Time-resolved photoluminescence studies in Eu-doped SiO 2 – HfO 2 – ZnO glass-ceramic waveguides

Effect of structural evolution of ZnO/HfO2nanocrystals on Eu2+/Eu3+emission in glass-ceramic waveguides for photonic applications

“…Various excitation bands are observed in the 350-500 nm wavelength regime. These sharp excitation bands relative to the intra 4f-4f transition of Eu 3+ centered at 363 nm, 383 nm, 396 nm, 412 nm and 465 nm can be attributed to 5 D 4 ← 7 F 0 , 5 L 7  ¬  7 F 0 , 5 L 6 ← 7 F 0 , 5 D 3 ← 7 F 0 and 5 D 2 ← 7 F 0 transitions respectively [19,[26][27][28]. More interestingly, 321 nm excitation band corresponds to the 5 H j ← 7 F 0 transition of Eu 3+ and it is also assigned to the Eu 2+ excitation transition as reported in the literature [19,27].…”

“…These sharp excitation bands relative to the intra 4f-4f transition of Eu 3+ centered at 363 nm, 383 nm, 396 nm, 412 nm and 465 nm can be attributed to 5 D 4 ← 7 F 0 , 5 L 7  ¬  7 F 0 , 5 L 6 ← 7 F 0 , 5 D 3 ← 7 F 0 and 5 D 2 ← 7 F 0 transitions respectively [19,[26][27][28]. More interestingly, 321 nm excitation band corresponds to the 5 H j ← 7 F 0 transition of Eu 3+ and it is also assigned to the Eu 2+ excitation transition as reported in the literature [19,27]. Hence, the appearance of 321 nm band in the excitation spectra not only confirms the existence of Eu 2+ in the glassceramic matrix but also a strong signature of energy transfer from 5d energy level of Eu 2+ to 4f energy level of Eu 3+ .…”

“…The broad emission band from 400 to 570 nm is attributed to 4f 6 5d  4f 7 transition of Eu 2+ ions in the glass-ceramic matrix [18,29]. This broad emission of Eu 2+ is different from ZnO defect state emission and has been observed in the absence of ZnO too [18,19]. Low intensity emission characteristic of Eu 3+ ions consisting of very sharp lines can also be observed in the inset of figure 5(a), which are assigned to 5 D 0  7 F j ( j=0, 1, 2, 3 and 4) transitions.…”

“…Earlier, we have extensively studied Eu-doped SiO 2 -HfO 2 -ZnO ternary glass-ceramic waveguides as a function of ZnO concentration from 0 to 10 mol% [18,19]. The propagation loss was observed to be as low as 0.5 dB cm −1 at 632.8 nm for the glass-ceramic waveguide with 7 mol% ZnO concentration [18], making it an attractive system for the development of active integrated optic devices.…”

Controllable synthesis of glass ceramics containing YF3:Eu3+ nanocrystals: Well‐preserved Eu and prolonged lifetime

“…Herein, dispersing the YF 3 :Eu 3+ NCs into glass proved to be an ideal option to effectively improve the thermal stability and maintain the high luminescent efficiency and long lifetime, [11][12][13][14][15][16][17][18][19] simultaneously. By conventional melt-quenching method, fluorescent glass ceramics (GCs) containing Cr 3+ /Eu 3+ doped Ga 2 O 3 -YF 3 NCs have been successfully prepared, 20 presenting red and blue emissions.…”