EPR spectroscopic investigations of metal halides doped with transition metal ions. II. Iridium (III) -doped AgCl and AgBr

The paramagnetic species (IrCl6)4− and (IrBr6)4− have been identified as products in the light-induced decomposition of iridium (III) -doped AgCl and AgBr single crystals. Evidence is presented to show that secondary electron and hole traps such as Ni2+ and Fe2+ grossly affect the rate of filling and emptying of the more abundant Ir3+ sites. Kinetic data obtained from the thermally induced decay of the Ir2+ traps locate these levels 0.5±0.01 eV and 0.44±0.01 eV below the conduction bands in silver chloride and silver bromide, respectively.