Regulating Crystal Packing by Terminal tert-Butylation for Enhanced Solid-State Emission and Efficacious Charge Transport in an Anthracene-Based Molecular Crystal.

ABSTRACT

Organic semiconductors with combinative high carrier mobility and efficient solid-state emission are full of challenges but urgently pursued for developing new emerging optoelectronics. Herein, by delicately regulating the crystal packing of an anthracene-based molecular crystal via terminal tert-butylation, we developed a superior high mobility emissive molecule, 2,6-di(6-tert-butylnaphthyl)anthracene (TBU-DNA). The unique "slipped herringbone" packing motif of TBU-DNA enables its appropriate exciton-exciton coupling and electron-phonon coupling, thus resulting in remarkably high solid-state emission (photoluminescence quantum yield, ΦF ≈74.9 %) and efficacious charge transport (carrier mobility, µ=5.0 cm2 V-1 s-1 ). Furthermore, OLETs based on TBU-DNA show an external quantum efficiency (EQE) of 1.8 %, which is among the highest EQE values for single component OLETs reported till now. This work presents a crystal engineering strategy via exquisite molecular design to realize high mobility emissive organic semiconductors.