Investigation on Structural and Green-Orange-Red Emission of Sm<sup>3+</sup> Ions Doped P<sub>2</sub>O<sub>5</sub>-ZnO-SrO-Li<sub>2</sub>O Glasses for Light Application

Phosphate glasses, characterized by their high thermal expansion coefficients, low melting temperatures, and excellent transparency across a wide spectral range are ideal for optical applications. In particular, phosphate-based glasses are effective hosts for rare earth ions due to their ability to incorporate heavy metal oxides while retaining an amorphous structure. Building on these properties, a series of (50-x)P 2 O 5 -20ZnO-15SrO-15Li 2 O-xSm 2 O 3 where x = 0, 0.5, 1.0, 1.5 and 2.0 mol% were prepared by using melt-quenching technique to explore the effects of Sm 2 O 3 concentration on structural and optical properties. This study addresses the challenge of optimizing Sm 2 O 3 concentration in phosphate glasses to enhance properties such as density, structural stability and emission intensity for efficient green-orange-red luminescence. XRD spectra confirmed the amorphous nature and indicate that samples are glass. The physical measurements indicated that density and molar volume of increased with Sm 2 O 3 concentration from 0 to 1.5 mol% and decreased when Sm 2 O 3 further increase to 2.0 mol%. FTIR spectra revealed seven spectra bands within range 650 to 1500 nm. The emission spectra were recorded under 402 nm excitation, emits strong emission band at 562, 593, 644 and 705 nm which correspond to excitation from 6 H 5/2 ground state. The optimal emission intensity was observed at 1.0 mol% Sm 2 O 3 , highlighting the potential of these glasses for applications in green-orange-red emitting materials.