Concentration effect on oxygen quenching behavior of EuxY0.08‐xZr0.92O1.96 and DyxY0.08‐xZr0.92O1.96 phosphors

Abstract

AbstractThe effect of oxygen partial pressure on the phosphorescence of EuxY0.08‐xZr0.92O1.96 and DyxY0.08‐xZr0.92O1.96 (x = 0.001, 0.005, 0.01, 0.02, 0.05) phosphors was investigated and compared to explore the Ln3+ (Ln3+ = Eu3+, Dy3+) concentration effect on oxygen quenching using a lifetime‐based measurement system equipped with a heatable and pressure controllable chamber. The phosphorescence lifetimes of these two series of phosphors were found to be sensitive to the oxygen partial pressure in high‐temperature environments. Surprisingly, the oxygen sensitivity of DyxY0.08‐xZr0.92O1.96 phosphors markedly increases as the Dy3+ concentration increases, while that of EuxY0.08‐xZr0.92O1.96 phosphors remains nearly constant. Further analysis shows that the oxygen quenching phenomenon is attributable to an oxygen vacancy‐induced non‐radiative decay reduction. However, the mechanisms of non‐radiative decay affected by oxygen vacancies differ, with a charge transfer state (CTS) transition mechanism in EuxY0.08‐xZr0.92O1.96 and a cross‐relaxation mechanism in DyxY0.08‐xZr0.92O1.96 phosphors. The CTS measured from the excitation spectrum is found to be independent of the Eu3+ concentration. In contrast, cross‐relaxation is closely related to the Dy3+ concentration, as demonstrated by the concentration‐quenching behaviours of the phosphorescence intensities and lifetimes, and the non‐exponential decay curves. The present research was expected to shed light on the development and optimization of oxygen/pressure sensors for high‐temperature service.