Time-resolved luminescence from annealed quartz

The influence of annealing on the lifetime and luminescence intensity has been studied in quartz annealed at 873, 1073, 1173, and 1273 K and in unannealed quartz. Luminescence was stimulated by pulsed green (525 nm) light. Luminescence intensity increased as a function of temperature from 293 K to a peak at 373 K, and decreased thereafter to 473 K, the maximum temperature in the investigations. Luminescence lifetimes from both unannealed quartz and samples annealed at 873 K for up to 5 min were constant at about 40 mus below 373 K. Lifetimes decreased strictly monotonically with temperature in samples annealed above 873 K. Values of the activation energy for thermal assistance accounting for the increase in luminescence intensity, and of thermal quenching describing the decrease of luminescence intensity and luminescence lifetimes are presented.