additional luminescent crystals 133 might emit light of a wavelength different to the second and/or further wavelength in response to excitation by light with a wavelength shorter than each of the first, second and/or further wavelength.

(30) FIG. 2 illustrates a light emitting device according to an embodiment of the fourth aspect of the invention comprising a luminescent component according to the second aspect of the invention. The light emitting device presently is a Light Emitting Diode LED. The device includes a luminescent component 104 of a sphere-like shape. As is indicated in FIG. 2, the luminescent component 104 includes multiple first elements 101. Each first element 101 includes luminescent crystals of the first solid polymer composition in addition to a polymer and surfactants, but no other luminescent crystals. The first elements 101 are embedded in the encapsulation 103 separate from each other, which encapsulation 103 is transmissive to light. Subject to the application of the resulting device other elements configured to emit light of one or more different wavelengths than the first elements may be incorporated in the encapsulation.

(31) Reference numeral 5 indicates an LED chip as a light source that is arranged on a carrier 6. The luminescent component 104 partly encloses—the top and the sides of—the LED chip 5. The LED chip 5 preferably is configured to emit blue light. In response to an excitation by blue light emitted from the LED chip 5, the luminescent crystals in the first elements 101 and/or further elements of the luminescent component 104 emit light of a different colour, e.g. red, green and/or yellow light. Hence, the present embodiment schematically illustrates an LED emitting e.g. additive colour mixtures of red and/or green and/or yellow with LED chip 5 blue light. As to the manufacturing of the device of FIG. 2, the LED chip 5 may be preassembled onto the carrier 6, and the luminescent component 104 may be dropped onto the LED chip 5/carrier 6 arrangement in liquid form, and then be hardened, cured or dried.

(32) In view of the luminescent component 104 being arranged directly on the LED chip 5, the luminescent component 104 preferably includes heat resistant materials. For example, the polymer in the first elements 101 and the encapsulation 103 may be a temperature stable polymer, and preferably may be Silicone or Polysilazane.

(33) FIG. 3 illustrates a light emitting device according to another embodiment of the fourth aspect of the present invention comprising a luminescent component according to the second aspect of the invention. The light emitting device presently is a Light Emitting Diode LED. The device includes a luminescent component 104 of a film-like shape. As is indicated in FIG. 3, the luminescent component 104 includes multiple first elements 101. Each first element 101 includes luminescent crystals of a first solid polymer composition in addition to a polymer and surfactants but no other luminescent crystals. The first elements 101 are embedded in the encapsulation 103 separate from each other, which encapsulation 103 is transmissive to light. Subject to the application of the resulting device other elements configured to emit light of one or more different wavelengths than the first elements 101 may be incorporated in the encapsulation 103.

(34) The luminescent component 104 is arranged on a transparent plate 9, e.g. of a housing or a front. The luminescent component 104/plate 9—combination is arranged distant from an LED chip 5 acting as a light source that is arranged on a carrier 6. The distant arrangement may be achieved by means of a housing 8. The LED chip 5 preferably is configured to emit blue light. Presently, the LED chip 5 is partly enclosed by a phosphor-free enclosure 7. In response to an excitation by blue light emitted from the LED chip 5, the luminescent crystals in the first elements 101 and/or further elements of the luminescent component 104 emit light of a different colour, e.g. red, green and/or yellow light. Hence, the present embodiment schematically illustrates an LED emitting e.g. additive colour mixtures of red and/or green and/or yellow with LED chip 5 blue light. As to the manufacturing of the device of FIG. 3, the LED chip 5 may be preassembled onto the carrier 6, while the luminescent component 104 may in its hardened form be attached to the plate 9.

(35) In contrast to the embodiment illustrated in FIG. 2, the luminescent component is arranged distant form the LED chip 5 such that the luminescent component may not be required to stand heat in the same way.

(36) FIG. 4 illustrates a light emitting device according to an embodiment of the fourth aspect of the present invention comprising a luminescent component according to the second aspect of the present invention. The light emitting device presently is an Organic Light Emitting Diode OLED. The device includes a luminescent component 104 of flat shape. As is indicated in FIG. 4, the luminescent component 104 includes multiple first elements 101. Each first element 101 includes luminescent crystals of a first solid polymer composition in addition to a polymer and surfactants, but no other luminescent crystals. The first elements 101 are embedded in the encapsulation 103 separate from each other, which encapsulation 103 is transmissive to light. Subject to the application of the resulting device other elements configured to emit light of one or more different wavelengths than the first elements may be incorporated in the encapsulation.

(37) Reference numeral 10 indicates an OLED stack as a light source that may be arranged on further carrier. The OLED stack 10 preferably is configured to emit blue light. In response to an excitation by blue light emitted from the OLED stack 10, the luminescent crystals in the first elements 101 and/or further elements of the luminescent component 104 emit light of a different colour, e.g. red, green and/or yellow light. Hence, the present embodiment schematically illustrates an OLED device emitting e.g. additive colour mixtures of red and/or green and/or yellow. As to the manufacturing of the device of FIG. 4, the OLED stack 10 may be preassembled onto a carrier, and the luminescent component 104 may be coated onto the OLED stack 10 in liquid form, and then be hardened, cured or dried.

(38) FIG. 5 illustrates a perspective view of a luminescent component according to an embodiment of a third aspect of the present invention. The luminescent component comprises a substrate 203, e.g. made from a non-opaque polymer or a non-opaque inorganic material such as glass. The substrate 203 has a top surface TS and a bottom surface BS opposite the top surface TS.

(39) A first film 201 is attached to the top surface TS of the substrate 203. A second film 202 is attached to the bottom surface BS of the substrate 203. The attachment may be achieved e.g. by bonding or by directly casting the respective film onto the substrate 203. Each of the first film 201, second film 202 and substrate 203 has a length along the x-axis, a width along the y-axis, and a thickness along the z-axis.

(40) The following description of characteristics of the first and the second film 201, 202 are applicable to all other embodiments introduced in this section.

(41) The first film 201 comprises a first solid polymer composition. The first solid polymer composition at least comprises a polymer, surfactants, and luminescent crystals 211, wherein these luminescent crystals 211 are selected from compounds of formula (I) as defined herein.

(42) The luminescent crystals 211 of the first solid polymer composition have a size between 3 nm and 500 nm. In response to excitation, these luminescent crystals 211 emit red light.

(43) The second film 202 comprises a second solid polymer composition. The second solid polymer composition comprises at least a polymer, surfactants, and luminescent crystals 221. The luminescent crystals 221 of the second solid polymer composition are selected from compounds of formula (I) as defined herein.

(44) The luminescent crystals 221 of the second film have a size between 3 nm and 500 nm. In response to excitation, the luminescent crystals 221 of the second film emit green light.

(45) The polymer of the first and the second solid polymer composition are preferably but not necessarily the same. The surfactants of the first and the second solid polymer composition are preferably but not necessary the same.

(46) As can be derived from FIG. 5, it is preferred that both the first and the second film 201, 202 extend all across the top and respective bottom surface TS, BS of the substrate 203. Hence, the footprint of the substrate 203 can fully be exploited.

(47) The luminescent crystals 211 of the first solid polymer composition and the luminescent crystals 221 of the second solid polymer composition are separated from each other. In this embodiment, the substrate 203 builds the separation. Hence, the first and second films 201, 202 are stable, also in a long-term. It is preferred—which feature is also true for any of the other embodiments—that the first film 201 exclusively comprises the luminescent crystals 211 of the first solid polymer composition emitting red light when excited, such that preferably there are no luminescent crystals 221 of the second solid polymer composition present in the first film 201, nor any other than the luminescent crystals 211 of the first solid polymer composition. Accordingly, it is preferred,—which feature is also true for any of the other embodiments—that the second film 202 exclusively comprises the luminescent crystals 221 of the second solid polymer composition emitting green light when excited, such that preferably there are no luminescent crystals 211 of the first solid polymer composition present in the second film 202, nor any other than the luminescent crystals 221 of the second solid polymer composition.

(48) As is indicated in FIG. 5, once such luminescent component is exposed to radiation, and in particular to blue radiation BL, the luminescent crystals of the first and second solid polymer composition 211 and 221 are excited and emit red and green light RD, GR respectively. Together with a portion of the blue light BL passing the luminescent component the output of the luminescent component is white light. Hence, the present device can preferably be used as a backlight illumination in an LCD, for example.

(49) FIG. 6 illustrates a perspective view of a luminescent component according to another embodiment of the third aspect of the present invention. Again, the luminescent component comprises a substrate 203 and a first and a second film 201, 202. The first film 201 preferably comprises luminescent crystals 211 of the first solid polymer composition only while the second film 202 preferably comprises luminescent crystals 221 of the second solid polymer composition only. Again, the first and the second films 201 and 202 fully extend across a surface of the substrate 203. In contrast to FIG. 5, however, the first and the second films 201 and 202 are not arranged on different sides of the substrate 203, but are arranged at the same side of the substrate 203 on top of each other. Preferably, in such an embodiment, the substrate 203 might also act as a barrier film or might be formed as a barrier film 203 itself. Hence, a stack built from the first and the second film 201 and 202 is deposited on a surface of the substrate 203, e.g. the bottom surface BS. This stack may also be divided by a layer of a different solid polymer composition. In the example shown in FIG. 6, the first film 201 is attached to the bottom surface BS of the substrate 203, while the second film 202 is arranged on bottom of the exposed surface of the first film 201. In a different arrangement, the second film 202 is attached to the bottom surface BS of the substrate 203 while the first film 201 is attached to the exposed surface of the second film 202. Of course, when it comes to manufacturing the luminescent component, the films may be attached in sequence to the substrate 203. In a different embodiment, the first and the second films 201, 202 are attached to each other forming a stack prior to attaching the stack to the substrate 203.

(50) FIGS. 7 and 8 illustrate perspective views of luminescent components according to further embodiments of the third aspect of the present invention. Instead of providing only a single first film 201 and a single second film 202 such as in the embodiments of FIGS. 5 and 6, multiple first films 201 and multiple second films 202 are provided, wherein the number of two films per type is only exemplary. Instead of arranging the first and second films 201, 202 on different levels, i.e. on different vertical (z-) positions such as in the embodiments of FIGS. 5 and 6, the luminescent films 201 and 202 are arranged in the same level on the z-axis. Hence, the first and the second films 201 and 202 are arranged next to each other in the same plane, and, as a result, the first and the second film 201, 202 are both arranged on a common surface of the substrate 203, e.g. its bottom surface BS. In the embodiment of FIG. 7, the first and second films 201 and 202 are arranged alternating and in contact with each other, while in the embodiment of FIG. 8, the first and second films 201 and 202 are arranged alternating and separated from each other by air gaps. It is noted that the spatial arrangement preferably is in such a small size that it is not visible by eye in the final application.

(51) FIG. 9 illustrates a schematic block diagram of a light emitting device 204 according to an embodiment of the fourth aspect of the present invention comprising a luminescent component according to the third aspect of the present invention. The device 204 includes a luminescent component 241 according to FIG. 5, and a light source 50 for emitting blue light, the light source 50 being arranged such that the emitted blue light excites the luminescent component 241. Preferably, the light source 50 is embodied as an element of the same length and width as the first and second film 201,202, and is attached to the luminescent component 241.

(52) In any of the embodiments of the luminescent components of FIGS. 5 to 9, otherwise exposed surfaces ES of the first or second film 201 or 202 are preferably covered by a barrier film for protecting the luminescent crystals in the respective films 201 and 202. Preferably, such one or two barrier films fully extend across the otherwise exposed surface, but not necessarily across side surfaces of the first or second films 201, 202 represented by the thickness of the subject films 201, 202, along the z-direction.

(53) FIG. 10 shows an X-ray diffraction pattern (measurement tool: MiniFlex 600, Rigaku) of the starting material FAPbBr.sub.3 according to Example 1. X-axis: 2theta (°); y axis: intensity (arbitrary units).

(54) To further illustrate the invention, the following examples are provided. These examples are provided with no intend to limit the scope of the invention

Example 1: Synthesis of a Polymer Film with Green Luminescent Crystals

(55) Formamidinium lead tribromide (FAPbBr.sub.3) was synthesized by milling PbBr.sub.2 and FABr. Namely, 16 mmol PbBr.sub.2 (5.87 g, 98% ABCR, Karlsruhe (DE)) and 16 mmol FABr (2.00 g, Dyesol, Queanbeyan, (AU)) were milled with Yttrium stabilized zirconia beads (5 mm diameter) for 6 h to obtain pure cubic FAPbBr.sub.3, confirmed by XRD (X-ray diffraction; FIG. 10, bottom spectrum). This material did not show any luminescence. The hydrodynamic particle size distribution (volume weighted) was obtained by centrifugal sedimentation method (LUMiSizer, LUM GmbH, Berlin (DE)) mixing 12 mg of powder with 10 ml of S20 Viscosity Oil Standard (PSL Rheotek, Essex (UK)) and using a 2 mm polyamide cuvette. An average particle size (D50) of 7 μm and a size range (D10-D90) of 1-12 μm resulted. The average particle size is defined by the average particle diameter by mass, wherein e.g. D10, D50, and D90 denote the particle size where 10%, 50%, and 90% respectively of the cumulative mass of the distribution is observed.

(56) The orange FAPbBr.sub.3 powder was added to Oleic acid (90%, Sigma Aldrich, Missouri (US)), Oleylamine (80-90, Acros Organics, Geel (BE)) (FAPbBr.sub.3:Oleic acid:Oleylamine=2:1:1) and Cyclohexane (>99.5%, puriss, Sigma Aldrich). The final concentration of FAPbBr.sub.3 was 1 wt %. The mixture was then dispersed by ball milling using Yttrium stabilized zirconia beads with a diameter size of 200 μmat ambient conditions (if not otherwise defined, the atmospheric conditions for all experiments are: 35° C., 1 atm, in air) for a period of 1 h yielding an ink with green luminescence.

(57) Analysis: Luminescent properties of the ink were measured in a 10 mm quartz cuvette (3 μl of the ink diluted in 3 ml of toluene) with a spectrofluorimeter equipped with an integrating sphere (Quantaurus Absolute PL quantum yield measuring system C1134711, Hamamatsu). The photoluminescence quantum yield (PLQY) of above ink was 97% with an emission peak centered at 522 nm (=peak position, PP). The FWHM of the emission was determined as 42 nm.

(58) Film formation: The green emitting ink was then mixed with 10% cyclic olefin copolymer solution in toluene, coated on a glass substrate and dried at 60° C. for 15 minutes. After drying the resulting optical properties of film were measured with a spectrofluorimeter equipped with an integrating sphere (Quantaurus Absolute PL quantum yield measuring system C1134711, Hamamatsu, Hamamatsu (JP)).

(59) Analysis: The photoluminescence quantum yield of the film was 90% with an emission peak centered at 528 nm. The FWHM was determined as 30 nm. The resulting film was subjected to a degradation test for 2 h with increased temperature in a drying oven (80° C., ambient humidity). The photoluminescence quantum yield of the film after degradation was 79% with an emission peak centered at 527 nm. The FWHM was determined as 30 nm.

(60) Conclusion: This example shows the effectiveness of luminescent crystals of formula (I) implemented into a solid polymer composition.

Example 2: Synthesis of a Polymer Film with Red Luminescent Crystals

(61) Step (a): Commercial formamidinium iodide (>99%, Dyesol) and PbI.sub.2 (98.5%, Alfa Aesar, Massachusetts (US)) were mixed in equal molar ratio leading to a net stoichiometric composition of FAPbI.sub.3. The powder mixture was dry-milled using Yttrium stabilized zirconia beads with a size of 5 mm at ambient conditions for a period of 400 min, and subsequently dried at 80° C.

(62) Step (b): The salt mixture was added to oleylamine (80-90%, Acros Organics) and oleic acid (90%, Sigma Aldrich) (CsPbBr.sub.3:Oleylamine:oleic acid=2:1:1) in cyclohexane 99%, Sigma Aldrich). The final concentration of FAPbI.sub.3 was 1% wt. The mixture was then dispersed by ball milling using Yttrium stabilized zirconia beads with a size of 200 μm at ambient conditions for a period of 60 min yielding an ink with red luminescence. Film sample was prepared analogous to the procedure in Example 1.

(63) Analysis: The photoluminescence quantum yield of above polymer film was 71% with an emission peak centered at 758 nm. The FWHM of the emission was determined as 89 nm.

(64) Conclusion: This result shows how to obtain a red emitting solid polymer composition comprising FAPbI.sub.3.

Example 3: Thermal Stability Comparison of Organic, Inorganic and Organic-Inorganic Solid Polymer Compositions in the Form of a Film

(65) Synthesis: The following compositions of material were obtained by the same dry milling method as described in Example 1 or 2: CsPbBr.sub.3, Cs.sub.0.85FA.sub.0.15PbBr.sub.3, Cs.sub.0.5FA.sub.0.5PbBr.sub.3, Cs.sub.0.15FA.sub.0.85PbBr.sub.3. Luminescent inks and films were prepared analogous to the procedure described in Example 2.

(66) Analysis: XRD revealed no peaks of the solid material (dry milled starting material) CsBr, FABr nor PbBr.sub.2 corroborating the formation of a single phase of mixed cations in the crystal lattice.

(67) Centrifugal sedimentation method (LUMiSizer, LUM GmbH) showed similar hydrodynamic size distribution for all materials with D10 between 0.8-2 μm, D50 between 1-12 μm, and D90 between 4-35 μm.

(68) TEM (transmission electron microscopy) images of inks from FAPbBr.sub.3 (FIG. 11), Cs.sub.0.85FA.sub.0.15PbBr.sub.3 (FIG. 12) and Cs.sub.0.5FA.sub.0.5PbBr.sub.3 (FIG. 13) show LCs of size in the range of 5-50 nm.

(69) Table 1 shows the optical properties of the ink and the film as initially obtained. Table 2 shows the properties of the film after degradation for 2 hours at 80° C. and ambient humidity (i.e. approximately 5% relative humidity) as well as after degradation for 2 hours at 60° C. at 90% relative humidity.

(70) TABLE-US-00001 TABLE 1 Ink properties Film properties PLQY PP FWHM PLQY PP FWHM Composition (%) (nm) (nm) (%) (nm) (nm) CsPbBr.sub.3 42* 507* 40* 90 514 23 Cs.sub.0.99FA.sub.0.01PbBr.sub.3 42* 507* 46* 86 515 23 Cs.sub.0.95FA.sub.0.05PbBr.sub.3 38* 506* 48* 80 514 25 Cs.sub.0.85FA.sub.0.15PbBr.sub.3 54* 504* 38* 74 513 25 Cs.sub.0.5FA.sub.0.5PbBr.sub.3 58* 496* 50* 74 510 27 Cs.sub.0.15FA.sub.0.85PbBr.sub.3 88* 512* 38* 85 522 26 FAPbBr.sub.3 97* 522* 42* 92 530 31 *measurement result might be biased because of dilution effects of the ink

(71) TABLE-US-00002 TABLE 2 Degraded film Degraded film properties properties 2 h 80° C. 2 h 60° C./90% RH PLQY PP FWHM PLQY PP FWHM Composition (%) (nm) (nm) (%) (nm) (nm) CsPbEr.sub.3 68 515 24 60 515 22 Cs.sub.0.99FA.sub.0.01PbBr.sub.3 66 516 23 80 517 21 Cs.sub.0.95FA.sub.0.05PbBr.sub.3 58 515 25 68 517 22 Cs.sub.0.85FA.sub.0.15PbBr.sub.3 37 514 25 53 519 22 Cs.sub.0.5FA.sub.0.5PbBr.sub.3 29 512 25 66 512 26 Cs.sub.0.15FA.sub.0.85PbBr.sub.3 60 521 26 58 519 26 FAPbBr.sub.3 76 530 30 86 525 28

(72) Conclusion: The data clearly show the high PLQY for both, ink and film. For films, this high PLQY is maintained even after stress-test under severe conditions.

Example 4

(73) Luminescent Crystals of Composition Cs.sub.0.15FA.sub.0.85PbBr.sub.3 emitting green light were used for the following experiment as described in example 3. The load of the solid polymer composition was measured to be 0.38 wt % by heating up to 450° C. and thus evaporating the solvent and burning away the surfactants.

(74) The ink was mixed with a cyclic olefin copolymer solution in cyclohexane (4 wt % polymer in solvent) to yield a Pb concentration of 20,000 ppm. Spray drying in an inert loop (nitrogen) of the green polymer solution was used to obtain a powder exhibiting a particle size of 1-100 μm as confirmed by scanning electron microscopy. The resulting powder showed a quantum yield of 85%, peak position of 519 nm, and FWHM of 28 nm.

(75) 0.030 g of the green powder was mixed with an UV curable monomer (1.2 g Miramer SIU2400 with 3% wt initiator TPO-L, Rahn AG, Switzerland) in a speed mixer and the resulting mixture was cured between two glass slides (18×18 mm) for 60 s in UV (with a mercury lamp). This film sample showed a total quantum yield of 68%, a peak at 517 nm with FWHM of 29 nm.

(76) The sample was subjected to a degradation test for 70 h with increased temperature in a drying oven (80° C., ambient humidity, i.e. approximately 5% relative humidity). The photoluminescence quantum yield of the sample after degradation was 71% with an emission peak centered at 514 nm. The FWHM was determined as 28 nm.

(77) Conclusion: This example shows that the material as described in the present invention does not show pronounced degradation (drop of quantum yield, change of peak position or FWHM) when subjected to high temperature (80° C.) for 70 h.

Example 5

(78) The luminescent crystal ink in cyclohexane of Example 1 emitting green light was used for the following experiment.

(79) 0.5 g of the ink was mixed with 1.5 g of isobornyl-acrylate (Sartomer), 100 mg Decane-diol-acrylate (Sartomer), 50 mg 2-Hydroxy-2-methylpropiophenone (Sigma Aldrich). This mixture was applied on a glass slide and the cyclohexane was dried-off for 5 min at 60° C. in air. Afterwards a second glass slide was put on top of the dried ink and the resin mixture was UV cured using a mercury lamp for 30 s.

(80) The optical performance of the final cured film showed a quantum yield of 71%, a peak position at 528 nm, and a FWHM of 31 nm.

(81) Conclusion: This result clearly shows that LC containing polymer compositions can be obtained starting from an acrylate monomer.

Example 6-11: Synthesis of Green Emitting LCs and Transfer into Different Solid Polymer Compositions

(82) FAPbBr.sub.3 was obtained as described in Example 1. The orange FAPbBr.sub.3 powder was added to (Lauryldimethylammonio)acetate (>95%, Sigma Aldrich), Oleylamine (80-90%, Acros) (FAPbBr.sub.3: (Lauryldimethyl-ammonio)acetate:Oleylamine=1:0.1:0.3) and toluene (>99.7%, Fluka). The final nominal concentration of FAPbBr.sub.3 was 1 wt %. The mixture was then dispersed by ball milling using Yttrium stabilized zirconia beads with a size of 200 microns at ambient conditions for a period of 1 h yielding an ink with green luminescence.

(83) Analysis: Luminescence properties of the ink were recorded as presented in Example 1. The photoluminescence quantum yield (PLQY) of above ink was 88% with an emission peak centered at 528 nm (=peak position, PP). The FWHM of the emission was determined as 24 nm.

(84) Film formation: The green emitting ink was then mixed with different polymers/pre-polymers. For acrylates 1 wt % Irgacure 184 as an initiator was mixed with the acrylate. The toluene from the acrylate/ink mixture was evaporated at room temperature by vacuum (10.sup.−2 mbar) and the mixture was coated between two glass substrates with a thickness of 100 μm and cured with UV (Hoenle UVAcube 100, Hg lamp with quartz filter, 1 min). The glass slides were removed for further analysis and testing of the film. For cyclic olefin copolymer, polycarbonate (Makrolon OD2015), polystyrene (Mw=35,000, Sigma Aldrich), Poly(9-vinylcarbazole) (PVK, average Mn 25,000-50,000, Sigma Aldrich) and PVK: 2-(4-Biphenylyl)-5-phenyl-1,3,4-oxadiazole (PBD, Sigma Aldrich) mixtures (64 wt %:36 wt %) films were obtained as described in Example 1.

(85) Analysis: Table 3 shows the optical properties of the film as initially obtained and after degradation for 20 hours at 80° C. and ambient humidity (i.e. approximately 5% relative humidity). The resulting optical properties of the film was measured with a spectrofluorimeter equipped with an integrating sphere (Quantaurus Absolute PL quantum yield measuring system C1134711, Hamamatsu).

(86) TABLE-US-00003 TABLE 3 Initial film Degraded film properties properties 20 h 80° C. PLQY PP FWHM PLQY PP FWHM Ex. # Polymer (%) (nm) (nm) (%) (nm) (nm) 6: Acrylate* 79 531 27 60 531 26 7: Cyclic 83 531 24 57 531 24 olefin copolymer 8: polycar- 86 525 27 63 528 29 bonate** 9: Polystyrene 84 531 26 63 530 25 10: Poly(9- 60 534 25 17 534 28 Com- vinyl- parative carbazole) 11: PVK:PBD 65 531 24 14 538 26 Com- (64 wt %: parative 36 wt %) *Sartomer SR506D: Sartomer SR595 (95 wt %:5 wt %); **Makrolon OD2015

(87) Conclusion: These results show that LCs as described in this invention exhibit excellent initial properties and maintain high optical performance after accelerated degradation at 80° C. with acrylate, cyclic olefin copolymer, polycarbonate and polystyrene. The comparative examples with PVK and mixtures of PVK and PBD showed inferior initial optical properties and a significantly more pronounced degradation, rendering these polymers unsuitable for application in TVs or the like.

Example 13

(88) A green luminescent crystal ink with FAPbBr.sub.3 was prepared according to the procedure described in Example 1 but using toluene (>99.5%, puriss, Sigma Aldrich) as the solvent and (Lauryldimethylammonio acetate (>95%, Sigma Aldrich), Oleylamine (80-90%, Acros) (FAPbBr.sub.3:(Lauryldimethylammonio) acetate:Oleylamine 1:0.1:0.3). The concentration of FAPbBr.sub.3 was 1 wt %. Luminescent crystals emitting red light were produced as described by Protesescu et al. (Nano Lett., 2015, 15, 3692-3696). The resulting solids load was measured to be 0.53 wt % for red, by heating up to 350° C. and thus evaporating the solvent and burning away the ligands. The optical properties of the resulting nanocrystal formulation were measured with a Hamamatsu Quantaurus C11347-11 device (equipped with an integration sphere, 450 nm excitation) and a quantum yield of 90% at an emission peak wavelength of 645 nm with a FWHM of 38 nm for red was achieved. This nanocrystal formulation was mixed with a cyclic olefin copolymer solution in toluene (20 wt % polymer in solvent) to yield a polymer:nanocrystal ratio of 20:1 and subsequently diluted with toluene to a final polymer content in the formulation of 4 wt %. Spray drying in an inert loop (nitrogen) of the red polymer solution was used to obtain a powder exhibiting a particle size of 1-20 μm as confirmed by scanning electron microscopy. The red powder showed a quantum yield of 87%, peak position of 647 nm, and FWHM of 38 nm.

(89) 0.6 g of the green ink was mixed with 4.0 g of isobornyl-acrylate (SR506D, Sartomer):Decane-diol-diacrylate (SR595, Sartomer) in a weight ratio of 95:5 and 40 mg Irgacure 184 (Ciba). The toluene was evaporated in vacuum (10.sup.−2 mbar) at room temperature. 0.02 g of the red powder was added and homogenized in a speed mixer. The final mixture was applied between two glass slides and the resin mixture was UV cured using a mercury lamp for 60 s.

(90) The optical performance of the final cured film showed a quantum yield of 68%, a peak position at 528 nm, and a FWHM of 24 nm for green and 643 nm and 38 nm for red, respectively.

(91) Conclusion: This result confirms that LC polymer compositions containing one fraction of LCs in an element dispersed within an encapsulation polymer containing the second fraction of LCs can be obtained by the present invention.

Example 14

(92) A green luminescent crystal ink with FAPbBr.sub.3 was prepared according to the procedure described in Example 13. The ink was roughly 10 times concentrated by evaporation at 50° C. and 130 mbar. The resulting solids load was measured to be 4.5 wt %, by heating up to 350° C. and thus evaporating the solvent and burning away the ligands. The photoluminescence quantum yield (PLQY) of above concentrated ink was 84% with an emission peak centered at 525 nm. The FWHM of the emission was determined as 25 nm. 2.8 g concentrate was then mixed with 1 g of an acrylate (Sartomer SR506D:Sartomer SR595, 95 wt %:5 wt %) and 1 wt % Irgacure 184 as an initiator. The mixture was coated on a glass substrates dried at room temperature and cured with UV (Hoenle UVAcube 100, Hg lamp with quartz filter, 1 min). The film thickness was 4.5 μm measured by atomic force microscopy and the LC weight per area was 0.5 g/m.sup.2 exhibiting a PLQY of 80% a PP of 533 nm and a FWHM of 25 nm. The leakage of blue light through this film was measured by placing it in front of the blue Samsung SUHD TV backlight (Model UE48JS8580T). The resulting spectra was recorded with a spectrometer (UPRtek, MK350N) and a ratio of green peak:blue peak of 1:0.1 was recorded, indicating that most of the blue light was absorbed.

(93) Conclusion: This result confirms that LC polymer compositions obtained by the present invention; with a certain LC weight loading per area of film allow for absorption of most of a commercial TV set blue light and the transformation of this blue light into another color with larger wavelength.

Example 15: Synthesis Using Alternative Surfactants, Solvents

(94) Step (a): Formamidinium lead tribromide (FAPbBr.sub.3) was synthesized as described above.

(95) Step (b): The following further experiments were all conducted by ball milling using similar process parameters (LCs/QDs:total surfactant ratio=2:1, milling bead size=200 microns, milling time=60 min, LCs/QDs concentration in the ink=1%, filtered by 0.45 um PTFE syringe filter for optical characterization, optical characterization was identical as in Example 1):

(96) TABLE-US-00004 Solid Peak emission/ Ex. # material Surfactant solvent FWHM/QY 15-1 FAPbBr.sub.3 (N,N-dimethyl-octa- cyclo- yellow-green, decylammonio) propane hexane 534 nm/23 nm/ sulfonate 91% 15-2 FAPbBr.sub.3 N-Oleoyl-gamma- cyclo- Green, NA/NA/ aminobutyric acid hexane NA 15-3 FAPbBr.sub.3 Oleylammonium bromide toluene Green, 518 nm/ 26 nm/76% 15-4 FAPbBr.sub.3 N-Dodecyl-N,N-(di- toluene Green/NA/ methylammonio)butyrate NA/NA (zwitterionic carboxylate) 15-5 FAPbBr.sub.3 N-Dodecyl-N,N-(di- toluene Green/532 nm/ methylammonio)butyrate 21 nm/86% (zwitterionic carboxylate):Oleylamine 1:2 15-6 FAPbBr.sub.3 Hexadecyl phospho- toluene Green/537 nm/ choline (zwitterionic 26 nm/40% phosphonate)

(97) Above suspensions are also suited for incorporation in a solid polymer composition as outlined in previous examples.

(98) Conclusion: These example shows the effectiveness of the invention using different surfactant classes and solvents.