“…The increase in the lifetime value of Rh-110 in sol-gel (t= 4.19 ns) compared to that in methanol (t =3.9 ns) is correlated with the high rigidity of the sol-gel matrix [16], which prevents the free intramolecular rotation of dye molecules that can result in the subsequent reduction of the nonradiative deactivation processes or quenching (S 1 -S 0 internal conversion processes) [16,23,[33][34][35][36]. In the present study, the concentration of the dye molecules was in the range of 10 15 -10 18 molecules/cm 3 .…”