Title : Structural and photoluminescence investigation of Y₂O₃:Sm3⁺ nano-powders: organic agent’s effect
Abstract:
In this study, we delve into the synthesis of Y2O3:Sm3+ nanopowders using the sol-gel method, employing organic agents such as ethylene glycol (EG) and polyethylene glycol (PEG). Our thorough investigation focuses on the structural, morphological, and photoluminescence characteristics of these nanopowders, with particular consideration for their potential applications in the field of optical devices.
X-ray diffraction patterns indicate that all powders crystallize in pure cubic phases (Ia-3). Transmission electron microscopy (TEM) analysis reveals the presence of particles with dimensions less than 70 nm. Specifically, morphological and structural data suggest that the crystallite size of nanopowders prepared with PEG exceeds that of nanopowders prepared with EG.
In exploring the photoluminescence properties, the emission spectra of the powders, recorded at λem= 600nm, exhibit two absorption bands attributed to the charge transfer state (CTS) from O2- → Sm3+, with a maximum absorption at 223nm, and to the intraconfigurational transition 4f5-4f5 of Sm3+. A red/orange emission, attributed to the 4G5/2 → 6H7/2 transition, predominates under these conditions. A significant improvement in the intensity of photoluminescence is notably observed in samples prepared with organic agents compared to those prepared without agents. Finally, chromatic coordinates underscore the strong potential of Y2O3:Sm3+ nanopowders as promising phosphors for lighting applications.
Keywords: Y2O3:Sm3+ nano-powders, organic agents (EG, PEG), photoluminescence, sol gel
