Figure 2
From: Singlet Exciton Fraction in Electroluminescence from Conjugated Polymer
(a) The transient response of Ir(btp)2acac emission (610 nm) in 0.75 wt% Ir(btp)2acac doped SPFLMW. The rise after electric pulse indicates triplet-triplet ET from SPF to Ir(btp)2acac. The representative excitation condition (21 V, 200 ns in width) adopted for the PLED is also shown in the figure. The open circle shows fit to Equation 1. (b) The negligible effect of reverse bias applied on transient EL emission of Ir(btp)2acac (triangle) supports triplet-triplet ET from SPF to Ir(btp)2acac. (c) The onset times compared for SPFLMW (410 nm, tH onset) and Ir(btp)2acac (610 nm, tG onset) emissions. The device structure is ITO/PEDOT:PSS/emitting layer/TPBI/Ca/Al. The representative excitation condition adopted for the PLED is 22 V (200 ns in width).
