An upconversion luminescence and temperature sensor based on Yb³⁺/Er³⁺ co-doped GdSr₂AlO₅

Concentration and pump power-mediated color tunability, optical heating and temperature sensing via TCLs of red emission in an Er3+/Yb3+/Li+ co-doped ZnGa2O4 phosphor

“…The Er 3+ ion has suitable TCLs, which result in a good t of FIR not only for induced optical heating but also for temperature sensing of phosphor materials. [23][24][25][26][27][28] In the UC photoluminescence of Er 3+ /Yb 3+ co-doped phosphors, the Er 3+ ion weakly absorbs an incident near infrared (NIR) 980 nm photon and gives poor UC emission intensity. However, its efficiency can be enriched signicantly via the doping of Yb 3+ ions.…”

“…[1][2][3][4] A number of studies was carried out by researchers using Er 3+ /Yb 3+ ions in different phosphor materials. [23][24][25][26][27][28]50 These authors have found FIR by taking UC emission intensities of TCLs of green emission as a function of temperature. It is well known that the 2 H 11/2 and 4 S 3/2 levels of Er 3+ ion are thermally coupled and they give rise to different values of UC emission intensities as a function of external temperature.…”

Preparation, structure and up-conversion luminescence properties of novel cryolite K3YF6:Er3+, Yb3+

“…The electrons in the ground state of Er 3+ absorb the energy transmitted by Yb 3+ and transited to the 4 I 11/2 level. Since the Er 3+ and Yb 3+ levels match very well, the electrons of the activator Er 3+ can also directly absorb a photon of 980 nm from the ground state level 4 Some electrons at the 4 I 11/2 level of Er 3+ directly accept the energy released from the electronic transition in the excited state of Yb 3+ back to the ground state, and jump up to the 4 F 7/2 level. Since the energy gap between 4 F 7/2 and 2 H 11/2 , 2 H 11/2 and 4 S 3/2 is small, electrons at the 4 F 7/2 level will quickly relax to the 2 H 11/2 / 4 S 3/2 level without radiation.…”

“…The up-converting luminescent material can be excited with low energy near infrared (NIR) radiation, and emits the light of higher energy in a visible range, due to the multi-photon absorption followed by an anti-Stokes emission. [4][5][6][7][8] So far, rare earth doped up-conversion materials have aroused widespread attention due to their important applications [9][10][11][12][13][14] in the elds of the national economy and national defense construction, such as in infrared quantum vibrational properties of K 3 YF 6 solid solution and considered it suitable as luminescent materials. These works mainly focus on the down-conversion of cryolite structure.…”

Multifunctional BiF3:Ln3+ (Ln = Ho, Er, Tm)/Yb3+ nanoparticles: an investigation on the emission color tuning, thermosensitivity, and bioimaging

“…It was well known that the change of the transitions of 2 H 11/2 / 4 I 15/2 (524 nm) and 4 S 3/2 / 4 I 15/2 (542 nm) at different temperatures owing to 2 H 11/2 and 4 S 3/2 levels were related to the thermal coupling of Er 3+ ion. The ratio (R) of emission intensities at 524 nm and 542 nm followed the formula based on the Boltzmann distribution theory: [42][43][44]…”