Das Perowskitsystem CH₃NH₃ [Pb,Sn_1-nX₃] (X = Cl, Br, I) / The Perovskite System CH₃NH₃[PbnSn_1-nX₃] ( X = C1, Br, I)

Abstract

Abstract The mixed Sn(II)/Pb(II) compounds of the type CH 3 NH 3 [PbwSn 1-n X 3 ] (X=Cl, Br, I) have the cubic perovskite structure which is established by X-ray powder data and 119 Sn Mössbauer spectroscopy. With exception of the chloro system the coloured compounds show electrical conductivity which increases with increasing Sn(II) content. Their physical properties can be interpreted by means of a "p-resonance bonding". Replacement of Sn(II) by Pb(II) and I by Br and Cl decreases this bonding effect, which is produced by the interaction of filled X p-orbitals with empty p-orbitals of Sn(II) or Pb(II). The synthesis is described