Luminescence properties of flux-grown α-Al2O3 single crystals

Luminescence dosimetry remains a cornerstone in radiation measurement technology, with ongoing advancements to improve its precision, adaptability, and application scope. This work reports, for the first time, the luminescence and dosimetric properties of flux-grown undoped sapphire (Al 2 O 3 ) single crystals, with a focus on the influence of MoO 3 flux purity. Crystals were grown using fluxes of purities from 99.0% to 99.95%, and characterized using thermoluminescence (TL) and optically stimulated luminescence (OSL). Different MoO 3 purity produced crystals with different trap distribution. Both TL and OSL responses were found to depend strongly on flux purity, with a marked improvement in signal intensity and reproducibility observed up to 99.9% purity. TL signals displayed linear dose dependence with no saturation up to 62 Gy. OSL responses followed a power-law behavior, without saturation, and showed high reproducibility (< 2% variation). The crystals grown with 99.9% purity MoO 3 offered the best balance between performance and material cost. These findings highlight the potential of the flux-growth method as a cost-effective approach for producing Al 2 O 3 -based dosimetric materials, particularly for high-dose applications. Further improvements in crystal quality and sensitivity may be achieved through optimized growth conditions and targeted doping strategies. • First luminescence study of flux-grown undoped sapphire (α-Al 2 O 3 ) crystals. • Cr 3+ identified as main impurity-related emission center. • Flux purity strongly affects traps distribution and luminescent properties • MoO 3 99.9% purity offers best balance between performance and material cost.