Extended Data Fig. 4: Decay kinetics of GSB for triplet-sensitized BTA3 film excited at 380 nm.
From: Ultrahigh-radiance near-infrared organic light-emitting diodes
a, Transient absorption spectra of BTA3: 20 wt% PtOEP film pumped at high intensity of 206 μJ cm‒2 with a 380 nm femtosecond laser, at different time delays. b, Decay kinetics of GSB (circles) for a triplet-sensitized BTA3 film. Transient absorption dynamics49 of a neat BTA3 film at high pump intensities suffers significantly from SSA (Supplementary Note 3). Sensitized film with 20 wt% PtOEP populating the triplet states in BTA3 via the short-range triplet–triplet Dexter energy transfer mechanism, which bypasses the strong SSA was adopted. The experimentally obtained GSB decay kinetics for the triplet sensitized film well match theoretical calculations performed with the rate equation (equation 4 in Supplementary Note 1). The best fit to the data leads to an annihilation rate of 2.0×10−10 cm3 s−1, which agrees with the value of kTT determined from the transient EL measurements.
