Highly sensitive optical thermometry operation using Eu3+:Y2O3 powders excited under low-intensity LED light source at 395 nm

Temperature determination is of fundamental importance for a wide variety of applications in scientific research, technological developments, biomedical applications, and control of many industrial processes. To supply all these needs, a variety of sensors and devices using different methods have been developed. In this work, we propose a new alternative for a luminescent thermometer based on the visible emission of the europium ion (Eu3+) in the Y2O3 matrix. The sharp emission peak observed at 612 nm was achieved by exciting the Y2O3:Eu3+ ceramic powders with a broadband LED light source centered at 395 nm. The temperature-sensing behavior was explored based on the valley-to-peak ratio (VPR) approach. Thermal sensing performance based on red-emitting level (D-5(0) -> F-7(2)) as a function of the temperature, in the range of 298-573 K, has been considered to evaluate the thermometric parameters. The evaluated thermal sensitivity in Y2O3:Eu3+ is around 0.53% K-1 at 298 K in our experimental range. Results imply that the present phosphor Y2O3:Eu3+ exhibits high and stable sensitivity in a wide temperature range. Hence, this work demonstrates the basis for the manufacture of thermometer of low cost, using simple commercial LED as a source of excitation.