Growth and Spectroscopic Properties of Pr³⁺ Doped Lu₂S₃ Single Crystals

For the first time Lu₂S₃ (undoped and Pr-doped) single crystals were successfully grown from melt using micro-pulling-down (mPD) technique. Customization of halide mPD apparatus allowed us to grow rod-shaped ( 2 mm and length around 20 mm) crystals of Lu₂S₃ with high melting temperature (~1750 ^∘C). X-ray powder diffraction revealed that the grown crystals exhibit the {ε}-Lu₂S₃ crystal structure (α-Al₂O₃ type, space group R-3c). Optical and scintillation properties of both the undoped and Pr³⁺ doped Lu₂S₃ were investigated. Fast 5d-4f Pr³⁺ luminescence was observed in both photoluminescence and radioluminescence spectra. The presented technology is an effective tool for the exploration of a large family of high-melting sulfides. Such materials show promise for application as scintillators, active laser media, and optoelectronic components.