UVB Luminescence and Structural Insights of Gd 3+ ‐Activated Na 2 O–Ga 2 O 3 –B 2 O 3 –Y 2 O 3 Glasses for Applications in Phototherapy Devices

ABSTRACT In this work, the UVB emission of Gd 3+ ions incorporated into the Na 2 O–Ga 2 O 3 –B 2 O 3 –Y 2 O 3 glass matrix was thoroughly investigated by varying the concentration of Gd 2 O 3 . Photoluminescence measurements revealed a strong and well‐defined emission peak at 312 nm, related to the 6 P 7/2 → 8 S 7/2 transition of Gd 3+ ions under 273 nm excitation. Notably, the emission intensity increased nearly threefold as the Gd 2 O 3 concentration rose from 0.2 to 0.8 mol%. The results were examined using Judd–Ofelt analysis and supported by decay kinetics, infrared spectra, ESR spectra, and DSC studies. The enhancement of luminescence was mainly attributed to reduced phonon losses associated with Ga 2 O 3 . However, a decline in emission intensity at 1.0 mol% Gd 2 O 3 was observed, which was ascribed to ion clustering and cross‐relaxation processes. Overall, this study demonstrates that tailoring the Gd 2 O 3 concentration provides an effective approach to enhance UVB output in alkali–yttria–gallium–borate glasses. The composition containing 0.8 mol% of Gd 2 O 3 is identified as a promising luminescent material for phototherapeutic applications, particularly in the treatment of skin disorders such as psoriasis and vitiligo, and for use in the fabrication of phototherapy devices.