Optical and Structural Properties of Samarium-Doped Oxyfluoroborate Glasses for Optoelectronic Applications

Abstract

A series of new oxyflouroborate glass systems with the composition 75B₂O₃-5Al₂O₃-(5-x) Li₂O-15MgF₂ embedded with samarium ions with different molar ratios are prepared and studied their optical properties based on vibrational, transitional, and photoluminescence characteristics to be applicable in optoelectronic applications. The gain results show that as the amounts of Sm₂O₃-embedding of oxyflouroborate glass increase, the absorption coefficient decreases with increasing wavelength up to a certain wavelength, which affects the energy band gap directly and indirectly, the network's polarizability and the skin depth. The skin effect may affect the optical energy band gap of any glass structure based on the VB to CB transition, affecting the ionicity of oxygens and the interatomic distance due to the charges on the oxygen anion in borate glasses made of Sm₂O₃ and Li₂O. Thus, it indicates ionic bond formation and a significant shift in polarizability, molar refractivity, steepness parameter, metallization, optical electronegativity, electron polarizability, and optical basicity. Besides, the 0.4 mol% Sm³⁺-embedded glass sample has the highest emission intensity, related to the non-bridging oxygen involved in Sm³⁺ incorporation into host glasses. Also, the glass samples showed that Sm₂O₃ concentration increased the two absorption bands at 700 cm⁻¹, related to the bond-bending vibrational mode of bridging oxygen atoms, and to some extent, the shifting of bands could not follow any trend with the continuous addition of samarium oxide. These results promise to know the influence of inserting Sm₂O₃ on the borate glass structure, as the junction point determines the optical band edge for up-conversion laser and photonic applications.