Structural and photoluminescence investigation of Y₂O₃: Sm³⁺nano powders: Organic agent's effect

Abstract

In this article, the authors delve into the synthesis of Y₂O₃:Sm³⁺ nanopowders using the solgel method, employing organic agents such as ethylene glycol (EG) and polyethylene glycol (PEG). This 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 (la-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 = 600 nm, exhibit two absorption bands attributed to the charge transfer state (CTS) from O²⁻ → Sm³⁺, with a maximum absorption at 223 nm, and to the intraconfigurational transition ⁴f₅-⁴f₅ of Sm³⁺. A red/orange emission, attributed to the ⁴G₅/₂ ⁵H₇/₂ transition, predominates under these conditions. A significant improvement in the intensity of photolumi nescence 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.