Spectroscopic Properties of Pr3+, Tm3+, and Ho3+ in Germanate-Based Glass Systems Modified by TiO2

Abstract

In this paper, the effect of the GeO2:TiO2 molar ratio in glass composition on the spectroscopic properties of germanate glasses was systematically investigated. The visible luminescence bands associated with characteristic 1D2 → 3H4 (red), 5S2, 5F4 → 5I8 (green), and 1D2 → 3F4 (blue) transitions of Pr3+, Ho3+, and Tm3+ ions in systems modified by TiO2 were well observed, respectively. It was found that the luminescence intensity of glasses containing Pr3+ and Ho3+ ions increases, whereas, for Tm3+-doped systems, luminescence quenching with increasing content of TiO2 was observed. Based on Commission Internationale de I’Eclairage (CIE) chromaticity coordinates (x, y) analysis, it was demonstrated that the value of chromaticity coordinates for all glasses depends on the GeO2:TiO2 molar ratio. The addition of TiO2 to system compositions doped with Tm3+ ions shifts the (x, y) to the center of the CIE diagram. However, chromaticity coordinates evaluated for glasses containing Pr3+ ions move to a purer red color. Our results confirm that the spectroscopic properties of the studied glasses strongly depend on TiO2 content. Moreover, it can be stated that germanate-based glass systems modified by TiO2 can be used for optoelectronics in RGB technology as red (Pr3+), green (Ho3+), and blue (Tm3+) emitters.

Synthesis, Structural and Luminescent Properties of TmMgB5O10 Crystals

“…The standard sharp lines for Tm 3+ were registered for PL spectrum (Figure 9b). The maxima centered at 455, 479, 667 and 753 nm correspond to 1D2 → 3 F4, 1 G4 → 3 H6, 1 G4 → 3 F4 and 3 H4 → 3 H6 transitions according to [27]. The most intensive transition is observed for 1 D2 → 3 F4, which emitting in blue region.…”

The Synthesis, Structure, and Luminescent Properties of TmMgB5O10 Crystals

“…The standard sharp lines for Tm 3+ were registered for the PL spectrum ( Figure 9 b). The maxima centered at 455, 479, 667, and 753 nm correspond to the 1 D 2 → 3 F 4 , 1 G 4 → 3 H 6 , 1 G 4 → 3 F 4 , and 3 H 4 → 3 H 6 transitions according to [ 26 ]. The most intensive transition is observed for 1 D 2 → 3 F 4 , which emits in the blue region.…”

Optical, vibrational, and photoluminescence properties of holmium‐doped boro‐bismuth‐germanate glasses

“…Rare-earth (RE 3+ )-doped oxide glasses, particularly boron (B)/ bismuth (Bi)/germanium (Ge)-rich glasses, were explored for optical fibers, solid-state lasers, sensors, solar energy converters, waveguides, eye-safe lasers, display devices, scintillators, military, biomedical devices, optical refrigeration, optical data storages, etc., owing to their excellent physical and chemical stability, relatively moderate melting point (800-1400 C), low non-linear refractive index, low-to-moderate phonon energy (700-1400 cm À1 ), decent density range (3-5 g/cc), good RE 3+ ion solubility, and interesting luminescence properties [1][2][3][4][5][6][7][8][9][10][11][12]. However, these glasses have their disadvantages.…”

“…For instance, borate glasses have high phonon energy and low density which would limit them in using for practical applications such as efficient light emitters and scintillators [3,7,13], whereas bismuth-rich glasses exhibit poor transparency despite a good density restricts many photonic applications [2,13]. Germanate glass has a disadvantage in the form of a high melting point despite its superior thermal stability, chemical durability, and relatively low phonon energy [5,8,13,14].…”