Crystal growth and optical properties of Dy-doped potassium lead bromide (KPb2Br5)

Results of the material synthesis and infrared (IR) optical characterization of Dy3+-doped potassium lead bromide (KPb2Br5) are reported. KPb2Br5 was synthesized using commercial PbBr2 and KBr powders and purified through zone refinement in an evacuated quartz ampoule. Following the purification, Dy-doped KPb2Br5 crystals were grown by self-seeded Bridgman technique. The main emission bands of Dy:KPb2Br5 under 800 nm excitation were centered in the near-IR (1.14, 1.33, 1.55, and ∼1.7 μm) and mid-IR regions (2.2, 2.4, 2.9, 4.3 μm). The efficient IR emission from Dy:KPb2Br5 is due to the small maximum phonon energy (∼140 cm−1) of KPb2Br5, which leads to reduced non-radiative decay rates between excited states of Dy3+ with small energy separation.