Study of frequency upconversion in Yb3+/Eu3+ by cooperative energy transfer in oxyfluoroborate glass matrix

Energy transfer in Er:Eu:Yb co-doped tellurite glasses: Yb as enhancer and quencher

“…The Er 3+ ion concentration was kept fixed at 0.5 mol% through out the experiment. The method used for glass preparation is described earlier [14]. The fluorescence spectra of rare-earthdoped glasses were monitored using 980 nm (600 mW) and 796 nm (500 mW) radiations from diode lasers.…”

“…However it starts decreasing on addition of Eu 3+ ion further. In our earlier studies it has been observed that the emission of Eu 3+ ions get quenched for more than 1 mol% concentration by ion diffusion (excited Eu 3+ -unexcited Eu 3+ ) process [14].…”

Up and down conversion fluorescence studies on combustion synthesized Yb3+/Yb2+: MO-Al2O3 (M=Ca, Sr and Ba) phosphors

“…Frequency upconversion (UC) of incident infrared radiation into visible/ultraviolet radiation by RE doped phosphors is another topic of interest [13][14][15][16][17]. Ytterbium is of special interest as it can be used as a luminescence center as well as a sensitizer, for other codoped rare earths as Yb can exist in Yb 2 + as well as Yb 3 + states simultaneously in different crystals and glassy systems [18,19].…”

Unusual radiative transitions of Eu3+ ions in Yb/Er/Eu tri-doped NaYF4 nanocrystals under infrared excitation

“…The ET from Yb 3+ to Eu 3+ occurs through Yb 3+ + Yb 3+ cooperative sensitizing and merely results in 5 D 0 ? 7 F J emissions near 600 nm [7][8][9][10]13]. However, the most important mechanism in populating the upper levels of Eu 3+ is the ET from excited Er 3+ to Eu 3+ ions.…”

“…have been studied extensively for their upconversion luminescence (UCL) in ultraviolet-visible-infrared regions [4][5][6]. However, as excellent red emitters and famous structural probes, Eu 3+ ions emit fluorescence usually limiting in the visible light region both in downconversion and upconversion schemes [7][8][9][10][11][12]. Until recently, some breakthroughs have been made in our group: not only the violet UC fluorescence, but also the ultraviolet (UV) five-order UC fluorescence of Eu 3+ in YF 3 nanocrystals (NCs) have been observed by using Yb 3+ and Tm 3+ as sensitizers and 980 nm NIR diode laser as pump light [13].…”