Optical absorption, thermoluminescence glow and emission spectra of RbBr:Ca2+ and RbBr:OH− have been studied and analysed. It is observed that both Ca2+ and OH− ions enhance theF-centre concentration.FZ1 band in RbBr:Ca2+ appears at 1.55 eV. TL glow peak corresponding toFZ1 centre on analysis gives a trap depth of 0.84 eV. OH− ions in the crystal seem to act as TL ‘killers’. Spectral distribution of emission under the glow peaks shows five bands around 1.5, 1.8, 2.1, 2.5 and 2.9 eV. Probable models of TL mechanism are suggested to explain the observed TL emission bands.
