Dose enhancing behavior of hydrothermally grown Eu-doped SnO₂ nanoparticles

Hydrothermally grown SnO₂ and SnO₂:Eu nanoparticles of 4-11 nm size range were analyzed by photoluminescence (PL) and therrmoluminescence (TL) spectroscopy to study the effect of Eu-doping on their emission behaviors. It has been observed that most of the incorporated Eu ³⁺ ions remain at the interstitial sites of SnO₂ lattice. High Eu-contents in the nanoparticles generate lattice deformation, formation of Eu³⁺/Eu⁰ clusters at interstitial sites, or segregation to their surfaces. Formation of Eu clusters at interstitial sites enhances electronic defect density in the crystal lattice, reorganizes carrier trapping centers, and modifies their activation energies. Room temperature PL emission and beta-irradiated TL dose response of SnO₂ nanoparticles enhance significantly when doped with 0.5 and 1.0 mol. % nominal of Eu³⁺, respectively, opening up their possibilities of applications in bio-imaging and radiation therapy. Possible mechanisms of enhanced PL and TL responses of the samples have been discussed.