Recombination processes leading to the tunnelling afterglow and photostimulated luminescence in systems based on host ionic crystals with impurity-related nanostructures-promising phosphors for x-ray storage-were studied by means of luminescence, EPR and optically detected magnetic resonance. It was found that in the x-ray irradiated CsBr:Eu and CsBr:Pb crystals the energy released in the spin-dependent tunnelling recombination of electron-hole pairs and self-trapped excitons in the host crystal is directionally transferred to the impurity-related low-dimensional structures. To identify the origin of recombining electron and hole centres, their EPR spectra were detected by monitoring the tunnelling afterglow and the photostimulated luminescence including the emission bands of the low-dimensional structures.