Luminescent object comprising aligned polymers having a specific pretilt angle
A first aspect of the invention relates to a luminescent object comprising an aligned polymer that contains an oriented photoluminescent material, said aligned polymer having a pretilt angle of 10-90°. The luminescent object according to the present invention may advantageously be employed in luminescent solar concentrator systems as it enables highly efficient transportation of radiation emitted by the photoluminescent material following exposure to incident solar light. Another aspect of the invention concerns a photovoltaic device comprising an electromagnetic radiation collection medium containing the aforementioned luminescent object and a photovoltaic cell capable of converting optical radiation to electrical energy which is optically coupled to the luminescent object. Further aspects of the invention include a fluorescent light activated display and a room lighting system comprising the aforementioned luminescent object.
1. A luminescent object comprising:
a luminescent layer; and
a waveguide, wherein the object is an optical laminate or an optical fiber coupled optically to the waveguide and comprises an aligned polymer that contains an oriented photoluminescent material, the oriented photoluminescent material comprising oriented photoluminescent molecules immobilized within the aligned polymer with a pretilt angle of 10-90° relative to the surface of the object;
wherein the aligned polymer comprises mesogenic groups and the oriented photoluminescent molecules are aligned in essentially a same direction as the mesogenic groups of the aligned polymer.
2. The luminescent object according to claim 1 , wherein the oriented photoluminescent material has a dichroic ratio of at least 2.0 in a planar cell.
3. The luminescent object according to claim 1 , wherein the oriented photoluminescent material has a dichroic ratio of at least 3.0 in a planar cell.
4. The luminescent object according to claim 1 , wherein the oriented photoluminescent material has a dichroic ratio of at least 5.0 in a planar cell.
5. The luminescent object according to claim 1 , wherein the aligned polymer has a pretilt angle of 30-80°.
6. The luminescent object according to claim 1 , wherein the aligned polymer has a pretilt angle of 30-70°.
7. The luminescent object according to claim 1 , wherein the aligned polymer has a pretilt angle of 40-70°.
8. The luminescent object according to claim 7 , wherein the aligned polymer has a pretilt angle of 40-60°.
9. The luminescent object according to claim 1 , wherein the oriented photoluminescent material emits optical radiation in the range of 100-2500 nm.
10. The luminescent object according to claim 9 , wherein the oriented photoluminescent material emits optical radiation in the range of 250-1500 nm.
11. The luminescent object according to claim 10 , wherein the oriented photoluminescent material emits optical radiation in the range of 400-1000 nm.
12. The luminescent object according to claim 1 , wherein the object comprises two or more stacked layers of aligned polymer comprising oriented photoluminescent material.
13. Luminescent object according to claim 12 , wherein each aligned polymer layers contains a different photoluminescent material.
14. The luminescent object according to claim 12 , wherein the pretilt angle of the aligned polymer in each aligned polymer layer changes from layer to layer.
15. The luminescent object according to claim 1 , said object comprising a waveguide that is optically coupled to an aligned polymer layer containing the oriented photoluminescent material, wherein the refractive index of the waveguide (nw) is such that nw>n0−0.005, wherein n0 is the ordinary refractive index of the aligned polymer.
16. The luminescent object according to claim 15 , wherein the refractive index of the waveguide is between the ordinary and extraordinary refractive indices of the aligned polymer layer.
17. The luminescent object according to claim 1 further comprising an inorganic or organic polymeric wavelength-selective mirror that is at least 50% transparent to light absorbed by the photoluminescent material and that is at least 50% reflective to non-polarized radiation that is emitted by the photoluminescent material.
18. The luminescent object according to claim 1 further comprising a wavelength-selective mirror, wherein the wavelength-selective mirror comprises a cholesteric layer of chiral nematic polymer.
19. The luminescent object according to claim 18 , wherein the polymeric wavelength-selective mirror comprises:
one or more cholesteric layer(s) reflecting right-handed circularly polarized light; or
one or more cholesteric layer(s) reflecting left-handed circularly polarized light; or
both one or more cholesteric layer(s) reflecting right-handed circularly polarized light and one or more cholesteric layer(s) reflecting left-handed circularly polarized light.
20. The luminescent object according to claim 1 , wherein the object is predominantly transparent for optical radiation in the range of 400-500 nm, 600-700 nm, or both.
21. The luminescent object according to claim 1 , wherein the object is an optical fiber comprising a luminescent layer and a waveguide core.
22. The luminescent object according to claim 1 , wherein the object is an optical fiber comprising a luminescent core and a waveguide.
23. The luminescent object according to claim 1 , wherein the waveguide does not comprise a fluorescent dye.
24. A photovoltaic device comprising:
an electromagnetic radiation collection medium containing a luminescent object comprising:
a luminescent layer; and
a waveguide, wherein the object is an optical laminate or an optical fiber coupled optically to the waveguide and comprises an aligned polymer comprising mesogenic groups, wherein the aligned polymer contains an oriented photoluminescent material comprising oriented photoluminescent molecules immobilized within the aligned polymer with a pretilt angle of 10-90° relative to the surface of the object, wherein the oriented photoluminescent molecules are aligned in essentially a same direction as the mesogenic groups of the aligned polymer; and
a photovoltaic cell capable of converting optical radiation to electrical energy which is optically coupled to the luminescent object.
25. A window comprising the photovoltaic device according to claim 24 .
26. A fluorescent light activated display comprising a luminescent object comprising:
a luminescent layer; and
a waveguide, wherein the object is an optical laminate or an optical fiber coupled optically to the waveguide and comprises an aligned polymer comprising mesogenic groups, wherein the aligned polymer contains an oriented photoluminescent material comprising oriented photoluminescent molecules immobilized within the aligned polymer with a pretilt angle of 10-90° relative to the surface of the object, wherein the oriented photoluminescent molecules are aligned in essentially a same direction as the mesogenic groups of the aligned polymer.
27. A method of concentrating incident optical radiation comprising: administering of a luminescent object comprising:
a luminescent layer; and
a waveguide, wherein the object is an optical laminate or an optical fiber coupled optically to the waveguide and comprises an aligned polymer comprising mesogenic groups, wherein the aligned polymer contains an oriented photoluminescent material comprising oriented photoluminescent molecules immobilized within the aligned polymer with a pretilt angle of 10-90° relative to the surface of the object, wherein the oriented photoluminescent molecules are aligned in essentially a same direction as the mesogenic groups of the aligned polymer.