Materials development and mid-infrared emission properties of Dy-doped TlPb2Br5 and CsPbCl3

We report on the materials development and infrared (IR) optical spectroscopy of Dy³⁺-doped into the ternary lead halides compounds TlPb₂Br₅ and CsPbCl₃ for photonic applications. The investigated Dy-doped ternary lead halides were synthesized from purified starting materials followed by melt-growth using vertical Bridgman technique. Under optical pumping at 1.35 μm (⁶H_15/2→⁶H _9/2+⁶F_11/2), broad mid-IR emissions in the ~2.9 μm (⁶H_13/2→⁶H_15/2), ~4.3 μm (⁶H_11/2→⁶H _13/2), and ~5.4 μm (⁶H_9/2 +⁶F_11/2 →⁶H_15/2) regions were observed at room-temperature. Compared to Dy: TlPb₂Br₅, the mid-IR emission from Dy: CsPbCl₃ was significantly weaker suggesting the existence of non-radiative losses. Temperature dependent lifetime studies and a Judd-Ofelt analysis were performed for Dy: TlPb₂Br₅.