Triplet excitation scavenging in solid-state organic materials

摘要

The present invention is directed to solid state organic light emitting devices and to methods for triplet excitation scavenging in such devices. More particularly, the present invention relates to a method for substantially reducing a triplet population in a solid state organic material, the method comprising providing molecules exhibiting non-vertical triplet energy transfer in the solid state organic material or at a distance smaller than a triplet exciton diffusion length from the solid state organic material.

主权项

1. A method for reducing a triplet population in a solid state organic semiconductor material of an organic light emitting device, the method comprising:
incorporating, into the organic light emitting device, molecules exhibiting non-vertical triplet energy transfer in the solid state organic semiconductor material or at a distance smaller than a triplet exciton diffusion length from the solid state organic semiconductor material, wherein said molecules exhibiting non-vertical triplet energy transfer comprise non-vertical triplet scavenging material, wherein the non-vertical triplet scavenging material comprises a non-vertical triplet scavenger, wherein: a) a triplet level of the non-vertical triplet scavenger is lower than a triplet level of the solid-state organic semiconductor material; b) a singlet level of the non-vertical triplet scavenger is higher than a singlet level of the solid-state organic semiconductor material; c) the non-vertical triplet scavenger possesses an intrinsic triplet lifetime which is shorter than a triplet lifetime of the solid-state organic semiconductor material; d) the non-vertical triplet scavenger does not enhance intersystem crossing of the solid-state organic semiconductor material; and e) the molecules exhibiting non-vertical triplet energy transfer are selected from the group consisting of cyclooctatetraene (COT), cycloheptatriene (CHT), cis-stilbene, and combinations thereof.