The luminescence regulation effect of Na+ on the Yb3+/Er3+ co-doped Y2O3 up-conversion films

Effect of Bi3+ ion on upconversion-based induced optical heating and temperature sensing characteristics in the Er3+/Yb3+ co-doped La2O3 nano-phosphor

“…9(a) shows large number of peaks at 381, 490, 523, 548 and 671 nm and they are attributed to 2 I 15/2 / 4 G 11/2 , 4 F 5/2 , 2 H 11/2 , 4 S 3/2 and 4 F 9/2 transitions of Er 3+ ion, respectively. [12][13][14][15][16][17][18] The gure also shows a broad band centered at 976 nm due to 2 F 7/2 / 2 F 5/2 transition of Yb 3+ ion. 15 When the Bi 3+ ion is added in the phosphor the spectrum contains additional bands in the 220-340 nm region due to Bi 3+ ion (see Fig.…”

“…The phosphor sample gives a weak blue (at 492 nm), strong green (at 523 and 548 nm) and red (at 660 and 671 nm) upconversion emissions due to 4 F 5/2 / 4 I 15/2 , 2 H 11/2 / 4 I 15/2 , 4 S 3/2 / 4 I 15/2 , and 4 F 9/2 / 4 I 15/2 transitions of Er 3+ ion, respectively. [12][13][14][15][16][17][18] The blue emission arises due to absorption of three 976 nm photons whereas the green and red emissions have been observed due to absorption of two 976 nm photons, respectively. 15 The emission intensity of the phosphors has been measured for different concentrations of Bi 3+ ions while the concentrations of Er 3+ and Yb 3+ ions are xed at 0.7 and 3.0 mol%, respectively.…”

“…Finally, the 4 F 5/2, 2 H 11/2 , 4 S 3/2 and 4 F 9/2 states are populated, which give radiative transitions at 493, 523, 548 and 671 nm wavelengths, respectively. [12][13][14][15][16][17][18]20 3.2.4 Induced optical heating measurements. The induced optical heating in the Er 3+ /Yb 3+ co-doped phosphors have been widely studied by different groups of researchers in different host materials.…”

“…The optical properties of the Er 3+ /Yb 3+ co-doped phosphor materials have been studied in detail by different groups. [12][13][14][15][16][17][18][19][20] They have reported intense green and weak red upconverted emissions upon 976 nm excitation in which the green emission arises due to the transition from the thermally coupled energy levels (viz. 2 H 11/2 and 4 S 3/2 ) to the ground level ( 4 I 15/2 ) of Er 3+ ion.…”