Luminescence of $Cu^{+}$ and $Cu^{2+}$ Ions in CsBr Crystals

The luminescence of $Cu^{+}$ and $Cu^{2+}$ ions in CsBr:Cu and CsBr:$CuBr_{2}$ crystals, respectively, is investigated under excitation by synchrotron radiation in the CsBr fundamental absorption range at 10 K and 300 K. The existence of the luminescence bands of different origin: (i) the intrinsic radiative transition of $Cu^{+}$ ions in the bands peaked at 2.61 eV and 2.23 eV, (ii) the recombination luminescence of $Cu^{2+}$ ions in the bands peaked at 2.55 eV and 2.13 eV, (iii) the luminescence of excitons localized around $Cu^{+}$ and $Cu^{2+}$ ions in the band peaked at 3.08 eV and 3.38 eV, respectively, was found in CsBr:Cu and CsBr:$CuBr_{2}$ crystals. The energies of creation of exciton localized around $Cu^{+}$ and $Cu^{2+}$ ions (6.06 eV and 6.09 eV, respectively, at 10 K) and excitons bound with these ions (5.83 eV and 5.99 eV at 300 K) were determined as well.