Spectral structure of the X-ray stimulated phosphorescence of monocrystalline ZnSe

• ZnSe has intensive X-ray luminescence and phosphorescence in the spectral range from 600 nm to 1000 nm.
• We measured the phosphorescence of ZnSe for different wavelengths of 591 nm, 635 nm and 679 nm.
• The dominant emission band of ZnSe with a maximum at 635 nm is a combination of at least three emission bands.
• We propose and verify an energy model of the traps and recombination centres in monocrystalline ZnSe.

This work presents the extensive experimental studies of the X-ray stimulated luminescence, conductivity, phosphorescence and electric current relaxation, and the thermally stimulated luminescence and conductivity of monocrystalline ZnSe. It was found that the luminescence emission band with a maximum at 635 nm is a combination of at least three emission bands and that the appropriate recombination centres implement both electronic and hole recombination mechanisms. We propose an energy model of the traps and recombination centres in monocrystalline ZnSe and show that the majority of the generated free electrons and holes recombine in the luminescence centres with an estimated probability of 94.3% and that only a small fraction (5.7%) of generated charge carriers are accumulated in traps during the X-ray excitation of the ZnSe sample.