An efficient green-emitting luminescent material: Tb3+-activated monoclinic Gd2O3

UV-A and UV-B excitation region broadened novel green color-emitting CaGd2ZnO5:Tb3+ nanophosphors

“…31 No 5 D 3 emissions were observed even at dilute concentrations. This sort of result was also observed by Blasse et al 32 in the case of monoclinic Gd 2 O 3 :Tb 3+ phosphors, indicating that the nonradiative transition occurs from 5 D 3 to 5 D 4 level via f-d transition instead of cross-relaxation process. This is possible only if the f-d transition appears in the low energy region (longer wavelength side).…”

X-ray-Induced Singlet Oxygen Activation with Nanoscintillator-Coupled Porphyrins

“…These bands correspond, respectively, to the exciton-like absorption correlated to the direct excitation of the lattice (VB → CB) and to the electric dipole allowed transition of Tb 3+ 4f 8 → 4f 7 5d 1 . 27 The emission spectrum measured for a direct excitation of terbium (300 nm) corresponds to the well-known green emission consisting of four peaks centered at 488 nm (intraconfigurational transition 4f 8 −4f 8 5 D 4 → 7 F 6 ), 545 nm ( 5 D 4 → 7 F 5 ), 588 nm ( 5 D 4 → 7 F 4 ), and 625 nm ( 5 D 4 → 7 F 3 ). 17,27 We recorded the terbium emission spectrum with a large time gate in agreement with the well-known millisecond fluorescence decay time of Tb 3+ .…”

“…27 The emission spectrum measured for a direct excitation of terbium (300 nm) corresponds to the well-known green emission consisting of four peaks centered at 488 nm (intraconfigurational transition 4f 8 −4f 8 5 D 4 → 7 F 6 ), 545 nm ( 5 D 4 → 7 F 5 ), 588 nm ( 5 D 4 → 7 F 4 ), and 625 nm ( 5 D 4 → 7 F 3 ). 17,27 We recorded the terbium emission spectrum with a large time gate in agreement with the well-known millisecond fluorescence decay time of Tb 3+ . The same spectrum is obtained under X-ray excitation (Figure 3a) and under 226 nm excitation.…”

White‐Emitting Tuning and Energy Transfer in Eu2+/Mn2+‐Substituted Apatite‐Type Fluorophosphate Phosphors

“…An intense peak at 275 nm due to the 8 S 7/2 – 6 I 7/2 transition of Gd 3+ dominates the excitation spectrum. The PLE spectrum displays several weak sharp lines at about 247, 254, 307, and 312 nm which are assigned to the 8 S 7/2 – 6 D 7/2 , 8 S 7/2 – 6 D 9/2 , 8 S 7/2 – 6 P 5/2 , and 8 S 7/2 – 6 P 7/2 transitions of Gd 3+ , respectively . The weak sharp bands in the wavelength range 400–500 nm, which are associated with the transitions of Mn 2+ ions from ground level 6 A 1 ( 6 S) to [ 4 A 1 ( 4 G), 4 E( 4 G)], 4 T 2 ( 4 G), and 4 T 1 ( 4 G) excited levels, respectively .…”