Luminescence and electrical conductivity of CsSnBr3, and related phases

The black cubic compound CsSnBr3 shows intense red luminsecene under blue light or electron beam excitation. A second emisssion band occurs in the near IR. This compound shows semiconductor behaviour with a band gap of 0.34 eV up to 303 K when a minor phase transition occurs. As bromide is replaced by chloride the emission band and the absorption edge move to higher energy and the electrical conductivity decreases by a factor of 105. These results are discussed in terms of a possible band structure.