Enhanced upconversion from Er3+/Yb3+ co-doped alkaline earth aluminates phosphor in presence Zn2+: A comparative study

Highly sensitive optical temperature sensing based on pump-power-dependent upconversion luminescence in LiZnPO4:Yb3+–Er3+/Ho3+ phosphors

“…† The sharp pic in the NIR region at 980 nm can be assigned to the 2 F 7/2 → 2 F 5/2 electronic transitions of Yb 3+ . 39 Therefore, doping Yb 3+ ions is beneficial to enhance the up-conversion luminescence intensity and efficiency for LiZnPO 4 :Er 3+ , Ho 3+ . The RE 3+ activators create some heavy absorption lines.…”

“…For example, those at $379/521 nm are from the 4 I 15/2 / 4 G 11/2 / 2 H 11/2 transitions of Er 3+ and those at $363/451 nm belong to the 5 I 8 / 5 G 2 / 5 F 1 transitions of Ho 3+ . 39,40 Furthermore, the Kubelka-Munk function can be used to determine the magnitude of the band-gap (E g ). This function was used to transform the measured reectance into an analogous absorption range, which was normalized by the reectance of the regular reference.…”

Enhancement of Long-Persistent Phosphorescence by Solid-State Reaction and Mixing of Spectrally Different Phosphors

“…Barry et al and Yao et al investigated Eu 2+ → Mn 2+ energy transfer in BaMg 2 Si 2 O 7 , whereas Yang et al reported a similar effect in the Eu 2+ - and Mn 2+ -coactivated CaAl 2 Si 2 O 8 phosphors, all of which involved Eu 2+ → Mn 2+ energy transfer in the same host crystal. − The electron transfer in Er 3+ /Yb 3+ co-doped phosphors has been reported as well. Several groups have reported that the energy is transferred from Yb 3+ (donor) to Er 3+ (acceptor), resulting in the upconversion luminescence process in various host materials . The energy transfer from Bi 3+ to Eu 3+ was also observed in Ba 2 Y­(BO 3 ) 2 Cl:Bi 3+ , Eu 3+ phosphors.…”

“…While sulfide-based phosphors suffer from rapid degradation, rare-earth-doped oxide-based phosphors are chemically and thermally stable . The high heat resistance, high brightness, long persistence time, low toxicity, and tunable emission wavelength from the UV to visible range make them suitable phosphor materials. − It leads to wide applications, such as usage in solid-state lasers, fluorescent lamps, cathode ray tubes, field emission display (FED) devices, plasma display panels (PDP), fiber amplifiers, radiation dosimetry, optoelectronics for image storage, X-ray imaging, noncontact temperature sensing, etc. , …”

Elucidating the role of metal-ion co-doping towards boosting upconversion luminescence in gadolinium vanadate

“…Various ions such as Li + (ionic radius 92 pm) 15 , Zn 2+ (90 pm) 16 , Na + (118 pm) 17 , and Bi 3+ (117 pm) 18 have been systematically investigated as both alio (oxygen imbalance) and homovalent (charge balanced) dopants. Especially, Li + and Zn 2+ co-doping has attracted considerable attention for a range of inorganic phosphors including fluorides [19][20][21] , binary oxides [22][23][24][25][26] , aluminates 27 , titanates 28,29 , and vanadates 16,[30][31][32][33] . It is reported that with optimized doping concentration, a large (≥10×) improvement in luminescence can be readily obtained.…”