Dual-mode green emission and temperature sensing properties of rare-earth-element-doped biphasic calcium phosphate composites

Multifunctional optical thermometry using dual-mode green emission of CaZrO3:Er/Yb/Mo perovskite phosphors

“…The intense green UC emission of phosphor can be due to the ET from Yb 3+ –MoO 4 2− dimer to Er 3+ ions, which is similar to the enhancement mechanism of the UC emission. 23,54 By contrast, the weak red emission may correspond to the relatively small population in the 4 F 9/2 level of Er 3+ (Fig. 6).…”

“…The energy transfer effectively process from the high-energy excited state (j 2 F 7/2 , 3 T 2 i) of the Yb 3+ -MoO 4 2− dimer to the 4 F 7/2 level of the Er 3+ ion is responsible for the strong green emission of phosphors. 15,23,37 When Mo 6+ doping content is higher than 3% mol, the UC emission intensity decreases because of the energy migration between Yb 3+ -MoO 4 2− dimers 23,37 and between the MoO 4 2− groups as a donor in the energy transfer process. 38 On the contrary, the weak absorption cross-section of the 4 I 13/2 state of the Er 3+ ions led to weak red emission intensities.…”

“…19,20 Most recently, our previous works explored the super enhancement of green UC emission by using the Yb 3+ -MoO 4 2− dimer sensitizer for Er 3+ ion on HA/TCP (650 times) 21 and HA (70 times), 22 thereby achieving good temperature sensing properties in BCP host. 23 Based on previous works, the strong green UC emission of phosphors can be achieved by using Er-Yb-Mo tri-doped systems, leading to the enhancement of sensing sensitivity. 15,23 Furthermore, several works 1,3,23,24 have observed that temperature sensitivity depends on the host lattice.…”

“…23 Based on previous works, the strong green UC emission of phosphors can be achieved by using Er-Yb-Mo tri-doped systems, leading to the enhancement of sensing sensitivity. 15,23 Furthermore, several works 1,3,23,24 have observed that temperature sensitivity depends on the host lattice.…”

High-efficiency energy transfer in the strong orange-red-emitting phosphor CeO2:Sm3+, Eu3+

“…1b) after being doped with a larger ionic radius Eu 3+ (1.06 Å) since the ionic radius of Ce 4+ is 0.97 Å, leading to a lattice expansion, 18 confirming that Eu 3+ ions have been incorporated in the Ce 4+ cites of the CeO 2 host. Furthermore, the crystallite size of all investigated phosphors was determined using the Scherrer equation: 27 where D is crystallite size (nm), 0.9 is Scherrer constant, λ is the wavelength of the X-ray sources (0.15406 nm), β (radians) and θ (radians) are full width at half maximum (FWHM) and peak position, respectively. The diffraction peak corresponding to the (111) plane of CeO 2 was chosen to calculate crystallite size, as shown in Table 1.…”