We report on the characteristics of a host-guest lasing system obtained by co-evaporation of an oligo(9,9-diarylfluorene)
derivative named T3 with the red-emitter
(DCM). We demonstrate that the ambipolar semiconductor T3 can be implemented as active matrix in the realization of a
host-guest system in which an efficient energy transfer takes place from T3 matrix to the lasing DCM molecules. We
performed a spectroscopic study on the system by systematically varying the DCM concentration in the T3 matrix.
Measurements of steady-state photoluminescence (PL), PL quantum yield (PLQY) and amplified spontaneous emission
(ASE) threshold are used to optimize the acceptor concentration at which the ASE from DCM molecules takes place
with the lowest threshold.
Organic light-emitting diodes (OLEDs) implementing the DCM:T3
host-guest system as recombination layer are
fabricated for verifying the optical properties of the optimised blend in real working devices.
Indeed, the very low ASE threshold of T3:DCM makes the investigated blend an appealing system for use as active layer
in lasing devices. In particular, the ambipolar charge transport properties of the T3 matrix and its field-effect
characteristics make the host-guest system presented here an ideal candidate for the realization of electrically-pumped