Dominant red emission (4F9/2→4I15/2) via upconversion in YAG (Y3Al5O12):Yb3+,Er3+ nanopowders

Synthesis and up-conversion luminescence properties of Er3+/Yb3+ co-doped Sr2CeO4 phosphors

“…However, its relatively low absorption cross-section of 1.7 × 10 −21 cm 2 makes its ground state absorption (GSA) at 975 nm very weaken weak, leading to a the reduction in the emission intensity and pump efficiency [10]. To overcome these drawbacks and enhance the UC emission efficiency, Yb 3+ ions are generally used as co-doped ions because they have a due to their large absorption cross-section of 11.7 × 10 −21 cm 2 around 980 nm and can efficiently transfer the excitation energy to other activators [11][12][13][14][15]. Therefore, the Yb 3+ -Er 3+ couple is also used to produce visible green or red UC emission [16].…”

Pure red upconversion emission from Yb3Al5O12 phase doped with high Er3+ concentration

“…Dong, Liu, et al [8][9][10][11][12] reported high emission intensity ratio of the red to the green (R/G) in Er 3+ /Yb 3+ co-doped upconversion materials with the excitation of 980 nm LD, but the purity was not high enough. Liu et al [9,13] reported that the high concentration of Yb 3+ ion would bring high value of R/G. According to the Bai et al [14], it is possible to obtain single color upconversion emission when the concentration of Yb 3+ and Er 3+ ions is optimized.…”

Enhancement of upconversion emission in Y3Al5O12:Er3+ induced by Li+ doping at interstitial sites

“…YAG is selected as the host lattice due to its high melting point, high chemical stability and relatively low phonon energy. Moreover, Er 3+ doped YAG has been established as one of the model systems for generating efficient UC radiation under 980 nm laser excitation, since the abundant energy levels of Er 3+ favor a lot of UC processes and the long lifetime 4 I 11=2 level of Er 3+ can be easily populated by 980 nm pump laser [14,15].…”