Luminescence of s2 ions in CsCdBr3 and CsMgCl3

Abstract

The luminescence properties of Bi3+ in CsMgCl3, of Bi3+ and Pb2+ in CsCdBr3, and of undoped CsCdBr3 are reported. For CsMgCl3---Bi3+ two luminescent centers are observed. One is ascribed to isolated Bi3+ ions and the other to a Bi3+-vacancy-Bi3+ complex. For CsCdBr3 only one luminescent center is observed. The Stokes shift amounts 2.1 eV and the quenching temperature is low (40 K). Undoped CsCdBr3 shows also luminescence which seems to be related to structural disorder. Finally, the luminescence properties of CsCdBr3---Pb2+ are discussed. Below 80 K luminescence of intrinsic Pb2+ ions is observed. This luminescence is in the green spectral region. The luminescence above 100 K is ascribed to Pb2+ ions in a layer of slightly disordered bromine ions: excitation occurs in these bromine ions and is transferred to Pb2+ ions.