Short-lived luminescence of mixed silver halides

Two kinds of excitonic luminescence were investigated for the entire series of solid solutions, AgBr_1-xCl_x, (0 {slanted equal to or less-than} x {slanted equal to or less-than} 1). The time-resolved spectra observed around 2.5 eV after both pulsed high-power electron beam and N₂-laser irradiations are analyzed in terms of the diffusion-controlled recombination of Frenkel defects Ag⁰_i and Ag²⁺V^-_c. It is shown that the effective activation energy of Ag⁰_i migration is a linear function of the composition x; and predominantly two kinds of nearest neighbours contribute to this process. The position of maximum of the excitonic molecule luminescence found in mixed monocrystals and fibers reveals a distinctive dependence on the composition x. Its amplitude and half-width correlate with the optical losses in fibers which could be used for their characterization.