Excitation pathway and temperature dependent luminescence in color tunable Ba5Gd8Zn4O21:Eu3+ phosphors

Judd-Ofelt and structural analysis of colour tunable BaY 2 ZnO 5 :Eu 3+ nanocrystals for single-phased white LEDs

“…Furthermore, fluorescence branching ratios are derived from the equation (6) and are listed in Table 5. nanophosphor with other Eu 3+ doped host materials [41][42][43][44]. Furthermore, the value of Ω 6 for most of the hosts is negligible, which may attributed to the absence of the 5 D 0 → 7 F 6 transition intensity.…”

“…Moreover, it can also be seen from Table 6 that the Ω 2 value is much larger than those of Ω 4 and Ω 6 . Hence the radiative rate for the 5 D 0 → 7 F 2 transition in Eu 3+ doped BaY 2 ZnO 5 system is much larger resulting in better luminescence with high colour purity, claiming its practical application in white LEDs [38,44]. Moreover, the relative quantum yield for solid samples can be determined from the integrated emission intensity as reported by Germer et al [46].…”

Luminescence studies of Sm3+ single-doped and Sm3+, Dy3+ co-doped NaGdTiO4 phosphors

“…Recently, some researchers have studied the thermal quenching behavior of 5 D 0 level of Eu 3 þ and confirmed that crossover process is responsible for the temperature dependent luminescence quenching [23,25]. Crossover process is a thermal excitation process in which the populated electron in the emission level can reach the intersect point of this level and a higher excitation band (such as the charge transfer band and the broad absorption band of host) by overcoming an energy barrier, and then relax to the intersect point of the ground state levels and the same higher excitation band, finally, relax to the ground state level and arouse temperature dependent luminescence quenching.…”

“…However, the luminescence intensities of all the emission bands decrease with increasing temperature, implying thermal quenching occurs. Generally, both the energy transfer rate and the multiphonon non-radiative relaxation rate increase with the increase of sample temperature, which can result in the increase of the quenching probability of the emission level, and then inducing the luminescence intensity decreases [23,24]. To study the effect of sample temperature on the rates of energy transfer and non-radiative relaxation, temperature dependent fluorescence decay curves were measured at various temperatures.…”

Effects of crystalline growth on structural and luminescence properties of Ca(10−3x)Eu2x(PO4)6F2 nanoparticles fabricated by using a microwave driven hydrothermal process

“…The R value was increasing with increase of annealing temperature from 1.96 for as-prepared material to 6.04 for material heat treated at 1000°C (see Table 1 In order to get deeper insight into fluorapatite structure, emission spectra of the Ca 9.85 Eu 0.1 (PO 4 ) 6 F 2 annealed at 600° and 800°C per 3 h were measured at three different temperatures (10, 77 and 300 K, see Figure 10). All emission spectra were normalized to the The simplified Judd-Ofelt theory was used to determine the Ω 2 and Ω 4 intensity parameters based on proceeding given in references 19,48,49 . Calculations were collected in …”