Doubly boron-doped pentacenes as emitters for OLEDs

Abstract

A new class of benchtop-stable boron-doped pentacenes, i.e., 5,14-dimesityl-5,14-dihydro-5,14-diborapentacene (3^H) and its 2,3-dihalogenated derivatives, 3^F and 3^Cl, have been successfully applied as emitters in fluorescent organic light-emitting diodes (OLEDs). The best performance was achieved with 2% of the blue emitter 3^H doped in 9,10-di-(2-naphthyl)anthracene (ADN) as the emitting layer (turn-on voltage V_on = 3.3 V, λ_em = 476 nm, maximum external quantum efficiency η_ext = 3.4% with a negligible roll-off up to 10 000 cd m⁻², maximum luminance L_max = 39 180 cd m⁻²). Contrary to the blue-emitting 3^H-based device, 3^F- and 3^Cl-containing OLEDs produced turquoise (484 nm) and green (492 nm) light, respectively.