Tm3+ Modified Optical Temperature Behavior of Transparent Er3+-Doped Hexagonal NaGdF4 Glass Ceramics

Abstract

Er3+-doped and Er3+-Tm3+-co-doped transparent hexagonal NaGdF4 glass ceramics are fabricated via melt-quenching method. The emissions of Er3+-doped NaGdF4 glass ceramics are adjusted from the green to red by varying the concentration of Tm3+ ion under the excitation of 980 nm. The spectrum, thermal quenching ratio, fluorescence intensity ratios, and optical temperature sensitivity of the transparent glass ceramics are observed to be dependent on the pump power. The maximum value of relative sensitivity reaches 0.001 K−1 at 334 K in Er3+-doped NaGdF4, which shifts toward the lower temperature range by co-doping with Tm3+ ions, and has a maximum value of 0.00081 K−1 at 292 K. This work presents a method to improve the optical temperature behavior of Er3+-doped NaGdF4 glass ceramics. Moreover, the relative sensitivity SR is proved to be dependent on the pump power of 980-nm lasers in Er3+-doped NaGdF4 and Er3+-Tm3+-co-doped NaGdF4.

Polymer Microfibers Incorporated with Silver Nanoparticles: a New Platform for Optical Sensing

“…This phenomenon is caused by temperature excitation between thermally coupled levels. Therefore, the populations of 2 H 11/2 and 4 S 3/2 satisfy the Boltzmann statistics resulting in variation of population rates of 2 H 11/2 → 4 I 15/2 and 4 S 3/2 → 4 I 15/2 levels [45]. The mechanism of up-conversion process in Er 3+ /Yb 3+ is illustrated in Fig.…”

Color-Tunable Upconversion in Er3+/Yb3+-Codoped KLaF4 Nanophosphors by Incorporation of Tm3+ Ions for Biological Applications

“…Finally, the effective energy transfer between Er 3+ and Tm 3+ that leads to an increase in red emission could be 4 S 3/2 (Er 3+ ): 4 I 9/2 (Er 3+ ): 4 I 11/2 (Er 3+ ): 3 F 4 (Tm 3+ ): 4 F 9/2 (Er 3+ ). 32 The conventional DC spectra in the NIR region of doped KLaF 4 :Er 3+ /Tm 3+ /Yb 3+ phosphors excited with a 980 nm CW laser is presented in Figure 4c. The emission bands centered at 1468 and 1535 nm correspond to the intra-4f electronic transitions, 3 H 4 → 3 F 4 (Tm 3+ ) and 4 I 13/2 → 4 I 15/2 (Er 3+ ).…”

“…In our experiments, when 1 mol % Er 3+ content is incorporated into the KLaF 4 :1% Tm 3+ /20% Yb 3+ sample, the lifetime of 1 G 4 state (Figure S2) does not change significantly, suggesting that the energy transfer from Er 3+ to Tm 3+ ions does not occur through higher states of Tm 3+ ( 1 G 4, 1 D 2 ) ions, but the favorable energy transfer process could be 3 F 4 (Tm 3+ ) + 4 I 11/2 (Er 3+ ) → 3 H 6 (Tm 3+ ) + 4 F 9/2 (Er 3+ ). Finally, the effective energy transfer between Er 3+ and Tm 3+ that leads to an increase in red emission could be 4 S 3/2 (Er 3+ ): 4 I 9/2 (Er 3+ ): 4 I 11/2 (Er 3+ ): 3 F 4 (Tm 3+ ): 4 F 9/2 (Er 3+ ) . The conventional DC spectra in the NIR region of doped KLaF 4 :Er 3+ /Tm 3+ /Yb 3+ phosphors excited with a 980 nm CW laser is presented in Figure c.…”