Effect of ion irradiation on optoelectronic properties of Ba0.12Sr0.88SO4: Eu phosphor

Nanocrystalline Ba0.12Sr0.88SO4 phosphor doped with Eu at 0.1 mol% optimum concentration was prepared by the chemical co-precipitation method. X-ray diffraction study of the prepared sample suggests the orthorhombic structure with an average grain size of 62 nm. The band gap was found to be 4.3 eV. The samples were irradiated with 1.2 MeV argon ions at fluences varying between 1011 and 1015 ions/cm2, i.e. in the dose range of 59 kGy to 590 MGy. A prominent photoluminescence (PL) emission peak is seen around 376 nm due to transition from an excited state 4f65d to 8S7/2 state of Eu2+ ions. The broadening of bands in FTIR spectrum at 1110, 990, 643 and 617 cm−1 is an evidence of the generation of SO4−, SO3−, SO2−, O−, etc. radicals after ion irradiation. The effect of ion irradiation on luminescence properties was studied.