Optimization of Energy Transfer in Tb3+/Sm3+ Ions Doped Silico Boro Tellurite Scintillation Glass for X-ray Imaging Application

Abstract

The present work focuses on synthesizing 30TeO2: 20B3O3: (20-x)SiO2: 10Na2O: 15BaO: 5Tb2O3: xSm2O3 glasses with varying Sm2O3 concentrations (0.00- 2.00 mol%) to study energy transfer between Tb3+ and Sm3+ ions. The glass samples were characterized for density, molar volume, refractive index, absorption spectra, photoluminescence, quantum yield, lifetime, and energy transfer efficiency. Structural analysis by XRD confirmed their amorphous nature. FTIR and Raman studies revealed increased network connectivity and reduced non-bridging oxygen content with Sm2O3 addition. The optical bandgap values ranged from 2.961 to 3.132 eV, with a minimum at 0.5 mol% Sm2O3, while the Urbach energy show no clear trend with increasing Sm2O3 content and fall within the range of 0.233–0.303 eV, suggesting minimal variation in structural disorder. Absorption spectra were evaluated in the wavelength region between 400 and 2500 nm, showing 11 absorption peaks at 944, 1083, 1238, 1383, 1485, and 1543 nm, corresponding to energy transitions of Sm3+ ion from the ground level of 6H5/2 to 6F11/2, 9/2, 7/2, 5/2, 3/2, 6H15/2, and 6F1/2. Additionally, absorption peaks for Tb3+ ion were observed at 484, 1892, and 2200 nm, corresponding to transitions from 7F6 to 5D4 and 7F0,1,2, respectively. Photoluminescence studies showed efficient Tb3+→Sm3+ energy transfer with maximum emission at 0.5 mol% Sm2O3. The glasses emitted visible light under X-ray excitation, confirming their potential for X-ray imaging applications.