Utilizing formation of dye aggregates with aggregation-induced emission characteristics for enhancement of two-photon absorption

Abstract

Femtosecond Z-scan measurements of aggregates of a quadrupolar D-π-D dye, 9,10-bis(N-hexylcarbazol-2-yl-vinyl-2)anthracene (BHCVA), provide direct evidence that aggregation of this AIE (aggregation-induced emission) chromophore leads to a sizeable enhancement of the intrinsic two-photon absorption cross section. Aggregation-induced improvement of nonlinear response is explained by theoretical analysis of electronic structure and geometrical parameters of aggregates.