Light-emitting arrangement with organic phosphor
The invention provides a light-emitting arrangement ( 100 ) comprising a light source ( 105 ) adapted to emit light of a first wavelength, and a wavelength converting member ( 106 ) arranged to receive light of said first wavelength and adapted to convert at least part of the light of said first wavelength to light of a second wavelength, said wavelength converting member comprising i) a carrier polymeric material comprising a polyester backbone comprising an aromatic moiety, and ii) at least one wavelength converting material of a specified general formula. The perylene derived compounds have been found to have excellent stability when incorporated into said matrix material.
1. A light-emitting arrangement comprising a light source adapted to emit light of a first wavelength, and a wavelength converting member arranged to receive light of said first wavelength and adapted to convert at least part of the light of said first wavelength to light of a second wavelength, said wavelength converting member comprising i) a carrier polymeric material comprising a polyester comprising an aromatic moiety incorporated into the polymer backbone, and ii) at least one wavelength converting material having the following general formula I:
in which
G 1 is a linear or branched alkyl group or oxygen-containing alkyl group C n H 2n+1 O m , n being an integer from 1 to 44 and m<n/2, or Y;
each of A, B, C, J and Q independently is hydrogen, isopropyl, t-butyl, fluorine, methoxy, or unsubstituted saturated alkyl C n H 2n+1 , n being an integer from 1 to 16;
each of G 2 , G 3 , G 4 and G 5 independently is hydrogen, fluorine, methoxy, or unsubstituted saturated alkyl group C n H 2n+1 , n being an integer from 1 to 16, or X; and each of D, E, I, L and M independently is hydrogen, fluorine, methoxy, or unsubstituted saturated alkyl group C n H 2n+1 , n being an integer from 1 to 16.
2. A light-emitting arrangement according to claim 1 , wherein G 1 is Y.
3. A light-emitting arrangement according to claim 2 , wherein each of G 2 , G 3 , G 4 and G 5 is X, each of A and C is isopropyl, and each of B, J, Q D, E, I, L and M is hydrogen.
4. A light-emitting arrangement according to claim 1 , wherein the polymeric material comprises a polyester homopolymer derived from at least one aromatic diacid having a number (n) of repeating units of the general formula II:
wherein A is selected from the following moieties:
and wherein B is selected from the following moieties:
5. A light-emitting arrangement according to claim 4 , wherein the polymeric material comprises a polyester copolymer comprising first repeating units comprising any combination of said moieties at positions A and B, and comprising second repeating units comprising another combination of said moieties at positions A and B.
6. A light-emitting arrangement according to claim 1 , wherein the polymeric material comprises polyethylene terephthalate and/or a copolymer thereof and/or polyethylene naphthalate and/or a copolymer thereof.
7. A light-emitting arrangement according to claim 1 , wherein the polymeric material comprises polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), or a copolymer thereof partly or completely derived from 1,4-cyclohexanedimethanol.
8. A light-emitting arrangement according to claim 1 , wherein the wavelength converting compound is dispersed in said polymeric material.
9. A light-emitting arrangement according to claim 8 , wherein said polymeric material is in the form of a film.
10. A light-emitting arrangement according to claim 8 , wherein the content of said wavelength converting material in the wavelength converting member is 1% or less by weight.