Structural and optical properties of 5 mol% ErF₃-doped fluoride crystals

Abstract The influence of the fluoride host matrix MeF 2 (Me = Ca, Ba) on the structural and optical properties of 5 mol% ErF 3 -doped single crystals was investigated. The MeF 2 :Er 3+ crystals were successfully grown using the Stockbarger–Bridgman technique and analyzed through laboratory x-ray diffraction and spectroscopic methods. Structural refinements revealed distinct behavior upon erbium doping: an expansion of the CaF 2 lattice and a contraction of the BaF 2 lattice, correlated with host-specific charge compensation mechanisms and local lattice distortions. Room temperature absorption and photoluminescence spectra recorded under UV excitation ( λ exc = 255 nm and 378 nm) showed intense visible emissions in the blue, green, and red domains. Judd–Ofelt analysis provided the intensity parameters Ω 2 , Ω 4 , and Ω 6 , and radiative lifetimes were calculated and compared with literature data. The distinct structural responses and luminescent behavior of MeF 2 (Me = Ca, Ba) hosts at high Er concentrations suggest their suitability for applications in solid-state lasers, visible light-emitting devices, and optical amplifiers. These findings contribute to the optimization of Er 3+ -doped fluorides for use in solid-state lasers, optical amplifiers, and visible light-emitting devices.