Photoluminescence of Lu₂O₃:Eu³⁺ phosphors obtained by glycine-nitrate combustion synthesis

Eu³⁺-doped Lu₂O₃ phosphors were synthesized through a novel solution combustion route using glycine as the fuel. The influence of the glycine-to-nitrate (G/N) mole ratio on the crystallite size, specific surface area, morphology, and photoluminescence of the synthesized phosphors was investigated. The ignition temperature on the properties of the products was also studied. With G/N ratio increasing from 1.0 to 1.7, the grain size increased from 35 to 118 nm accordingly, resulting in the obvious changes of the photoluminescence properties. Concentration dependence of the emission intensity revealed that the quenching concentration of europium dopant was around 5 mol% for G/N = 1.7. The intensity of the peak emission due to the ⁵D₀ → ⁷F₂ transition of the Eu³⁺ ions dropped as the grain size decreased. The charge transfer band position of Eu³⁺-doped lutetia phosphors shifted toward lower energy (red shift) with the reduction of crystallite sizes and also with the increase of Eu³⁺ concentrations.