Photoluminescence and excited states dynamics of Tm²⁺-doped CsCa(Cl/Br)₃ and CsCa(Br/I)₃ perovskites

In this study, we systematically vary the Cl/Br and Br/I ratios in CsCaX₃:Tm²⁺ (X = Cl, Br, I) and hereby gradually shift the positions of the Tm²⁺ 4f¹²5d¹-levels as relative to the two 4f¹³ levels. At low temperatures up to five distinct Tm²⁺ 4f¹²5d<sup>1...

Engineering near-infrared emitting scintillators with efficient Eu²⁺ → Sm²⁺ energy transfer

Recently, we proposed a concept for a new class of near infrared (NIR) scintillators by employing efficient Eu²⁺ → Sm²⁺ energy transfer. In this article we investigate the optical spectroscopy of Sm²⁺ in BaBrI, CsSrI₃, and CsBa₂I₅ halide hosts. A criterion was derived for fast...

Concentration and temperature dependent luminescence properties of the SrI₂-TmI₂ system

The concentration dependent luminescence of the SrI₂-TmI₂ system was investigated. For Tm²⁺ concentrations up to 5 mol %, the quantum efficiency (QE) of the ²F_5/2→²F_7/2 emission exhibits a constant value above 50%. The QE drops for higher Tm²⁺...