Upconversion luminescence of Er³⁺ doped KPb₂Cl₅ and RbPb₂Br₅ crystals

Er³⁺ doped alkali-lead-halide crystals incorporate a number of properties making them interesting for practical use in light conducting and converting materials. So, appropriate spectroscopic properties should be analyzed, such as luminescence temperature dependencies and average levels lifetimes. In current work we have studied temperature dependences of up-converison luminescence intensities for most significant lines (530, 550 and 650 nm) under 980 nm excitation wavelength. Luminescence decay kinetics have been measured under 313 and 365 nm excitation in KPb₂Cl₅: Er³⁺, RbPb₂Br₅: Er³⁺ and KPb₂Cl₅: Er³⁺+Yb³⁺ single crystals and theoretical estimation of lifetimes conducted through Judd-Ofelt calculation have been made. Derived results could be used for laser systems design and for evaluation of Judd-Ofelt theoretical calculation to rare-earth doped alkali-lead-halide crystals.