Photoluminescence and thermoluminescence properties of dysprosium doped zinc metaborate phosphors

Polycrystalline powder samples of dysprosium doped Zn(BO2)2 phosphors were prepared by solid state reaction in air at high temperature and characterized by X-ray powder diffraction. The IR, Photoluminescence (PL), diffuse reflectance and three-dimensional (3D) thermoluminescence (TL) emission spectrum after 60Co gamma ray irradiation were investigated. The characteristic 3D TL emission bands at about 425, 481 and 573 nm with a main emission band of around 573 nm were attributed to the host emission, 4F9/2 → 6H15/2 and F9/2 → 6H13/2 f-f transitions of Dy3+ ions. No emission from Dy2+ ions was observed in the measurement wavelength range. The TL-dose response of the Zn(BO2)2:Dy polycrystalline powder sample to gamma ray radiation in the range from 1 to 100 Gy at clinical dose levels was almost linear. The experimental results showed that Zn(BO2)2:Dy had potential use as the materials of gamma-ray thermoluminescence dosimeter (TLD) for clinical dosimetry.