Hydration-induced coupling of the excitonic state of Y₂O₃with its phonon: Negative effect on the luminescence efficiency of Y₂O₃:Eu⁺³nanophosphor

Abstract

Luminescence properties of a series of samples of Y2O3:Eu+3 red phosphor of particle sizes ranging from 50 to 300 nm were investigated as a function of time to decipher the long-standing mystery of the effect of reduction of particle size on the luminescence efficiency of the phosphor. The samples were found to lose luminescence efficiency and suffer a change in the excitation profile with time. Infrared studies showed that although the samples at their freshly prepared stage were almost free from contaminated water, on aging in air at room temperature, they absorbed the latter. The phenomenon of hydration-induced coupling of the excitonic state of Y2O3 with one of its Fu modes was detected in the case of the aged sample, which was shown to be instrumental in introducing newer nonradiative channels in the system. Because of larger surface-to-volume ratio, the effect was most pronounced in the case of nanocrystalline samples.

Microwave-assisted solvothermal synthesis and characterization of SnO2:Eu3+ phosphors

“…The feasibility and mechanisms of synthesizing spherical powders in this way are explained below. When SnCl 4 ·5H 2 O is dissolved in ethanol, the quadrivalent tin ions form complexes with ethanol molecules as shown in the following equation [24]:…”

Rare-Earth-Doped and Codoped Y2O3Nanomaterials as Potential Bioimaging Probes

“…The peaks at 1549 and 1454 cm −1 are attributed to CC stretching and C−O−H in-plane bending bands. The peak at 570 cm −1 is for Y−O vibration bands . The spectrum of amine-functionalized nanocrystals is shown in Figure a(ii).…”

Synthesis of Y2O3:Bi3+,Yb3+ nanosheets from layered yttrium hydroxide precursor and their photoluminescence properties

“…The broad absorption band around 3450 cm À1 is assigned to the stretching vibrations of O-H (n(O-H)). 41 The narrow band around 570 cm À1 is assigned to the stretching vibration of Y-O (n(Y-O)). 41 On this basis, the amount of O-H in each sample was evaluated by dividing the absorbance of (n(O-H)) by the absorbance of (n(Y-O)).…”