Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7839822 | Journal of Luminescence | 2018 | 32 Pages |
Abstract
Based on the luminescence ratiometric method, here we systematically investigate the relative sensitivity (Sr) of three pairs of typical thermally coupled energy levels (TCELs), that are, the 2H11/2/4S3/2 levels of Er3+, the two sub-Stark 5F5 levels of Ho3+, and the 3F3/3H4 levels of Tm3+, embedded in the CaWO4 host. On the basis of the emission spectra of the CaWO4:Yb3+-X3+ (Xâ¯=â¯Er/Ho/Tm) phosphors, the gaps that separate the 2H11/2/4S3/2, the two sub-Stark 5F5, and the 3F3/3H4 TCELs are calculated to be 719, 402, and 1785â¯cmâ1, respectively. According to the expression Srâ¯=â¯ÎE/kT2 (where ÎE is the energy gap, k is the Boltzmann constant and T is the absolute temperature), the maximum relative sensitivities of these three pairs of TCELs are expected to be 1.12, 0.63, and 2.79%â¯Kâ1 at room temperature 303â¯K. However, the practical relative sensitivities 1.03, 0.23, and 0.22%â¯Kâ1 are achieved at 303â¯K for these three pairs of TCELs accordingly. It is then demonstrated that not only at 303â¯K but over the whole experimental temperature range, the relative sensitivities of these three pairs of TCELs are confirmed to be overestimated to some degree. The work not only presents the practical relative sensitivities of these three pairs of TCELs, but also probably discloses a quite common phenomenon that the real relative sensitivity of TCELs is often overestimated. Therefore, it is expected to provide guidance for the practical applications of the luminescence ratiometric thermometry in the future.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Leipeng Li, Feng Qin, Yuan Zhou, Yangdong Zheng, Hua Zhao, Zhiguo Zhang,