Concentration-dependent upconversion emission in Er-doped and Er/Yb-codoped LiTaO3 polycrystals

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

“…Owing to the population of the 4 F 9/2 state through the SETU process ( 2 F 5/2 + 4 I 13/2 → 2 F 7/2 + 4 F 9/2 ), the increased population of the 4 F 9/2 state leads to enhanced red light emission and reduced green light emission [30]. Therefore, with the increase in Yb 3+ concentration, the ratio of relative intensity of the red to green emission increased (Fig.…”

Upconversion 32Nb2O5–10La2O3–16ZrO2 glass activated with Er3+/Yb3+ and dye sensitized solar cell application

“…2 Transmittance spectra of the undoped NLZ glass and doped NLZ4 sample. [29]. The increasing concentration of Er 3+ ions shortens the distance between two neighboring Er 3+ ions.…”

“…In SiO 2 and other traditional networker formers, the rare earth element ion concentration can be increased, but unfortunately result in the formation of clusters due to the network rigidity of these glasses. In the glasses containing modified ions, the local environment of rare earth ions is defined preferentially by non-bridging oxygens [29]. In NLZ glass, Nb 2 O 5 is used as network modifier, which has non-bridging oxygens [21] and contributes to the glass matrix to host a high content of rare earth ions.…”

Femtosecond-pulse laser-ablation-induced synthesis and improved emission properties of ultrafine Y2O3:Er3+, Yb3+ nanoparticles with reduced nonradiative relaxation

“…Then, some of the excited ions decay from the 4 I 11/2 excited state to a long-lived 4 I 13/2 state through the nonradiative relaxation (NR I) process, 4 I 11/2 (Er 3þ ) / 4 I 13/2 (Er 3þ ). For high Yb 3þ concentration, the energy-back transfer (EBT) process, 4 S 3/2 (Er 3þ ) þ 2 F 7/2 (Yb 3þ ) / 4 I 13/2 (Er 3þ ) þ 2 F 5/2 (Yb 3þ ), becomes more prominent [7,35]. This process is also responsible for the population of the 4 I 13/2 state.…”