The decay kinetics of excitonic luminescence, which was observed at 2.5eV after pulsed laser irradiation, was measured at temperatures ranging from 10 to 200K; using pulse durations of 20ns to 0.01s. It was shown that, at low temperatures, the decay of the luminescence was due to the static tunnelling recombination of unidentified shallow electron centers (with a wave function radius of about 3nm) and immobile self trapped holes. At temperatures above 80K, the luminescence decay began to differ from that at 10K and did not obey the usual exponential, or second-order, kinetics. This was attributed to the diffusion-controlled annihilation, within close (geminate) Frenkel pairs, of irradiation defects. The latter were assumed to be Ag2+Vc- and interstitial Ag atoms, Agi0, respectively. The Ag atoms were characterized by 0.15eV activation energies for hops, and a small wave function radius of about 0.1 nm. Thermal quenching of the luminescence was monitored, and its activation energy of 0.33eV corresponded to that for cation vacancy migration.

The Decay Kinetics of Excitonic Luminescence in AgCl Crystals. L.G.Grigorjeva, E.A.Kotomin, D.K.Millers, R.I.Eglitis: Journal of Physics - Condensed Matter, 1995, 7[7], 1483-91