Structural Defect Effect on the Concentration Quenching of TbxY2–xO3 Phosphor Thin Films

Abstract

This study investigates the structural defect effect on the luminescence properties of TbxY2–xO3 (x = 0–0.5) composition-gradient films using combinatorial pulsed laser deposition (PLD). TbxY2–xO3 films were grown on a SrTiO3 (001) substrate in an O2/He mixed atmosphere at PO2 = 1 × 10–4 Torr. A He buffer gas moderated the kinetic energy of the PLD plume and suppressed the resputtering of the film surface, resulting in the fabrication of defect-rich and poor TbxY2–xO3 films. The TbxY2–xO3 composition-gradient films exhibited varying green emissions from the Tb-doped Y2O3 films. The luminescence intensity of the defect-rich film was significantly weaker than that of the defect-poor film. Furthermore, concentration quenching of the luminescence occurred at high Tb concentrations. The analysis of the decay profiles of the luminescence as a function of the Tb concentration suggested two possible reasons for luminescence quenching: dynamic quenching induced by structural defects and static quenching induced by the shorter average distance of adjacent Tb ions. The investigation of the structural defect effect on the luminescence properties provides insights into the primary material parameters of phosphor materials and offers a pathway for enhancing their luminescence properties.