Circularly polarized OLED emitting layer composition

1 . An active light-emitting layer composition comprising a TADF molecule with TADF properties as a host material and a luminescent molecule with circular polarisation properties as a dopant;

wherein the luminescent molecule is carbo[6]helicene derivate with the general formula, in an M or P configuration:

wherein B′ is a linker and R is a chemical group.

2 . The active light-emitting layer composition of claim 1 , wherein the TADF molecule exhibits a singlet state energy level and a triplet state energy level and the luminescent molecule exhibits a singlet state energy level lower than the singlet state and triplet state energy levels of the TADF molecule.

3 . The active light-emitting layer composition of claim 1 , wherein the luminescent molecule has an absorption spectrum and the TADF molecule has a luminescence spectrum overlapping the absorption spectrum of the luminescent molecule.

4 . The active light-emitting layer composition of claim 1 , wherein the composition exhibits at least one of the following properties:

a TADF quantum yield of 0.01 or higher;

a luminescence quantum yield of 0.10 or higher; and

a luminescence polarization measured through the g lum value which is different from 0.

5 . The active light-emitting layer composition of claim 1 , wherein the luminescent molecule is a chiral molecule selected from the group consisting of a helicene derivative, a helicenoid compound, a biarylic system, and a molecule with planar chirality.

6 . The active light-emitting layer composition of claim 1 , wherein B′ is a linker with one of the following formulae:

or a combination thereof.

7 . The active light-emitting layer composition of claim 1 , wherein R is one of the following formulae:

8 . The active light-emitting layer composition of claim 1 , wherein the luminescent molecule is one of:

4,4′-(hexahelicene-2,15-diylbis(ethyne-2,1-diyl))dibenzonitrile;

4,4′-(hexahelicene-2,15-diylbis(ethyne-2,1-diyl))dipyridine;

4,4′-(hexahelicene-2,15-diylbis(ethyne-2,1-diyl))dianiline;

4,4′-(hexahelicene-2,15-diylbis(ethyne-2,1-diyl))di(N,N-dimethylaniline);

4,4′-(hexahelicene-2,15-diylbis(ethyne-2,1-diyl))di(trimethylsilane);

4,4′-(hexahelicene-2,15-diylbis(ethyne-2,1-diyl))di(N-hexyl-1,8-naphthalimide); and

4,4′-(hexahelicene-2,15-diylbis(ethyne-2,1-diyl))di(2,5-N-octyl-3,6-di-2-thienyl-pyrrolo[3,4-c] pyrrole-1,4-dione);

in their P or M isomeric configuration.

9 . The active light-emitting layer composition of claim 1 , wherein the TADF molecule is an achiral molecule.

10 . The active light-emitting layer composition of claim 1 , with one of the following combination of TADF molecule and luminescent molecule:

9,9′-(sulfonylbis(4,1-phenylene))bis(3,6-di-tert-butyl-9H-carbazole) and 4,4′-(hexahelicene-2,15-diylbis(ethyne-2,1-diyl))dibenzonitrile;

9-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-1,3,6,8-tetramethyl-9H-carbazole and 4,4′-(hexahelicene-2,15-diylbis(ethyne-2,1-diyl))di(N-hexyl-1,8-naphthalimide; and

2,4,5,6-tetra(9H-carbazol-9-yl)isophthalonitrile and 4,4′-(hexahelicene-2,15-diylbis(ethyne-2,1-diyl))di(2,5-N-octyl-3,6-di-2-thienyl-pyrrolo [3,4-c] pyrrole-1,4-dione).

11 . A light-emitting device having an active light-emitting layer made of the active light-emitting layer composition of claim 1 .

12 . The light-emitting device of claim 11 , wherein the light-emitting device is an OLED.

13 . An active light emitting layer composition comprising a TADF molecule with TADF properties as a host material and a luminescent molecule with circular polarisation properties as a dopant;

wherein the achiral molecule is one of the following:

9,9′-(sulfonylbis(4,1-phenylene))bis(3,6-di-tert-butyl-9H-carbazole);

9-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-1,3,6,8-tetramethyl-9H-carbazole; and

2,4,5,6-tetra(9H-carbazol-9-yl)isophthalonitrile.