The usability of the Judd-Ofelt theory for luminescent thermometry using Eu3+-doped phosphate glass

The Judd-Ofelt theory, which is the most thorough and insightful method to determine theoretically the lumi-nescent properties of the trivalent rare earth dopants, is here tested on Eu3+-doped glasses in the P2O5 - SrO - CaO - Na2O system to assess their usefulness as luminescent thermometers. It is demonstrated that the ther-mometric sensitivity (change of the emission lines ratio in response to change in temperature) can be estimated using the Judd-Ofelt theory and aligns well with the experimentally obtained values. It is shown here that the addition of B2O3 or SiO2 in a phosphate network increases the absolute sensitivity due to an increase in the phosphate network connectivity while having no significant impact on the site of Eu3+ ions. The applicability of the Judd-Ofelt theory for predicting the thermometric parameters of a glass luminescent material, without the time-consuming measurement of the glasses spectroscopic properties as a function of temperature, is clearly demonstrated and allows for further development of novel efficient luminescent thermal sensors with high sensitivity.

Automated summary

The Judd-Ofelt theory was tested on Eu3+-doped glasses to evaluate their potential as luminescent thermometers. The theory accurately estimated the thermometric sensitivity, and the addition of B2O3 or SiO2 increased the absolute sensitivity without affecting the position of Eu3+ ions.