Growth and characterization of pure and Pr3+-doped Cs4PbBr6 crystals

Centimeter-sized single crystals of pure and Pr3+-doped Cs4PbBr6 were successfully grown using a high-temperature solution (HTS)-based vertical Bridgman–Stockbarger method in silica ampoules sealed under Ar gas. The resulting single crystals are bright orange transparent, non-hygroscopic, with a low phonon energy and a wide transparency in the middle infrared (MIR) region. We present the growth conditions together with a characterization of the single crystals by means of calorimetry measurements, room temperature single crystal and powder X-ray diffraction (XRD), Raman, visible and Fourier-transform infrared (FT-IR) spectroscopies. Cs4PbBr6 crystallizes at room temperature in the trigonal space group R-3c, with a=b=13.7219(2) A, c=17.3153(3) A, α=β=90°, γ=120° and Z=6. Pr3+ ions can be dissolved into Cs4PbBr6 crystals, resulting in broad MIR absorption bands.