Formation of extremely long-lived charge-separated state by two-photon ionization in poly(N-vinylcarbazole) adsorbed on a macroreticular resin

Extremely long-lived (≫8 h) cationic species were observed following two-photon ionization in poly(N-vinylcarbazole) as well as in its monomer model, N-ethylcarbazole, adsorbed on a macroreticular resin, Amberlite XAD-8 at room temperature. The formation and deactivation of the long-lived charge-separated states were attributed to the trapping process of the ejected electron and the cationic species fixing the rather large inter-ionic distance followed by long-distance back electron transfer in the ion pair. Based on the dynamic behaviors, the role of the hole migration resulting in an increase in the survival time of the cationic species in the polymer system is discussed.