Laser compatible emission and enhanced microhardness in Y2O3 and Nd2O3 - doped borosilicate glasses incorporating construction demolition waste

Abstract The present research focuses on the innovative and sustainable utilization of construction demolition waste (CDW) through its incorporation into a novel class of rare earth-doped borosilicate-based glass systems. Glass samples were synthesized using a conventional melt-quenching followed by annealing technique, with 10 wt% of CDW introduced as a partial glass network modifier. The structural, optical, and mechanical properties of the prepared glasses were systematically investigated using X-ray diffraction (XRD), UV-Visible spectroscopy, photoluminescence (PL) spectroscopy, and Fourier-transform infrared (FTIR) spectroscopy. XRD patterns confirmed the amorphous nature of all synthesized glass samples. UV-Visible absorption spectra displayed strong ultraviolet absorption in the range of 231 to 312 nm, indicative of the intrinsic electronic transitions in the glass matrix. In Nd 2 O 3 -doped samples, ten pronounced absorption bands were observed between 431 and 874 nm, corresponding to intra − 4f transitions of Nd 3+ ions embedded in the glass network. The optical band gap energy of the glasses ranged from 2.553 to 3.030 eV, showing a compositional dependency that directly influences the electronic and optical behaviors. Parallel variations in Urbach energy (∆E) and refractive index (n) were also recorded, reflecting changes in the degree of disorder and density of electronic states within the band structure. Photoluminescence analysis of Nd 3+ -doped glasses revealed characteristic excitation peaks between 358 and 873 nm, with prominent emission at ~ 1060 nm attributed to the 4 F 3/2 → 4 I 11/2 transition. Two additional, lower intensity emissions at 875 nm( 4 F 3/2 → 4 I 9/2 ) and 1329 nm ( 4 F 3/2 → 4 I 13/2 ) were also detected, confirming the potential applicability of these materials in solid-state lasers and photonic devices. The addition of CDW significantly enhanced the physical and structural properties of the Nd 2 O 3 -doped borate glasses. Increased density and microhardness indicate improved network compactness and mechanical strength. FTIR spectra revealed vibrational bands (400–1000 cm − 1 ) associated with B-O and Si-O bonds, with a distinct ~ 1000 cm − 1 band suggesting enhanced network polymerization due to silicate integration from CDW. These results confirm the role of CDW in reinforcing the glass matrix while contributing to sustainable material development for photonic and laser applications.