Upconversion photoluminescence properties of Er 3+ doped CaBi 2 Nb 2 O 9 phosphors for temperature sensing

Abstract

The CaBi₂Nb₂O₉ materials have ultrahigh Curie temperature (T_c ∼ 1216 K). Therefore, such compound as the host would make their luminescent materials have wide temperature range for application. In this work, the Er³⁺ doped CaBi₂Nb₂O₉ phosphors were synthesized to investigate upconverion emission properties and their optical sensing behavior. The analyses based on photoluminescence and decay time upon the 980 nm excitation demonstrated that the phosphors had an intense green emission by two-photo process. Using the fluorescence intensity ratio technique, temperature sensing performances based on the green emission were evaluated in the wide-range 90–570 K, which fitted well with the theoretical equation. These results indicate that Er doped CaBi₂Nb₂O₉ could be promising temperature sensor for wide range and high temperature application.