Luminescence enhancement of rhodamine 6G in sol-gel films containing silver aggregates

Spectroscopic properties and lifetimes of a luminescent dye, rhodamine 6G (Rh6G), incorporated into films of sol-gel glasses in the presence of silver aggregates have been studied. The intensity of luminescence is dependent on the preparation conditions and up to a twofold enhancement of steady-state luminescence has been observed. The lifetime of Rh6G in sol-gel films is 2.9± 0.1 ns and its decay curve is exponential, while the decay curves of Rh6G in the presence of silver show a deviation from exponentiality at short (0.2-0.3 ns) times, becoming exponential with a lifetime of 2.8±0.2 ns at longer times. The presence of silver aggregates causes substantial depolarization of the luminescence.