NIR photoluminescence of bismuth-doped CsCdBr₃ – The first ternary bromide phase with a univalent bismuth impurity center

Single crystals of ternary bromide phase CsCdBr₃ doped with univalent bismuth cations are prepared for the first time by the Bridgman method. Bi⁺ impurity center emits a broadband long-lived near-infrared photoluminescence with a maximum at ~1053 nm. The characteristics of this photoluminescence and its relations with the energy spectrum of Bi⁺ impurity center are discussed. A comparison of Bi⁺ photoluminescence in CsCdBr₃ and ternary chlorides (studied previously) is performed. - Highlights: • Single crystals of Bi⁺-doped ternary bromide CsCdBr₃ were prepared. • Broadband NIR photoluminescence was observed from Bi⁺-doped CsCdBr₃. • Single optical center is responsible for NIR emission in Bi⁺-doped CsCdBr₃