Dumbbell-Shaped Spirocyclic Aromatic Hydrocarbon to Control Intermolecular π−π Stacking Interaction for High-Performance Nondoped Deep-Blue Organic Light-Emitting Devices

Abstract

Dumbbell-shaped spirocyclic aromatic hydrocarbons on the basis of molecular modeling exhibit no π−π stacking interaction among chromophores in the molecular packing diagrams. A model compound of 1,6-di(spiro[fluorene-9,9′-xanthene]-2-yl)pyrene (DSFXPy) with the pyrene−pyrene distance of up to 10.4 Å has been synthesized for high-performance nondoped deep-blue organic light-emitting devices. The proof-of-concept nondoped OLEDs have been fabricated with the configuration of ITO/MoOx(2 nm)/NPB(30 nm)/DSFXPy(30 nm)/TPBi(40 nm)/LiF(1 nm)/Al. DSFXPy-based nondoped OLED exhibits a maximum current efficiency of 7.4 cd/A (4.6% at 260 cd m−2) and excellent CIE coordinates (0.16, 0.15) (at 6500 cd m−2), surpassing most reported nondoped deep-blue OLEDs. Dumbbell-shaped spirocyclic arenes will be promising candidates for OLEDs.