Temperature sensing from the emission rise times of Eu3+ in SrY2O4

Abstract

The emission rise time of Eu³⁺-doped SrY₂O₄ was investigated in the temperature range of 20–200 °C for application in luminescence thermometry. After pulsed excitation, the energy transfer between the adjacent Eu³⁺ ions causes a emission build-up from the ⁵D₀ level of Eu³⁺ and a notable emission rise occurs prior to decay. The emission rise-time values linearly decrease with temperature, providing an absolute sensitivity of 0.66 μs °C⁻¹ and a maximal relative sensitivity of 5.53% °C⁻¹ at 200 °C, for samples containing 0.5 at% Eu³⁺ ions. It is shown that the time after excitation at which emission reaches a maximum (time-to-max) can also be exploited for temperature sensing, since it is easily measurable and shows a linear dependence with temperature.