The energy transfer of electronic excitations to impurities in dosimetric phosphors BaSO4-Dy

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Beam interactions with materials and atoms, 2024-10, Vol.555, Article 165459
• Main Authors: Nurakhmetov, T.N., Zhangylyssov, K.B., Shamiyeva, R.K., Alibay, T.T., Salikhodzha, Zh.M, Sadykova, B.M., Tolekov, D.A., Yussupbekova, B.N.
• Format: Article
• Language: English
• Subjects: Band gap; Defects; Dosimeter; Luminescence; Sulfate; Trapping centers
• ISSN: 0168-583X
• DOI: 10.1016/j.nimb.2024.165459

•Electron trapping centers in the range of 2.95–3.1 eV was studied by vacuum ultraviolet and thermal activation spectroscopy;•Sulfate anion and Dy3+ (O2-→Dy3+) and the creation of a combined radiative state SO43-→SO4-,•During thermal or optical excitation process, Dy2+ and SO43- electronic centers are ionized. The formation of new radiative states from the combination of Dy2+-SO4- and SO43--SO4- electron trapping centers in the range of 2.95–3.1 eV has been investigated using VUV and thermal activation spectroscopy. During the excitation process, there is a charge transfer between the oxygen ion of the sulfate anion and Dy3+ leading to the formation of a combined emissive state SO43-→SO4-. These states can be formed from the electron-hole trapping centers of Dy2+-SO4- and SO43--SO4-. The combined radiative state at 2.95–3.1 eV and impurity emission at 2.16 eV and 2.56 eV are excited simultaneously by photons of 3.95 eV and 4.5 eV, respectively. During the thermal or optical excitation process, the Dy2+ and SO43- electronic centers are ionized. Electrons recombine with a hole trapped by the ground state of the impurity (SO4--Dy3+), and the released energy is transferred to the Dy3+ impurities.