Physical and optical properties of dysprosium ion doped strontium borate glasses

The effect of dysprosium ion (Dy3+) on the optical absorption and band gap energy of strontium borate glass systems prepared by melt quenching technique have been reported. The results show that the broad absorption edge of doped glasses shifts back and forth as a function of Dy2O3 concentrations. The intensities of five prominent and two weak optical transitions change accordingly with Dy2O3 concentrations. The defect centres are induced with the presence of Dy3+ ions in glass samples. This attributes to the intra-configurational (f–f) transitions of Dy3+ ions in glass network. In addition, the decreasing trend of optical band gap energy and Urbach energy can be related to defect centres created by Dy3+ ions. The FTIR study reveals the presence of BO3, BO4 vibration groups and the bending of B–O–B units. The asymmetric stretching of BO3 and BO4 was apparent at higher Dy2O3 concentrations. More tetrahedral BO4 units were formed by increasing Dy2O3 concentrations. The dependency of Dy2O3 concentrations on the optical properties is further discussed with other important physical properties.