Spectral properties and NIR photoluminescence of Bi+ impurity in CsCdCl3 ternary chloride

Bi+-doped single crystals of triple chloride CsCdCl3 were prepared by the Bridgman method. Bismuth monocation is responsible for characteristic two-peaked absorption feature in visible and long lived NIR luminescence in this crystal. The splitting of the Bi+ lowest electronic states by crystal field is considered. The absorption spectrum is assigned to optical transitions of A→E type in two nonequivalent Bi+ positions of D3h and C3v symmetry. The possibility of Jahn-Teller effect in Bi+ excited states of E type is discussed in relation with absorption and luminescence excitation spectra properties.