Bviously, Tm3 ions have absorption band matching the 980 nm excitation (shown in viously, Tm3 ions have nono absorption band matching the 980nm excitation (shown in Figure three). This enhancing UC emissions phenomenon is possibly IL-4R alpha Protein HEK 293 assigned to the CR2 and Figure 3). This enhancing UC emissions phenomenon is possibly assigned for the CR2 and ET1 mechanism processes illustrated in Figure 7. To summarize, the ET1, ET2, CR1, CR2, ET1 mechanism processes illustrated in Figure 7. To summarize, the ET1, ET2, CR1, CR2, CR3 processes all have Serpin B3 Protein Human significant effects narrowing the lifetime gap of upperlying Er3 CR3 processes all have considerable effects onon narrowing the lifetime gap of upperlying: 4I 3 4 11/2 11/2 and lowerlying : I 4I13/2 levels and even achieving population conversion of these Er3: 4Iand lowerlying Er Er3: 13/2 levels or even achieving population conversion of those two levels, thereby getting effective enhanced 2.78 m emission. two levels, thereby acquiring effective enhanced two.78 emission.4I 13/Figure 8. Upconversion emissions of Er: PbF2 , and Er/Tm: PbF22 crystals in the array of 76060 nm emissions of Er: PbF2 Er/Tm: PbF crystals within the variety (ex = 980nm). (ex = 980nm).four.6. Fluorescence Decay Curves and Fluorescence Lifetimes For additional demonstrating the power interaction mechanism in between Er3 and Tm3 ions, the timeresolved decay curves of your Er3 ion two.78 m (4I11/2 4I13/2) and 1.55 m (4I13/2 4I13/2) fluorescence emission for the Er/Tm: PbF2 and Er: PbF2 crystals were measured and shown in Figure 9. The lifetimes of 4I13/2 levels had been measured beneath the conditions of 1.55 m emission (4I13/2 4I15/2) and 1.49 m excitation (4I15/2 4I13/2). The decayCrystals 2021, 11,ten of4.six. Fluorescence Decay Curves and Fluorescence LifetimesFor further demonstrating the power interaction mechanism among Er3 and Tm3 ions, the timeresolved decay curves of the Er3 ion two.78 (4 I11/2 four I13/2 ) and 1.55 (four I13/2 4 I13/2 ) fluorescence emission for the Er/Tm: PbF2 and Er: PbF2 crystals have been measured and shown in Figure 9. The lifetimes of 4 I13/2 levels have been measured under the conditions of 1.55 emission (four I13/2 4 I15/2 ) and 1.49 excitation (four I15/2 4 I13/2 ). The decay curves in the Er3 : four I11/2 and Er3 : four I13/2 levels are well fitted with singleexponential behavior. As shown in Figure 9a,b, the measured lifetime on the upperlying 4I 11/2 level within the Er/Tm: PbF2 crystal (six.91 ms) is 14.six longer compared together with the Er: PbF2 crystal (6.03 ms), that is assigned to the sensitization effect on the Tm3 ion around the upperlying Er3 : four I11/2 level. Moreover, as shown in Figure 9c,d, the measured lifetime in the lowerlying 4 I13/2 level in the Er/Tm: PbF2 crystal is 3.14 ms, which can be 73.96 shorter compared together with the Er: PbF2 crystal (12.06 ms). This remarkable lower of your lifetime of lowerlying four I13/2 level denotes that Tm3 ions can significantly depopulate the Er3 : 4 I13/2 level Crystals 2021, 11, x FOR PEER Evaluation via ET2, CR1, CR2, CR3 processes, thereby enhancing the two.78 emission in PbF2 crystals. The ET2, CR1, CR2, CR3 processes all have important effects on narrowing the lifetime gap of upperlying Er3 : four I11/2 and lowerlying Er3 : four I13/2 levels or even achieving population conversion of those two levels. Besides, the energy transfer efficiency ET2 was calculatedshows the lifetimes ofthe11/2, 4I13/ 2deactivation impact in the 2, Er: ion forcrystals, an Table 1 to be 73.96 , confirming 4I effective levels of Er/Tm: PbFT.
