Abstract
We report on an efficient wide-band-gap host material for blue electrophosphorescence devices, namely, 1,2-trans-di-9-carbazolylcyclobutane (DCz). Photophysical studies show that lower-energy excimer formation between the carbazole units can be efficiently suppressed in a DCz film, thus maintaining its high triplet-state energy and inducing an exothermic energy transfer from DCz to iridium(III)bis[(4,6-difluorophenyl)-pyridinato-N,C2′]picolinate (FIrpic). Electrophosphorescent devices comprising a FIrpic:DCz emitting layer exhibit a superior performance with a maximum external quantum efficiency of 9.8%, a maximum luminance efficiency of 21.5cd∕A, and a maximum power efficiency of 15.0lm∕W at 0.01mA∕cm2.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
