Exciton diffusion is considered to be of prime importance for controlling the recombination
zone in organic light emitting devices. This is particularly relevant for organic lasers based
on single crystals, where undesirable exciton-exciton annihilation at high concentrations is
inevitable. Here, exciton diffusion is studied in bifluorene single crystals specifically
designed for organic laser applications, therefore featuring exceptionally low threshold of
light amplification. The non-destructive light induced transient grating (LITG) technique …