Non-symmetric 9,10-Di(2-naphthyl)anthracene derivatives as hosts and emitters for solution-processed blue fluorescent organic light emitting diodes

Abstract

A series of new asymmetric anthracene derivatives have been successfully synthesized for use in the light emitting layer of solution processed blue fluorescent organic light emitting diodes (OLEDs), which could be used both as host and dopant. Especially, new synthetic blue fluorescent materials with anthracene moieties without any alkyl chains showed high solubility in common organic solvents probably due to their severely twisted internal structures. They also show moderately high thermal stability due to their rigid internal core units. With those novel soluble blue fluorescent materials, we created moderately efficient solution-processed fluorescent OLEDs. And a new anthracene derivative [9-(9,10-di(naphthalen-2-yl)anthracen-2-yl)-9H-carbazole (DN-2-CzA)] as a host material exhibited moderately high efficiency and external quantum efficiency of up to 3.2cd/A and 1.6%, respectively, when we utilized 4,4′-bis[4-(diphenylamino)styryl]biphenyl as a dopant. Meanwhile, the [N-(naphthalen-1-yl)-9,10-di(naphthalen-2-yl)-N-phenylanthra-cen-2-amine (DN-2-NPAA)] as a dopant material showed pretty good device performance, up to 5.2cd/A and 2.2% (EQE), when we utilized 2-tert-butyl-9,10-di(naphth-2-yl)anthracene as a host.