The effects of intermolecular interactions on the photoluminescence (PL) quantum efficiency of differently substituted thienylene-S,S-dioxide derivatives in the crystalline phase are investigated. The exciton resonance interactions and the transfer integrals are evaluated using a quantum chemistry approach by considering the supramolecular structures obtained from X-ray data. Two classes of thienylene-S,S-dioxides are investigated: (1) rigid, fused ring compounds, for which the PL quantum efficiency can be well correlated with the rate of formation of non-radiatively decaying charge-transfer pairs upon photoexcitation; (2) flexible oligothiophenes for which the high PL quantum efficiency in the solid-state is assigned to a decrease of intramolecular internal conversion process, as confirmed by time-resolved PL measurements in solvents of different viscosity.
Effects of Intermolecular Interactions on Photoluminescence Efficiency of Crystalline Thienylene-S,S-Dioxide Molecular Semiconductors
DELLA SALA, FABIO;GIGLI, Giuseppe;ANNI, Marco;PISIGNANO, Dario;CINGOLANI, Roberto;
2004-01-01
Abstract
The effects of intermolecular interactions on the photoluminescence (PL) quantum efficiency of differently substituted thienylene-S,S-dioxide derivatives in the crystalline phase are investigated. The exciton resonance interactions and the transfer integrals are evaluated using a quantum chemistry approach by considering the supramolecular structures obtained from X-ray data. Two classes of thienylene-S,S-dioxides are investigated: (1) rigid, fused ring compounds, for which the PL quantum efficiency can be well correlated with the rate of formation of non-radiatively decaying charge-transfer pairs upon photoexcitation; (2) flexible oligothiophenes for which the high PL quantum efficiency in the solid-state is assigned to a decrease of intramolecular internal conversion process, as confirmed by time-resolved PL measurements in solvents of different viscosity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
