The Structural and Luminescent Features of Strontium Alumino Borosilicate Glass with CuO for Optical Device...

Melt quenched borosilicate glasses with fixed Sr²⁺ ions Strontium alumino-borosilicate doped with CuO (SABSC) glasses with the composition 35SrO-(5-x)Al₂O₃-20B₂O₃-40SiO₂:xCuO (0.1 ≤ x ≤ 0.8 mol%) were prepared using the conventional melt-quench process. The X-Ray diffraction studies confirmed the amorphous state of synthesized glasses. The morphology and composition of glasses was studied from SEM and energy dispersive spectroscopy. The Raman spectra exhibited the presence of non-bridging oxygen through the modifications in the glass network. In optical absorption spectra, the broad bands in the 780-830 nm region along with at 270 nm is attributed to ² B_1g→² B_2g transition in distorted octahedral coordination and charge transfer and d-d transitions confirming the presence of both Cu²⁺ and Cu ⁺ The EPR spectra revealed well-defined hyperfine structures, representing the distribution of Cu²⁺ ions in distorted octahedral symmetry through calculated 'g' and 'A' values. Photoluminescence spectra exhibited five emission bands at 334 nm, 478 nm, 495 nm,575 nm and 850 nm respectively were attributed to Cu²⁺ electronic transitions, with intensity variations linked to local structural disorder and non-radiative processes. The intense narrow emission band attributed to T_2g - ¹A_g transition at 575 nm indicated existence of Cu⁺ ions due to interaction of Cu²⁺ ions with NBO. The spin allowed T_2g - ¹A_g transition at 575 nm in all glasses have shown branching ratio β_R> 50% (i.e. 66%) indicating possibility of stimulated emission. The emission wavelengths in green -yellow region were confirmed through CIE coordinates, color purity and correlated color temperatures (CCT) values ranging from 4918 K to 5011 K. Moreover, the sharp narrow emission band at 575 nm in emission spectrum, calculated stimulated emission cross-section, radiative lifetime and optical gain made SABSC glasses at lower concentration of CuO suitable materials for LASER, and optical device applications.