Fig. 4: Effect of doping wt% on the photophysical behaviour of BF2 films.

a The photoluminescence quantum efficiency (PLQE) of BF2 doped in CBP at varying wt% (excitation 520 nm). The films were measured with and without exposure to the oxygen in ambient air, which results in the partial quenching of the delayed fluorescence contribution to the PLQE. The error bars represent the uncertainty in the PLQE measurements, as determined from the measured laser power fluctuations of 1% and the film absorption. b The normalised ultrafast transient absorption kinetics of the BF2 stimulated emission (SE), excited at 600 nm. Kinetic traces have been averaged between 680–730 nm for 2, 4, 6, 8, and 10 wt% films, 700–750 nm for 20 and 40 wt% films, and 720–770 nm for the neat BF2 film. Excitation fluences are provided in Supplementary Fig. 27.